DE102021131006A1 - Apparatus and method for free space quantum key distribution - Google Patents

Abstract

The invention relates to a vehicle system with a vehicle and device parts (401, 601). At least a first device part is part of the vehicle. The vehicle system includes a QKD system (401, 601, 452, 428). At least the first part of the device exchanges a key for encrypting data using the QKD system (401, 601, 452, 428) with another second part of the device of the vehicle system. The first part of the device then exchanges data encrypted by means of this key with the second part of the device, at least in part. The second device part is preferably a car key or also a part of the vehicle or an infrastructure facility or another vehicle.

Description

The invention relates to a single photon transmission device for enabling secure authentication comprising a plurality of single photon sources, a control device which is set up to control one of the single photon sources separately, and an optical sub-device which is set up to transmit single photon streams of photons emitted by the at least one single photon source to a QKD -To bring the coupling beam together, consisting of a common stream of single photons.

The invention further relates to a single-photon receiving device for receiving a QKD coupled beam transmitted by a single-photon transmitting device.

The invention further relates to a method for generating a common quantum key for a single-photon transmission device and a single-photon reception device.

The invention further relates to an integrated QKD circuit.

The invention further relates to a car key comprising a single-photon transmission device and/or a single-photon reception device.

The invention further relates to a car comprising a single-photon transmission device and/or a single-photon reception device.

The invention further relates to the use of a single-photon transmission device and/or a single-photon reception device for data exchange.

The invention further relates to a SPAD diode for a sensor element of a single photon detector for a single photon transmission device and/or for a single photon reception device.

The general principles of quantum cryptography were first introduced by Bennett and Brassard in their article "Quantum Cryptography: Public key distribution and coin tossing" in "Proceedings of the International Conference on Computers, Systems and Signal Processing", Bangalore, India, 1984, p. 175 -179 (IEEE, New York, 1984).

The general procedure for performing the quantum key distribution is given in the book by Bouwmeester et al. "The Physics of Quantum Information", Springer-Verlag 2001, in section 2.3, pages 27-33 described.
The encryption devices enable secure transmission of payload data by performing a type of symmetric encryption using the keys exchanged through quantum key distribution. Specific quantum key distribution systems are for example in the U.S. 5,307,410 and CH Bennett's article entitled "Quantum Cryptography Using Any Two Non-Orthogonal States", Phys. Rev. Lett. 68 3121 (1992). Quantum cryptography has developed in an interdisciplinary manner between the scientific fields of quantum physics, quantum optics, information theory, cryptography and computer science. The articles by N. Gisin, G. Ribordy, W. Tittel and H. Zbinden, "Quantum Cryptography", Reviews of Modern Physics provide an overview of the fundamentals and methods as well as the historical development of quantum cryptography. 74, 145 (2002).

Quantum cryptography or quantum key distribution, hereinafter also referred to as QKD, is a method that enables the distribution of a secret key between two remote parties, a sender named "Alice" and a receiver named "Bob", with proven absolute security. The distribution of quantum keys is based on the principles of quantum physics and the encryption of information in quantum states or qubits, as opposed to classical communication, which uses bits. Normally, photons are used for these quantum states. Quantum key distribution takes advantage of certain properties of these quantum states to ensure their security.
QKD is a protocol that allows the exchange of secret keys in an active scenario. In a QKD protocol, the communication channel between the two users is called a quantum channel. A quantum channel is a communication channel that transmits quantum particles, typically photons, in a way that preserves their quantum properties. There are two groups of parameters used for quantum encoding. One parameter is the polarization of the photons and the other parameter is the phase, which requires the use of interferometers. Both have their advantages and disadvantages depending on the physical layer of the quantum channel and the type of QKD protocol.

In contrast to classical cryptography, whose security depends on a computational complexity, the security of quantum cryptography is based on numerous quantum mechanical principles, including the quantum mechanical principle that every measurement of a quantum system in an unknown state changes the state of this quantum system.
The security of this method arises in particular from the fact that measuring the quantum state of an unknown quantum system changes the system itself. In other words, a spy dubbed "Eve" eavesdropping on a quantum communications channel cannot obtain information about the key without introducing errors into the key exchanged between the sender and receiver. If a spy "Eve" tries to intercept or otherwise measure the exchanged qubits, errors occur that reveal his presence. In this way, the user is informed of an attempted eavesdropping.

The basic idea of QKD is that the spy, also known as the eavesdropper, can intercept the signal and process it in any way compatible with quantum mechanics. Nonetheless, the legitimate users, known as Alice and Bob, are able to exchange a secure key.

A typical implementation of a cryptographic application based on QKD consists of a cryptographic application running between two remote sites. This implementation includes at least a pair of Quantum Key Distribution devices and a pair of cryptographic application devices using the secret keys exchanged over QKD.
One device of each pair is installed at a first location while the other device is at the other second location.
The QKD devices are connected via a quantum communication channel and a first bidirectional classic communication channel, also called the service channel. In this case, the quantum communication channel is realized by a first optical fiber and the service channel is realized by a second optical fiber that is separate from the first optical fiber.
The cryptographic application devices are connected via a second bidirectional classic communication channel, also known as a data channel.
Eavesdropping detection occurs on the quantum communication channel (quantum channel), and not on the service channel or on the data channel running parallel to the quantum communication channel.

Several implementation options are possible for the quantum and service channels in quantum key distribution systems.
The most common is the use of separate physical media to carry these communication channels.

In general, the physical medium used for the transmission of optical communication channels consists of optical fibers. However, other media are also possible, e.g. B. the propagation in free space.
In the case of communication channels transmitted over separate optical fibers, the optical fiber dedicated to the quantum channel is called dark fiber. The bi-directional service channel is also transmitted over two separate optical fibers. Each fiber carries one direction of the communication channel. With this option, there is no interaction between the different channels as they are transmitted over a physically separate medium.

For a correctly functioning communication channel it is important that a signal-to-noise ratio of the received logical signal is high enough.
One of the effects of optical fibers on both quantum and classical optical logic signals is the attenuation of these signals during their propagation. This means that as the signal propagates down a fiber optic cable, the signal level decreases. On the other hand, the noise in both quantum and classical channels is mainly due to the noise of the detection system. The noise level is therefore independent of the propagation distance in the optical waveguide. Therefore, the signal-to-noise ratio of both types of communication channels decreases as the propagation distance of the signal increases. This effect results in a maximum propagation distance (or maximum loss value) over which a channel can function.
With the classic communication channels, the parameter used to determine whether the channel has a sufficiently good signal-to-noise ratio is the optical intensity of the signal that reaches the receiver. If the value of this parameter is within a range specified by the manufacturer, the channel is functioning correctly.
In the case of quantum communication channels, the parameter used to determine whether the channel has a sufficiently good signal-to-noise ratio is called the quantum bit error rate (QBER). This parameter is, so to speak, the reciprocal of the signal-to-noise ratio. The QBER value is measured by QKD systems. If the QBER value is above a predefined threshold, the QKD system cannot generate secret keys from the qubit exchange. The higher the QBER value, the greater the error rate relative to the signaling rate. An increase in the error rate can either be due to a decrease in the quantum signal, or a change in some QKD system parameters, or an attempted eavesdropping. A change A change in QKD system parameters can be caused by, for example, a temperature change that changes the orientation of the optical system, or a change in the inherent noise of the single photon detectors in the QKD receiver.

• • E91, basierend auf Verschränkung;
• • B92 auf der Grundlage von nur zwei Quantenzuständen, die jedoch einen interferometrischen Nachweis erfordern; und
• • COW, welches eine Variante des Phasenparameters verwendet und die Erkennungszeit zur Kodierung nutzt.

The most well-known protocol for QKD is the BB84 protocol, which is based on four different quantum states and is explained in Bennett & Brassard, 1984.
Other well-known protocols include:

• • E91, based on entanglement;
• • B92 based on only two quantum states, but requiring interferometric detection; and
• • COW, which uses a variant of the phase parameter and uses the detection time for encoding.

Typically in implementations of QKD for quantum coding, a phase parameter or a related time parameter for the COW protocol is used. This is because polarization is not preserved in an optical fiber and polarization processes require complicated and expensive components.
On the other hand, interferometric detection is easier to implement in single-mode optical fibers, which is why single-mode optical fibers are a preferred medium.

To increase the range, one solution is to rely on free-space optical communication (FSO) QKD, where the quantum channel runs in free space, which does not have the same loss limitations as fiber optics.

Another possibility is optical free space communication (FSO) QKD, in which the quantum channel runs in free space.

For examples of free space QKD implementations, see R. Bedington et al. "Progress in satellite quantum key distribution", https://arxiv.org/abs/1707.03613v2 , or in J-P Bourgoin et al. "A comprehensive design and performance analysis of LEO satellite quantum communication", https://arxiv.org/abs/1211.2733.

Free space optical communication (FSO) is an optical communication technology that uses light propagating in free space to transmit data wirelessly for telecommunications or computer networks.
"Free space" is understood to mean air, vacuum or something similar, i.e. a medium in which light can propagate in a straight line.

This is in contrast to guided optics such as e.g. B. in optical fibers, or more generally optical waveguides, wherein the light is guided and directed through the waveguide.

Like any other type of communication, free-space optical communication requires security to prevent eavesdropping. The most common solutions for realizing an exchange of secret information over FSO between a sender and a receiver are based on an exchange of secret keys over FSO channels. After exchanging secret keys, these keys are used to exchange messages in a secure way, for example by encrypting the messages.

However, FSO QKD presents a challenge because due to atmospheric distortions, the wavefront of a wave is distorted during propagation, resulting in poor interference at the receiver. This can be improved by using mirrors with adaptive optics, but has the disadvantage that the complexity and costs of a corresponding system are considerable.
In free space, light is polarized, making polarization-based systems more attractive.
However, a problem with the transmission of QKD photons in free space is background noise, which arises due to scattered light.

If a receiver moves relative to the transmitter or vice versa, the polarization of the photons changes during the movement of the moving transmitter/receiver, for example a car key with a QKD system, which requires polarization-compensating components.

The object is therefore to provide a device that enables secure encryption between a transmitter and a receiver, with the transmitter being able to move relative to the receiver or the receiver being able to move relative to the transmitter.

To solve the problem, a device and a method according to the independent claim are proposed.
Further advantageous configurations of the invention can be found in the dependent claims, the description and the figures.

The proposed solution provides a single-photon transmission device and a single-photon reception device, which are coupled by means of a QKD coupling beam transmitted by the single-photon transmission device and received by the single-photon reception device can exchange a key for secure communication.

The single photon transmission device according to the invention for enabling secure authentication comprises a plurality of single photon sources, a control device which is set up to control one of the single photon sources separately, and an optical sub-device which is set up to convert single photon streams of photons emitted by the at least one single photon source into a QKD coupling beam , consisting of a common stream of single photons.
In particular, the single-photon transmission device includes a control device for the single-photon sources, which single-photon sources each include an illuminant and a power source, with the illuminant emitting polarized single photons or single photons of different polarization, which are polarized in a subsequent beam path by means of polarization filters or polarizing optical functional means.
In particular, the single photon transmission device comprises at least one data bus. In particular, the single-photon transmission device includes at least one microcontroller core, which is set up to control the control device via the internal data bus. In particular, the single-photon transmission device includes at least one control line, which connects the drive device to an adjustable voltage regulator.
In particular, the single-photon transmission device comprises at least one power supply for the single-photon sources, the power supply being set up to regulate an operating voltage of the single-photon sources, in particular to regulate it by means of a linear regulator.
In particular, the control device is set up to set a voltage between a supply voltage line of the single photon sources and a reference potential by means of the control line.
In particular, the power source of each single photon source is set up to set a single photon rate of the respective associated lamp depending on signals from a control line associated with the respective power source, in particular depending on control data for the single photon sources transmitted by the control device, and thus a photon density of a light emission from the single photon sources.

In particular, the control device is set up to control an electric current through the respective power source of the respective single-photon source.
In particular, the single photon sources are set up to feed the respective single photon streams into the QKD coupling beam depending on the control by the control device.

In one configuration, the single-photon transmission device includes a plurality of the data buses and a plurality of the microcontroller cores.
In particular, the plurality of microcontroller cores can simultaneously access different sub-devices of the single-photon transmission device independently of one another.

In a further refinement, the single-photon transmission device comprises a beam splitter or mirror and a photodetector for measuring and calibrating a photon rate. In particular, the beam splitter or mirror is set up to direct at least part of the QKD coupling beam onto the photodetector.

In a further refinement, the microcontroller core is set up to determine a single photon density in the QKD coupled beam using the photodetector.

In a further refinement, the microcontroller core is set up to insert the beam splitter or mirror into the QKD coupling beam, in particular by means of an actuator, with the microcontroller core controlling the actuator via the internal data bus.

In a further refinement, the microcontroller core is set up to operate one of the individual photon sources separately and to detect an individual photon density associated with this individual photon source.

In a further embodiment, the microcontroller core is set up to calibrate the single photon densities of the various single photon sources in that the microcontroller core readjusts the current sources of the respective single photon sources in such a way that the single photon density of the respective single photon source detected by the photodetector is within a designated single photon density range value interval, and/or the Photodetector detected single photon density of the respective single photon source differs from the single photon density of another of the single photon sources by no more than 10%, better than 5%, better than 2%, better than 1%, better than 0.5%, better than 0.2%, better than 0.1% , better 0.05%, better 0.02%, better 0.01% differs.

In a further refinement, the microcontroller core is set up to, after the calibration of the individual photon densities of the various removing the beam splitter or mirror from the QKD coupled beam from the single-photon sources, in particular by means of an actuator, with the microcontroller core controlling the actuator via the internal data bus.

In a further embodiment, the sub-device comprises a conical mirror and a spatial filter, in particular comprising a first pinhole and a second pinhole. In particular, the conical mirror is set up to direct individual photons emitted by the individual photon sources into a common beam direction and thus to bring them together to form a common stream of individual photons, the QKD coupling beam.

In a further configuration, the dividing device comprises at least one λ/4 plate, which is set up to rotate photons emitted by the plurality of single photon sources by 45°, at least one beam splitter, and a control device.
In particular, the at least one beam splitter is set up to combine photons emitted by the at least one single photon source into a common stream of single photons, the QKD coupling beam.

In a further configuration, the single-photon transmission device comprises at least one read/write memory, at least one non-writable volatile memory, and at least one read-only memory.
In particular, the microcontroller core is set up to process program code and/or program data contained in the at least one read/write memory and/or in the at least one read memory. In particular, the single-photon transmission device includes access logic for this purpose.
In particular, the microcontroller core is set up to access the at least one read/write memory by means of the internal data bus.
In particular, the microcontroller core is set up to access the at least one non-writable volatile memory by means of the internal data bus.

In a further refinement, the single-photon transmission device comprises at least one non-volatile manufacturer memory which is writable and/or non-writable. In particular, the manufacturer's non-volatile memory includes boot software for the microcontroller core.

In a further refinement, the single-photon transmission device comprises at least one cryptography accelerator.
In particular, the at least one cryptography accelerator is connected to the microcontroller core via the internal data bus.

In a further refinement, the single-photon transmission device comprises at least one manufacturer memory firewall which is set up to prevent unauthorized access to the manufacturer memory and only allows it after appropriate authentication. In particular, the at least one manufacturer memory firewall is provided between the manufacturer memory and the internal data bus.

In a further refinement, the single-photon transmission device comprises at least one CRC (Cyclic Redundancy Check) module, which is set up to calculate a CRC check data word for a predefined quantity of data.

In a further refinement, the single-photon transmission device comprises at least one clock generator module which is set up to provide system clocks for operating individual device parts of the single-photon transmission device.

In a further refinement, the single-photon transmission device comprises at least one timer module which is set up to control time sequences within the single-photon transmission device.

In a further refinement, the single photon transmission device comprises at least one security monitoring and control circuit which is set up to monitor the integrity of the single photon transmission device and, if necessary, to initiate countermeasures in the event of an attack.
In particular, the at least one security monitoring and control circuit is set up to detect an attack and, if necessary, to block the single-photon transmission device from accessing memory contents of the memory for a preferably predetermined period of time and/or to delete contents of the memory in whole or in part, and/or To set the contents of the memory to predefined values and/or to overwrite them with nonsensical data and/or to manipulate them in any other way.

In a further refinement, the single-photon transmission device comprises at least one quantum-process-based generator which is set up to generate genuine random numbers.

In a further refinement, the at least one data interface comprises.

In a further refinement, the single-photon transmission device comprises at least one base clock generator which is set up to provide the at least one clock generator module with a base clock in each case.

In a further configuration, the single photon transmission device comprises at least one reset circuit which is set up to set the single photon transmission device and/or sub-devices of the single photon transmission device to a predefined state when predetermined or determinable reset conditions and/or combinations and/or time sequences of such reset conditions are present.

In a further configuration, the single-photon transmission device comprises at least one power supply or VCC circuit with voltage regulators, which power supply or VCC circuit is set up to provide an operating voltage.

In a further refinement, the single-photon transmission device comprises at least one ground circuit which is set up to protect the single-photon transmission device against polarity reversal and attacks via a ground line.

In a further refinement, the single-photon transmission device comprises at least one input/output circuit which is set up to allow the single-photon transmission device to control or read out other devices or to communicate with them in some other way.

In a further refinement, the single-photon transmission device comprises at least one processing module which is set up to communicate with the microcontroller core via the internal data bus, in particular the at least one processing module comprises the at least one CRC module and/or the at least one cryptography accelerator and/or or the at least one clock generator module, and/or the at least one timer module, and/or the at least one security monitoring and control circuit, and/or the at least one quantum process-based true random number generator, and/or the at least one microcontroller core, and/or or the at least one data interface.

In a further refinement, the single-photon transmission device comprises at least one watchdog timer, which is set up to monitor the processing of various program parts by the at least one microcontroller core, in particular the at least one watchdog timer is integrated in the at least one safety monitoring and control circuit.

In a further refinement, the single-photon transmission device is set up to transmit further data, e.g. one or more lifetime and usage data, and/or logistic data, and/or commercial data, and/or website and email addresses, and/or image data, and/or a set of instructions for a car's control units which the microcontroller core of the single-photon transmission device communicates via the at least one data interface of the single-photon transmission device, and/or to store further application data.

In a further configuration, one or more of the at least one ground circuit and/or one or more of the at least one power supply or VCC circuit are configured to interact in such a way that a modulation of a current consumption and/or an internal resistance and/or a voltage drop between supply voltage terminals the single-photon transmission device does not allow any conclusions to be drawn about an operational sequence and/or a state of the single-photon transmission device, at least temporarily.

In a further refinement, the single-photon transmission device comprises an analog/digital converter which is set up to allow the microcontroller core to monitor internal analog values, such as an operating voltage, and external analog values.

In a further refinement, the at least one quantum process-based generator is set up to generate one or more random numbers, in particular at the request of the at least one microcontroller core.

In a further refinement, the at least one microcontroller core is set up to generate one or more keys with the aid of a respective program from one or more of its memory elements and with the aid of one or more of the generated random numbers.

In a further configuration, the at least one microcontroller core is set up to encrypt and/or decrypt data with the aid of a respective program of the microcontroller core in question and with the aid of a respective key of the generated keys, which data is typically transmitted from the at least one microcontroller core via the at least one data interface the single photon transmission device exchanges with devices external to the single photon transmission device.

In a further refinement, the single-photon transmission device comprises at least one wireless data interface for communication with another computer system, in particular via a respective antenna of the at least one wireless data interface. In particular, the respective antenna is set up to emit an electromagnetic signal, which the single-photon transmission device exchanges with a single-photon reception device in a wired or wireless manner.

In a further embodiment, the single-photon transmission device is a mobile device, in particular a mobile phone, or a smartphone, or a laptop, or a tablet PC, or a key, or a vehicle key, or a security key for a weapon or other military device, or a key for activating and/or controlling an aircraft or ship's hull or a projectile, or an access key to a secured area or to a vault or safe, or an activation key for a secured mechanical device, or an activation key for a protected process, that for example, to run a secured device, or an activation key for a protected device that is to run, for example, a secured method.

In a further refinement, the single-photon transmission device comprises at least one biometric sensor.

In a further refinement, the single-photon transmission device comprises at least one means for identifying a person using the single-photon transmission device.

In a further refinement, the single-photon transmission device has alignment aids, in particular a laser pointer diode, for aligning the single-photon transmission device with respect to a single-photon reception device.

The single photon receiving device according to the invention for receiving a QKD coupled beam transmitted by a single photon transmitting device according to the invention as described above comprises a single photon detector system which is set up to receive a polarization-modulated single photon signal.
In particular, the single photon detector system has at least one single photon detector.
In particular, the at least one single photon detector is set up to detect the QKD coupling beam of the single photon transmission device.
In particular, the single photon receiving device comprises at least one microcontroller core.
In particular, the single photon receiving device comprises at least one internal data bus.

In one configuration, the microcontroller core of the single photon receiving device is set up to handle internal data communication via the internal data bus of the single photon receiving device.

In a further refinement, the single-photon receiving device has at least one read/write memory RAM for storing and for providing and using data and program commands by the microcontroller core.

In a further refinement, the single-photon receiving device has at least one writable non-volatile memory.

In a further refinement, the single-photon receiving device has at least one non-volatile, read-only memory.

In a further refinement, the microcontroller core of the single photon receiving device is set up to process program code and program data which is stored in the writable, non-volatile memory and/or in the non-volatile, read-only memory of the single photon receiving device.

In a further refinement, the single-photon receiving device has at least one non-volatile, writable and/or non-writable manufacturer memory.

In a further refinement, the single-photon receiving device has at least one cryptography accelerator.

In a further refinement, the single-photon receiving device comprises at least one manufacturer memory firewall which is set up to prevent unauthorized access to a manufacturer memory and only allows it after appropriate authentication, for example using a password.

In a further refinement, the single-photon receiving device has at least one CRC (Cyclic Redundancy Check) module.

In a further configuration, the single-photon receiving device has at least one clock generator module.

In a further refinement, the single-photon receiving device comprises at least one timer module which is set up to control time sequences within the single-photon receiving device.

In a further refinement, the single photon receiving device has at least one security monitoring and control circuit which is set up to monitor the integrity of the single photon receiving device and, if necessary, to initiate countermeasures in the event of an attack.

In a further refinement, the single-photon receiving device has at least one quantum-process-based generator for true random numbers.

In a further refinement, the single-photon receiving device has at least one data interface which is set up to carry out data communication with other computer systems.

In a further configuration, the single-photon receiving device comprises at least one basic clock generator.

In a further refinement, the single-photon receiving device has at least one reset circuit.

In a further refinement, the single-photon receiving device comprises at least one power supply or Vcc circuit with a voltage regulator.
In particular, the power supply or Vcc circuit of the single photon receiving device is configured to provide an operating voltage for a microcontroller system of the single photon receiving device and other sub-devices of the single photon receiving device.

In another embodiment, the power supply or Vcc circuitry of the single photon receiving device includes a charging circuit and a first charging coil for inductively coupling to a second charging coil.

In a further refinement, the single-photon receiving device has at least one ground circuit which is set up to protect the device against polarity reversal and attacks via the ground line.

In a further refinement, the single photon receiving device has at least one input/output circuit which is set up to allow the single photon receiving device to control or read out other devices or to communicate with them in some other way.

In a further refinement, the reset circuit of the single-photon receiving device comprises a watchdog timer.

In a further configuration, one or more of the at least one ground circuit and/or one or more of the at least one power supply or Vcc circuit of the single-photon receiving device are set up to interact in such a way that a modulation of the current consumption and/or the internal resistance and/or the voltage drop between Supply voltage terminals of the single photon receiving device does not allow any conclusions to be drawn about operating processes and / or states of the single photon receiving device at least temporarily.

In a further refinement, one or more of the at least one microcontroller core of the single-photon receiving device are set up to generate one or more keys using a respective program from one or more of its memory elements and with the aid of one or more generated random numbers.
In particular, the at least one microcontroller core of the single photon receiving device is set up to encrypt and/or decrypt data, which are exchanged via one or more data interfaces of the single photon receiving device with devices outside the single photon receiving device, with the aid of a respective program of the relevant microcontroller core and with the aid of a respective key of the generated keys.

In a further configuration, the single-photon receiving device has at least one wireless and/or at least one wired data interface.
In particular, the wired data interface of the single photon receiving device is set up to exchange data between the single photon receiving device and the single photon transmitting device via a wired data channel using an electromagnetic data signal.
In particular, the wireless data interface of the single-photon receiving device has at least one antenna in each case.

In a further refinement, the single-photon receiving device has an evaluation circuit.

In a further refinement, the single photon detector system of the single photon receiving device comprises at least one receiving channel for single photons.
Optionally, the single photon detector system of the single photon receiving device includes at least one receiving optics, which is set up to focus incoming single photons of the QKD coupled beam of the single photon transmitting device onto the single photon detectors of the single photon detector system of the single photon receiving device. In particular, the single photon detector system comprises at least one polarizing beam splitter.
In particular, the single photon detector system of the single photon receiving device comprises at least one λ/4 plate and/or a polarization rotation device.

In a further configuration, the single photon receiving device has an alignment receiver for aligning the single photon transmitting device with respect to the single photon receiving device.
In particular, the alignment receiver of the single photon receiving device is set up to detect a laser pointer beam of the single photon transmitting device.

In a further refinement, the alignment receiver of the single photon receiving device comprises a receiver.
In particular, the receiver is set up to detect the laser pointer beam. In particular, the alignment receiver comprises an optical system.
In particular, the alignment receiver includes an interface which is set up to receive measurement data from the receiver, in particular the interface is set up to signal the microcontroller core of the single photon receiving device via the internal data bus of the single photon receiving device whether the receiver has sufficient light from the laser pointer via the optical system Beam of the single photon transmission device for aligning the single photon transmission device receives.

In a further configuration, the microcontroller core of the single photon receiving device is set up to start generation of a common quantum key for the single photon transmitting device and the single photon receiving device in accordance with a signaling of the interface of the single photon receiving device.

According to the method according to the invention for generating a common quantum key for a single photon transmission device, as described above, and a single photon reception device, as described above, a microcontroller core of the single photon reception device starts the generation of the common quantum key for the single photon transmission device and the single photon reception device in accordance with a signaling of an interface of the single photon reception device by the microcontroller core of the single photon receiving device signals a microcontroller core of the single photon transmitting device that a quantum key agreement can start.
In particular, the microcontroller core of the single photon transmission device causes the single photon transmission device to generate a polarization-modulated stream of single photons as a QKD coupled beam, in particular using a random number of its quantum process-based true random number generator of the single photon transmission device. In particular, the single-photon receiving device receives the polarization-modulated single-photon data stream of the QKD coupled beam generated by the single-photon transmitting device.

An integrated QKD circuit according to the invention comprises a single-photon transmission device as described above and/or a single-photon reception device as described above.

A car key according to the invention comprises a single photon transmission device as described above and/or a single photon reception device as described above.

A car according to the invention comprises a single photon transmission device as described above and/or a single photon reception device as described above.

• • zwischen einem erfindungsgemäßen Autoschlüssel und einem erfindungsgemäßen Auto,
• • zwischen einem ersten erfindungsgemäßen Auto und einem zweiten erfindungsgemäßen Auto,
• • zwischen einem erfindungsgemäßen Auto und einer Infrastrukturvorrichtung, wie beispielsweise eine Ladesäule, und
• • innerhalb eines erfindungsgemäßen Autos für eine verschlüsselte Kommunikation innerhalb des erfindungsgemäßen Autos.

The single photon transmission device according to the invention described above and/or the single photon receiving device according to the invention described above is used in particular for data exchange

• • between a car key according to the invention and a car according to the invention,
• • between a first car according to the invention and a second car according to the invention,
• • between a car according to the invention and an infrastructure device, such as a charging station, and
• • within a car according to the invention for encrypted communication within the car according to the invention.

• • wenigstens eine Shallow-Trench-Isolation,
• • wenigstens einen Anodenkontakt,
• • wenigstens einen Kathodenkontakt,
• • wenigstens ein Abdeckoxid,
• • wenigstens eine optisch transparente Isolierschicht,
• • wenigstens ein hoch dotierte erstes Anschlussgebiet eines ersten Leitungstyps,
• • wenigstens eine erste dotierte Wanne eines zweiten Leitungstyps,
• • wenigstens eine zweite dotierte Wanne eines zweiten Leitungstyps,
• • eine epitaktische Schicht eines zweiten Leitungstyps,
• • ein Basismaterial eines halbleitenden einkristallinen Wafers,
• • eine zweite dotierte Wanne eines zweiten Leitungstyps unterhalb des Anodenkontakts,
• • wenigstens ein hoch dotiertes zweite Anschlussgebiet des zweiten Anschlusstyps, und
• • wenigstens eine Isolation.

A SPAD diode according to the invention for a sensor element of a single photon detector for a single photon transmission device according to the invention and/or for a single photon reception device according to the invention

• • at least one shallow trench isolation,
• • at least one anode contact,
• • at least one cathode contact,
• • at least one covering oxide,
• • at least one optically transparent insulating layer,
• • at least one highly doped first connection region of a first conductivity type,
• • at least one first doped well of a second conductivity type,
• • at least one second doped well of a second conductivity type,
• • an epitaxial layer of a second conductivity type,
• • a base material of a semiconducting monocrystalline wafer,
• • a second doped well of a second conductivity type below the anode contact,
• • at least one highly doped second connection region of the second connection type, and
• • at least one insulation.

In particular, the SPAD diode according to the invention comprises at least one metal-optical filter and at least one optically transparent slot in the metal-optical filter.

In particular, in a SPAD diode array made up of a plurality of SPAD diodes according to the invention, the plurality of SPAD diodes are arranged such that the respective metal-optical filters of the respectively adjacent SPAD diodes are arranged at a 45° angle to one another.

The single photon transmission device according to the invention and the single photon reception device according to the invention have the advantage that they can carry out a secure data exchange using the method according to the invention, whereby the single photon transmission device according to the invention and/or the single photon reception device according to the invention can be a mobile device, or these can be in a mobile device Device are integrated, such as in the car key according to the invention and the car according to the invention.
An application for data exchange between a mobile device, for example a key or a smartphone or the like, and an infrastructure, for example a building, is also possible.
An application for data exchange between a mobile device, for example a smartphone or the like, and a controllable device, for example a smart home application, is also possible in a safe manner with the single photon transmission device according to the invention and the single photon reception device according to the invention.

In this case, the single-photon transmission device according to the invention and the single-photon reception device according to the invention have a very compact design. In particular in the form of the integrated QKD circuit according to the invention.
The CPK is improved in particular by a monolithic integration of the single-photon transmission device according to the invention and/or the single-photon reception device according to the invention. This results in a narrow distribution and a small spread, so that a spread among the components of the single-photon transmission device and/or single-photon reception device becomes smaller.

Further advantageous configurations, features and functions of the invention are explained in connection with the examples shown in the figures.

• 1 eine schematische Darstellung eines optischen Systems eines QKD-Empfängers gemäß dem Stand der Technik;
• 2 eine schematische Darstellung eines optischen Systems einer QKD-Einzelphotonensendevorrichtung gemäß dem Stand der Technik;
• 3 eine schematische Darstellung eines weiteren optischen Systems einer QKD-Einzelphotonensendevorrichtung gemäß dem Stand der Technik;
• 4 eine schematische Darstellung einer erfindungsgemäßen Einzelphotonensendevorrichtung in einer ersten Ausführungsform;
• 5 eine schematische Darstellung einer erfindungsgemäßen Einzelphotonensendevorrichtung in einer weiteren Ausführungsform;
• 6 eine schematische Darstellung einer erfindungsgemäßen Einzelphotonenempfangsvorrichtung;
• 7 ein schematisches Blockschaltbild eines beispielhaften integrierten Schaltkreises für die Verwendung als integrierter QKD-Schaltkreis in automobilen QKD Systemen;
• 8 eine schematische Darstellung einer Kopplung einer erfindungsgemäßen Einzelphotonensendevorrichtung mit einer erfindungsgemäßen Einzelphotonenempfangsvorrichtung mittels eines QKD-Kopplungsstrahls;
• 9 schematische Darstellung einer Nutzung eines Laser-Pointer-Strahls zur Ausrichtung der erfindungsgemäßen Einzelphotonensendevorrichtung auf die erfindungsgemäße Einzelphotonenempfangsvorrichtung;
• 10 schematische Darstellung der Vereinbarung eines QKD-Schlüssels zwischen einem eine erfindungsgemäße Einzelphotonensendevorrichtung umfassenden Autos und einer eine erfindungsgemäße Einzelphotonenempfangsvorrichtung umfassende Infrastrukturvorrichtung in Form einer Ladesäule;
• 11 schematische Darstellung eines beispielhaften Zusammenwirkens zwischen einem Software-Update-Gerät umfassend die erfindungsgemäße Einzelphotonensendevorrichtung und einem Auto umfassend die erfindungsgemäße Einzelphotonenempfangsvorrichtung;
• 12 Auto umfassend eine erfindungsgemäße Einzelphotonensendevorrichtung und eine erfindungsgemäße Einzelphotonenempfangsvorrichtung, wobei Teilvorrichtungen des Autos über ein zugehöriges QKD-System einen QKD-Schlüssel erzeugen und für eine verschlüsselte Kommunikation in dem Auto nutzen;
• 13 schematische Darstellung eines beispielhaften Zusammenwirkens zwischen zwei Autos umfassend eine erfindungsgemäße Einzelphotonensendevorrichtung und eine erfindungsgemäße Einzelphotonenempfangsvorrichtung;
• 14 schematische Darstellung einer beispielhaften SPAD-Diode für den Einsatz als Sensorelement eines Einzelphotonendetektors einer erfindungsgemäßen Einzelphotonensendevorrichtung und/oder einer erfindungsgemäßen Einzelphotonenempfangsvorrichtung; und
• 15 eine schematische Darstellung eines metalloptischen Filters mit metalloptischen Teilfiltern für ein SPAD-Dioden-Array von SPAD-Dioden gemäß 14.

This shows:

• 1 a schematic representation of an optical system of a QKD receiver according to the prior art;
• 2 a schematic representation of an optical system of a QKD single photon transmission device according to the prior art;
• 3 a schematic representation of another optical system of a QKD single photon transmission device according to the prior art;
• 4 a schematic representation of a single photon transmission device according to the invention in a first embodiment;
• 5 a schematic representation of a single photon transmission device according to the invention in a further embodiment;
• 6 a schematic representation of a single photon receiving device according to the invention;
• 7 Figure 12 is a schematic block diagram of an exemplary integrated circuit for use as a QKD integrated circuit in automotive QKD systems;
• 8th a schematic representation of a coupling of a single photon transmission device according to the invention with a single photon reception device according to the invention by means of a QKD coupling beam;
• 9 schematic representation of a use of a laser pointer beam for aligning the single photon transmission device according to the invention to the single photon reception device according to the invention;
• 10 Schematic representation of the agreement of a QKD key between a car comprising a single photon transmitting device according to the invention and an infrastructure device comprising a single photon receiving device according to the invention in the form of a charging station;
• 11 schematic representation of an exemplary interaction between a software update device comprising the single-photon transmission device according to the invention and a car comprising the single-photon receiving device according to the invention;
• 12 Car comprising a single-photon transmission device according to the invention and a single-photon reception device according to the invention, with sub-devices of the car generating a QKD key via an associated QKD system and using it for encrypted communication in the car;
• 13 schematic representation of an exemplary interaction between two cars comprising a single photon transmission device according to the invention and a single photon reception device according to the invention;
• 14 schematic representation of an exemplary SPAD diode for use as a sensor element of a single photon detector of a single photon transmission device according to the invention and/or a single photon reception device according to the invention; and
• 15 a schematic representation of a metal-optical filter with metal-optical sub-filters for a SPAD diode array of SPAD diodes according to 14 .

1 10 shows a schematic and simplified representation of an optical system of a QKD receiver 101 according to the prior art, the QKD receiver being a single photon receiver 101. FIG.
It is a single photon receiver for a polarization modulated single photon beam. A direction-of-polarization-modulated stream of single photons 102 arrives via a receiving path 152 in a QKD receiving system of the single-photon receiver 101 for a polarization-modulated single-photon beam. A non-polarizing first beam splitter 183 splits the polarization direction modulated flow of the individual photons 102 in the reception path 152 into a first signal path 1604 and a second signal path 187 . A single photon of the polarization direction-modulated stream of single photons 102 in the receiving path 152 will reach the first signal path 1604 with a probability of 50%, and a single photon of the polarization direction-modulated stream of single photons 102 in the receiving path 152 will reach the second signal path 187 with a probability of 50% second polarizing beam splitter 184 splits the one first single photon stream 1604 into a third horizontally polarized single photon stream and a fourth vertically polarized photon stream. The second polarizing beam splitter 184 directs the photons of the light in the first signal path 1604, which have a horizontal polarization, to a first single photon detector 177 for horizontally polarized single photons and the photons of the light in the first signal path, which have a vertical polarization, to a second single photon detector 176 for vertically polarized single photons. A λ/4 plate 188 rotates the photons in the second signal path 187 by 45° and feeds these rotated photons into a rotated second signal path 189 . A third polarizing beam splitter 190 directs the -45° polarized single photons of the light in the rotated second signal path 189 to a fourth single photon detector 178 and the +45° polarized single photons of the light in the rotated second signal path 189 to a third single photon detector 179.
In this way, the proposed single photon receiver 101 for a polarization direction modulated stream 102 of the single photons can detect the polarization modulation of the polarization direction modulated stream 102 of the single photons in the reception path 152 and make it available to a computer, for example a microcontroller core.

2 FIG. 12 shows a schematic and simplified representation of an optical system of a QKD single-photon transmission device 201 according to the prior art.
It is a single photon transmission direction 201 for transmitting a stream of polarization-modulated single photons 102. The polarization direction-modulated stream of single photons 102 leaves the QKD single-photon transmitting device 201 via the receiving path 152 as a polarization-modulated single-photon beam 102.
The polarization modulatable single photon source 201 comprises a first single photon source 236 for horizontally polarized single photons and a second single photon source 237 for vertically polarized single photons and a third single photon source 238 for horizontally polarized single photons and a fourth single photon source 239 for vertically polarized single photons. The single photons of the third single photon source 238 for horizontally polarized single photons and the fourth single photon source 239 for vertically polarized single photons must pass through a λ/4 plate 288 before leaving the polarization-modulated single photon source 201 . This λ/4 plate 288 rotates the polarization of the single photons of the third single photon source 238 for horizontally polarized single photons and the single photons of the fourth single photon source 239 for vertically polarized single photons by 45°. Therefore, the third single-photon source 238 for horizontally polarized single photons is actually a third single-photon source 238 for +45° polarized single photons with respect to the receiving path 152. Likewise, for this reason, the fourth single-photon source 239 for vertically polarized single photons is actually one fourth single photon source 238 for -45° polarized single photons related to the receiving path 152.
A first beam splitter 283 and a second beam splitter 284 and a third beam splitter 290 combine the single photons of the first single photon source 236 and the second single photon source 237 and the third single photon source 238 and the fourth single photon source 239 into a common stream 102 of single photons in the reception path 152.

A control device, typically a microcontroller core, now controls only one single photon source of the four single photon sources for a very short time, so that polarization modulation of the stream 102 of the single photons in 45° steps is possible overall.

3 12 shows another possibility for mixing together individual photons from differently polarized individual photon sources 336 to 339 to form a common beam 102 of individual photons according to the prior art.
In the example of 3 For example, n=4 single photon sources are arranged around the system axis. The system axis is preferably substantially equal to the optical axis of the stream 102 of single photons. The respective optical emission axes of the respective single photon sources 336 to 339 are arranged perpendicularly to the system axis of the beam 102 of the single photons. The respective optical emission axes of the respective single photon sources 336 to 339 are preferably located essentially in a plane which is arranged perpendicularly to the system axis of the beam 102 of the single photons. The respective optical emission axes of the respective single photon sources 336 to 339 preferably essentially cross at a crossing point. An exemplary cone-shaped mirror 1301 has a specular surface in the shape of a cone and a rotational axis of symmetry. The rotational axis of symmetry of the conical mirror 1301 is preferably arranged essentially parallel and essentially congruent to the system axis. The crossing point of the respective optical emission axes of the respective single photon sources 336 to 339 is preferably essentially on the system axis and essentially on the rotational axis of symmetry of the conical mirror 1301 and typically within the conical mirror 1301. The n=4 respective optical emission axes of the respective single photon sources 336 to 339 differ from each other by an angle of (k-1)/(2*n)*360° where k is the number of the respective single photon source 336 to 339. In the example of the 3 n=4 is chosen. The angles of the respective optical emission axes of the respective single photon sources 336 to 339 differ by 45° compared to the respective optical emission axes of the directly adjacent single photon sources of the single photon sources 336 to 339. Other numbers of single photon sources are possible. For example, 8 or 16 single photon sources are conceivable. n≥2 is preferred. n≥4 is better. A spatial filter 1302 eliminates slight variations in photon density per unit time depending on the single photon emitter 336-339 emitting a single photon. The spatial filter 1302 consists in the example of FIG 3 of a first pinhole 344 and a second pinhole 345 spaced apart from it. By arranging the n single photon sources in an arrangement plane perpendicular to the beam axis of the stream 102 of the single photons and by rotating the optical emission axes of the single photon sources by (k-1)/(2 *n) *360° to each other, the presented device can carry out a quantized modulation of the polarization of the individual photons in steps of (k-1)/(2*n) *360°. The conical mirror 1301 deflects the individual photons of the respective individual photon sources 336 to 339, whose respective emission axes are oriented differently in the arrangement plane, into the common beam direction of the beam axis of the individual photons 102. Possibly occurring smaller single photons The spatial filter 1304 eliminates source-specific deviations.

4 shows a schematically simplified example of a single photon transmission device 401 according to the invention using the example of a car key system 401 without alignment aids for a car.
The core of the car key system 401 is a microcontroller core 416. Essential parts of the single-photon transmission device, in particular the car key system, 401 are preferably microintegrated on a semiconductor substrate. These parts are preferably manufactured using CMOS, BiCMOS or bipolar technology.
The single photon transmission device 401 preferably includes one or more internal data buses 402, via which the microcontroller core 416 of the single photon transmission device 401 preferably handles the internal data communication. Furthermore, the single photon transmission device preferably includes one or more read/write memories RAM 403 for storing and providing use of data and program instructions by the microcontroller core 416. In addition, the single photon transmission device 401 preferably has one or more writeable non-volatile memories 404. These non-volatile memories may include EEPROM memory 404 or flash memory 404 or OTP memory 404, for example. Furthermore, the single-photon transmission device 401 preferably has one or more non-volatile read-only memories 405, such as a ROM 405, for example. These preferably contain program code and program data for the microcontroller core 416, which typically processes this program code. Program code and program data may also be stored in the one or more writable non-volatile memories 404 .
The exemplary single-photon transmission device 401 preferably includes one or more non-volatile, writable and/or non-writable manufacturer memories 406. In the case of a non-writable manufacturer memory 406, the manufacturer memory 406 can be, for example, a manufacturer ROM. Furthermore, the exemplary single-photon transmission device 401 preferably includes one or more cryptography accelerators 407, for example a DES accelerator and/or an AES accelerator 407, in order to accelerate the processing of the cryptography algorithms by the microcontroller core 416 of the exemplary single-photon transmission device 401. The exemplary single-photon transmission device 401 preferably also includes one or more manufacturer memory firewalls 408, which prevent unauthorized access to the manufacturer memory 406 and only allow it after appropriate authentication, for example using a password. Preferably, the manufacturer memory firewalls will irrevocably block access if more than an allowed number of unsuccessful attempts to access the manufacturer memory 406 have been made. Another device for increasing efficiency can be one or more CRC (Cyclic Redundancy Check) modules 411 of the exemplary single-photon transmission device 401 . These calculate a CRC check data word for a specified amount of data, as is used in many data communication protocols, for example. Furthermore, the exemplary single-photon transmission device 401 typically has one or more clock generator modules (Clock Driver, CLK) 412 that provide the system clocks for operating the device parts of the exemplary single-photon transmission device 401 . The example single photon transmission device 401 preferably includes one or more timer modules 413 that control timing within the example single photon transmission device 401 . Preferably, the example single photon transmission device 401 includes one or more security monitoring and control circuits 414 that monitor the integrity of the example single photon transmission device 401 and, if necessary, initiate countermeasures in the event of an attack. The exemplary single-photon transmission device 401 preferably comprises at least one preferably quantum process-based generator for genuine random numbers (Quantum Random Number Generator: QRNG) 415. Such a generator has the advantage that the entropy of its random number is particularly well suited for encryption. Typically, the example single photon transmission device 401 includes one or more 8/16/32/64-bit microcontroller cores 416 that execute the programs in the example single photon transmission device 401 memory. The exemplary single photon transmission device 401 preferably includes one or more optional data interfaces 417, in particular one or more universal asynchronous receiver transmitters (UART) for supporting high-speed serial data, for data communication with other computer systems.
One or more base clock generators 421 (CLK) are preferably part of the example single photon transmission device 401. The example single photon transmission device 401 preferably includes one or more reset circuits 422. One or more power supply or Vcc circuits 423 with voltage regulators that set the operating voltages for the microcontroller system of the provide example single photon transmission device 401 and other sub-devices of example single photon transmission device 401 . Preferably, the one or more power supply or Vcc circuits 423 also include at least one energy reserve, such as a battery or accumulator. More preferably, the one or more power supply or Vcc circuits 423 also include a Charging circuit and a first charging coil, which is typically not a device part of the example single photon transmission device 401, are used for inductive coupling to a second charging coil, which is preferably part of a device external to the example single photon transmission device 401 and/or separate from the example single photon transmission device 401. The external charging device transmits energy by means of an inductive coupling from an energy system, for example a battery or an alternator or the like, or from an energy system of the external charging device, for example an energy store or a generator or a solar cell or a power grid or the like, by means of the charging circuit of the one or more power supply or Vcc circuits 423 of the example single photon transmission device 401 on the energy reserve of the one or more power supply or Vcc circuits 423 of the example single photon transmission device 401. The example single photon transmission device 401 typically has one or more ground circuits 424, which protect the device against reverse polarity and protect against attacks via the ground line. The example single photon transmission device 401 also typically includes one or more input/output circuits 425 that allow the example single photon transmission device 401 to drive, read, or otherwise communicate with other devices.
4 FIG. 12 shows, by way of example and schematically, the block diagram of an example system for the use of the example single photon transmission device 401 in, for example, automotive car keys. 4 12 shows a diagram of an example of an example single photon transmission device 401. The example single photon transmission device 401 includes, for example, memory elements that are connected to an internal data bus 402 of the example single photon transmission device 401. FIG. The memory elements of the example single photon transmission device 401 may include, for example, one or more random access memories RAM 403, one or more writable non-volatile memories such as EEPROM memory 404 or flash memory 404 or OTP memory 404. Furthermore, the example single-photon transmission device 401 preferably includes one or more non-volatile, read-only memories 405, such as a ROM. In addition, the example single-photon transmission device 401 preferably includes one or more non-volatile, writable and/or non-writable manufacturer memory 406. In the case of non-writable manufacturer memory, the manufacturer memory 406 may be a manufacturer ROM. Preferably, the manufacturer ROM 406 comprises the boot software for the microcontroller core 416 of the example single-photon transmission device 401. The example single-photon transmission device 401 includes, for example, one or more cryptographic accelerators 407, for example a DES accelerator and/or an AES accelerator 407, which is preferred are connected to the microcontroller core 416 of the example single photon transmission device 401 via the internal data bus 402 of the example single photon transmission device 401 . For example, one or more manufacturer memory firewalls 408 may be provided between the manufacturer memory 406 of the example single photon transmission device 401 and the internal data bus 402 of the example single photon transmission device 401 . For example, the example single photon emitting device 401 preferably includes processing modules of the example single photon emitting device 401 that communicate with the microcontroller core 416 of the example single photon emitting device 401 via the internal data bus 402 of the example single photon emitting device 401 . The processing modules of the exemplary single photon transmission device 401 preferably comprise at least one of the following modules: a CRC (Cyclic Redundancy Check) module 411 of the exemplary single photon transmission device 401, a clock generator module 412 of the exemplary single photon transmission device 401, one or more timer modules 413 of the exemplary single photon transmission device 401, a Security monitoring and control circuitry 414 of the exemplary single photon transmitter device 401, one or more preferably quantum process-based true random number generators (QRNG) 415 of the exemplary single photon transmitter device 401, one or more 8/16/32/15-bit microcontroller cores 416 of the exemplary single photon transmission device 401 and one or more data interfaces 417 of the exemplary single photon transmission device 401, in particular one or more universal asynchronous receiver transmitters (UART) for supporting high-speed serial data. The other circuit parts of the exemplary single-photon transmission device 401 include, for example, one or more basic clock generators 421 (CLK) and/or one or more clock generator modules 412, a reset circuit 422, a power supply or Vcc circuit 423 with voltage regulators that provide the operating voltage, a ground circuitry 424 and an input/output circuitry 425. Preferably, the example single-photon transmission device 401 is configured to provide secure authentication. For example, the example single photon transmission device 401 preferably stores alongside the authentication code further data, e.g. B. one or more lifetime and usage data and / or eg logistical data and / or eg commercial data and / or website and email addresses and / or image data, a set of instructions for control devices of a car 802, with which the microcontroller core 416 of the example single-photon transmission device 401 communicates via a data interface of the example single-photon transmission device 401 . In addition, the example single photon transmission device 401 may store other application data.
Preferably, the example single photon transmission device 401 includes, for example, a microcontroller core 416 configured to facilitate secure authentication of a product.
The internal data bus 402 of the example single photon transmission device 401 can include multiple data buses 402 for multiple microcontroller cores 416 of the example single photon transmission device 401, so that these multiple microcontroller cores 416 can access different sub-devices of the example single photon transmission device 401 independently of one another at the same time. Typically, however, the example single photon transmission device 401 comprises only one internal data bus 402 and only one microcontroller core 416. The microcontroller core 416 of the example single photon transmission device 401 is preferably an ARM processor or the like. It is preferably an 8-bit or a 16-bit or a 32-bit or a 64-bit microcontroller core 416.
The exemplary single-photon transmission device 401 preferably includes one or more read/write memories RAM 403. These can be, for example, SRAMs and/or MRAMs and/or FRAMS or the like. The one or more read/write memories RAM 403 of the example single-photon transmission device 401 can also be wholly or partially dynamic read/write memories such as DRAMs, for example, which the microcontroller core 416 or a refresh device of the example single-photon transmission device 401 at regular time intervals in read and rewrite in a refresh cycle. For the access of the microcontroller core 416 to a memory of the example single-photon transmission device 401, the example single-photon transmission device 401 can have an access logic which regularly executes this refresh and controls this access. However, DRAM typically opens up opportunities for attack and is typically a potential vulnerability. The microcontroller core 416 of the exemplary single photon transmission device 401 can preferably access this write/read memory RAM 403 of the exemplary single photon transmission device 401 by means of the internal data bus 402 of the exemplary single photon transmission device 401 .

The exemplary single photon transmitter device 401 preferably comprises one or more writable and non-volatile memories 404. The microcontroller core 416 of the exemplary single photon transmitter device 401 can preferably access these writable and non-volatile memories 404 of the exemplary single photon transmitter device 401 by means of the internal data bus 402 of the exemplary single photon transmitter device 401. This non-volatile memory 404 of the example single-photon transmission device 401 may include EEPROM memory 404 or flash memory 404 or OTP memory 404, for example. OTP stands for English One Time Programmable, which means only once programmable. One possibility for an attack may be the erasure of the non-volatile memory 404 by means of radiation, for example X-rays and/or ionizing radiation, and/or the heating of memory cells. To this end, the example single photon transmission device 401 preferably includes one or more security monitoring and control circuits 414 of the example single photon transmission device 401 that monitor the data integrity of the memory cells of the erasable memories 404 of the example single photon transmission device 401 . The memory cells of erasable memory 404 of exemplary single-photon transmission device 401 preferably have redundancy such that at least two check bits are provided for a data word, which is preferably a data word with a length of 8 bits, i.e. one byte, and that there are always at least a first check bit must have the content 1 and another, wide check bit, which is assigned to this first check bit, must have the content 0. For example, the first check bit can be a parity bit of the byte and the second check bit can be the inverse bit of the parity bit relative to the first check bit. If an attack with ionizing radiation or the like then occurs, the attack resets both test bits to the same value. This is an illegal condition that the example single photon transmission device 401 can detect. The one or more security monitoring and control circuits 414 of the exemplary single-photon transmission device 401 detect such a deviation and, if necessary, block the exemplary single-photon transmission device 401 from further access at least for a preferably predetermined period of time.
Each bit of the memory of the exemplary single-photon transmission device 401 is preferably designed twice, so that each logical data bit is preferably implemented as a pair of a first physical data bit with a first internal logical value and a second physical data bit with a second internal logical value. Included typically the second internal logical value is the logical inverse of the first internal logical value. The one or more safety monitoring and control circuits 414 of the exemplary single photon transmission device 401 again preferably monitor that this is always the case. The one or more safety monitoring and control circuits 414 of the exemplary single photon transmission device 401 again detect deviations and, for example, preferably block further execution if necessary of programs or specific program parts and/or access to data, for example for the microcontroller core 416 in the event of deviations. Preferably, the example single photon transmission device 401 comprises one or more reset circuits 422 of the example single photon transmission device 401. The reset circuits 422 of the example single photon transmission device 401 each set the example single photon transmission device 401 and/or sub-devices of the example single photon transmission device 401 to predefined states when predetermined or determinable reset conditions and/or combinations and/or temporal sequences of such reset conditions exist. For example, these conditions may be signaling from the one or more safety monitoring and control circuits 414 of the example single photon transmission device 401 to one or more reset circuits 422 of the example single photon transmission device 401, for example. These conditions can also be changes and/or values of electrical node potentials compared to the potential of a reference node or a reference potential line, that is, for example, one or more operating voltages of the exemplary single-photon transmission device 401. A watchdog timer may be part of a reset circuit 422 of the example single photon transmission device 401 . Furthermore, such conditions may affect the integrity of the housing of the example single photon transmission device 401 . The housing of the exemplary single photon transmission device 401 preferably includes a detector for opening or damaging the housing of the exemplary single photon transmission device 401. For example, this can be a single line that, for example as a textile network, surrounds or covers the exemplary single photon transmission device 401 or at least parts of the exemplary Single photon transmission device 401 covers. It can also be a network of lines that cover the exemplary single photon transmission device 401 exclusively for detecting an attack. For example, the exemplary single-photon transmission device 401 can in each case feed an electric current into one or more such lines by means of a first input/output line and withdraw this again at one or more second input/output lines. If the flow of current is interrupted, this is an indication of an attack which one or more of the one or more security monitoring and control circuits 414 of the example single photon transmission device 401 can detect and which then, for example, the microcontroller core 416 of the example single photon transmission device 401 signal this attack. For example, in such a case of suspected violation of the integrity of the housing of the example single photon transmission device 401, one or more of the one or more safety monitoring and control circuits 414 of the example single photon transmission device 401 can block write and/or read access to memory contents of the memory of the example single photon transmission device 401 and/or delete such contents of the memory of the example single photon transmission device 401 in whole or in part, or set these contents of the memory of the example single photon transmission device 401 to predefined values or overwrite them with nonsensical data or otherwise manipulate them. The memories of the example single-photon transmission device 401 preferably include one or more non-volatile, read-only memories 405, such as ROM. The ROM of the exemplary single-photon transmission device 401 preferably contains data and/or program instructions specified by the design. The exemplary single-photon transmission device 401 preferably has one or more non-volatile, writable and/or non-writable manufacturer memories 406 in which the semiconductor manufacturer or another supplier can store their production and security data, such as serial numbers, etc. After the last production test has been carried out, the semiconductor manufacturer preferably blocks access to this writable and/or non-writable non-volatile manufacturer memory 406 of the exemplary single-photon transmission device 401. Access to the writable and/or non-writable manufacturer memory 406 of the exemplary single-photon transmission device 401 is preferred using one or more manufacturer passwords. In some cases, a double key procedure makes sense. In this case, a customer following the semiconductor manufacturer stores a customer password in a customer lock register of the exemplary single-photon transmission device 401 that can also be locked for access with a password. The semiconductor manufacturer can preferably only access all memory areas of the exemplary single-photon transmission device 401 with the customer password and the semiconductor password. Preferably, the semiconductor manufacturer provides an analysis password, by means of which one or more of the one or more security monitoring and control circuitry 414 of the example single photon transmission device 401, typically with the aid of the reset circuit 422 of the example single photon transmission device 401, to delete the customer content in the memories of the example single photon transmission device 401 and then to make all memory areas of the example single photon transmission device 401 accessible for the analysis of errors close. In the case of a non-writable manufacturer memory of the example single photon transmission device 401, the manufacturer memory 406 of the example single photon transmission device 401 can be a manufacturer ROM, for example, the content of which is defined, for example, during the manufacture of the semiconductor circuit of the example single photon transmission device 401. The exemplary single-photon transmission device 401 is typically intended to receive encrypted data and/or program code parts and/or commands using cryptographic methods that are stored in the memories of the exemplary single-photon transmission device 401 and that one or more of the microcontroller cores 416 of the exemplary single-photon transmission device 401 execute and /or to send such. The encryption is preferably a QKD encryption in each case. Some of these methods require considerable computing power. It has therefore proven itself that not only does the microcontroller core 416 of the example single-photon transmission device 401 execute certain program parts of these cryptography methods in the form of partial steps of these cryptography methods, but also that one or more special hardware accelerators of the example single-photon transmission device 401 preferably in the form of one or more cryptography accelerators 407 of the exemplary single photon transmission device 401 execute these program parts. For this purpose, the exemplary single-photon transmission device 401 preferably has, for example, a DES accelerator 407 for the DES algorithm and/or an AES accelerator 407 for executing the AES algorithm. The microcontroller core 416 of the example single photon transmission device 401 typically addresses these hardware accelerators of the example single photon transmission device 401 via the internal data bus 402 of the example single photon transmission device 401 . The microcontroller core 416 of the exemplary single-photon transmission device 401 preferably has a redundant clock system of the exemplary single-photon transmission device 401 in order to be able to recognize access to the clock system of the exemplary single-photon transmission device 401 . One or more of the one or more security monitoring and control circuits 414 of the example single photon transmission device 401 monitors the consistency of the logical contents of these preferred plurality of redundant clock systems of the example single photon transmission device 401 to detect attacks and errors. One or more manufacturer memory firewalls 408 of the example single photon transmission device 401 preferably prevent the microcontroller core 416 of the example single photon transmission device 401 and the test logic of the example single photon transmission device 401 from accessing the manufacturer memory of the example single photon transmission device 401. These manufacturer firewalls 408 of the example single photon transmission device 401 can be preferred , as described, can be unlocked with a manufacturer password. The number of incorrect entries is preferably very limited in order to minimize the probability of a successful attack. Preferably, the exemplary single-photon transmission device 401 comprises one or more CRC (Cyclic Redundancy Check) modules 411 of the exemplary single-photon transmission device 401, so that the exemplary single-photon transmission device 401 for serial data communication uses the CRC data that is used in most data protocols to detect faulty data transmissions, for can generate one efficiently in the case of a transmission process and, on the other hand, can quickly check the correct receipt of the data message when it is received. Preferably, the example single photon transmission device 401 includes one or more clock driver (CLK) modules 412 that generate one or more clock signals for operating the circuitry of the example single photon transmission device 401 . The one or more clock generator modules (Clock Driver, CLK) 412 of the exemplary single-photon transmission device 401 preferably generate redundant clock signals that indicate an attack on the clock system of the exemplary single-photon transmission device 401 . Typically, the exemplary single-photon transmission device 401 comprises one or more timer modules 413, such as those required by the microcontroller core 416 for the detection of time-outs. The exemplary single-photon transmission device 401 preferably includes one or more watchdog timers that monitor the processing of the various program parts by the one or more microcontroller cores 416 of the exemplary single-photon transmission device 401 . These watchdog timers may be part of the one or more of the one or more security monitoring and control circuits 414 of the example single photon transmission device 401 . According to the proposal, the exemplary single photon transmission device 401 comprises at least one preferably quantum process-based generator for true random numbers (English: quan tum Random Number Generator: QRNG) 415. Quantum-based processes have the advantage that they are based on real chance. In the 1970s, the physicist Bell proved that the theory of "hidden parameters" was wrong. That is, there are no hidden causes for the randomness of quantum mechanical events, such as the emission of photons. The microcontroller core 416 of the exemplary single-photon transmission device 401, which has already been mentioned several times, can be, for example, an 8-bit microcontroller core or a 16-bit microcontroller core or a 32-bit microcontroller core or a 64-bit microcontroller core or a 128-bit microcontroller core or the like. The example single photon transmission device 401 can have one or more 8/16/32/15-bit microcontroller cores 416, which can preferably access the other sub-devices of the example single photon transmission device 401 via one or more internal data buses 402 of the example single photon transmission device 401. Preferably, the example single photon transmission device 401 includes one or more data interfaces 417 of the example single photon transmission device 401. Such data interfaces 417 may be, for example, one or more Universal Asynchronous Receiver Transmitters (UART) for supporting high-speed serial data. The exemplary single-photon transmission device 401 preferably has one or more base clock generators 421 (CLK), which preferably each provide a base clock to one or more clock generator modules (English clock driver, CLK) 412 of the exemplary single-photon transmission device 401 . The basic clock generators 421 (CLK) of the exemplary single-photon transmission device 401 are preferably oscillators. Preferably, the example single photon transmission device 401 also includes one or more power supply or Vcc circuits 423 with voltage regulators that provide the operating voltages for the example single photon transmission device 401 . Preferably, the example single-photon transmission device 401 also includes one or more ground circuits 424, which include, for example, reverse polarity protection and protection circuits against manipulation of the electrical potential of the semiconductor substrate of the semiconductor crystal of the microintegrated tele of the example single-photon transmission device 401. For example, it is useful if one or more of the one or more ground circuits 424 of the exemplary single photon transmission device 401 have reverse polarity protection. For example, it is useful if one or more of the one or more ground circuits 424 of the example single photon transmission device 401 and/or one or more of the one or more power supply or Vcc circuits 423 of the example single photon transmission device 401 cooperate to modulate the current consumption and/or or the internal resistance and/or the voltage drop between the supply voltage connections of the example single-photon transmission device 401 does not allow any conclusions to be drawn about the operating sequences and/or states of the example single-photon transmission device 401 at least at times.

For controlling other devices and/or for communicating with other devices and/or for monitoring other devices, it is typically useful for the example single photon transmitting device 401 to include one or more input/output circuits 425, typically implemented as digital Inputs and / or as digital outputs, which can preferably also take a tri-state state, are executed. The example single-photon transmission device 401 may include an analog-to-digital converter that allows the microcontroller core 416 to monitor internal analog values, such as operating voltage, and external analog values. The analog-to-digital converter may be provided with an analog multiplexer to monitor a plurality of internal electrical nodes of the example single-photon transmission device 401 for the correctness of the values of the electric potential against a reference potential of the example single-photon transmission device 401 . Preferably, the microcontroller core 416 of the exemplary single photon transmission device 401 controls this analog multiplexer. If necessary, the exemplary single-photon transmission device 401 can be provided with one or more driver stages 692 in order to be able to drive actuators 694, for example. These actuators 694 can be, for example, motors and/or other ohmic and/or inductive and/or capacitive loads and the like. Such a driver stage 692 of the exemplary single-photon transmission device 401 can be, for example, a half-bridge and/or an H-bridge or the like. It is also conceivable that power current sources of the exemplary single-photon transmission device 401 can be used, for example for lighting means such as LEDs.

The document presented here thus proposes an exemplary single-photon transmission device 401, in particular for the safe control of devices in automobiles, which comprises a semiconductor crystal. Preferably, the exemplary single photon transmission device 401 is fabricated in CMOS circuitry, or in bipolar circuitry, or in BiCMOS circuitry. The exemplary single-photon transmission device 401 preferably includes memory elements, one or more internal data buses 402, one or more 8/16/32/15-bit microcontroller cores 416, and one or more preferably quantum process-based generators 415 for the generation of true or high-quality random numbers (English: Quantum Random Number Generator: QRNG). The internal data bus 402 of the example single photon transmission device 401 may include multiple data buses. The memory elements of the example single photon transmission device 401 are typically connected to the internal data bus 402 of the example single photon transmission device 401 . The data interfaces of the example single photon transmission device 401 are typically connected to the internal data bus 402 of the example single photon transmission device 401 . The one or more random number generators (QRNG) 415 of the example single photon transmission device 401 are also preferably connected to the internal data bus 402 of the example single photon transmission device 401 . The one or more microcontroller cores 416 of the example single photon transmission device 401 are also preferably connected to the internal data bus 402 of the example single photon transmission device 401 . The one or more random number generators (QRNG) 415 preferably and typically generate one or more random numbers upon request of the microcontroller core 416 of the example single photon transmission device 401 . One or more of the one or more microcontroller cores 416 of the exemplary single photon transmission device 401 preferably generate one or more keys using a respective program from one or more of their memory elements of the exemplary single photon transmission device 401 and using one or more of the generated random numbers. Typically, one or more microcontroller cores 416 of the exemplary single-photon transmission device 401 encrypt and/or decrypt data using a respective program of the relevant microcontroller core 416, which originates from one or more of its memory elements, and using a respective key of the generated keys, data that these microcontroller cores 416 typically communicate via one or more data interfaces of the example single photon transmission device 401 the one or more data interfaces of the example single photon transmission device 401 with devices external to the example single photon transmission device 401 .

In a development of exemplary single-photon transmission device 401, the memory elements of exemplary single-photon transmission device 401 include one or more read/write memories RAM 403 and/or one or more writable non-volatile memories, in particular EEPROM memories 404 and/or flash memories 404 and/or OTP memory 404, and/or one or more read-only memories, and/or one or more non-volatile manufacturer memories. The one or more manufacturer memories of the example single photon transmission device 401 may include, for example, one or more manufacturer ROMs 406 and/or one or more manufacturer EEPROMs and/or one or more manufacturer flash memories.

In a second development, the manufacturer memory of the example single photon transmission device 401, in particular a manufacturer ROM 406 of the example single photon transmission device 401, includes the boot software for starting the microcontroller core 416 of the example single photon transmission device 401 in order to reliably start the example single photon transmission device 401.

In a third development, the example single-photon transmission device 401 has a manufacturer memory firewall 408 of the example single-photon transmission device 401 between the manufacturer memory 406 of the example single-photon transmission device 401 and the internal data bus 402 of the example single-photon transmission device 401, which restricts access to the manufacturer memory 406 of the exemplary single photon transmission device 401 prevented without authentication.

In a fourth development, the exemplary single-photon transmission device 401 has one or more of the following components: A base clock generator 421 (CLK), a clock generator circuit 412, a reset circuit 422, a power supply circuit or a Vcc circuit 423 with voltage regulators that regulate the operating voltages at least for the provide exemplary single photon transmission device 401, ground circuitry 424, input/output circuitry 425, one or more processing modules. The processing modules of the exemplary single photon transmission device 401 communicate with the internal data bus 402 of the exemplary single photon transmission device 401 and thus typically with a microcontroller core 416 of the exemplary single photon transmission device 401. The processing modules of the exemplary single photon transmission device 401 preferably include one or more of the following modules: A CRC module (Cyclic Redundancy check) 411 of the exemplary single photon transmission device 401, a clock generator module 412 of the exemplary single photon transmission device 401, a crypto accelerator 407 of the exemplary single photon transmission device 401, in particular a DES accelerator and/or an AES accelerator 407, one or more timer modules 413 of the exemplary single photon transmission device 401 , one or more safety monitoring and control circuits 414 (of the example single photon transmission device 401) of the example single photon transmission device 401, as well as, one or more data interfaces of the example single photon transmission device 401, in particular a Universal Asynchronous Receiver Transmitter (UART) 417.
In a further development of exemplary single-photon transmission device 401, at least one data interface of the one or more data interfaces of exemplary single-photon transmission device 401 is a wired automotive data bus interface. In this case, the wired automotive data bus interface can, for example, be a CAN data bus interface or a CAN FD data bus interface or a Flexray data bus interface or a PSl5 data bus interface or a DSL3 data bus interface or a LIN data bus interface or an Ethernet data bus interface or a LIN data bus interface or a MELIBUS data bus interface.
In a further development of the exemplary single photon transmission device 401, at least one data interface of the one or more data interfaces of the exemplary single photon transmission device 401 is a wireless data bus interface. The wireless data bus interface can be a WLAN interface or a Bluetooth interface, for example.
In a further development of the exemplary single photon transmission device 401, at least one data interface of the one or more data interfaces of the exemplary single photon transmission device 401 is a wired data bus interface. The wireless data bus interface of the exemplary single photon transmission device 401 can be, for example, a KNX data bus interface or an EIB data bus interface or a DALI data bus interface or a PROFIBUS data bus interface.

The exemplary single photon transmission device 401 preferably has one or more wireless data interfaces 426 for communication with other computer systems. For example, the example single photon transmission device 401 can communicate via a respective antenna 427 of a respective wireless interface 426 of the example single photon transmission device 401 . In this case, the antenna 427 emits an electromagnetic data signal 428 which the single-photon transmission device 401 exchanges with a single-photon reception device 601 in a wired or wireless manner. In the case of a car key as the single-photon transmission device 401, the car key 401 exchanges data with the single-photon reception device 601, preferably by means of a wireless data interface 426 and its antenna 427.
For the generation of a polarization-modulated single-photon beam 452, the single-photon transmission device 401 preferably has a control device 429 for the single-photon sources 436, 437, 438, 439, 440. The microcontroller core 416 controls the control device 429 via the internal data bus 402. For this purpose, the microcontroller core 416 can transmit configuration data from the control device 429 to the control device 429 using the internal data bus 402 and can read status information from the control device 429 via the data bus 402. Such status information can be, for example, measurement data from the single photon sources 436 to 440 or from device parts associated with them. A control line 430 connects the drive device 429 to an adjustable voltage regulator 442. The drive device 429 uses the control line 430 to set the voltage between a supply voltage line 441 of the individual photon sources 436, 437, 438, 439, 440 and a reference potential. The reference potential is typically an internal ground potential of an internal ground line of the single-photon transmission device 401. The adjustable voltage regulator 442 uses the potential of the supply voltage line 443 to generate the potential of the supply voltage line 441 of the single-photon sources 436, 437, 438, 439,440 set by the control device 429 in relation to the internal reference potential of the single-photon transmission device 401
The single photon transmission device 401 includes one or more energy supplies 442 for the single photon sources 436 to 440 or n single photon sources. The energy source, for example a key battery, supplies the energy supply 442 of the single photon sources 436 to 440 with electrical energy via an illuminant supply voltage line 443. The energy supply 442 regulates the operating voltage of the single photon sources 436 to 440, preferably by means of a linear regulator, in order to cause as few disturbances as possible. If necessary, the control device for the single photon sources 436, 437, 438, 439, 440 does not track the regulation of the voltage between the supply voltage line 441 of the single photon sources and a reference potential (typically ground) during the generation of a QKD key, in order not to cause any interference from the regulation . The energy supply 442 preferably includes a small energy reserve, for example a capacitor, for stabilization.

The supply voltage line 441 connects the respective loads within the single photon transmission device 401 to one or more power supply or Vcc circuits 423 with voltage regulators that control the operating voltage provide genes for the microcontroller system of the single photon transmission device 401 and the polarization-modulated single photon transmitter of the single photon transmission device 401 . The supply voltage line 441 can also include a number of lines which, for example, each connect a consumer of electrical energy, i.e. a sub-device of the single-photon transmission device 401, to a voltage regulator or a current source of the one or more power supply or Vcc circuits 423. The adjustable adjustable voltage regulator 442 reduces the voltage between the potential of the supply voltage line 443 to such an extent that the potential of the supply voltage line 441 of the single photon sources 436, 437, 438, 439,440 is sufficient in relation to the internal reference potential of the single photon transmission device 401 that the single photon transmission device 401 just about all single photon sources 436 to 440 can operate. The single photon sources 436 to 440 each comprise lighting means 464 and respective power sources 463 of the respective single photon source of the single photon sources 436 to 440. The power source 463 sets the single photon rate of the respective associated lighting means 464 of its single photon source of the single photon sources 436 to 440 depending on signals from the control line of the control lines 431 associated with it to 435 for the associated current source 463 of the associated single photon source of the single photon sources 436 to 440. The respective current sources 463 of the respective single photon sources 436 to 440 perform the actual adjustment of the photon density of the light emission from the single photon sources 436 to 440 . The respective current sources 463 of the respective single photon sources 436 to 440 carry out this setting as a function of control data for the single photon sources 436 to 440 transmitted by the control device 429 using the respective control line of the control lines 431 to 435 .

The microcontroller core 416 preferably controls the control device 429 via the internal data bus 402. The microcontroller core 416 preferably exchanges data with the control device 429 via the internal data bus 402.

A first control line 431 connects the control device 429 to the first power source 463 of the first single photon source 436. The control device 429 controls the electric current through the first power source 463 of the first single photon source 436 via the first control line 431 for the first power source 463 of the first single photon source 436 the control device 429 controls the electric current through the first illuminant 464 of the first single-photon source 436 by means of the first control line 431. In this way, the control device 429 controls the polarized first illuminant 464 of the first single-photon source 436. The first illuminant 464 of the first single-photon source 436 either radiates directly polarized single photons or emits single photons of different polarizations, which then polarize the polarization filter or polarizing optical functional means in the subsequent beam path. The first control line 431 preferably also reports status data and/or measured values and/or other status parameters in digital or analog form of the first single photon source 436 and its sub-devices via the control device 429 for the single photon sources 436, 437, 438, 439, 440 to the microcontroller core 416 . The first control line 431 can include one or more digital or analog signal lines.

A second control line 432 connects the control device 429 to the second power source 463 of the second single photon source 437. The control device 429 controls the electric current through the second power source 463 of the second single photon source 437 via the second control line 432 for the second power source 463 of the second single photon source 437 the control device 429 controls the electric current through the second illuminant 464 of the second single-photon source 437 by means of the second control line 432. In this way, the control device 429 controls the polarized second illuminant 464 of the second single-photon source 437. The second illuminant 464 of the second single-photon source 437 either radiates directly polarized single photons or emits single photons of different polarizations, which then polarize the polarization filter or polarizing optical functional means in the subsequent beam path. The second control line 432 preferably also reports status data and/or measured values and/or other status parameters in digital or analog form of the second single-photon source 437 and its sub-devices via the control device 429 for the single-photon sources 436, 437, 438, 439, 440 to the microcontroller core 416 . The second control line 432 may include one or more digital or analog signal lines.

A third control line 433 connects the control device 429 to the third power source 463 of the third single photon source 438. The control device 429 controls the electric current through the third power source 463 of the third single photon source 438 via the third control line 433 for the third power source 463 of the third single photon source 438 the control device 429 controls the electric current through the third illuminant 464 of the third single-photon source 438 by means of the third control line 433. On this The control device 429 controls the polarized third light source 464 of the third single photon source 438. The third light source 464 of the third single photon source 438 either emits directly polarized single photons or emits single photons of different polarizations, which then polarize the polarization filters or polarizing optical functional means in the subsequent beam path. The third control line 433 preferably also reports status data and/or measured values and/or other status parameters in digital or analog form of the third single-photon source 438 and its sub-devices via the control device 429 for the single-photon sources 436, 437, 438, 439, 440 to the microcontroller core 416 . The third control line 433 may include one or more digital or analog signal lines.

A fourth control line 434 connects the control device 429 to the fourth power source 463 of the fourth single-photon source 439. The control device 429 controls the electric current through the fourth power source 463 of the fourth single-photon source 439 via the fourth control line 434 for the fourth power source 463 of the fourth single-photon source 439 the control device 429 controls the electric current through the fourth illuminant 464 of the fourth single-photon source 439 by means of the fourth control line 434. In this way, the control device 429 controls the polarized fourth illuminant 464 of the fourth single-photon source 439. The fourth illuminant 464 of the fourth single-photon source 439 either radiates directly polarized single photons or emits single photons of different polarizations, which then polarize the polarization filter or polarizing optical functional means in the subsequent beam path. The fourth control line 434 preferably also reports status data and/or measured values and/or other status parameters in digital or analog form of the fourth single-photon source 439 and its sub-devices via the control device 429 for the single-photon sources 436, 437, 438, 439, 440 to the microcontroller core 416 . The fourth control line 435 may include one or more digital or analog signal lines.

In the example of 4 For example, the single photon emitting device 401 has five single photon sources 436-440. In the preferred configurations, the single photon emitting device includes only 4 single photon sources 436-439 4 is only intended to clarify that the single-photon transmission device 401 can include more than four single-photon sources 436-440. The single photon transmission device 401 preferably comprises n single photon sources 436 to 440 which feed single photons into the QKD coupled beam 452 as a function of the control by the driving device 429 . Typically, each of these n single-photon sources feeds the single photons emitted by it into the QKD coupling beam 452 with a different polarization direction. The single photon sources of the single photon transmitting device 401 can be numbered from 1 to n with a single photon source number k. The polarization direction of the single photons of a single photon source with the single photon source number k is preferably rotated by 360°*(k-1)/(2*n) compared to the polarization direction of the single photons of a single photon source with the single photon source number 1. The number n of single-photon sources of the single-photon transmission device 401 is particularly preferably a power of 2. It should preferably be n=2 ^(m−1) with m∈ℕ. The corresponding single photon receiving device 601 (s. 6 ) should then have a corresponding number of single photon detectors 677 to 680 (see for example 6 for example n=4). In this respect, the examples of 4 and 5 with n=5 only as an example.

In the examples of 4 and 5 the single-photon transmission device 401 therefore also includes a fifth control line 435. The fifth control line 435 connects the control device 429 to the fifth power source 463 of the fifth single-photon source 440. The control device 429 controls the electric current via the fifth control line 435 for the fifth power source 463 of the fifth single-photon source 440 through the fifth current source 463 of the fifth single-photon source 440. The control device 429 thus controls the electric current through the fifth illuminant 464 of the fifth single-photon source 440 by means of the fifth control line 435. In this way, the control device 429 controls the polarized fifth illuminant 464 of the fifth single-photon source 440. The fifth illuminant 464 of the fifth single-photon source 440 either emits directly polarized single photons or emits single photons of different polarizations, which then polarize the polarization filters or polarizing optical functional means in the subsequent beam path. The fifth control line 435 preferably also reports status data and/or measured values and/or other status parameters in digital or analog form of the fifth single-photon source 440 and its sub-devices via the control device 429 for the single-photon sources 436, 437, 438, 439, 440 to the microcontroller core 416 back. The fifth control line 435 can include one or more digital or analog signal lines.

The single-photon transmission device 401 can have n single-photon sources with n being a positive integer greater than 1. This general case is in the 4 and 5 not shown. However, a technically competent person will be able to easily rework this case based on the examples presented here. In such a case, the single-photon transmission device 401 therefore also includes an nth control line. The nth control line connects the drive device 429 to the nth current source 463 of the nth single photon source. The control device 429 controls the electric current through the nth current source 463 of the nth single photon source via the nth control line for the nth current source 463 of the nth single photon source. The control device 429 thus controls the electric current through the nth luminous means 464 of the nth single photon source by means of the nth control line. In this way, the control device 429 controls the polarized nth luminous means 464 of the nth single photon source. The nth illuminant 464 of the nth single photon source either emits directly polarized single photons or emits single photons of different polarizations, which then polarize the polarization filters or polarizing optical functional means in the subsequent beam path. The nth control line 435 preferably also reports status data and/or measured values and/or other status parameters in digital or analog form of the nth single-photon source and its sub-devices to the microcontroller core 416 via the control device 429 for the single-photon sources. The nth control line can include one or more digital or analog signal lines.

If the single-photon transmission device 401 includes n single-photon sources, an nth control line connects the drive device 429 to the nth current source 463 of the nth single-photon source. The control device 429 controls the electric current through the nth current source 463 of the nth single photon source via the nth control line for the nth current source 463 of the nth single photon source. The control device 429 thus controls the electric current through the nth luminous means 464 of the nth single photon source by means of the nth control line. In this way, the control device 429 controls the polarized nth luminous means 464 of the nth single photon source. The nth illuminant 464 of the nth single photon source either emits directly polarized single photons or emits single photons of different polarizations, which then polarize the polarization filters or polarizing optical functional means in the subsequent beam path. Preferably, the nth control line also reports status data and/or measured values and/or other status parameters in digital or analog form of the nth single photon source and its sub-devices via control device 429 for the single photon sources with k=1 to n to microcontroller core 416 return. The nth control line can include one or more digital or analog signal lines.

The first single photon source 436 typically includes a polarized first illuminant 464 and a first current source 463. For a better overview, these parts of the device are shown in FIGS 4 and 5 drawn hidden. They correspond to the representation for the fifth single-photon source 440. The first power source 463 energizes the first illuminant 464 of the first single-photon source 436 so briefly and with such low energy that the first illuminant 464 of the first single-photon source 436 is essentially only individual, spatially and temporally separate emits photons. This energization of the first illuminant 464 of the first single photon source 436 by the first current source 463 of the first single photon source 436 is preferably shorter than 1 ns, better shorter than 500 ps, better shorter than 200 ps, better shorter than 100 ps, better shorter than 50 ps, better shorter than 20 ps, better than 10ps, better than 5ps, better than 2ps, better than 1ps. This energizing of the first illuminant 464 of the first single photon source 436 by the first current source 463 of the first single photon source 436 is very particularly preferably shorter than 10 ps.
The second single photon source 437 typically includes a polarized second illuminant 464 and a second current source 463. For a better overview, these parts of the device are shown in FIGS
4 and 5 drawn hidden. They correspond to the representation for the fifth single-photon source 440. The second power source 463 energizes the second illuminant 464 of the second single-photon source 437 so briefly and with such low energy that the second illuminant 464 of the second single-photon source 437 is essentially only individual, spatially and temporally separate emits photons. This energizing of the second illuminant 464 of the second single photon source 437 by the second current source 463 of the second single photon source 437 is preferably shorter than 1 ns, better shorter than 500 ps, better shorter than 200 ps, better shorter than 100 ps, better shorter than 50 ps, better shorter than 20 ps, better than 10ps, better than 5ps, better than 2ps, better than 1ps. This energizing of the second illuminant 464 of the second single photon source 437 by the second current source 463 of the second single photon source 437 is very particularly preferably shorter than 10 ps.

The third single photon source 438 typically includes a polarized third illuminant 464 and a third current source 463. For the better Overview are these device parts in the 4 and 5 drawn hidden. They correspond to the representation for the fifth single-photon source 440. The third power source 463 energizes the third illuminant 464 of the third single-photon source 438 so briefly and with such low energy that the third illuminant 464 of the third single-photon source 438 is essentially only individual, spatially and temporally separate emits photons. This energization of the third illuminant 464 of the third single photon source 438 by the third current source 463 of the third single photon source 438 is preferably shorter than 1 ns, better shorter than 500 ps, better shorter than 200 ps, better shorter than 100 ps, better shorter than 50 ps, better shorter than 20 ps, better than 10ps, better than 5ps, better than 2ps, better than 1ps. This energizing of the third illuminant 464 of the third single photon source 438 by the third current source 463 of the third single photon source 438 is very particularly preferably shorter than 10 ps.

The fourth single-photon source 439 typically includes a polarized fourth illuminant 464 and a fourth current source 463. For a better overview, these parts of the device are shown in FIGS 4 and 5 drawn hidden. They correspond to the representation for the fifth single-photon source 440. The fourth power source 463 energizes the fourth illuminant 464 of the fourth single-photon source 439 so briefly and with such low energy that the fourth illuminant 464 of the fourth single-photon source 439 is essentially only individual, spatially and temporally separate emits photons. Preferably, this energizing of the fourth illuminant 464 of the fourth single-photon source 439 by the fourth current source 463 of the fourth single-photon source 439 is shorter than 1 ns, better shorter than 500 ps, better shorter than 200 ps, better shorter than 100 ps, better shorter than 50 ps, better shorter than 20 ps, better than 10ps, better than 5ps, better than 2ps, better than 1ps. This energizing of the fourth illuminant 464 of the fourth single-photon source 439 by the fourth current source 463 of the fourth single-photon source 439 is very particularly preferably shorter than 10 ps.
The fifth single photon source 440 additionally shown as an example in the example in the figure typically comprises a polarized fifth illuminant 464 and a fifth power source 463. The fifth power source 463 energizes the fifth illuminant 464 of the fifth single photon source 440 so briefly and with such little energy that the fifth illuminant 464 of the fifth single-photon source 440 essentially only emits single, spatially and temporally separated photons. Preferably, this energizing of the fifth illuminant 464 of the fifth single-photon source 440 by the fifth power source 463 of the fifth single-photon source 440 is shorter than 1 ns, better shorter than 500 ps, better shorter than 200 ps, better shorter than 100 ps, better shorter than 50 ps, better shorter than 20 ps, better than 10ps, better than 5ps, better than 2ps, better than 1ps. This energizing of the fifth illuminant 464 of the fifth single-photon source 440 by the fifth power source 463 of the fifth single-photon source 440 is very particularly preferably shorter than 10 ps.
In the case of n single photon sources as part of the single photon transmission device 401, which is not shown in the figures, the nth single photon source typically comprises a polarized nth light source 464 and an nth current source 463. The nth current source 463 energizes the nth light source 464 of the n-th single-photon source is preferably so short and with such low energy that the n-th illuminant 464 of the n-th single-photon source essentially only emits single, spatially and temporally separate single-photons. This energizing of the nth illuminant 464 of the nth single photon source by the nth current source 463 of the nth single photon source is preferably shorter than 1 ns, better shorter than 500 ps, better shorter than 200 ps, better shorter than 100 ps, better shorter than 50 ps , better than 20ps, better than 10ps, better than 5ps, better than 2ps, better than 1ps. This energizing of the nth illuminant 464 of the nth single photon source by the nth current source 463 of the nth single photon source is very particularly preferably shorter than 10 ps.

In the example of 4 and 5 An optical sub-device of the single-photon transmission device 401 combines the respective single-photon streams of the single-photon sources 336 to 440 to form a QKD coupling beam 452 made up of polarization-modulated single photons. In the example of 4 and 5 this optical sub-device is a conical mirror 1408. In the example of FIG 4 and 5 the single photon sources 436 to 440 emit polarized single photons with a respective polarization direction specific to the single photon sources. The single photon sources 436 to 440 emit the single photons with a direction vector of a respective emission axis, which lie essentially in a common emission plane. This common emission plane is preferably arranged essentially perpendicularly to the system axis of the single-photon transmission device 401 . The directions of polarization of the single photon sources preferably lie in the common emission plane. The emission axes of the n single-photon sources lie in the emission plane and preferably intersect at a point in the common emission plane. Typically, the emission axis of a kth single photon source is rotated by (k−1)/(2*n)*360° in relation to the first single photon source 436 . Typically, the system axis is the single photon emitter Device 401 is essentially the same as the optical axis of the QKD coupling beam 452. A first pinhole 444 and a second pinhole 445 form a spatial filter 1302, which prevents the positioning of the single photon sources 436 to 440, which is typically imperfect due to manufacturing fluctuations, from being detected from the outside and for one attack can be used. The cone axis of the conical mirror 1408 penetrates the common emission plane, preferably essentially at the intersection of the emission axes of the single photon sources in the common emission plane. As a result, the conical mirror 1408 reflects the individual photons from the different emission axes of the different individual photon sources in the direction of a common system axis, which essentially corresponds to the optical axis of the QKD coupling beam 452 . An optional first lens 446 and an optional second lens 447 improve the optical alignment of the QKD coupling beam 452. The first lens 446 and the second lens 447 together form a telescope that focuses the beam of single photons only to the beam of the QKD coupling beam 452 .
One problem is different single photon densities of the single photon sources 436 to 440 of the single photon transmission device 401. To solve this problem, the single photon transmission device 401 preferably has a first beam splitter 448 in the transmission path of the single photon transmission device 401 and a photodetector 451. The first beam splitter 448 of the transmission path is used to branch off some Photons to measure photon rate. An actuator, which the microcontroller core 416 controls via an actuator control via the internal data bus 402, preferably removes the beam splitter or mirror 448 from the beam path of the transmitter when the calibration of the photon rates of the single photon sources 436 to 440 is complete. The microcontroller core 416 uses the photodetector 451 to determine the photon density in the beam path 449 of the single-photon transmission device 401 . A potential problem is that the transmitted polarization of the single photons must not be linked to the temporal density of the single photons, i.e. the number of single photons per second. The microcontroller core 416 therefore inserts the mirror 448 into the beam path 446 of the single-photon transmission device 401, for example by means of an actuator which it controls via the internal data bus 402. The microcontroller core 416 then uses the photodetector 451 to detect the single photon density in the beam path 449 of the single photon transmission device 401. The microcontroller core 416 always operates a single photon source of the single photon sources 436 to 440 of the single photon transmission device 401 and detects a single photon density associated with this single photon source. A received signal 453 of the photodetector 451 connects the photodetector 451 to an evaluation circuit 454 of the photodetector 451. The evaluation circuit 454 is preferably coupled to the microcontroller core 416 via the internal data bus 402. The evaluation circuit 454 of the photodetector 451 detects the values of the received signal 453 of the photodetector 451, which depend on the individual photons in the beam path of the single-photon receiving device 401 from the first beam splitter or mirror 448 to the photodetector 451, converts these preferably into digitized values, for example with the aid of an analog to digital converter ADC and transmits the measured values recorded in this way relating to the individual photons in the beam path of the individual photon receiving device 401 from the first beam splitter or mirror 448 to the photodetector 451 to the microcontroller core 416 via the internal data bus 402. The microcontroller core 416 then controls the current sources 463 of the respective individual photon sources 436 to 440 so that the single photon density of a single photon source of the single photon sources 436 to 440 of the single photon transmission device 401 detected by the photodetector 451 by means of the value of the received signal 453 of the photodetector 451 is firstly within a provided single photon density range value interval and secondly does not differ by more than 10%, better 5%, better 2%, better 1%, better 0.5%, better 0.2%, better 0.1%, better 0.05%, better 0.02%, better 0.01% from the single photon densities of all other single photon sources of the single photon sources 436 to 440 of the single photon transmission device 401 differs. After the single photon densities of the various single photon sources of the single photon transmitter device 401 have been calibrated, the microcontroller core 416 preferably removes the mirror 446 again from the beam path 449 of the single photon transmitter device 401, which then transports the single photons in the beam path 449 of the single photon transmitter device 401 as a QKD coupling beam 452 to a receiver, for example a Single photon receiving device 601, radiates.
In many applications, the single photon transmission device 401 is a mobile device. For example, the single photon transmission device 401 can be a mobile phone or a smartphone or a laptop or a tablet PC or a key or a vehicle key or a security key for a weapon or other military device or a key for activating and/or controlling a flight or hull, or a missile, or an access key to a secured area, or a safe, or a safe, or an activation key for a secured mechanical device, or an activation key for a protected process, such as a secured pre direction (e.g. 601), or an activation key for a protected device (e.g. 601) which is to carry out a secure method, for example, or the like.
In the case of a key, the single photon device (401) preferably comprises a human-machine interface 465 (HMI interface with HMI=Human Machine Interface) in order to enable communication between the single photon transmitting device 401 on the one hand and the single photon receiving device 601 of the QKD-coupled device to be controlled ( eg a car 802) with a person operating the system. As an example, the writing presented here takes a car key as a single-photon transmitter 401 and an exemplary car 802 as a device to be controlled with a single-photon receiving device 601. In the sense of the presented writing, the HMI interface (HMI=Human Machine Interface) 465 connects an input terminal 466 for the Interaction with a user with the microcontroller core 416 via the internal data bus 402 of the single photon transmission device 401. The input terminal 466 of the single photon transmission device 401 can preferably include one or more buttons 467 or switches 467 or other mechanical input devices for manual inputs, for example in the case of a car key. The input terminal 466 of the single-photon transmission device 401 can also preferably include one or more biometric sensors 468, for example in the case of a car key. The biometric sensors 468 may be, for example, one or more fingerprint sensors, and/or one or more cameras, and/or one or more microphones, and/or one or more speech analysis devices, and/or one or more speaker recognition devices, and/or one or more face recognition devices and/or one or more retina scanners or the like. In the case of a car key, for example, the input terminal 466 of the single photon transmission device 401 can preferably act on one or more actuators 470 for feedback from the single photon transmission device 401 to the person using it. An actuator 470 within the meaning of the document presented here can be, for example, a mechanical vibration transmitter or a loudspeaker or a beeper or another sound converter or a heater or the like. The actuator 470 is typically used to transmit a mechanical signal to the user. But it can also serve their mechanical purposes. In addition to this mechanical/thermal feedback, the input terminal 466 of the single-photon transmission device 401, for example in the case of a car key, can preferably include one or more optical signaling means 469, for example in the form of an optical output element for signaling to a user. The visual signaling means 469 may comprise one or more screens and/or one or more illuminants and/or one or more means that change their absorption properties, such as LCD displays or e-ink displays. The single photon transmission device 401 preferably comprises one or more means 1409 for identifying a person using the single photon transmission device 401 . For example, one of the means 1409 for identifying a person using the single photon transmission device 401 can be a SIM card (SIM=Subscriber Identification Module). If necessary, the single-photon transmission device 401 can therefore be a mobile phone or a smartphone. One of the wireless data interfaces of the single-photon transmission device 401 can thus be, for example, a mobile radio data interface in a mobile radio network or a WLAN network or the like. It can therefore also be useful, among other things, if the single-photon transmission device 401 sets up an authentication data channel to the server of a service provider, for example an automobile manufacturer, via this interface.

The 5 largely corresponds to the 4 . Now, however, the single photon emitting device 471 has alignment tools (456, 457, 460, 455, 459, 461) for aligning the single photon emitting device 471 with respect to the single photon receiving device 601 (See 6 ) on. The single photon transmission device 471 typically includes a power supply 456 for a laser pointer laser diode 459. The laser pointer laser diode 459 typically emits a laser pointer beam 462 when energized Single photon transmission device 471, for example a car key, use a single photon reception device 601. The laser pointer beam 462 preferably has a wavelength which is different from the wavelength of the individual photons in the QKD coupled beam 452 . The single photon detectors 436 to 440 of the single photon receiving device 601 are preferably not sensitive to the wavelength of the radiation of the laser pointer beam 462 . The single photon detectors 436 to 440 of the single photon receiving device 601 are preferably protected by screens, housing and/or filters. Typically, the single photon transmission device 471 includes a controller 457 for the current source 460 of the laser pointer diode 459, which controls the level of electrical current through the laser pointer diode. Microcontroller core 416 of single-photon transmission device 401 controls control device 457, for example via internal data bus 402. Laser pointer diode 459 preferably emits visible light that is typically recognizable to a human user is. This allows the user to identify and correct incorrect alignments. The current source 460 of the laser pinter diode 459 adjusts the operating current through the laser pinter diode 459 depending on the signals from the control device 457 for the current source 460 of the laser pinter diode 459 . A projection optics 461 of the laser pinter device improves the beam quality of the laser pointer beam 462 for aligning the car key.

6 shows a schematically simplified example of a single photon receiving device 601 using the example of a car 802.
The core of the single photon receiving device 601 is a microcontroller core 616. Essential parts of the single photon receiving device 601 are preferably microintegrated on a semiconductor substrate. These parts are preferably manufactured using CMOS, BiCMOS or bipolar technology. The single photon receiving device 601 preferably includes one or more internal data buses 602, via which the microcontroller core 616 of the single photon receiving device 601 preferably handles the internal data communication. Furthermore, the single photon receiving device 601 preferably comprises one or more read/write memories RAM 603 for storing, providing and using data and program commands by the microcontroller core 616 of the single photon receiving device 601. In addition, the single photon receiving device 601 preferably has one or more writable non-volatile memories 604 on. These non-volatile memories may include EEPROM memory 604 or flash memory 604 or OTP memory 604, for example. Furthermore, the single photon receiving device 601 preferably has one or more non-volatile read-only memories 605, such as a ROM 605, for example. These preferably contain program code and program data for the microcontroller core 616, which typically processes this program code. Program code and program data may also be stored in the one or more writable non-volatile memories 604 .
The exemplary single photon receiving device 601 preferably includes one or more non-volatile, writable and/or non-writable manufacturer memories 606. In the case of a non-writable manufacturer memory 606, the manufacturer memory 606 can be, for example, a manufacturer ROM. Furthermore, the single photon receiving device 601 preferably includes one or more cryptography accelerators 607, for example a DES accelerator and/or an AES accelerator 607, in order to accelerate the processing of the cryptography algorithms by the microcontroller core 616 of the single photon receiving device 601. The single-photon receiving device 601 preferably also includes one or more manufacturer memory firewalls 608, which prevent unauthorized access to the manufacturer memory 406 and only allow it after appropriate authentication, for example using a password. The manufacturer memory fire walls preferably block access irrevocably if more than a permitted number of unsuccessful attempts to access the manufacturer memory 606 of the single-photon receiving device 601 have been made. Another device for increasing the efficiency can be one or more CRC (Cyclic Redundancy Check) modules 611 of the single-photon receiving device 601 . These calculate a CRC check data word for a specified amount of data, as is used in many data communication protocols, for example. Furthermore, the exemplary single photon transmission device 601 typically has one or more clock generator modules (Clock Driver, CLK) 612 which provide the system clocks for operating the device parts of the single photon reception device 601 . The exemplary single photon receiving device 601 preferably includes one or more timer modules 613 that control timing within the single photon receiving device 601 . The single photon receiving device 601 preferably comprises one or more security monitoring and control circuits 614, which monitor the integrity of the single photon receiving device 601 and, if necessary, initiate countermeasures in the event of an attack. The single photon receiving device 601 preferably comprises at least one preferably quantum process-based generator for true random numbers (Quantum Random Number Generator: QRNG) 615. Such a generator has the advantage that the entropy of its random number is particularly well suited for encryption. Typically, the single photon receiving device 601 includes one or more 8/16/32/64-bit microcontroller cores 616 that execute the programs in the memory of the example single photon transmitting device 601 . The single photon receiving device 601 preferably comprises one or more optional data interfaces 617, in particular one or more universal asynchronous receiver transmitters (UART) for supporting high-speed serial data, for data communication with other computer systems.

One or more basic clock generators 621 (CLK) are preferably part of the single-photon receiving device 601. The single-photon receiving device 601 preferably includes one or more reset circuits 622. One or more power supply or Vcc circuits 623 with voltage regulators that set the operating voltages for the microcontroller system of the single-photon emp capture device 601 and other sub-devices of the single photon receiving device 601 provide. Preferably, the one or more power supply or Vcc circuits 623 also include at least one energy reserve, such as a battery or accumulator. In some applications, the one or more power supply or Vcc circuits 623 also include a charging circuit and a first charging coil, which is typically not a device part of the single photon receiving device 601, for inductively coupling to a second charging coil, which is preferably part of a device external to the single photon receiving device 601 and /or is separate from the single photon receiving device 601. The external charging device transmits energy by means of an inductive coupling from an energy system, for example a battery or an alternator or the like, or from an energy system of the external charging device, for example an energy store or a generator or a solar cell or a power grid or the like, by means of the charging circuit of the one or more power supply or Vcc circuits 623 of the single photon receiving device 601 on the power reserve of the one or more power supply or Vcc circuits 623 of the exemplary single photon transmitting device 401 and/or the single photon receiving device 601. The single photon receiving device 601 typically has one or more ground circuits 624 that protect the device against polarity reversal and attacks via the ground line. The single photon receiving device 601 also typically includes one or more input/output circuits 625 that allow the single photon receiving device 601 to drive, read, or otherwise communicate with other devices. 6 1 shows, by way of example and schematically, the block diagram of an example system for the use of the single photon receiving device 601, for example in automobile locking systems in cars. 6 12 shows a diagram of an example of an exemplary single photon receiving device 601. The exemplary single photon receiving device 601 includes, for example, memory elements that are connected to an internal data bus 602 of the exemplary single photon receiving device 601. FIG. The memory elements of the example single photon receiving device 601 may include, for example, one or more random access memories RAM 603, one or more writable non-volatile memories such as EEPROM memory 604 or flash memory 604 or OTP memory 604. Furthermore, the example single-photon receiving device 601 preferably includes one or more non-volatile, read-only memories 605, such as ROM. Additionally, the example single photon receiving device 601 preferably includes one or more non-volatile, writable and/or non-writable manufacturer memory 606. In the case of non-writable manufacturer memory, the manufacturer memory 606 may be manufacturer ROM. Preferably, the manufacturer ROM 606 includes the boot software for the microcontroller core 416 of the example single-photon receiving device 601. The example single-photon receiving device 601 includes, for example, one or more cryptographic accelerators 607, for example a DES accelerator and/or an AES accelerator 607, which is preferred are connected to the microcontroller core 616 of the example single photon receiving device 601 via the internal data bus 602 of the example single photon receiving device 601 . For example, one or more manufacturer memory firewalls 608 may be provided between the manufacturer memory 606 of the single photon receiving device 601 and the internal data bus 602 of the single photon receiving device 601 . For example, the exemplary single photon receiving device 601 preferably includes processing modules of the single photon receiving device 601 that communicate with the microcontroller core 616 of the single photon receiving device 601 via the internal data bus 602 of the single photon receiving device 601 . The processing modules of the single photon receiving device 601 preferably comprise at least one of the following modules: a CRC (Cyclic Redundancy Check) module 611, a clock generator module 612, one or more timer modules 613, a safety monitoring and control circuit 614, one or more preferably quantum process-based generators for true random numbers (English: Quantum Random Number Generator: QRNG) 615, one or more 8/16/32/15-bit microcontroller cores 616 and one or more data interfaces 617, in particular one or more Universal Asynchronous Receiver Transmitters (UART) for support high-speed serial data. The other circuit parts of the exemplary single-photon receiving device 601 include, for example, one or more basic clock generators 620 (CLK) and/or one or more clock generator modules 612, a reset circuit 622, a power supply or Vcc circuit 623 with voltage regulators that provide the operating voltage, a ground circuitry 624 and an input/output circuitry 625. Preferably, the example single photon receiving device 601 is configured to enable secure authentication. For example, the exemplary single-photon receiving device 601 preferably stores other data in addition to the authentication code, e.g. B. a or more lifetime and usage data and/or eg logistical data and/or eg commercial data and/or website and email addresses and/or image data, a set of instructions for control units of a car 802 with which the microcontroller core 616 of the exemplary Single photon receiving device 601 communicates via a data interface of the exemplary single photon receiving device 601 . In addition, the example single photon receiving device 601 may store other application data.

Preferably, the example single photon receiving device 601 includes, for example, a microcontroller core 616 configured to facilitate secure authentication of a product.

The internal data bus 602 of the example single photon receiving device 601 can include multiple data buses 602 for multiple microcontroller cores 616 of the example single photon receiving device 601, so that these multiple microcontroller cores 616 can access different sub-devices of the example single photon receiving device 601 independently of one another at the same time. Typically, however, the example single photon receiving device 601 includes only an internal data bus 602 and only one microcontroller core 616. The microcontroller core 616 of the example single photon receiving device 601 is preferably an ARM processor or the like. It is preferably an 8-bit or a 16-bit or a 32-bit or a 64-bit microcontroller core 616.

The exemplary single-photon receiving device 601 preferably comprises one or more read/write memories RAM 603. These can be, for example, SRAMs and/or MRAMs and/or FRAMS or the like. The one or more read/write memories RAM 603 of the example single-photon receiving device 601 can also be wholly or partially dynamic read/write memories such as DRAMs, for example, which the microcontroller core 616 or a refresh device of the example single-photon receiving device 601 at regular time intervals in read and rewrite in a refresh cycle. For the access of the microcontroller core 616 to a memory of the exemplary single-photon receiving device 601, the exemplary single-photon receiving device 601 can have an access logic which regularly executes this refresh and controls this access. However, DRAM typically opens up opportunities for attack and is typically a potential vulnerability. The microcontroller core 616 of the exemplary single photon receiving device 601 can preferably access this read/write memory RAM 603 of the exemplary single photon receiving device 601 by means of the internal data bus 602 of the exemplary single photon receiving device 601 .

The exemplary single photon receiving device 601 preferably comprises one or more writable and non-volatile memories 604. The microcontroller core 616 of the exemplary single photon receiving device 601 can preferably access this writable and non-volatile memory 604 of the exemplary single photon receiving device 601 by means of the internal data bus 602 of the exemplary single photon receiving device 601. This non-volatile memory 604 of the exemplary single-photon receiving device 601 may include EEPROM memory 604 or flash memory 604 or OTP memory 604, for example. OTP stands for English One Time Programmable, which means only once programmable.

One possibility for an attack may be the erasure of the non-volatile memory 604 by means of radiation, for example X-rays and/or ionizing radiation, and/or the heating of memory cells. To this end, the example single photon receiving device 601 preferably includes one or more safety monitoring and control circuits 614 of the example single photon receiving device 601 that monitor the data integrity of the memory cells of the erasable memories 604 of the example single photon receiving device 601 . The memory cells of the erasable memory 604 of the exemplary single-photon receiving device 601 preferably have redundancy such that at least two check bits are provided for a data word, which is preferably a data word with a length of 8 bits, i.e. one byte, and that there are always at least a first check bit must have the content 1 and another, wide check bit, which is assigned to this first check bit, must have the content 0. For example, the first check bit can be a parity bit of the byte and the second check bit can be the inverse bit of the parity bit relative to the first check bit. If an attack with ionizing radiation or the like then occurs, the attack resets both test bits to the same value. This is an illegal condition that the example single photon receiving device 601 can detect. The one or more security monitoring and control circuits 614 of the exemplary single-photon receiving device 601 detect such a deviation and, if necessary, block the exemplary single-photon receiving device 601 from further access at least for a preferably predetermined period of time.

Each bit of the memory of the exemplary single-photon receiving device 601 is preferably designed twice, so that each logical data bit is preferably implemented as a pair of a first physical data bit with a first internal logical value and a second physical data bit with a second internal logical value. In this case, the second internal logical value is typically the logical inverse of the first internal logical value. The one or more safety monitoring and control circuits 614 of the exemplary single photon receiving device 601 again preferably monitor that this is always the case. The one or more safety monitoring and control circuits 614 of the exemplary single photon receiving device 601 again detect deviations and, for example, preferably block further execution if necessary of programs or specific program parts and/or access to data, for example for the microcontroller core 616 in the event of deviations. The exemplary single photon receiving device 601 preferably comprises one or more reset circuits 622 of the exemplary single photon receiving device 601. The reset circuits 622 of the exemplary single photon receiving device 601 each set the exemplary single photon receiving device 601 and/or sub-devices of the exemplary single photon receiving device 601 to predefined states when predetermined or determinable reset conditions and/or combinations and/or temporal sequences of such reset conditions exist. For example, these conditions may be signaling from the one or more safety monitoring and control circuits 614 of the example single photon transmitting device 601 to one or more reset circuits 622 of the example single photon receiving device 601, for example. These conditions can also be changes and/or values of electrical node potentials compared to the potential of a reference node or a reference potential line, that is, for example, one or more operating voltages of the exemplary single-photon receiving device 601. A watchdog timer may be part of a reset circuit 622 of the example single photon receiving device 601 . Furthermore, such conditions may affect the integrity of the housing of the example single photon receiving device 601 . The housing of the exemplary single photon receiving device 601 preferably includes a detector for opening or damaging the housing of the exemplary single photon receiving device 601. For example, this can be a single line that, for example as a textile network, surrounds or covers the exemplary single photon receiving device 601 or at least parts of the exemplary Single photon receiving device 601 covers. It may also be a network of lines covering the example single photon receiving device 601 solely for detecting an attack. For example, the exemplary single-photon receiving device 601 can in each case feed an electric current into one or more such lines by means of a first input/output line and withdraw this again at one or more second input/output lines. If the flow of current is interrupted, this is an indication of an attack which one or more of the one or more security monitoring and control circuits 614 of the example single photon receiving device 601 can detect and which then, for example, the microcontroller core 616 of the example single photon receiving device 601 signal this attack. For example, in such a case of suspected violation of the integrity of the housing of the exemplary single-photon receiving device 601, one or more of the one or more safety monitoring and control circuits 614 of the exemplary single-photon receiving device 601 can block write and/or read access to memory contents of the memory of the exemplary single-photon receiving device 601 and/or delete such contents of the memory of the exemplary single photon receiving device 601 in whole or in part, or set these contents of the memory of the exemplary single photon receiving device 601 to predefined values or overwrite them with nonsensical data or otherwise manipulate them. The memories of the example single-photon receiving device 601 preferably include one or more non-volatile, read-only memories 605, such as ROM. The ROM of the exemplary single-photon transmission device 601 preferably contains data and/or program instructions specified by the design. The exemplary single-photon receiving device 601 preferably has one or more non-volatile, writable and/or non-writable manufacturer memories 606, in which the semiconductor manufacturer or another supplier can store their production and security data, such as serial numbers, etc. After the last production test has been carried out, the semiconductor manufacturer preferably blocks access to this writable and/or non-writable non-volatile manufacturer memory 606 of the exemplary single-photon receiving device 601. Access to the writable and/or non-writable manufacturer memory 406 of the exemplary single-photon receiving device 601 is preferred using one or more manufacturer passwords. In some cases, a double key procedure makes sense. In this case, a subsequent semiconductor manufacturer saves Customer enters a customer password in a customer lock register of the exemplary single-photon receiving device 601 that can also be locked for access with a password. The semiconductor manufacturer can preferably access all memory areas of the example single-photon receiving device 601 using only the customer password and the semiconductor password. Preferably, the semiconductor manufacturer provides an analysis password, by means of which it can cause one or more of the one or more security monitoring and control circuits 614 of the exemplary single photon receiving device 601, typically with the aid of the reset circuit 622 of the exemplary single photon receiving device 601, to reset the customer content in the memories of the exemplary single photon receiving device 601 and then make all memory areas of the example single photon receiving device 601 available for analysis of errors. In the case of a non-writable manufacturer memory of the exemplary single photon receiving device 601, the manufacturer memory 606 of the exemplary single photon receiving device 601 can be, for example, a manufacturer ROM, the content of which is defined, for example, during the manufacture of the semiconductor circuit of the exemplary single photon receiving device 601. The exemplary single photon receiving device 601 is typically intended to receive encrypted data and/or program code parts and/or commands using cryptographic methods that are stored in the memories of the exemplary single photon receiving device 601 and which one or more of the microcontroller cores 616 of the exemplary single photon receiving device 601 execute and /or to send such. The encryption is preferably a QKD encryption in each case. Some of these methods require considerable computing power. It has therefore proven itself that not only does the microcontroller core 616 of the exemplary single-photon receiving device 601 execute certain program parts of these cryptography methods in the form of partial steps of these cryptographic methods, but also that one or more special hardware accelerators of the exemplary single-photon receiving device 601 preferably in the form of one or more cryptography accelerators 607 of the exemplary single photon receiving device 601 execute these program parts. For this purpose, the exemplary single-photon receiving device 601 preferably has, for example, a DES accelerator 607 for the DES algorithm and/or an AES accelerator 607 for executing the AES algorithm. The microcontroller core 616 of the example single photon receiving device 601 typically addresses these hardware accelerators of the example single photon receiving device 601 via the internal data bus 602 of the example single photon receiving device 601 . The microcontroller core 616 of the exemplary single-photon receiving device 601 preferably has a redundant clock system of the exemplary single-photon receiving device 601 in order to be able to recognize access to the clock system of the exemplary single-photon receiving device 601 . One or more of the one or more security monitoring and control circuits 614 of the example single photon receiving device 601 monitors the consistency of the logical contents of these preferred plurality of redundant clock systems of the example single photon receiving device 601 to detect attacks and errors. One or more manufacturer memory firewalls 608 of the example single photon receiving device 601 preferably prevent the microcontroller core 616 of the example single photon receiving device 601 and the test logic of the example single photon receiving device 601 from accessing the manufacturer memory of the example single photon receiving device 601. These manufacturer firewalls 608 of the example single photon receiving device 601 can be preferred , as described, can be unlocked with a manufacturer password. The number of incorrect entries is preferably very limited in order to minimize the probability of a successful attack. The exemplary single-photon receiving device 601 preferably comprises one or more CRC modules (Cyclic Redundancy Check) 611 of the exemplary single-photon receiving device 601, so that the exemplary single-photon receiving device 601 for serial data communication can use the CRC data that is used in most data protocols to detect faulty data transmissions, for can generate one efficiently in the case of a transmission process and, on the other hand, can quickly check the correct receipt of the data message when it is received. The exemplary single photon receiving device 601 preferably comprises one or more clock generator modules (English Clock Driver, CLK) 612 of the exemplary single photon receiving device 601, which generate one or more clock signals of the exemplary single photon receiving device 601 for operating the circuits of the exemplary single photon receiving device 601. Preferably, the one or more clock generator modules (Clock Driver, CLK) 612 of the exemplary single-photon receiving device 601 generate redundant clock signals that indicate an attack on the clock system of the exemplary single-photon receiving device 601 . Typically, the example single photon receiving device 601 includes one or more timing modules 613 of the example single photon receiving device 601, as required by the microcontroller core 616, for example to detect timeouts. The exemplary single photon receiving device 601 preferably includes one or more watchdog timers of the exemplary single photon receiving device 601, which monitor the processing of the various program parts by the one or more microcontroller cores 616 of the exemplary single photon receiving device 601. These example single photon receiving device 601 watchdogs may be part of the one or more of the one or more security monitoring and control circuits 614 of the example single photon receiving device 601 . According to the proposal, the exemplary single photon receiving device 601 comprises at least one preferably quantum process-based generator for genuine random numbers (English: Quantum Random Number Generator: QRNG) 615. Quantum-based processes have the advantage that they are based on genuine randomness. In the 1970s, the physicist Bell proved that the theory of "hidden parameters" was wrong. That is, there are no hidden causes for the randomness of quantum mechanical events, such as the emission of photons. The microcontroller core 616 of the exemplary single-photon receiving device 601, which has already been mentioned several times, can be, for example, an 8-bit microcontroller core or a 16-bit microcontroller core or a 32-bit microcontroller core or a 64-bit microcontroller core or a 128-bit microcontroller core or the like. The example single-photon receiving device 601 may include one or more 8/16/32/15-bit microcontroller cores 616 that can preferably access the others of the example single-photon receiving device 601 via one or more internal data buses 602 of the example single-photon receiving device 601 . Preferably, the example single-photon receiving device 601 includes one or more data interfaces 617 of the example single-photon receiving device 601. Such data interfaces 617 may be, for example, one or more Universal Asynchronous Receiver Transmitters (UART) for supporting high-speed serial data. The exemplary single photon receiving device 601 preferably has one or more base clock generators 621 (CLK) of the exemplary single photon receiving device 601, which preferably each provide a base clock to one or more clock generator modules (English Clock Driver, CLK) 612 of the exemplary single photon receiving device 601. The basic clock generators 621 (CLK) of the exemplary single-photon receiving device 601 are preferably oscillators. Preferably, the example single photon receiving device 601 also includes one or more power supply or Vcc circuits 623 of the example single photon receiving device 601 with voltage regulators that provide the operating voltages for the example single photon transmitting device 401 . Preferably, the exemplary single-photon transmission device 401 also includes one or more ground circuits 424 of the exemplary single-photon receiving device 601, which include, for example, reverse polarity protection and protection circuits against manipulation of the electrical potential of the semiconductor substrate of the semiconductor crystal of the microintegrated parts of the exemplary single-photon receiving device 601. For example, it is useful if one or more of the one or more ground circuits 624 of the exemplary single-photon receiving device 601 have reverse polarity protection. For example, it is useful if one or more of the one or more ground circuits 624 of the example single photon receiving device 601 and/or one or more of the one or more power supply or Vcc circuits 623 of the example single photon receiving device 601 cooperate to modulate the current consumption and/or or the internal resistance and/or the voltage drop between the supply voltage connections of the exemplary single-photon receiving device 601 does not allow any conclusions to be drawn about the operating processes and/or states of the exemplary single-photon receiving device 601 at least at times. For the control of other devices and/or for the communication with other devices and/or for the monitoring of other devices, it is usually useful if the exemplary single photon receiving device 601 has one or more input/output circuits 625 of the exemplary single photon receiving device 601, which are shown in are generally embodied as digital inputs and/or as digital outputs of the exemplary single-photon receiving device 601, which can preferably also assume a tri-state state. The example single photon receiving device 601 may include an analog-to-digital converter of the example single photon receiving device 601 that allows the microcontroller core 616 of the example single photon receiving device 601 to monitor internal analog values, such as operating voltage, and external analog values. The analog-to-digital converter may be provided with an analog multiplexer to monitor a plurality of internal electrical nodes of the example single-photon receiving device 601 for the correctness of the values of the electric potential against a reference potential of the example single-photon receiving device 601 . Preferably, the microcontroller core 616 controls the exemplary single photon emp capture device 601 this analog multiplexer. If necessary, the exemplary single-photon receiving device 601 can be provided with one or more driver stages 692 of the exemplary single-photon receiving device 601 in order to be able to drive actuators 694, for example. These actuators 694 can be, for example, motors and/or other ohmic and/or inductive and/or capacitive loads and the like. Such a driver stage 692 of the exemplary single-photon receiving device 601 can be, for example, a half-bridge and/or an H-bridge or the like. It is also conceivable that power current sources of the exemplary single-photon receiving device 601 can be used, for example for lighting means such as LEDs.

The document presented here thus proposes an exemplary single-photon receiving device 601, in particular for the safe control of devices in automobiles, which comprises a semiconductor crystal. The exemplary single-photon receiving device 601 is preferably manufactured in whole or in part in a CMOS circuit technology or a bipolar circuit technology or a BiCMOS circuit technology. The exemplary single photon receiving device 601 preferably comprises memory elements, one or more internal data buses 602 of the exemplary single photon receiving device 601, one or more 8/16/32/15-bit microcontroller cores 616 of the exemplary single photon receiving device 601, one or more data interfaces of the exemplary single photon receiving device 601 and one or more preferably quantum process-based generators 615 of the exemplary single-photon receiving device 601 for the generation of true or high-quality random numbers (English: Quantum Random Number Generator: QRNG). The internal data bus 602 of the example single photon receiving device 601 may include multiple data buses. The storage elements of the example single photon receiving device 601 are typically connected to the internal data bus 602 of the example single photon receiving device 601 . The data interfaces of the example single photon receiving device 601 are typically connected to the internal data bus 602 of the example single photon receiving device 601 . The one or more random number generators (QRNG) 615 of the example single photon receiving device 601 are also preferably connected to the internal data bus 602 of the example single photon receiving device 601 . The one or more microcontroller cores 616 of the example single photon receiving device 601 are also preferably connected to the internal data bus 602 of the example single photon receiving device 601 . The one or more random number generators (QRNG) 615 preferably and typically generate one or more random numbers upon request of the microcontroller core 616 of the example single photon receiving device 601 . One or more of the one or more microcontroller cores 616 of the exemplary single photon receiving device 601 preferably generate one or more keys using a respective program from one or more of their memory elements of the exemplary single photon receiving device 601 and using one or more of the generated random numbers. Typically, one or more microcontroller cores 616 of the exemplary single photon receiving device 601 encrypt and/or decrypt using a respective program of the relevant microcontroller core 616 of the exemplary single photon receiving device 601, which in each case originates from one or more of its memory elements of the exemplary single photon receiving device 601, and using a respective key of the generated key data that these microcontroller cores 616 of the example single photon receiving device 601 typically exchange via one or more data interfaces of the example single photon receiving device 601 the one or more data interfaces of the example single photon receiving device 601 with devices outside of the example single photon receiving device 601.

In a development of the exemplary single-photon receiving device 601, the memory elements of the exemplary single-photon receiving device 601 include one or more read/write memories RAM 603 and/or one or more writable non-volatile memories, in particular EEPROM memories 604 and/or flash memories 604 and/or OTP memory 604, and/or one or more read-only memories, and/or one or more non-volatile manufacturer memories. The one or more semiconductor memories of the example single photon receiving device 601 may include, for example, one or more manufacturer ROMs 606 and/or one or more manufacturer EEPROMs and/or one or more manufacturer flash memories.

In a second development, the manufacturer memory of the exemplary single-photon receiving device 601, in particular a manufacturer ROM 606 of the exemplary single-photon receiving device 601, includes the boot software for starting the microcontroller core 616 of the exemplary single-photon receiving device 601 in order to reliably start the exemplary single-photon receiving device 601.

In a third development, exemplary single-photon receiving device 601 has a manufacturer memory firewall 608 of exemplary single-photon receiving device 601 between manufacturer memory 606 of exemplary single-photon receiving device 601 and internal data bus 602 of exemplary single-photon receiving device 601, which restricts access to manufacturer memory 706 of the exemplary single photon receiving device 601 is prevented without authentication.

In a fourth development, the exemplary single-photon receiving device 601 has one or more of the following components: A base clock generator 621 (CLK), a clock generator circuit 612, a reset circuit 622, a power supply circuit or a Vcc circuit 623 with voltage regulators that regulate the operating voltages at least provide for the example single photon receiving device 601, a ground circuit 624, an input/output circuit 625, one or more processing modules. The processing modules of the exemplary single photon receiving device 601 communicate with the internal data bus 602 of the exemplary single photon receiving device 601 and thus typically with a microcontroller core 616 of the exemplary single photon receiving device 601. The processing modules of the exemplary single photon receiving device 601 preferably include one or more of the following modules: A CRC module (Cyclic Redundancy Check) 611, a clock generator module 612, a crypto accelerator 607, in particular a DES accelerator and/or an AES accelerator 607, one or more timer modules 613, one or more security monitoring and control circuits 614, as well as one or more Data interfaces, in particular a universal asynchronous receiver transmitter (UART) 617.

In a further development of the exemplary single photon receiving device 601, at least one data interface of the one or more data interfaces of the exemplary single photon receiving device 601 is a wired automotive data bus interface. In this case, the wired automotive data bus interface can, for example, be a CAN data bus interface or a CAN FD data bus interface or a Flexray data bus interface or a PSl5 data bus interface or a DSL3 data bus interface or a LIN data bus interface or an Ethernet data bus interface or a LIN data bus interface or a MELIBUS data bus interface.
In a further development of the exemplary single photon receiving device 601, at least one data interface of the one or more data interfaces of the exemplary single photon receiving device 601 is a wireless data bus interface. The wireless data bus interface can be a WLAN interface or a Bluetooth interface, for example.
In a further development of the exemplary single photon receiving device 601, at least one data interface of the one or more data interfaces of the exemplary single photon receiving device 601 is a wired data bus interface. The wireless data bus interface of the exemplary single-photon receiving device 601 can be, for example, a KNX data bus interface or an EIB data bus interface or a DALI data bus interface or a PROFIBUS data bus interface.
The exemplary single photon receiving device 601 preferably comprises one or more wireless and/or wired data interfaces 626. The data transmission channel 428 to a single photon transmitting device 401 can be wired or wireless. In the case of a car, the communication channel 428 is preferably wireless. The data transmission channel 428 is then typically an electromagnetic data signal which the single photon receiving device 601 exchanges with the single photon transmitting device 401 in a wireless manner. In the case of a car with a single-photon transmission device 401, the car exchanges data with the single-photon transmission device 401, preferably by means of a wireless data interface 626 and its antenna 627. In the case of a wired data transmission channel, the data transmission channel is then typically an electromagnetic data signal which the single photon receiving device 601 exchanges with the single photon transmitting device 401 by wire. In this wireless data interface case, the exemplary single-photon receiving device 601 typically includes one or more respective antennas 627 of the respective wireless interface 626.

The exemplary single photon receiving device 601 preferably includes an evaluation circuit 672 for the received signals 673 to 676 of the single photon detectors 677 to 680 for differently polarized single photons. Evaluation circuit 672 receives measured values in the form of signals from single photon detectors 677 to 680 for differently polarized single photons via said received signals 673 to 676. Evaluation circuit 672 processes these measured values and makes the result of this processing available to microcontroller core 616 via internal data bus 602.
The example single photon receiving device 601 preferably includes a single photon end detector system 1603 for receiving a polarization-modulated single-photon signal. The single photon detector system 1603 preferably comprises n receiving channels for single photons. The receiving channels each detect the individual photons with a rotation of the plane of polarization of (k−1)/(2*n)*360° in relation to a basic direction. The receiving channels can be numbered consecutively starting with 1. where k is the number of the receiving channel. Here n is the number of receiving channels and k is a number with 1≤k≤n. The single photon detector system provides the microcontroller core 616 with data on the received single photons, this data preferably including the direction of polarization and the period or time of reception. The exemplary single photon detector system 1603 preferably comprises a first single photon detector 677 for horizontally polarized single photons and a second single photon detector 678 for vertically polarized single photons and a third single photon detector 679 for +45° polarized single photons and a fourth single photon detector 680 for -45° polarized single photons. The proposed single photon detector system 1603 is preferably a single photon detector system 1603 for polarization modulated single photons.
The exemplary single photon receiving device 601 preferably comprises a first single photon detector 677 for horizontally polarized single photons, for example a first SPAD diode. The document presented here assumes that, in the case of a SPAD diode, the first single photon detector 677 includes the drive circuit and evaluation circuit for operating the SPAD diode. The semiconductor substrate of the microcontroller core 616 preferably also includes the first SPAD diode with the necessary operating circuits and the connection to a supply voltage and thus the first single photon detector 677. The first single photon detector for horizontally polarized single photons 677 is integrated into the single photon receiving device 601 in such a way that the first Single photon detector for horizontally polarized single photons 677 essentially only horizontally polarized single photons of the QKD coupling beam 452 emitted by a single photon transmitting device 401 is detected. The construction of the first single photon detector 677 can already ensure, for example, that the first single photon detector 677 for horizontally polarized single photons essentially only detects horizontally polarized single photons of the OKD coupling beam 452 . Such a construction can, for example, provide a first micro-optical grating as a polarization device that only lets through single photons of a horizontal polarization direction. However, such a construction can also include, for example, the second polarizing beam splitter 684 as a micro-integrated micro-optical functional element and the second single-photon detector 678 . The first single photon detector 677 converts the received single photons of the third horizontally polarized single photon stream into a first received signal 673 of the first single photon detector 677 for horizontally polarized single photons 673. The first single photon detector 677 therefore preferably essentially only converts the received horizontally polarized single photons into the first received signal 673 of the first horizontally polarized single photon single photon detector 677;

A first received signal 673 from the first single photon detector 677 for horizontally polarized single photons 677 signals the evaluation circuit 672 that single photons have been received.

The exemplary single photon receiving device 601 preferably comprises a second single photon detector 678 for vertically polarized single photons, for example a second SPAD diode. The document presented here assumes that, in the case of a SPAD diode, the second single photon detector 678 includes the drive circuit and evaluation circuit for operating the SPAD diode. The semiconductor substrate of the microcontroller core 616 preferably also includes the second SPAD diode with the necessary operating circuits and the connection to a supply voltage and thus the second single photon detector 678. The second single photon detector for vertically polarized single photons 678 is preferably integrated into the single photon receiving device 601 in such a way that the second Single photon detector for vertically polarized single photons 678 essentially only vertically polarized single photons of the QKD coupling beam 452 detected. For example, the construction of the second single photon detector 678 can already ensure that the second single photon detector for vertically polarized single photons 678 essentially only detects vertically polarized single photons of the QKD coupled beam 452 . Such a construction can, for example, provide a second micro-optical grating as a polarization device that only lets through single photons of a vertical polarization direction. However, such a construction can also include, for example, the second polarizing beam splitter 684 as a micro-integrated micro-optical functional element and the first single-photon detector 677 . The second single photon detector 678 converts the received single photons of the fourth horizontally polarized single photon stream 686 into a second received signal 674 of the second single photon detector 678 for vertically polarized single photons. The second single photon detector 678 thus preferably essentially only converts the received vertically polarized single photons into the second received signal 674 of the second single photon detector 678 for vertically polarized single photons. A second received signal 674 from the second single photon detector 678 for vertically polarized single photons 678 signals the evaluation circuit 672 that single photons have been received.

The exemplary single photon receiving device 601 preferably comprises a third single photon detector 679 for +45° polarized single photons, for example a third SPAD diode. The document presented here assumes that, in the case of a SPAD diode, the third single photon detector 678 includes the drive circuit and evaluation circuit for operating the SPAD diode. The semiconductor substrate of the microcontroller core 616 preferably also includes the third SPAD diode and thus the third single photon detector 679. The third single photon detector for +45° polarized single photons 679 is preferably integrated into the single photon receiving device 601 in such a way that the third single photon detector for +45° polarized single photons 679 essentially only +45° polarized single photons of the QKD coupling beam 452 are detected. The design of the third single photon detector 679 can already ensure, for example, that the third single photon detector for horizontally polarized single photons 679 essentially only detects +45° polarized single photons of the QKD coupled beam 452 . Such a construction can, for example, provide a third +45° oriented micro-optical grating as a polarization device on the surface of a third SPAD diode, ie at its light entry port, which only allows single photons of a +45° oriented polarization direction to pass. However, such a construction can also include, for example, the third polarizing beam splitter 690 as a micro-integrated micro-optical functional element and the fourth single-photon detector 680 . The third single photon detector 679 converts the received single photons of the fifth +45° polarized single photon stream 1605 into a third received signal 675 of the third single photon detector 679 for +45° polarized single photons 675. The third single photon detector 679 therefore preferably essentially only converts the received +45° polarized single photons into the third received signal 675 of the third single photon detector 679 for +45° polarized single photons. A third received signal 675 from the third single photon detector 679 for +45° polarized single photons 679 signals the evaluation circuit 672 that single photons have been received.

The exemplary single photon receiving device 601 preferably comprises a fourth single photon detector 680 for -45° polarized single photons, for example a fourth SPAD diode. The document presented here assumes that, in the case of a SPAD diode, the fourth single photon detector 679 includes the drive circuit and evaluation circuit for operating the SPAD diode. The semiconductor substrate of the microcontroller core 616 preferably also includes the fourth SPAD diode and thus the fourth single photon detector 680. The fourth single photon detector for -45° polarized single photons 680 is preferably integrated into the single photon receiving device 601 in such a way that the fourth single photon detector for -45° polarized single photons 680 essentially only -45° polarized single photons of the QKD coupling beam 452 are detected. The design of the fourth single photon detector 680 can already ensure, for example, that the third single photon detector for horizontally polarized single photons 680 essentially only detects -45° polarized single photons of the QKD coupled beam 452 . Such a construction can, for example, provide a third -45° oriented micro-optical grating as a polarization device on the surface of a fourth SPAD diode, ie at its light entry port, which only allows single photons of a -45° oriented polarization direction to pass. However, such a construction can also include, for example, the third polarizing beam splitter 690 as a micro-integrated micro-optical functional element and the third single-photon detector 679 . The fourth single photon detector 680 converts the received single photons of the sixth +45° polarized single photon stream 691 into a fourth received signal 680 of the fourth single photon detector 680 for -45° polarized single photons 676. The fourth single photon detector 680 therefore preferably converts essentially only the received -45° polarized single photons into the fourth received signal 676 of the fourth single photon detector 680 for -45° polarized single photons. A fourth received signal 676 of the fourth single photon detector 680 for -45° polarized single photons 680 signals the evaluation circuit 672 that single photons have been received.
The exemplary single photon receiving device 601 preferably includes a supply voltage line. 643. The supply voltage line 643 connects the respective loads within the proposed single photon receiving device 601 to one or more power supply or Vcc circuits 663 with voltage regulators, which provide the operating voltages for the microcontroller system of the single photon receiving device 601 and the QKD transmitter of the single photon receiving device 601. The supply voltage line 643 can also include several lines, each of which, for example, has a consumer of electrical energy, i.e. a sub-device of the proposed single-photon receiving device 601, each with a voltage regulator or a current source connect one or more power supply or Vcc circuits 623.
The exemplary single photon receiving device 601 preferably includes optional receiving optics 681 for the QKD coupled beam 452. The optional receiving optics 681 focuses the incoming single photons of the single photon beam of the QKD coupled beam 452 onto the single photon detectors 677, 678, 679, 680 of the exemplary single photon receiving device 601. After traversing of the beam path 682 for the single photons of the QKD coupling beam 452 between optional receiving optics for the QKD coupling beam 452 and non-polarizing beam splitter 683, the non-polarizing beam splitter 683 splits the QKD coupling beam 452. The non-polarizing beam splitter 683 splits the single photon stream of the QKD coupling beam 452 independent of the polarization of the single photons of the QKD coupling beam 452 into a first single photon stream 1604 and a second single photon stream 687. In doing so, the non-polarizing beam splitter 683 injects a single photon into the first single photon stream 1604 with a probability of substantially 50% and into the second single photon stream 686 with a probability of substantially 50%. A second polarizing beam splitter 684 splits the first single photon stream 1604 into a third horizontally polarized single photon stream 685 and a fourth vertically polarized photon stream 686 . The third polarizing single photon stream 685 comprises essentially only horizontally polarized single photons with which the third horizontally polarized single photon stream irradiates the first single photon detector 677 for horizontally polarized single photons.

The fourth polarized single photon stream 686 comprises essentially only vertically polarized single photons with which the fourth vertically polarized single photon stream 686 irradiates the second single photon detector 678 for vertically polarized single photons.

In the second single photon stream 687 there is preferably a λ/4 plate and/or a polarization rotating device 688. The λ/4 plate or the polarization rotating device 688 preferably rotates the polarization direction of the single photons in the second single photon stream 687 by 45° to form a rotated second single photon stream 689. A third polarizing beam splitter 690 splits the twisted second single photon stream 689 into a sixth -45° polarized single photon stream 691 and a fifth +45° polarized photon stream 1605 . The sixth polarized single photon stream 691 essentially comprises only -45° polarized single photons, with which the sixth -45° polarized single photon stream 691 irradiates the fourth single photon detector 680 for -45° polarized single photons. The fifth +45° polarized single photon stream 1605 essentially comprises only +45° polarized single photons, with which the fifth +45° polarized single photon stream 1605 irradiates the third single photon detector for +45° polarized single photons 679 .

If it is necessary to align the single photon transmitter device 401 with respect to the single photon receiver device 601, the single photon receiver device 601 comprises an alignment receiver 699, for example. The receiver 1601 of the alignment receiver 699 detects the laser pointer beam 462 for aligning the single photon transmitter device 401, 471, for example a car key. The interface 1606 of the alignment receiver 699 receives measurement data from the receiver 1601 of the alignment receiver 699 via the alignment receiver line 698. The interface 1606 of the alignment receiver 699 signals to the microcontroller core 616 via the internal data bus 602 whether the receiver 1601 of the alignment receiver 699 via the optical system 1602 of the alignment receiver 699 receives sufficient light from the laser pointer beam 462 to align the single photon transmitting device 471, for example a car key, with the single photon receiving device 601. Only when this is the case does the microcontroller core 616 preferably start generating a common quantum key for the single-photon transmission device 471, for example the car key 471, and the single-photon reception device 601 of the car 802. For this purpose, the microcontroller core 616 of the single-photon reception device 601 signals the microcontroller core 416 of the single-photon transmission device 471, So for example the car key 471, for example via a wireless data connection 626, 627,428, 427, 426, that the agreement of a quantum key can start. The microcontroller core 416 of the single photon transmission device 471, e.g. of the car key 471, then causes the single photon transmission device 1407 of the single photon transmission device 471 to generate a polarization-modulated stream of single photons as a QKD coupling beam 452, with the microcontroller core 416 of the single photon transmission device 471, e.g. of the car key 471, preferably as a modulation signal of the Direction of polarization of the emitted single photons uses a random number of its at least one quantum process-based generator for true random numbers (Quantum Random Number Generator: QRNG) 415 . The single photon receiving device 601 of the other device, for example a car 802, receives this polarization mode modulated single-photon data stream of the QKD coupling beam 452.

For example, the single photon receiving device 601 can control or influence an exemplary locking device 694 of a car 802 as a car key 401 or 471 . In the exemplary application of a door lock for opening a door 804 or another opening of a car 802 with a car key 401 or 471, the microcontroller core 616 exchanges an encryption code using a QKD method in a tap-proof manner. After the car key 401 or 471 has established a secure wireless connection 428 between the car key and the single-photon receiving device 601 by generating a shared, secret quantum key, the microcontroller core 416 of the car key 401, 471 can exchange authentication data with the microcontroller core 616 or a computer unit which is superordinate to the microcontroller core 616. If this computer unit 697, which is superordinate to microcontroller core 616, or microcontroller core 616, after comparison with a database, deems the authentication data to be trustworthy, microcontroller core 616, for example by means of suitable signaling via internal data bus 602, causes controller 692 to drive exemplary locking device 694 and the control line 693 for driving the example locking device 694 to open, unlock, lock or lock the example locking device 694 of the car 802 the door 804 or other opening of the car 802 .
Also, the single photon receiving device 601 may include a controller 692 for driving the exemplary closure device 694 . By means of a control line 693 for the drive of the exemplary locking device 694, the controller 692 for the drive of the exemplary locking device 694 exchanges control data and/or status data with the drive of the exemplary locking device 694 and makes them available to the microcontroller core 616 via the internal data bus 602 . The controller 692 for driving the exemplary closing device 694 exchanges control data and/or status data with the drive of the exemplary closing device 694 by means of the control line 693 for driving the exemplary closing device 694 .
The single photon receiving device 601 preferably comprises one or more data connections 696 from one or more data interfaces 695 of the single photon receiving device 601 to a higher-level computer unit 697 via a data bus 696 of the other device, for example the car 802. It can be, for example, a CAN data bus or a CAN FD data bus or a PSI5 data bus or a DSI3 data bus or an I ² C bus or an Ethernet connection or an optical data connection, for example an optical fiber, or an encrypted wireless connection such as WLAN or Bluetooth, or act like that. The superordinate computer unit 697 can be, for example, any computer unit of the motor vehicle. This higher-level computing unit usually controls the actions of the microcontroller core 616.

The respective sub-devices for transmitting and receiving the QKD coupled beam 452 of the single photon transmitting device 471 of 5 and the single photon receiving device 601 of FIG 6 can be interchanged and combined as desired.

7 FIG. 7 shows an exemplary and schematic block diagram of an exemplary integrated circuit for use as a QKD integrated circuit 701 in automotive QKD systems.

The proposed circuit is preferably a one-piece CMOS, BICMOS or bipolar circuit in or on a semiconductor substrate. The material of the semiconductor substrate preferably comprises silicon or SiC or a mixed crystal of elements from main groups III, IV and V of the periodic table. 7 FIG. 7 is a diagram of an example QKD integrated circuit 701. QKD integrated circuit 701 includes memory elements coupled to an internal data bus 702, for example. The memory elements can include, for example, one or more read/write memories RAM 703, one or more writable non-volatile memories such as EEPROM memory 704 or flash memory 704 or OTP memory 704. Furthermore, the QKD integrated circuit 701 preferably includes one or more non-volatile, read-only memories 705, such as a ROM. In addition, the QKD integrated circuit 701 preferably includes one or more non-volatile, writable and/or non-writable manufacturer memory 706. In the case of non-writable manufacturer memory, the manufacturer memory 706 may be a manufacturer ROM. Preferably, the manufacturer ROM 706 comprises the boot software for the microcontroller core 716 of the QKD integrated circuit 701. The QKD integrated circuit 701 comprises, for example, one or more cryptographic accelerators 707, for example a DES accelerator and/or an AES accelerator 707, which are preferably connected to the microcontroller core 716 via the internal data bus 702. For example, one or more manufacturer storage firewalls 708 between the manufacturer storage 706 and the internal Data bus 702 may be provided. For example, the QKD integrated circuit 701 preferably includes processing modules that communicate with the microcontroller core 716 of the QKD integrated circuit 701 via the internal data bus 702 . The processing modules of the QKD integrated circuit 701 preferably comprise at least one of the following modules: a CRC (Cyclic Redundancy Check) module 711, a clock generator module 712, one or more timer modules 713, a security monitoring and control circuit 714, one or more quantum process-based generator for true random numbers (English: Quantum Random Number Generator: QRNG) 715, one or more 8/16/32/15-bit microcontroller cores 716 and one or more data interfaces 717, in particular one or more Universal Asynchronous Receiver Transmitters (UART) to support high-speed serial data. The other circuit parts of the integrated QKD circuit 701 include, for example, one or more base clock generators 720 (CLK) and/or one or more clock generator modules 712, a reset circuit 722, a power supply or Vcc circuit 723 with voltage regulators that provide the operating voltage , a ground circuit 724 and an input/output circuit 725.

Preferably, the QKD integrated circuit 701 is configured to enable secure authentication. For example, the QKD integrated circuit 701 preferably stores other data in addition to the authentication code, e.g. B. one or more lifetime and usage data and / or eg logistical data and / or eg commercial data and / or website and email addresses and / or image data, a set of instructions for control devices of the car 802, with which the microcontroller core 716 communicates via a data interface. In addition, the QKD integrated circuit 701 can store other application data.
Preferably, the QKD integrated circuit 701 includes, for example, a microcontroller core 716 configured to facilitate secure authentication of a product.
Internal data bus 702 may include multiple data buses 702 for multiple microcontroller cores 716 of QKD integrated circuit 701 such that these multiple microcontroller cores 716 can independently access different sub-devices of QKD integrated circuit 701 simultaneously. As a rule, however, the QKD integrated circuit 701 only comprises an internal data bus 702 and only one microcontroller core 716. The microcontroller core 716 is preferably an ARM processor or the like. It is preferably an 8-bit or a 16-bit or a 32-bit or a 64-bit microcontroller core 716.
The integrated QKD circuit 701 preferably includes one or more read/write memories RAM 703. These can be, for example, SRAMs and/or MRAMs and/or FRAMS or the like. The one or more read/write memories RAM 703 can also be wholly or partly dynamic read/write memories such as DRAMs, which the microcontroller core 716 or a refresh device of the integrated QKD circuit 701 use at regular time intervals in a refresh -Read the cycle and rewrite it again. For the access of the microcontroller core 716 to a memory of the integrated QKD circuit 701, the integrated QKD circuit 701 can have access logic, which regularly carries out this refresh and controls this access. However, DRAM typically opens up opportunities for attack and is typically a potential vulnerability. The microcontroller core 716 of the QKD integrated circuit 701 can preferably access this read/write memory RAM 703 of the QKD integrated circuit 701 by means of the internal data bus 702 of the QKD integrated circuit 701
The integrated QKD circuit 701 preferably comprises one or more writable and non-volatile memories 704. The microcontroller core 716 of the integrated QKD circuit 701 can preferably access these writable and non-volatile memories 704 of the integrated QKD circuit 701 by means of the internal data bus 702 of the integrated QKD circuit 701 access. This non-volatile memory 404 of the QKD integrated circuit 701 can include EEPROM memory 704 or flash memory 704 or OTP memory 704, for example. OTP stands for English One Time Programmable, which means only once programmable.
One possibility of attack may be the erasure of the non-volatile memory 704 by means of radiation, for example x-rays and/or ionizing radiation and/or the heating of memory cells. To this end, the QKD integrated circuit 701 preferably has one or more safety monitoring and control circuits 714 of the QKD integrated circuit 701, which monitor the data integrity of the memory cells of the erasable memories 704 of the QKD integrated circuit 701. The memory cells of erasable memory 704 of integrated QKD circuit 701 preferably have redundancy such that at least two check bits are provided for a data word, which is preferably a data word with a length of 8 bits, i.e. one byte, and that always at least one first check bit must have the content 1 and another, wide check bit, which is assigned to this first check bit, must have the content 0. For example, the first check bit can be a parity bit of the byte and the second check bit can be the inverse bit of the parity bit relative to the first check bit. If an attack with ionizing radiation or the like then occurs, the attack resets both test bits to the same value. This is an illegal condition that the QKD integrated circuit 701 can detect. The one or more safety monitoring and control circuits 714 of the QKD integrated circuit 701 detect such a deviation and, if necessary, block the QKD integrated circuit 701 from further accesses, at least for a preferably predetermined period of time.
Each bit of the memory of the integrated QKD circuit 701 is preferably designed twice, so that each logical data bit is preferably implemented as a pair of a first physical data bit with a first internal logical value and a second physical data bit with a second internal logical value. In this case, the second internal logical value is typically the logical inverse of the first internal logical value. The one or more safety monitoring and control circuits 714 of the integrated QKD circuit 701 again preferably monitor that this is always the case. The one or more safety monitoring and control circuits 714 of the integrated QKD circuit 701 again detect deviations and, for example, preferably block The further execution of programs or certain program parts and/or access to data, for example for the microcontroller core 716 in the event of deviations. Preferably, the QKD integrated circuit 701 comprises one or more reset circuits 722 of the QKD integrated circuit 701. The reset circuits 722 of the QKD integrated circuit 701 respectively set the QKD integrated circuit 701 and/or sub-devices of the QKD integrated circuit 701 into predefined states , if predetermined or determinable reset conditions and/or combinations and/or time sequences of such reset conditions are present. For example, these conditions may be signaling from one or more safety monitoring and control circuits 714 of QKD integrated circuit 701 to one or more reset circuits 722 of QKD integrated circuit 701, for example. These conditions can also be changes and/or values of electrical node potentials compared to the potential of a reference node or a reference potential line, that is to say one or more operating voltages of the integrated QKD circuit 701, for example. A watchdog timer may be part of a reset circuit 722 of the QKD integrated circuit 701 . Furthermore, such conditions may affect the integrity of the QKD integrated circuit 701 package. The housing of the QKD integrated circuit 701 preferably includes a detector for opening or damaging the housing of the QKD integrated circuit 701. For example, this can be a single line that surrounds the QKD integrated circuit 701, for example as a textile network, or covers or at least covers parts of the QKD integrated circuit 701. It can also be a network of lines covering the QKD integrated circuit 701 solely for the purpose of detecting an attack. For example, the integrated QKD circuit 701 can in each case feed an electric current into one or more such lines by means of a first input/output line and draw it again from one or more second input/output lines. If the current flow is interrupted, this is an indication of an attack which one or more of the one or more security monitoring and control circuits 714 of the QKD integrated circuit 701 can detect and which then, for example, the microcontroller core 716 of the QKD integrated circuit 701 this attack signal. For example, in such a case of suspected violation of the integrity of the housing of the QKD integrated circuit 701, one or more of the one or more safety monitoring and control circuits 714 of the QKD integrated circuit 701 can prevent write and/or read access to memory contents of the memory of the block QKD integrated circuit 701 and/or delete such content of the memory of the QKD integrated circuit 701 in whole or in part or set this content of the memory of the QKD integrated circuit 701 to predefined values or overwrite it with nonsensical data or otherwise manipulate it. The memories of the QKD integrated circuit 701 preferably comprise one or more non-volatile, read-only memories 705, such as ROM. The ROM of the QKD integrated circuit 701 preferably contains design data and/or program instructions. The QKD integrated circuit 701 preferably has one or more non-volatile, writable and/or non-writable manufacturer memories 706, in which the semiconductor manufacturer or another supplier can store their production and security data, such as serial numbers, etc. The semiconductor manufacturer preferably blocks access to this writable and/or non-writable non-volatile manufacturer memory 706 of the QKD integrated circuit 701 after the last production test has been carried out. Access to the writable and/or non-writable manufacturer memory 706 of the integrated QKD circuit 701 using one or more manufacturer passwords possible. In some cases, a double key procedure makes sense. In this case, a customer following the semiconductor manufacturer also stores in one for access a password-lockable customer lock register of QKD integrated circuit 701 a customer password. Preferably, the semiconductor manufacturer can access all memory areas of the QKD integrated circuit 701 using only the customer password and the semiconductor password. Preferably, the semiconductor manufacturer provides an analysis password by means of which it can cause one or more of the one or more security monitoring and control circuits 714 of the QKD integrated circuit 701, typically with the aid of the reset circuit 722 of the QKD integrated circuit 701, the customer content in the memories of the QKD integrated circuit 701 and then to make all memory areas of the QKD integrated circuit 701 available for the analysis of errors. In the case of a non-writable manufacturer memory of the QKD integrated circuit 701, the manufacturer memory 706 of the QKD integrated circuit 701 can be a manufacturer ROM, for example, the content of which is defined, for example, during the manufacture of the semiconductor circuit of the QKD integrated circuit 701. The data and/or program code parts and /or receive and/or send commands in encrypted form. The encryption is preferably a QKD encryption in each case. Some of these methods require considerable computing power. It has therefore proven that not only the microcontroller core 716 of the integrated QKD circuit 701 executes certain program parts of these cryptographic methods in the form of partial steps of these cryptographic methods, but that one or more special hardware accelerators of the integrated QKD circuit 701 preferably in the form of one or more cryptography - Accelerator 707 of the QKD integrated circuit 701 execute these program parts. For this purpose, the integrated QKD circuit 701 preferably has, for example, a DES accelerator 707 for the DES algorithm and/or an AES accelerator 707 for executing the AES algorithm. The microcontroller core 716 of the QKD integrated circuit 701 typically addresses these hardware accelerators of the QKD integrated circuit 701 via the internal data bus 702 of the QKD integrated circuit 701 . The microcontroller core 716 of the integrated QKD circuit 701 preferably has a redundant clock system of the integrated QKD circuit 701 in order to be able to recognize access to the clock system of the integrated QKD circuit 701. One or more of the one or more security monitor and control circuits 714 of QKD integrated circuit 701 monitors the consistency of the logical contents of this preferred plurality of redundant clock systems of QKD integrated circuit 701 to detect attacks and errors. Access of the microcontroller core 716 of the QKD integrated circuit 701 and the test logic of the QKD integrated circuit 701 to the manufacturer memories of the QKD integrated circuit 701 is preferably prevented by one or more manufacturer memory firewalls 708 of the QKD integrated circuit 701. These manufacturer Firewalls 708 of the QKD integrated circuit 701 can preferably be unlocked by a manufacturer password, as described. The number of incorrect entries is preferably very limited in order to minimize the probability of a successful attack. Preferably, the s QKD integrated circuit 701 comprises one or more CRC modules (Cyclic Redundancy Check) 711 of the integrated QKD circuit 701, so that the integrated circuit QKD 701 for a serial data communication the CRC data, which is used in most data protocols for Detection of faulty data transmissions can be used, on the one hand, in the case of a transmission process, and on the other hand, the correct reception of the data message can be checked quickly when it is received. The QKD integrated circuit 701 preferably comprises one or more clock generator modules (English Clock Driver, CLK) 712 of the QKD integrated circuit 701, which generate one or more clock signals of the QKD integrated circuit 701 for operating the circuits of the QKD integrated circuit 701 . The one or more clock generator modules (English Clock Driver, CLK) 712 of the integrated QKD circuit 701 preferably generate redundant clock signals which indicate an attack on the clock system of the integrated QKD circuit 701 . Typically, the QKD integrated circuit 701 comprises one or more timer modules 713 of the QKD integrated circuit 701, as required by the microcontroller core 716, for example for the detection of time-outs. The QKD integrated circuit 701 preferably includes one or more watchdog timers of the QKD integrated circuit 701, which monitor the processing of the various program parts by the one or more microcontroller cores 716 of the QKD integrated circuit 701. These QKD integrated circuit 701 watchdog timers may be part of the one or more of the one or more security monitoring and control circuits 714 of the QKD integrated circuit 701 . According to the proposal, the QKD integrated circuit 701 comprises at least one quantum process-based generator for true random numbers (English: Quantum Random Number Generator: QRNG) 715. Quantum-based processes have the pre share that they are based on real coincidence. In the 1970s, the physicist Bell proved that the theory of "hidden parameters" was wrong. That is, there are no hidden causes for the randomness of quantum mechanical events, such as the emission of photons. The microcontroller core 716 of the integrated QKD circuit 701, which has already been mentioned several times, can be, for example, an 8-bit microcontroller core or a 16-bit microcontroller core or a 32-bit microcontroller core or a 64-bit microcontroller core or a 128-bit microcontroller core or the like be. The QKD integrated circuit 701 can have one or more 8/16/32/15-bit microcontroller cores 716, which preferably access the other sub-devices of the QKD integrated circuit 701 via one or more internal data buses 702 of the QKD integrated circuit 701 can. Preferably, the QKD integrated circuit 701 includes one or more data interfaces 717 of the QKD integrated circuit 701. Such data interfaces can be, for example, one or more universal asynchronous receiver transmitters (UART) for supporting high-speed serial data. The integrated QKD circuit 701 preferably has one or more base clock generators 721 (CLK) of the integrated QKD circuit 701, which preferably each have a base clock for one or more clock generator modules (English Clock Driver, CLK) 712 of the integrated QKD circuit 701 place. The base clock generators 721 (CLK) of the QKD integrated circuit 701 are preferably oscillators. Preferably, QKD integrated circuit 701 also includes one or more QKD integrated circuit 701 power supply or Vcc circuits 723 with voltage regulators that provide the QKD integrated circuit 701 operating voltages. Preferably, the QKD integrated circuit 701 also includes one or more ground circuits 724 of the QKD integrated circuit 701, which include, for example, reverse polarity protection and protection circuits against the manipulation of the electrical potential of the semiconductor substrate of the semiconductor crystal of the QKD integrated circuit 701. For example, it is useful if one or more of the one or more ground circuits 724 of the QKD integrated circuit 701 have reverse polarity protection. For example, it is useful if one or more of the one or more ground circuits 724 of the QKD integrated circuit 701 and/or one or more of the one or more power supply or Vcc circuits 723 of the QKD integrated circuit 701 cooperate so that the modulation the current consumption and/or the internal resistance and/or the voltage drop between the supply voltage connections of the integrated QKD circuit 701 does not allow any conclusions to be drawn about the operating processes and/or states of the integrated QKD circuit 701, at least at times.

For controlling other devices and/or for communicating with other devices and/or for monitoring other devices, it is usually useful if the QKD integrated circuit 701 has one or more input/output circuits 725 of the QKD integrated circuit 701 has, which are generally implemented as digital inputs and/or as digital outputs of the integrated QKD circuit 701, which can preferably also assume a tristate state. The QKD integrated circuit 701 may include a QKD integrated circuit 701 analog-to-digital converter that allows the microcontroller core 716 of the QKD integrated circuit 701 to monitor internal analog values, such as operating voltage, and external analog values. The analog-to-digital converter may be provided with an analog multiplexer to monitor a plurality of internal electrical nodes of the QKD integrated circuit 701 for the correctness of electrical potential values against a reference potential of the QKD integrated circuit 701 . Preferably, the microcontroller core 716 of the QKD integrated circuit 701 controls this analog multiplexer. If necessary, the QKD integrated circuit 701 can be provided with one or more driver stages 792 of the QKD integrated circuit 701 in order to be able to drive actuators 694, for example. These actuators 694 can be, for example, motors and/or other ohmic and/or inductive and/or capacitive loads and the like. Such a driver stage 792 of the QKD integrated circuit 701 can be, for example, a half-bridge of the QKD integrated circuit 701 and/or an H-bridge of the QKD integrated circuit 701 or the like. It is also conceivable that power current sources of the integrated QKD circuit 701 can be used, for example for light sources such as LEDs.
The document presented here thus proposes an integrated QKD circuit 701, in particular for the safe control of devices in automobiles, which comprises a semiconductor crystal. The QKD integrated circuit 701 is preferably manufactured in a CMOS circuit technology or a bipolar circuit technology or a BiCMOS circuit technology. The QKD integrated circuit 701 preferably comprises memory elements, one or more internal data buses 702 of the QKD integrated circuit 701, one or more 8/16/32/15-bit microcontroller cores 716 of the QKD integrated circuit 701, one or more data interfaces of the integrated QKD circuit 701 and one or more preferred quantum process-based generators 715 of the integrator th QKD circuit 701 for the generation of true or high quality random numbers (English: Quantum Random Number Generator: QRNG). Internal data bus 702 of QKD integrated circuit 701 may include multiple data buses. The storage elements of the QKD integrated circuit 701 are typically connected to the internal data bus 702 of the QKD integrated circuit 701 . The data interfaces of the QKD integrated circuit 701 are typically connected to the internal data bus 702 of the QKD integrated circuit 701 . The one or more random number generators (QRNG) 715 of the QKD integrated circuit 701 are also preferably connected to the internal data bus 702 of the QKD integrated circuit 701 . The one or more microcontroller cores 716 of the QKD integrated circuit 701 are also preferably connected to the internal data bus 702 of the QKD integrated circuit 701 . The one or more random number generators (QRNG) 715 preferably and typically generate one or more random numbers upon request of the microcontroller core 716 of the QKD integrated circuit 701 . One or more of the one or more microcontroller cores 716 of the QKD integrated circuit 701 preferably generate one or more keys with the aid of a respective program from one or more of their memory elements of the QKD integrated circuit 701 and with the aid of one or more of the generated random numbers. Typically, one or more microcontroller cores 716 of the QKD integrated circuit 701 encrypt and/or decrypt using a respective program of the relevant microcontroller core 716 of the QKD integrated circuit 701, which in each case originates from one or more of their memory elements of the QKD integrated circuit 701, and with the aid of a respective key of the generated key data which these microcontroller cores 716 of the QKD integrated circuit 701 typically communicate via one or more data interfaces of the QKD integrated circuit 701 the one or more data interfaces of the QKD integrated circuit 701 with devices outside of the QKD integrated circuit Replace circuit 701. Typically, the semiconductor crystal comprises all sub-devices of the QKD integrated circuit 701 integrally.
In a development of the integrated QKD circuit 701, the memory elements of the integrated QKD circuit 701 include one or more read/write memories RAM 703 and/or one or more writable non-volatile memories, in particular EEPROM memories 704 and/or flash memories 704 and/or OTP memory 704, and/or one or more read-only memories and/or one or more non-volatile manufacturer memories. The one or more semiconductor memories of the QKD integrated circuit 701 may include, for example, one or more manufacturer ROMs 706 and/or one or more manufacturer EEPROMs and/or one or more manufacturer flash memories.
In a second development, the manufacturer memory of the QKD integrated circuit 701, in particular a manufacturer ROM 706 of the QKD integrated circuit 701, includes the boot software for starting the microcontroller core 716 of the QKD integrated circuit 701 in order to configure the QKD integrated circuit 701 safe to start.

In a third development, the QKD integrated circuit 701 has a manufacturer memory firewall 708 of the QKD integrated circuit 701 between the manufacturer memory 706 of the QKD integrated circuit 701 and the internal data bus 702 of the QKD integrated circuit 701, which Access to manufacturer memory 706 of QKD integrated circuit 701 without authentication prevented.
In a fourth development, the integrated QKD circuit 701 has one or more of the following components: A base clock generator 721 (CLK) of the integrated QKD circuit 701, a clock generator circuit 712 of the integrated QKD circuit 701, a reset circuit 722, a power supply or a Vcc circuit 723 of the QKD integrated circuit 701 with voltage regulators that provide the operating voltages at least for the QKD integrated circuit 701, a ground circuit 724 of the QKD integrated circuit 701, an input/output circuit 725 of the QKD integrated circuit 701, one or more processing modules of the QKD integrated circuit 701. The processing modules of the QKD integrated circuit 701 communicate with the internal data bus 702 of the QKD integrated circuit 701 and thus typically with a microcontroller core 716 of the QKD integrated circuit 701. Preferably, the processing modules include of the QKD integrated circuit 701 one or more of the following modules: A CRC module (Cyclic Redundancy Check) 711, a clock generator module 712, a crypto accelerator 707, in particular a DES accelerator and/or an AES accelerator 707, one or more timers modules 713, one or more security monitoring and control circuits 714, one or more data interfaces, in particular a universal asynchronous receiver transmitter (UART) 717. In a further development of the integrated QKD circuit 701, at least one data interface of the one or more data interfaces of the integrated QKD circuit 701 a wired automotive data bus interface. In that case, the wired automotive data bus interface, for example a CAN data bus interface or a CAN FD data bus interface or a Flexray data bus interface or a PSI5 data bus interface or a DSI3 data bus interface or a LIN data bus interface or an Ethernet data bus interface or a LIN data bus interface or a MELIBUS data bus interface.
In a further development of the QKD integrated circuit 701, at least one data interface of the one or more data interfaces of the QKD integrated circuit 701 is a wireless data bus interface. The wireless data bus interface can be a WLAN interface or a Bluetooth interface, for example.

In a further development of the integrated QKD circuit 701, at least one data interface of the one or more data interfaces of the integrated QKD circuit 701 is a wired data bus interface. The wireless data bus interface of the integrated QKD circuit 701 can be, for example, a KNX data bus interface or an EIB data bus interface or a DALI data bus interface or a PROFIBUS data bus interface.
The QKD integrated circuit 701 preferably has one or more wireless data interfaces 726 for communication with other computer systems. For example, example QKD integrated circuit 701 may communicate via a respective antenna 727 of a respective wireless interface 726 of example QKD integrated circuit 701 . The antenna 427 emits an electromagnetic data signal 728, which the single-photon transmitting device 401, which preferably comprises the exemplary QKD integrated circuit 701, exchanges with the single-photon receiving device 601 of another device, for example a car, wired or wireless. In the case of a car key as a single-photon transmission device 401, which includes that of the exemplary integrated QKD circuit 701, the car key 401 exchanges data with the single-photon receiving device 601 of the car mentioned here as an example, preferably by means of the wireless data interface 726 of the exemplary integrated QKD circuit 701 and the antenna 427 of the single photon transmission device 401 out.
For the generation of a polarization-modulated single-photon beam 452, the integrated QKD circuit 701 preferably has a control device 729 for the n=4 single-photon sources 736, 737, 738, 739 here. The microcontroller core 716 of the integrated QKD circuit 701 controls the control device 729 of the integrated QKD circuit 701 via the internal data bus 702 of the integrated QKD circuit 701. For this purpose, the microcontroller core 716 can transmit configuration data of the control device 729 of the integrated QKD circuit 701 by means of the internal data bus 702 to the control device 729 of the integrated QKD circuit 701 and status information of the control device 729 read via the internal data bus 702 of the QKD integrated circuit 701. Such status information can be, for example, measurement data from the single photon sources 736 to 739 or from device parts that are associated with them. A control line 730 preferably connects the drive device 729 of the integrated QKD circuit 701 to an adjustable voltage regulator 742 of the integrated QKD circuit 701. The drive device 729 of the integrated QKD circuit 701 uses the control line 730 to set the voltage between a supply voltage line 741 of the single-photon sources 736, 737, 738, 739 and a reference potential. The reference potential is typically an internal ground potential of an internal ground line of the integrated QKD circuit 701. The adjustable voltage regulator 742 of the integrated QKD circuit 701 generates the potential of the supply voltage line 741 set by the drive device 729 from the potential of the supply voltage line 743 of the integrated QKD circuit 701 of the single photon sources 736, 737, 738, 739 of the QKD integrated circuit 701 with respect to the internal reference potential of the QKD integrated circuit 701.

The QKD integrated circuit 701 typically comprises one or more power supplies 742 for the single photon sources 736 to 739 of the QKD integrated circuit 701 or n single photon sources. The energy source, for example a key battery, supplies the energy supply 742 of the single photon sources 736 to 739 with electrical energy via an illuminant supply voltage line 743. The energy supply 742 regulates the operating voltage of the single photon sources 736 to 739, preferably by means of a linear regulator, in order to cause as little interference as possible. If necessary, the control device 729 for the single photon sources 736, 737, 738, 739 controls the voltage between the supply voltage line 741 of the single photon sources of the integrated QKD circuit 701 and a reference potential (typically ground) of the integrated QKD circuit 701 during the generation of a QKD Do not look up the key so as not to cause interference from the control. Preferably, the power supply 742 of the QKD integrated circuit 701 includes a small power reserve, such as a capacitor, for stabilization.

The supply voltage line 741 of the QKD integrated circuit 701 connects the respective loads within the QKD integrated circuit 701 to one or more power supply or Vcc circuits 723 with voltage regulators, which supply the operating voltages for the microcontroller system of the QKD integrated circuit 701 and the polarization modulated single photon transmitter of QKD integrated circuit 701 provide. The supply voltage line 741 can also include a number of lines, which, for example, each connect a consumer of electrical energy, i.e. a sub-device of the integrated QKD circuit 701, to a voltage regulator or a current source of the one or more power supply or Vcc circuits 723. The adjustable adjustable voltage regulator 742 of the integrated QKD circuit 701 reduces the voltage between the potential of the supply voltage line 743 of the integrated QKD circuit 701 to such an extent that the potential of the supply voltage line 741 of the integrated QKD circuit 701 of the single photon sources 736, 737, 738, 739 of the integrated QKD circuit 701 compared to the internal reference potential of the integrated QKD circuit 701 is sufficient that the integrated QKD circuit 701 can just about operate all single photon sources 736 to 739 of the integrated QKD circuit 701. The single-photon sources 736 through 739 of the QKD integrated circuit 701 each comprise illuminants 764 and respective current sources 463 of the respective single-photon source of the single-photon sources 736 through 739 of the integrated QKD circuit 701. The respective current source 763 provides the single-photon rate of the respective associated illuminant 764 of its single-photon source of the single-photon sources 736 to 739 of the QKD integrated circuit 701 depending on signaling of the associated control line of the control lines 731 to 735 for the associated current source 763 of the associated single photon source of the single photon sources 736 to 739 of the QKD integrated circuit 701. The respective current sources 763 of the respective single photon sources 736 to 739 of the QKD integrated circuit 701 perform the actual adjustment of the photon density of the light emission of the single photon sources 736 to 739 of the QKD integrated circuit 701 . The respective current sources 763 of the respective single photon sources 736 to 739 of the integrated QKD circuit 701 perform this setting as a function of control data transmitted by the control device 429 of the integrated QKD circuit 701 by means of the respective control line of the control lines 731 to 734 of the integrated QKD circuit 701 the single photon sources 736-739.

The microcontroller core 716 of the QKD integrated circuit 701 controls the driver 729 of the QKD integrated circuit 701, preferably via the internal data bus 702 of the QKD integrated circuit 701. The microcontroller core 716 of the QKD integrated circuit 701 preferably exchanges with the driver 729 of the QKD integrated -Circuit 701 data over the internal data bus 702 of the integrated circuit 701 QKD.

A first control line 731 connects the control device 729 to the first current source 763 of the first single-photon source 736 of the integrated QKD circuit 701. The control device 729 controls the first current source 763 of the first single-photon source 736 of the integrated QKD circuit 701 via the first control line 731 electric current through the first current source 763 of the first single photon source 736 of the integrated QKD circuit 701. The control device 729 thus controls the electric current through the first illuminant 764 of the first single photon source 736 of the integrated QKD circuit 701 by means of the first control line 731. In this way controls the control device 729 of the integrated QKD circuit 701 the polarized first illuminant 764 of the first single photon source 736 of the integrated QKD circuit 701. The first illuminant 764 of the first single photon source 736 emits either directly polarized single photons or emits single photons of different polarizations, the polarization filters or polarizing ones then polarize optical functional means in the subsequent beam path. The first control line 731 preferably also reports status data and/or measured values and/or other status parameters in digital or analog form to the first single-photon source 736 of the integrated QKD circuit 701 and its sub-devices via the control device 729 for the single-photon sources 736, 737, 738, 739 of the QKD integrated circuit 701 back to the microcontroller core 716 of the QKD integrated circuit 701. The first control line 731 can include one or more digital or analog signal lines.
A second control line 732 connects the control device 729 of the integrated QKD circuit 701 to the second current source 763 of the second single-photon source 737 of the integrated QKD circuit 701. Via the second control line 732 for the second current source 763 of the second single-photon source 737, the control device 729 controls the electric Current through the second current source 763 of the second single-photon source 737. The control device 729 thus controls the electric current through the second illuminant 764 of the second single-photon source 737 by means of the second control line 732. Open In this way, the control device 729 of the QKD integrated circuit 701 controls the polarized second illuminant 764 of the second single photon source 737 of the QKD integrated circuit 701. The second illuminant 764 of the second single photon source 737 of the QKD integrated circuit 701 either emits directly polarized single photons or radiates Individual photons of different polarizations, which then polarize the polarization filter or polarizing optical function means in the subsequent beam path. Preferably, the second control line 732 of the QKD integrated circuit 701 also reports status data and/or measured values and/or other status parameters in digital or analog form to the second single-photon source 737 of the QKD integrated circuit 701 and its sub-devices via the control device 729 for the single-photon sources 736 , 737, 738, 739 of the QKD integrated circuit 701 back to the microcontroller core 716 of the QKD integrated circuit 701. The second control line 732 of the QKD integrated circuit 701 may comprise one or more digital or analog signal lines.
A third control line 733 connects the control device 729 to the third current source 763 of the third single-photon source 738 of the integrated QKD circuit 701. Via the third control line 733 for the third current source 763 of the third single-photon source 738, the control device 729 of the integrated QKD circuit 701 controls the electric Current through the third current source 763 of the third single photon source 738 of the integrated QKD circuit 701. The control device 729 of the integrated QKD circuit 701 thus controls the electric current through the third illuminant 764 of the third single photon source 738 of the integrated QKD circuit 701 by means of the third control line 733. In this way, the control device 729 of the integrated QKD circuit 701 controls the polarized third illuminant 764 of the third single-photon source 738 of the integrated QKD circuit 701. The third illuminant 764 of the third single-photon source 738 emits either directly polarized single photons or emits single photons of different polarizations which then polarize the polarization filter or polarizing optical function means in the subsequent beam path. The third control line 733 preferably also reports status data and/or measured values and/or other status parameters in digital or analog form to the third single-photon source 738 and its sub-devices via the control device 729 of the integrated QKD circuit 701 for the single-photon sources 736, 737, 738, 739 of the QKD integrated circuit 701 back to the microcontroller core 716 of the QKD integrated circuit 701. The third control line 733 of the QKD integrated circuit 701 may comprise one or more digital or analog signal lines.
A fourth control line 734 connects the driving device 729 of the QKD integrated circuit 701 to the fourth current source 763 of the fourth single photon source 739 of the QKD integrated circuit 701. Via the fourth control line 734 for the fourth current source 763 of the fourth single photon source 739 of the QKD integrated circuit 701 the driver 729 of the QKD integrated circuit 701 controls the electric current through the fourth power source 763 of the fourth single photon source 739 of the QKD integrated circuit 701. The driver 729 of the QKD integrated circuit 701 thus controls the electric current through the fourth illuminant 764 of the fourth Single photon source 739 of the QKD integrated circuit 701 by means of the fourth control line 734. In this way, the driver 729 of the QKD integrated circuit 701 controls the polarized fourth illuminant 764 of the fourth single photon source 739 of the QKD integrated circuit 701. The fourth illuminant 764 of the fourth single photon source 739 either emits directly polarized single photons or emits single photons of different polarizations, which then polarize the polarization filters or polarizing optical functional means in the subsequent beam path. The fourth control line 734 preferably also reports status data and/or measured values and/or other status parameters in digital or analog form to the fourth single-photon source 739 of the QKD integrated circuit 701 and its sub-devices via the control device 729 of the QKD integrated circuit 701 for the single-photon sources 736, 737, 738, 739 of the QKD integrated circuit 701 back to the microcontroller core 716 of the QKD integrated circuit 701. The fourth control line 735 may include one or more digital or analog signal lines.

In the example of 7 The QKD integrated circuit 701 has, for example, four single photon sources 736 to 739. The QKD integrated circuit 701 preferably includes n single photon sources which, depending on the control by the control device 729 of the QKD integrated circuit 701, transmit single photons by means of suitable optical means into the QKD -Inject coupling beam 452. Typically, each of these n single photon sources of the integrated QKD circuit 701 feeds the single photons emitted by it with a different polarization direction into the QKD coupling beam 452 by means of these optical aids. The single photon sources of the QKD integrated circuit 701 can typically be numbered from 1 to n with a single photon source number k. The direction of polarization of the single photons of a single photon source of the integrated QKD switch Circuit 701 with single photon source number k is preferably rotated 360°*(k-1)/(2*n) with respect to the direction of polarization of the single photons of a single photon source of QKD integrated circuit 701 with single photon source number 1. The number n of the single photon sources of the integrated QKD circuit 701 is particularly preferably a power of 2. It should be considered preferable that n=2 ^(m−1) with m∈ℕ. The corresponding single photon receiving device 601 should then have a corresponding number of single photon detectors 677 to 680 (see for example 6 for example n=4). In this respect, the example is 7 with n=4 only as an example.
The QKD integrated circuit 701 can have n single photon sources with n being a positive integer greater than 1. This general case is in the 7 not shown. However, a technically competent person will be able to easily rework this case based on the examples presented here. In such a case, the integrated QKD circuit 701 therefore also includes an nth control line. The nth control line connects the drive device 729 to the nth current source 763 of the nth single photon source. The control device 729 controls the electric current through the nth current source 763 of the nth single photon source of the integrated QKD circuit 701 via the nth control line for the nth current source 763 of the nth single photon source integrated QKD circuit 701 the electric current through the nth illuminant 764 of the nth single photon source of the integrated QKD circuit 701 by means of the nth control line. In this way, the driver 729 of the QKD integrated circuit 701 controls the polarized nth illuminant 464 of the nth single photon source of the QKD integrated circuit 701. The nth illuminant 764 of the nth single photon source of the QKD integrated circuit 701 radiates either directly polarized single photons or emits single photons of different polarizations, which then polarize the polarization filter or polarizing optical functional means in the subsequent beam path. The nth control line 735 preferably also reports status data and/or measured values and/or other status parameters in digital or analog form to the nth single-photon source of the QKD integrated circuit 701 and its sub-devices via the control device 729 of the QKD integrated circuit 701 for the single photon sources of the QKD integrated circuit 701 back to the microcontroller core 716 of the QKD integrated circuit 701. The nth control line of the QKD integrated circuit 701 may comprise one or more digital or analog signal lines.

If the QKD integrated circuit 701 comprises n single photon sources, an nth control line of the QKD integrated circuit 701 connects the control device 729 of the QKD integrated circuit 701 to the nth current source 763 of the nth single photon source of the QKD integrated circuit 701 Via the nth control line for the nth current source 763 of the nth single photon source of the integrated QKD circuit 701, the driving device 729 controls the electrical current through the nth current source 763 of the nth single photon source of the integrated QKD circuit 701 The control device 729 of the QKD integrated circuit 701 thus controls the electrical current through the nth luminous means 764 of the nth single photon source of the QKD integrated circuit 701 by means of the nth control line. In this way, the control device 729 controls the polarized nth illuminant 764 of the nth single photon source of the integrated QKD circuit 701. The nth illuminant 764 of the nth single photon source emits either directly polarized single photons or emits single photons of different polarizations, then polarize the polarization filter or polarizing optical functional means in the subsequent beam path. The nth control line of the integrated QKD circuit 701 preferably also reports status data and/or measured values and/or other status parameters in digital or analog form to the nth single photon source of the integrated QKD circuit 701 and its sub-devices via the control device 729 for the single photon sources with k=1 to n back to the microcontroller core 716 of the QKD integrated circuit 701. The nth control line of the QKD integrated circuit 701 may comprise one or more digital or analog signal lines.

The first single photon source 736 of the QKD integrated circuit 701 typically comprises a polarized first illuminant 764 and a first current source 763. The first illuminant 746 is preferably a silicon PN light emitting diode or a SPAD diode used as the illuminant. The first current source 763 of the QKD integrated circuit 701 energizes the first illuminant 764 of the first single photon source 736 of the QKD integrated circuit 701 so briefly and with such low energy that the first illuminant 764 of the first single photon source 736 of the QKD integrated circuit 701 is essentially only emits single, spatially and temporally separated photons. Preferably, this energizing of the first illuminant 764 of the first single photon source 736 of the integrated QKD circuit 701 by the first current source 763 of the first single photon source 736 is shorter than 1 ns, better shorter than 500 ps, better shorter than 200 ps, better shorter than 100 ps, better shorter than 50 ps , Better than 20ps, Better than 10ps, Better than 5ps, Better than 2ps, Better than 1ps. This energizing of the first illuminant 764 of the first single photon source 736 of the integrated QKD circuit 701 by the first current source 763 of the first single photon source 736 of the integrated QKD circuit 701 is very particularly preferably shorter than 10 ps.

The second single photon source 737 of the QKD integrated circuit 701 typically comprises a polarized second illuminant 764 and a second current source 763. The second illuminant 746 of the QKD integrated circuit 701 is preferably a silicon PN light emitting diode or a SPAD diode used as the illuminant becomes. The second current source 763 energizes the second illuminant 764 of the second single-photon source 737 of the integrated QKD circuit 701 so briefly and with such low energy that the second illuminant 764 of the second single-photon source 737 of the integrated QKD circuit 701 is essentially only single, spatially and temporally emits separate single photons. This energizing of the second illuminant 764 of the second single-photon source 737 of the integrated QKD circuit 701 by the second current source 763 of the second single-photon source 737 of the integrated QKD circuit 701 is preferably shorter than 1 ns, preferably shorter than 500 ps, preferably shorter than 200 ps, preferably shorter than 100ps, better than 50ps, better than 20ps, better than 10ps, better than 5ps, better than 2ps, better than 1ps. This energizing of the second illuminant 764 of the second single photon source 737 of the integrated QKD circuit 701 by the second current source 763 of the second single photon source 737 of the integrated QKD circuit 701 is very particularly preferably shorter than 10 ps.

The third single photon source 738 typically includes a polarized third illuminant 764 and a third current source 763. The third illuminant 746 of the QKD integrated circuit 701 is preferably a silicon PN light emitting diode or a SPAD diode used as the illuminant. The third current source 763 energizes the third illuminant 764 of the third single-photon source 738 of the integrated QKD circuit 701 so briefly and with such low energy that the third illuminant 764 of the third single-photon source 738 of the integrated QKD circuit 701 is essentially only single, spatially and temporally emits separate single photons. This energizing of the third illuminant 764 of the third single photon source 738 of the integrated QKD circuit 701 by the third current source 763 of the third single photon source 738 of the integrated QKD circuit 701 is preferably shorter than 1 ns, preferably shorter than 500 ps, preferably shorter than 200 ps, preferably shorter than 100ps, better than 50ps, better than 20ps, better than 10ps, better than 5ps, better than 2ps, better than 1ps. This energizing of the third illuminant 764 of the third single photon source 738 of the integrated QKD circuit 701 by the third current source 763 of the third single photon source 738 of the integrated QKD circuit 701 is very particularly preferably shorter than 10 ps.

The fourth single photon source 739 of the QKD integrated circuit 701 typically comprises a polarized fourth illuminant 764 and a fourth current source 763. The fourth illuminant 746 of the QKD integrated circuit 701 is preferably a silicon PN light emitting diode or a SPAD diode used as the illuminant becomes. The fourth current source 763 energizes the fourth illuminant 764 of the fourth single-photon source 739 of the integrated QKD circuit 701 so briefly and with such low energy that the fourth illuminant 764 of the fourth single-photon source 739 of the integrated QKD circuit 701 essentially only single, spatially and temporally emits separate single photons. This energizing of the fourth illuminant 764 of the fourth single-photon source 739 of the integrated QKD circuit 701 by the fourth current source 763 of the fourth single-photon source 739 is preferably shorter than 1 ns, preferably shorter than 500 ps, preferably shorter than 200 ps, preferably shorter than 100 ps, preferably shorter than 50 ps , better than 20ps, better than 10ps, better than 5ps, better than 2ps, better than 1ps. This energizing of the fourth illuminant 764 of the fourth single photon source 739 of the integrated QKD circuit 701 by the fourth current source 763 of the fourth single photon source 739 of the integrated QKD circuit 701 is very particularly preferably shorter than 10 ps.

In the case, not shown in the figures, of n single photon sources as part of the QKD integrated circuit 701, the nth single photon source of the QKD integrated circuit 701 typically comprises a polarized nth illuminant 764 and an nth current source 763. The nth Current source 763 energizes the nth illuminant 764 of the nth single-photon source of the QKD integrated circuit 701 preferably so briefly and with such low energy that the nth illuminant 764 of the nth single-photon source of the integrated QKD circuit 701 essentially only emits individual, spatially and temporally separated single photons. This energizing of the nth illuminant 764 of the nth single photon source of the QKD integrated circuit 701 by the nth current source 763 of the nth single photon source of the QKD integrated circuit 701 is preferably shorter than 1ns, better shorter than 500ps, better free Zer than 200ps, better than 100ps, better than 50ps, better than 20ps, better than 10ps, better than 5ps, better than 2ps, better than 1ps. This energizing of the nth illuminant 764 of the nth single photon source of the integrated QKD circuit 701 by the nth current source 763 of the nth single photon source of the integrated QKD circuit 701 is very particularly preferably shorter than 10 ps.

In the example of 4 and 5 An optical sub-device of the single-photon transmission device 401 or 471 combines the respective single-photon streams of the single-photon sources 436 to 440 to form a QKD coupling beam 452 of polarization-modulated single photons. This optics is in the example 7 not marked. However, a person skilled in the art will be able to easily implement this function using means from the prior art.

A much smaller problem are different single photon densities of the single photon sources 736 to 739 of the integrated QKD circuit 701, since these are manufactured in one piece in the same semiconductor circuit manufacturing process. Nevertheless, the QKD integrated circuit 701 shows a photodetector 751 analogous to the photodetector 451 of FIG 4 . A person skilled in the art will provide the corresponding optical device parts in such a way that this photodetector 751 has a function analogous to that of the photodetector 451 of FIG 4 can fulfill. The integrated QKD circuit 701 preferably comprises an actuator controller for an actuator which the microcontroller core 716 of the integrated QKD circuit 701 can control using this actuator controller via the internal data bus 702 in order to form a beam splitter or mirror (e.g. 448 in 4 ) from the transmitter beam path when the calibration of the photon rates of the single photon sources 736 through 739 of the QKD integrated circuit 701 is complete. For example, the microcontroller core 716 of the QKD integrated circuit 701 preferably uses the photodetector 751 to determine the photon density in the beam path ( 4 Reference numeral 449) of the single photon transmission device 401 in 4 to determine. A potential problem is that the transmitted polarization of the single photons must not be linked to the temporal density of the single photons, i.e. the number of single photons per second. Therefore, the microcontroller core 716 of the QKD integrated circuit 701 adds the mirror ( 4 reference numeral 448) in the beam path ( 4 reference numeral 446) of the single photon transmission device ( 4 reference numeral 401). The microcontroller core 716 then uses the photodetector 751 to detect the single photon density in the beam path of the single photon transmission device ( 4 reference number 401). In this case, the microcontroller core 716 always operates a single photon source of the single photon sources 736 to 736 of the integrated QKD circuit 701 and detects a single photon density associated with this single photon source. A received signal 753 of the photodetector 751 connects the photodetector 751 of the integrated QKD circuit 701 to an evaluation circuit 754 of the photodetector 751. The evaluation circuit 754 of the integrated QKD circuit 701 is preferably connected to the microcontroller core 716 via the internal data bus 702 of the integrated QKD circuit 701 of the QKD integrated circuit 701 is coupled. The evaluation circuit 754 of the photodetector 751 detects the values of the received signal 753 of the photodetector 751, which are generated by the individual photons in the beam path of the individual photon receiving device ( 4 reference numeral 401) from the first beam splitter or mirror ( 4 reference numeral 448) to the photodetector 751 of the integrated QKD circuit 701, converts these preferably into digitized values, for example with the aid of an analog-to-digital converter ADC of the integrated QKD circuit 701, and conveys the measured value recorded in this way relating to the individual photons in the beam path the single photon receiving device ( 4 reference numeral 401) from the first beam splitter or mirror ( 4 Reference numeral 448) to the photodetector 751 of the QKD integrated circuit 701 to the microcontroller core 716 of the QKD integrated circuit 701 via the internal data bus 702 of the QKD integrated circuit 701. The microcontroller core 716 of the QKD integrated circuit 701 then controls the current sources 763 of the respective single photon sources 736 to 739 of the QKD integrated circuit 701 so that the single photon density of a single photon source of the single photon sources 736 to 739 of the QKD integrated circuit 701 firstly lies within a designated single photon density range value interval and secondly by no more than 10%, better than 5%, better than 2%, better than 1%, better than 0.5%, better than 0.2%, better than 0, 1%, better 0.05%, better 0.02%, better 0.01% from the single photon densities of all other single photon sources of the single photon sources 736 to 739 of the integrated QKD circuit 701 differs. After the single photon densities of the various single photon sources of the QKD integrated circuit 701 are calibrated, the microcontroller core 716 preferably removes the mirror (reference numeral 446 in 4 ) again from the beam path (reference number 449 in 4 ) the single photon transmitting device (reference numeral 401 in 4 ), which then separates the individual photons in the beam path (reference number 449 in 4 ) of the single photon transmitting device (reference number 401 in 4 ) radiates as a QKD coupling beam 452 to a receiver, e.g.

Preferably, the QKD integrated circuit 701 is part of a single photon transmission device such as the 4 and 5 show.

In the case of a key, the QKD integrated circuit 701 preferably includes circuits to support a human-machine interface 765 (HMI interface with HMI=Human Machine Interface) to enable communication between the QKD integrated circuit 701 on the one hand and the single-photon receiving device 601 of the OKD-coupled device to be controlled (e.g. a car) with a person operating the system. As an example, the document presented here assumes a car key as the single photon transmitting device 401 and an example car as the device to be controlled with a single photon receiving device 601 . The single photon transmitter device 401 of the car key in this sense comprises a QKD integrated circuit 701. For the purposes of the present specification, the support circuit of the QKD integrated circuit 701 for the HMI interface (HMI=Human Machine Interface) 765 connects a support circuit 766 for an input terminal 466 for interaction with a user with the microcontroller core 716 of the QKD integrated circuit 701 via the internal data bus 702 of the QKD integrated circuit 701. The support circuit 766 of the input terminal 466 of the QKD integrated circuit 701 can, for example in the case of a car key, preferably the Activation and reading of one or more buttons 467 or one or more switches 467 or other mechanical input devices for manual inputs by means of a support circuit 767 for reading and/or activating such buttons and switches. The support circuit 766 for the input terminal 466 of the integrated QKD circuit 701 can preferably include a support circuit 768 for operating one or more biometric sensors 468, for example in the case of a car key. The biometric sensors 468 supported by this support circuit 768 can be, for example, one or more fingerprint sensors and/or one or more cameras and/or one or more microphones and/or one or more speech analysis devices and/or one or more speaker recognition devices and/or or one or more facial recognition devices and/or one or more retina scanners or the like. The support circuit 766 for the input terminal 466 of the QKD integrated circuit 701, for example in the case of a car key, can preferably act as a support circuit 770 for one or more actuators 470 for feedback from the QKD integrated circuit 701 to the user. An actuator 470 that can be controlled and/or read out by this support circuit 770 within the meaning of the document presented here can be, for example, a mechanical vibration transmitter or a loudspeaker or a beeper, another sound transducer or a heater or the like. The actuator 470 is typically used to transmit a mechanical signal from the QKD integrated circuit 701 to the user. But it can also serve their mechanical purposes. In addition to this mechanical/thermal feedback, the support circuit 766 of the integrated QKD circuit 701 for the input terminal 466 of the integrated QKD circuit 701, for example in the case of a car key, can preferably support circuits 769 for one or more optical signaling means 469, for example in the form of an optical output element for signaling the QKD integrated circuit 701 to a user. The visual signaling means 469 supported by this support circuit 769 may comprise one or more screens and/or one or more illuminants and/or one or more means that change their absorption properties, such as LCD displays or e-ink displays. Preferably, the QKD integrated circuit 701 comprises a support circuit 1709 for one or more means 1409 for identifying a person using the single photon transmission device 401 comprising the QKD integrated circuit 701 . For example, the support circuit 1709 for the means 1409 for identifying a person using the single-photon transmission device 401 can be a circuit for controlling a SIM card (SIM=Subscriber Identification Module). If appropriate, the single-photon transmission device 401 can therefore be a mobile phone or a smartphone with the integrated QKD circuit 701 . One of the wireless data interfaces of the integrated QKD circuit 701 can thus be, for example, a mobile radio data interface in a mobile radio network or a WLAN network or the like. It can therefore also be useful, among other things, if the integrated QKD circuit 701 can set up an authentication data channel to the server of a service provider, for example an automobile manufacturer, via this interface.

The QKD integrated circuit 701 preferably includes one or more wireless and/or wired data interfaces 726. The data transmission channel 428 to a single photon transmission device 401 can be wired or wireless. In the case of a car, the communication channel 428 is preferably wireless. The data transmission channel 428 is then typically an electromagnetic data signal which the integrated circuit QKD 701 exchanges with a single-photon transmission device 401 in a wireless manner. In the case of a car with the integrated QKD circuit 701, the car exchanges data with the single-photon transmission device 401, preferably by means of a wireless data interface 726 and its antenna 727. In the case of a wired data transmission channel, the data transmission channel is then typically an electromagnetic data signal which the integrated QKD circuit 701 exchanges with the single-photon transmission device 401 in a wired manner. In this case of a wireless data interface, the QKD integrated circuit 701 typically comprises one or more respective antennas 727 of the respective wireless interface 726.

The integrated QKD circuit 701 preferably includes an evaluation circuit 772 for the received signals 773 to 776 of the individual photon detectors 777 to 780 for differently polarized individual photons. Evaluation circuit 772 receives measured values in the form of signals from single photon detectors 777 to 780 for differently polarized single photons via said received signals 773 to 776. Evaluation circuit 772 processes these measured values and makes the result of this processing available to microcontroller core 716 via internal data bus 702.

The QKD integrated circuit 701 preferably includes a single photon detector system 1703 for receiving a polarization modulated single photon signal. The single photon detector system 1703 preferably comprises n receiving channels for single photons. The receiving channels each detect the individual photons with a rotation of the plane of polarization of (k−1)/(2*n)*360° in relation to a basic direction. The receiving channels can be numbered consecutively starting with 1. where k is the number of the receiving channel. Here n is the number of receiving channels and k is a number with 1≤k≤n. The single photon detector system provides the microcontroller core 716 with data on the received single photons, this data preferably including the direction of polarization and the period or time of reception. The exemplary single photon detector system 1703 preferably comprises a first single photon detector 777 for horizontally polarized single photons and a second single photon detector 778 for vertically polarized single photons and a third single photon detector 779 for +45° polarized single photons and a fourth single photon detector 780 for -45° polarized single photons. The proposed single photon detector system 1703 is preferably a single photon detector system 1703 for polarization modulated single photons. The single photon detector system 1703 preferably comprises n receiving channels for single photons. The receiving channels each detect the individual photons with a rotation of the plane of polarization of (k−1)/(2*n)*360° in relation to a basic direction. The receiving channels can be numbered consecutively starting with 1. where k is the number of the receiving channel. Here n is the number of receiving channels and k is a number with 1≤k≤n. The single photon detector system provides the microcontroller core 716 with data on the received single photons, this data preferably including the direction of polarization and the period or time of reception.

The QKD integrated circuit 701 preferably comprises a first single photon detector 777 for horizontally polarized single photons, for example a first SPAD diode. The document presented here assumes that, in the case of a SPAD diode, the first single photon detector 777 includes the drive circuit and evaluation circuit for operating the SPAD diode. The semiconductor substrate of the microcontroller core 716 preferably also includes the first SPAD diode with the necessary operating circuits and the connection to a supply voltage and thus the first single photon detector 777. The first single photon detector for horizontally polarized single photons 777 is integrated into the integrated QKD circuit 701 in such a way that that the first single photon detector for horizontally polarized single photons 777 essentially only horizontally polarized single photons of the QKD coupling beam 452, which is emitted by a single photon transmitting device 401, for example a car key, is detected. The design of the first single photon detector 777 can already ensure, for example, that the first single photon detector 777 for horizontally polarized single photons essentially only detects horizontally polarized single photons of the QKD coupling beam 452 . Such a construction can, for example, provide a first micro-optical grating as a polarization device that only lets through single photons of a horizontal polarization direction. However, such a construction can also include, for example, the second polarizing beam splitter 684 as a micro-integrated micro-optical functional element and the second single-photon detector 778 . The first Single photon detector 777 converts the received single photons of the third horizontally polarized single photon stream into a first received signal 773 of the first single photon detector 777 for horizontally polarized single photons 773. The first single photon detector 777 therefore preferably essentially only converts the received horizontally polarized single photons into the first received signal 773 of the first single photon detector 777 for horizontally polarized single photons. A first received signal 773 from the first single photon detector 777 for horizontally polarized single photons 777 signals the evaluation circuit 772 that single photons have been received.

The QKD integrated circuit 701 preferably comprises a second single photon detector 778 for vertically polarized single photons, for example a second SPAD diode. The document presented here assumes that, in the case of a SPAD diode, the second single photon detector 778 includes the drive circuit and evaluation circuit for operating the SPAD diode. The semiconductor substrate of the microcontroller core 716 preferably also includes the second SPAD diode with the necessary operating circuits and the connection to a supply voltage and thus the second single photon detector 778. The second single photon detector for vertically polarized single photons 778 is preferably integrated into the integrated QKD circuit 701 in such a way that that the second single photon detector for vertically polarized single photons 778 essentially only detects vertically polarized single photons of the QKD coupled beam 452 . For example, the construction of the second single photon detector 778 can already ensure that the second single photon detector for vertically polarized single photons 778 essentially only detects vertically polarized single photons of the QKD coupling beam 452 . Such a construction can, for example, provide a second micro-optical grating as a polarization device that only lets through single photons of a vertical polarization direction. However, such a construction can also include, for example, the second polarizing beam splitter 784 as a micro-integrated micro-optical functional element and the first single-photon detector 777 . The second single photon detector 778 converts the received single photons of the fourth horizontally polarized single photon stream 786 into a second received signal 774 of the second single photon detector 778 for vertically polarized single photons. The second single photon detector 778 thus preferably converts essentially only the received vertically polarized single photons into the second received signal 774 of the second single photon detector 778 for vertically polarized single photons. A second received signal 774 from the second single photon detector 778 for vertically polarized single photons 778 signals the evaluation circuit 772 that single photons have been received.
The integrated QKD circuit 701 preferably comprises a third single photon detector 779 for +45° polarized single photons, for example a third SPAD diode. The document presented here assumes that, in the case of a SPAD diode, the third single photon detector 778 includes the drive circuit and evaluation circuit for operating the SPAD diode. The semiconductor substrate of the microcontroller core 716 preferably also includes the third SPAD diode and thus the third single photon detector 779. The third single photon detector for +45° polarized single photons 779 is preferably integrated into the single photon receiving device 701 in such a way that the third single photon detector for +45° polarized single photons 779 essentially only +45° polarized single photons of the OKD coupling beam 452 are detected. The construction of the third single photon detector 779 can already ensure, for example, that the third single photon detector for horizontally polarized single photons 779 essentially only detects +45° polarized single photons of the OKD coupling beam 452 . Such a construction can, for example, provide a third +45° oriented micro-optical grating as a polarization device on the surface of a third SPAD diode, ie at its light entry port, which only allows single photons of a +45° oriented polarization direction to pass. However, such a construction can also include, for example, the third polarizing beam splitter 690 as a micro-integrated micro-optical functional element and the fourth single-photon detector 780 . The third single photon detector 779 converts the received single photons of the fifth +45° polarized single photon stream 1605 into a third received signal 775 of the third single photon detector 779 for +45° polarized single photons 775. The third single photon detector 779 therefore preferably essentially only converts the received +45° polarized single photons into the third received signal 775 of the third single photon detector 779 for +45° polarized single photons. A third received signal 775 from the third single photon detector 779 for +45° polarized single photons 779 signals the evaluation circuit 772 that single photons have been received.
The integrated QKD circuit 701 preferably comprises a fourth single photon detector 780 for -45° polarized single photons, for example a fourth SPAD diode. The document presented here assumes that, in the case of a SPAD diode, the fourth single photon detector 779 includes the drive circuit and evaluation circuit for operating the SPAD diode. The semiconductor substrate of the microcontroller core 716 preferably also includes the fourth SPAD diode and thus the fourth individual photon detector 780. The fourth single photon detector for -45° polarized single photons 780 is preferably integrated into the integrated QKD circuit 701 in such a way that the fourth single photon detector for -45° polarized single photons 780 essentially only detects -45° polarized single photons of the OKD coupling beam 452 . The design of the fourth single photon detector 780 can already ensure, for example, that the third single photon detector for horizontally polarized single photons 780 essentially only detects -45° polarized single photons of the QKD coupled beam 452 . Such a construction can, for example, provide a third -45° oriented micro-optical grating as a polarization device on the surface of a fourth SPAD diode, ie at its light entry port, which only allows single photons of a -45° oriented polarization direction to pass. However, such a construction can also include, for example, the third polarizing beam splitter 790 as a micro-integrated micro-optical functional element and the third single-photon detector 779 . The fourth single photon detector 780 converts the received single photons of the sixth +45° polarized single photon stream 791 into a fourth received signal 780 of the fourth single photon detector 780 for -45° polarized single photons 776. The fourth single photon detector 780 therefore preferably converts essentially only the received -45° polarized single photons into the fourth received signal 776 of the fourth single photon detector 780 for -45° polarized single photons. A fourth received signal 776 of the fourth single photon detector 780 for -45° polarized single photons 780 signals the evaluation circuit 772 that single photons have been received.
The QKD integrated circuit 701 preferably includes a supply voltage line 743. The supply voltage line 743 connects the respective loads within the QKD integrated circuit 701 to one or more power supply or Vcc circuits 763 with voltage regulators that supply the operating voltages for the microcontroller system of the integrated QKD circuit 701 and the QKD transmitter of the QKD integrated circuit 701 provide. The supply voltage line 743 can also comprise a number of lines which, for example, each connect a consumer of electrical energy, i.e. a sub-device of the integrated QKD circuit 701, to a voltage regulator or a current source of the one or more power supply or Vcc circuits 723.
The QKD integrated circuit 701 is preferably coupled to optional receiving optics 681 for the QKD coupled beam 452 . The optional receiving optics 681 focuses the incoming single photons of the single photon beam of the QKD coupling beam 452 onto the single photon detectors 777, 778, 779, 780 of the integrated QKD circuit 701. Either the single photon detectors 777, 778, 779, 780 are sensitive to different polarization directions or the optional Receiving optics 681 focuses the incoming single photons of the single photon beam of the QKD coupling beam 452 onto different single photon detectors 777, 778, 779, 780 depending on the direction of polarization of the incoming single photons.
If alignment of the single photon transmitter device 401 with respect to the single photon receiver device 601 is necessary, an integrated QKD circuit 701 of the single photon receiver device 601 includes, for example, an alignment receiver 799. The receiver 1701 of the alignment receiver 799 detects the laser pointer beam 462 for aligning the single photon transmitter device 401, 471 , e.g of the alignment receiver 799 via the optical system 1602 of the alignment receiver 799 receives sufficient light of the laser pointer beam 462 to align the single photon transmitting device 471, for example a car key, on the integrated QKD circuit 701 of the single photon receiving device 601. Only when this is the case does the microcontroller core 716 preferably start generating a common quantum key for the single-photon transmitting device 471, for example the car key 471, and the single-photon receiving device 601 of the car 802. To this end, the microcontroller core 716 of the integrated QKD circuit 701 signals the single-photon receiving device 701 dem Microcontroller core 716 of the integrated QKD circuit 701 of the single-photon transmission device 471, for example the car key 471, for example via a wireless data connection 726, 727,428, 727, 726, that the agreement of a quantum key can start. The microcontroller core 716 of the integrated QKD circuit 701 of the single-photon transmission device 471, for example the car key 471, then causes the single-photon transmission device 1707 of the integrated QKD circuit 701 of the single-photon transmission device 471 to generate a polarization-modulated stream of single photons as a QKD coupling beam 452, wherein the microcontroller core 716 of the integrated QKD circuit 701 of the single photon transmission device 471, for example the car key, preferably as a modulation signal of the polarization direction of the transmitted single photons a random number of its uses at least one quantum process-based generator for true random numbers (English: Quantum Random Number Generator: QRNG) 715 . The QKD integrated circuit 701 of the single photon receiving device 601 of the other device, for example a car, receives this polarization-modulated single photon data stream of the QKD coupling beam 452. For example, the QKD integrated circuit 701 of the single photon receiving device 601 can use an exemplary locking device 694 of a car as a car key 401 or 471 control or influence. The microcontroller core 716 of the single photon receiving device 601 exchanges in the exemplary application of a door lock for opening a door 804 or another opening of a car with an integrated QKD circuit 701 of the single photon transmitting device 401 or 471, for example a car key 401 or 471, an encryption code by means of a QKD procedure tap-proof. After the QKD integrated circuit 701 of the single photon transmitting device 401 of the car key 401 or 471 a secure wireless connection 428 between the integrated QKD circuit 701 of the single photon transmitting device 401, i.e. the car key, and single photon receiving device 601, i.e. the car, by generating a shared secret quantum key has established, the microcontroller core 716 of the integrated QKD circuit 701 of the single-photon transmission device 401 or 471, i.e. the car key 401 or 471, can exchange authentication data with the microcontroller core 716 of the integrated QKD circuit 701 of the single-photon reception device 601 or with a computer unit that is superordinate to the microcontroller core 716. If this computer unit 697, which is superordinate to the microcontroller core 716, or the microcontroller core 716 of the integrated QKD circuit 701 of the single-photon receiving device 601, considers the authentication data to be trustworthy after comparison with a database, the microcontroller core 716 of the integrated QKD circuit 701 of the single-photon receiving device 601 initiates this, for example by means of a suitable Signaling via the internal data bus 702 of the QKD integrated circuit 701 of the single photon receiving device 601, the controller 792 of the QKD integrated circuit 701 of the single photon receiving device 601 for driving the exemplary closing device 694 and the control line 693 for driving the exemplary closing device 694 the exemplary closing device 694 of the car, to open, unlock, lock or close the door or other opening of the car.
Also, the QKD integrated circuit 701 of the single photon receiving device 601 may include a controller 792 for driving the example closure device 694 . By means of a control line 793 for driving the exemplary locking device 694, the controller 792 of the integrated QKD circuit 701 for driving the exemplary locking device 694 exchanges control data and/or status data with the drive of the exemplary locking device 694 and provides these for the microcontroller core 716 of the integrated QKD circuit 701 via the internal data bus 702 of the integrated QKD circuit 701 this available. Using the control line 793 of the QKD integrated circuit 701 for driving the exemplary closing device 694, the controller 792 of the integrated QKD circuit 701 for driving the exemplary closing device 694 exchanges control data and/or status data with the drive of the exemplary closing device 694.
The integrated QKD circuit 701 of the single photon receiving device 601 preferably comprises one or more data connections 796 from one or more data interfaces 795 of the integrated QKD circuit 701 of the single photon receiving device 601 to a higher-level computer unit 697 via a data bus 796 of the integrated QKD circuit 701 of the other device, for example the car. It can be, for example, a CAN data bus or a CAN FD data bus or a PSI5 data bus or a DSI3 data bus or an I ² C bus or an Ethernet connection or an optical data connection, for example an optical waveguide, or an encrypted radio connection, such as WLAN or Bluetooth, or the like. The superordinate computer unit 697 can be, for example, any computer unit of the motor vehicle. This higher-order processing unit usually controls the actions of the microcontroller core 716 of the integrated QKD circuit 701 of the single-photon receiving device 601 of the other device, for example the car.
The QKD integrated circuit 701 typically includes a power supply 756 for a laser pointer laser diode 459. The laser pointer laser diode 459 typically emits a laser pointer beam 462 when energized. A user may prefer the laser pointer beam 462 for aligning the single-photon transmission device 471, for example a car key, to a single-photon reception device 601. The laser pointer beam 462 preferably has a wavelength which is different from the wavelength of the individual photons in the QKD coupled beam 452 . The single photon detectors 436 to 440 of the single photon receiving device 601 are preferably not sensitive to the wavelength of the radiation of the laser pointer beam 462 . The single photon detectors 436 to 440 of the single photon receiving device 601 are preferably through Apertures, housing and/or filters protected. Preferably, the QKD integrated circuit 701 has a controller 757 for the current source 760 of the laser pointer diode 459, which controls the value of the electrical current through the laser pointer diode 459. The microcontroller core 716 of the integrated QKD circuit 701 controls the control device 757 via the internal data bus 702, for example. The laser pointer diode 459 preferably emits visible light that is typically recognizable to a human user. This allows the user to identify and correct incorrect alignments. The current source 760 of the laser pointer diode 459 adjusts the operating current through the laser pointer diode 459 depending on the signals from the control device 757 for the current source 760 of the laser pointer diode 459 . A projection optics 461 of the laser pinter device improves the beam quality of the laser pointer beam 462 for aligning the car key.

8th shows the coupling of a single photon transmitter device 401 to a single photon receiver device 601 by means of a QKD coupling beam 452.
In the example of 8th example car key includes single photon transmitting device 401 and example car 802 includes single photon receiving device 601.
The single-photon transmission device 401 preferably comprises a QKD integrated circuit 701. The single-photon receiving device 601 preferably also comprises a QKD integrated circuit 701.
The single-photon transmission device 401 determines a first random number and a second random number by means of its preferably quantum-process-based generator for genuine random numbers (English: Quantum Random Number Generator: QRNG) 415 . The single photon transmitting device 401 transmits the first random number and the second random number by means of the QKD coupling beam of polarization-modulated single photons to the single photon receiving device 601 of the other device, i.e. here the car 802. The microcontroller core 616 of the single photon receiving device 601 of the other device, i.e. here the car 802, then encrypts the second random number with the first random number as a QKD key to a QKD-encrypted second random number. The microcontroller core 616 of the single photon receiving device 601 of the other device, ie the car 802 here, then transmits the QKD-encrypted second random number by means of a conventional data transmission channel 428 to the single photon transmitting device 401, ie the car key. Microcontroller core 416 of single-photon transmission device 401, ie of the car key, decrypts the QKD-encrypted second random number received as a test message using the first random number as QKD key to form a decrypted second random number. The microcontroller core 416 of the single-photon transmission device 401, ie the car key, compares the second random number with the decrypted second random number. If they match, the microcontroller core 416 of the single photon transmitting device 401, ie the car key, and the microcontroller core 616 of the single photon receiving device 601, ie the car 802, have successfully agreed on a common key. From this point in time onwards, the microcontroller core 416 of the single photon transmission device 401, ie the car key, and the microcontroller core 616 of the single photon reception device 601, ie the car 802, can exchange encrypted data via conventional data transmission channels 428. The microcontroller core 416 of the single-photon transmission device 401, i.e. the car key, and the microcontroller core 616 of the single-photon reception device 601, i.e. the car 802, preferably agree on a new QKD key after a specified period of time has expired in order to prevent the key from being broken. The microcontroller core 416 of the single photon transmitting device 401, i.e. the car key, and the microcontroller core 616 of the single photon receiving device 601, i.e. the car 802, preferably exchange additional authentication data, which also includes GPS data, biometric data, key numbers, data from the automobile manufacturer and/or data from service providers etc. can count. For example, the configuration of the car, such as the maximum speed and/or the maximum acceleration, or the permitted radius of action around a reference point, or the permitted area, etc., may depend on the biometric features that the car key captures. If the authentication data for actuating the locking device 694 is correct and the car key transmits a QKD-encrypted command to unlock or lock or open or close an opening of the car 802, for example a door 804, the single-photon receiving device 601 or a higher-level device executes this command of the car key out of. Finally, it should be mentioned here that the body of the car 802 preferably has an optical window 803 transparent to the QKD coupling beam 452 so that the QKD coupling beam can reach the single photon receiving device 601 with a low photon loss rate.
It is obvious that the single photon receiving device 601 can be used in the car key instead of in the car 802 if the single photon transmitting device 401 is used in the car 802 instead. This reversal is hereby fully incorporated into the disclosure presented here and pertains to the entire text of the document presented here.

9 largely corresponds to the 8th with the difference that the user now uses a laser pointer beam 462 to align the single-photon transmitting device 401, ie the car key, with the single-photon receiving device 601, ie the door lock. Only when the laser pointer beam 462 of the laser pointer device 455 of the single photon transmitting device 401, i.e. the car key, hits the alignment receiver 699 of the single photon receiving device 601, i.e. the car 802, does the microcontroller core 616 signal the single photon receiving device 601 via the conventional data transmission channel 428 Single photon transmission device 401 that the agreement of a QKD key, as in the description 8th described can start. Then, the single photon transmitting device 401 starts negotiating a common secret QKD key.

10 shows the agreement of a QKD key between a car 802 and an infrastructure device, here a charging station. 1011 . The charging station 1011 of the 10 comprises an exemplary single photon receiving device 601. The exemplary wireless communication link 428 of FIG 4 , 5 and 6 is replaced by another, now wired data transmission link 428, for example. A charging cable 1012 connects the charging station 1011 to the car 802 via a charging connector 1013.
The charging cable 1012 preferably includes a waveguide, for example a fiber optic cable, for the transmission of the QKD coupling beam 452 from the single photon transmitting device 401 of the car 802 to the single photon receiving device 601 of the charging station 1011. Furthermore, the charging cable 1012 preferably includes an electrical line for exchanging data by means of a now wired data transmission path 428 between the microcontroller core 616 of the single photon receiving device 601 of the charging station 1011 on the one hand and the microcontroller core 416 of the single photon transmitting device 401 of the car 802 on the other hand, which now here plays the role of the key for enabling access to the charging station 1011. If the data transmission path 428 is radio-supported, this line can be dispensed with. Unlike in the scenario with a car key and a car, the data transmission path 428 can now also be explicitly wire-based. In this case, the charging cable preferably includes a corresponding data line. A laser pointer beam 462 is not necessary here. Finally, the charging cable typically includes the power lines for transporting electrical energy from the charging station to the car and possibly back. Firstly, the charging connector 1013 preferably comprises several electrical power connections for the transmission of electrical energy from the charging station 1011 to the car 802. The charging connector also preferably has a connector for the data connection of the data line of the charging cable 1012 with a data line of the car to the single-photon transmission device 401 around the To be able to establish data connection 428 between the single photon transmitting device 401 of the car 802 and the single photon receiving device 601 of the position column. As soon as the data connection is established, the car exchanges a QKD key with the charging station, as described above. The charging station and car can then exchange encrypted authentication data and other data.

11 shows an example interaction between a software update device 1114 and the car 802. The software update device 1114 works as a so-called trusted server. The computer 1117 of the software update device 1114 is connected to the server of a software provider 1118 by means of a data transmission path 428 which can be wired or wireless. This server of the SW provider 1118 can be a server of an automobile manufacturer, for example. The data transmission route 428 to the server of the SW provider 1118 can run entirely or partially on the Internet. The computer 1117 of the software update device 1114 exchanges a tap-proof QKD-generated key with the server of the software provider 1118 by means of a QKD interface (eg a single-photon receiving device 601 and a single-photon transmitting device 401).
The communication between the computer 1117 of the software update device 1114 and the server of a SW provider 1118 is preferably encrypted via a data transmission path 428. The computer 1117 of the software update device 1114 and the server of a SW preferably use provider 1118 the key generated using a QKD process for encrypting this communication. The computer 1117 of the software update device 1114 uses its single photon transmission device 401 of the software update device 1114 and the single photon reception device 601 of the car 802 to generate a key for using the QKD coupling beam 428 and a method for generating a quantum key the encryption of the data transmitted between the microcontroller core 616 of the single photon receiving device 601 of the car and the computer 1117 of the software update device 1114. An optical waveguide, which is preferably part of the data transmission cable 1115, preferably leads the single photons of the QKD coupling beam 452 from the single photon transmitting device 401 of the SW update device 1114 to the single photon receiving device 601 of the car 802. A data line, which is preferably part of the data transmission transmission cable 1115 enables conventional data communication between the computer 1117 of the software update device 1114 and the microcontroller core 616 of the single photon receiving device 601 of the car 802. Typically, the computer 1117 of the SW update device requests identification data via the QKD-encrypted data channel between the Single photon receiving device 601 of the car and the single photon transmitting device. The computer 1117 of the software update device 1114 requests corresponding authentication data from the server of the software provider 1118 via the QKD-encrypted data channel on the basis of the identification data received from the car 802 . The server of the SW provider 1118 checks the received identification data. If the identification data is correct, the server of the SW provider 1118 firstly provides suitable authentication data for access to the relevant data memory of the car 802 . Secondly, the server of the SW provider 1118 provides data that the SW update device 114 is to transmit to the car 802 and transmits this using the QKD-encrypted data transmission path 428 to the memory of the computer 1117 of the software update device 1114. The computer 1117 of the software update device 1114 authenticates itself via the QKD-encrypted data line 428 between the computer 1117 of the software update device 1114 and the single photon transmission device 401 on the one hand and the microcontroller core 616 of the single photon reception device 601 of the car 802 on the other hand with the microcontroller core 616 of the single photon reception device 601 of the car 802 with the authentication data from the server of the SW provider 1118. The microcontroller 616 of the single photon receiving device 601 verifies the authentication data received in this way. If the verification result is positive, which means that the data corresponds to an expected value, the microcontroller core 616 of the single photon receiving device 601 of the car 802 signals the computer 1117 of the software update device 1114 that the data can be downloaded. The computer 1117 of the software update device 1114 then transfers the data from its memory and/or from the software provider's server 1118 to a memory in the car 802. Some of the steps described here can also be carried out by other computers in the car 802 and /or the software update device 1114 are performed. After the download is complete, one or more of the car's computers may carry out additional security checks. If all safety checks have been carried out with positive results, the car's computers use the downloaded data in whole or in part. Unplugging the 1116 software update connector from the 802 car will break the data connection and end the download.

12 shows a car 802 in which sub-devices of the car generate a QKD key via a QKD system and use it for encrypted communication in a vehicle.
The vehicle according to the proposal comprises a single-photon waveguide for the QKD coupled beam 452. The single-photon waveguide is preferably a glass fiber cable. A first sub-device of the car, for example a first control unit of the car 802, comprises, for example, a single-photon transmitting device 401. A second sub-device of the car, for example a second control unit of the car 802, comprises, for example, a single-photon receiving device 601. The single-photon waveguide ensures that the QKD coupled beam of the single photons of the single photon transmission device 401 reaches the single photon reception device 601 . A conventional data bus enables conventional communication between single photon transmitter device 401 and single photon receiver device 601. If the establishment of a common QKD key fails or the authentication of the single photon transmitter device 401 at the single photon receiver device 601 fails or the authentication of the single photon receiver device 601 at the single photon transmitter device 401 fails, the single photon transmitter device 401 refuse and/or the single photon receiving device 601 prefers the work and/or collaboration at least in part or in full. If necessary, the systems go into an emergency mode.

13 largely corresponds to the situation in 9 with the difference that instead of the car key, one car now accesses another car. The first car (on the left) follows the car in front (on the right). The optical system of the single photon transmission device 471 of the following car now preferably comprises an actuator for aligning the laser pointer beam 462 to a predetermined point on the other car driving ahead. The single photon detectors of the single photon receiving device 601 of the preceding car are preferably located at this point. Preferably, a camera captures the position of the predetermined point on the other car ahead. An image recognition system recognizes this point and preferably provides the control data for the alignment devices of the laser pointer beam. The single photon receiving device 601 preferably also comprises an alignment device for aligning the QKD coupled beam of the single photons. The single photon transmitting device 471 of the following car preferentially causes the alignment devices of the laser pointer beam and the alignment device to align the QKD coupling beam of the single photons the laser pointer beam and the QKD to aim the coupling beam at the predetermined point on the other car ahead using this control data. When the single photon receiving device 601 of the leading car signals the single photon transmitting device 471 of the following car that the single photon receiving device 601 of the leading car is aligned with the single photon transmitting device 471 of the following car, the single photon transmitting device 471 of the following car begins to negotiate the QKD key. The other steps then proceed as described above. Here, therefore, the single-photon receiving device 601 of the car driving ahead and the single-photon-transmitting device 471 of the following car are not aligned with one another, but rather the beam path of the QKD single-photon beam is suitably deflected. Only when the laser pointer beam 462 of the laser pointer device 455 of the single photon transmitting device 401 hits the alignment receiver 699 of the single photon receiving device 601 does the microcontroller core 616 signal the single photon receiving device 601 via the conventional data transmission channel 428 to the single photon transmitting device 401 that the agreement of a QKD key, as in the description too 8th described can start. Then, the single photon transmitting device 401 starts negotiating a common secret QKD key. The two cars can then exchange encrypted data.

14 shows an exemplary SPAD diode 1820 for use as a sensor element of a single photon detector within the meaning of this document in a schematically simplified manner and not to scale. The example SPAD diode 1820 includes, by way of example, one or more shallow trench isolations (STI) 1821, one or more anode contacts 1822, one or more cathode contacts 1823, one or more cap oxides 1824, or one or more optically transparent insulating layers 1824, one or more Highly doped first connection regions 1825 of a first conductivity type, one or more first doped wells 1826 of a second conductivity type, one or more second doped wells 1827 of a second conductivity type, an epitaxial layer 1828 of a second conductivity type, a base material 1829 of the semiconducting monocrystalline wafer, second doped well 1830 of a second conduction type below the anode contact, one or more highly doped second connection regions 1831 of a second conduction type, one or more insulation 1832, one or more metal-optical filters 1833, one or more optically transparent slots 1834 in the metal-optical filter 1833.
The cathode contact 1823 of the example SPAD diode 1820 is preferably made of indium tin oxide (ITO) or another transparent and electrically conductive material. In CMOS technology with a p-doped wafer material, the highly doped first connection region 1825 of a first conductivity type can be an n+-doped region in the semiconducting substrate material of the SPAD diode 1820, for example. In a CMOS technology with a p-doped wafer material, the first doped well 1826 of a second conductivity type can be a p ⁻ -doped region in the semiconducting substrate material of the SPAD diode 1820, for example. In a CMOS technology with a p-doped wafer material, the second doped well 1827 of a second conductivity type can be a p − -doped region in the semiconducting substrate material of the SPAD diode 1820, for example. In a CMOS technology with a p-doped wafer material, the epitaxial layer 1828 of a second conductivity type can be a p-doped epitaxial layer in the semiconducting substrate material of the SPAD diode 1820, for example. The base material 1829 of the semiconducting single-crystal wafer typically has a second conductivity type. In a CMOS technology with a p-doped wafer material, the base material 1829 of the semiconducting monocrystalline wafer is a p-doped monocrystalline semiconductor wafer, for example. In a CMOS technology with a p-doped wafer material, the second doped well 1830 of a second conductivity type below the anode contact can be a p--doped region in the semiconducting substrate material of the SPAD diode 1820, for example. In CMOS technology with a p-doped wafer material, the highly doped second connection region 1831 of a second conductivity type can be a p+-doped region in the semiconducting substrate material of the SPAD diode 1820, for example. The insulation 1832 can be an oxide or the like, for example. The metal-optical filter 1833 preferably covers the SPAD diode 1820 to such an extent that light can no longer strike the SPAD diode 1820 from the sides. Preferably, the light reaches the SPAD diode 1820 from above. The incident light 1835 then has to pass through the slits 1834 in the metal layer 1833 of the metal-optical filter 1833 . If the slits are selected to be narrow enough, this is only possible if the direction of polarization of the E field of the electromagnetic wave 1835 is oriented parallel to the slits 1834 in the x-direction. Only those portions of the electromagnetic wave 1835 that have this polarization direction therefore reach the PN junction of the SPAD diode. A filter preferably filters the electromagnetic wave 1835 prior to impinging on the metal-optical filter 1834 such that only light with a wavelength greater than a maximum wavelength reaches the metal-optical filter 1833 . Preferred is the Optics constructed in such a way that the electromagnetic wave 1835 hits the metal-optical filter 1833 from a direction that is preferably always the same, since the filter properties of the metal-optical filter 1833 depend on the angle of incidence between the pointing vector of the electromagnetic wave 1835 and the normal vector of the plane of the metal-optical filter 1833. This impact angle is preferably 0°. The width of the optically transparent slits 1834 in the metal-optical filter 1833 determines the cut-off wavelength of the metal-optical filter. For electromagnetic radiation with wavelengths longer than the cut-off wavelength and an E-field vector perpendicular to the direction of the slits 1834, the metal-optical filter 1833 is opaque. In order to enable good polarization, the electromagnetic wave 1835 should therefore be filtered by a filter in such a way that it no longer has any radiation components with wavelengths shorter than the limit wavelength;
14 12 schematically shows an incident electromagnetic wave 1835 for illustrative purposes. The electromagnetic wave 1835 can be the wave of a single photon.

15A shows a metal-optical filter 1950 in a simplified schematic and not true to scale with four metal-optical sub-filters 1951, 1952, 1953, 1954 for a 2x2 SPAD diode array of four SPAD diodes with a polarization filter effect of the metal-optical sub-filters 1951, 1952, 1953 rotated in 45° steps , 1954 in supervision. The underlying SPAD diodes are not shown. The reference numeral 1951 designates an exemplary first metal-optical partial filter 1951, which is not sketched to scale, with vertical polarization direction of the E-field for a first SPAD diode, which is typically arranged under the first metal-optical partial filter 1951. The vertical polarization direction of the E-field for a first SPAD diode corresponds here to a 0° polarization direction of the E-field for a first SPAD diode;
The reference numeral 1952 designates an exemplary second metal-optical sub-filter 1952, not drawn to scale, with a 45° polarization direction of the E-field for a second SPAD diode, which is typically arranged under the second metal-optical sub-filter 1952 in the semiconductor substrate;
The reference numeral 1953 designates an exemplary third metal-optical partial filter 1953, which is not sketched to scale, with horizontal polarization direction of the E field for a third SPAD diode, which is typically arranged under the third metal-optical partial filter 1953 in the semiconductor substrate. The horizontal direction of polarization of the E-field for a third SPAD diode here corresponds to a 90° direction of polarization of the E-field for a third SPAD diode;
The reference numeral 1954 designates an exemplary fourth metal-optical sub-filter 1954, not sketched to scale, with vertical polarization direction of the E-field for a fourth SPAD diode, which is typically arranged under the fourth metal-optical sub-filter 1954 in the semiconductor substrate.
15B shows another exemplary metal-optical filter 1955 schematically simplified and not true to scale with sixteen metal-optical sub-filters for a 4x4 SPAD diode array of sixteen SPAD diodes with polarization filter effect of the metal-optical sub-filters rotated in 45° steps in plan view. The metal-optical filters are scrambled in the case of the further exemplary metal-optical filter 1955 .

16 equals to 5 with the difference that the 1411 is replaced by the 1603. The 16 thus represents a single photon receiving device 2417.

17 equals to 6 with the difference that the 1603 is replaced by the 1411. The 16 thus represents a single photon transmission device 2601.

18 equals to 5 with the difference that the 1411 is replaced by the 1603. In addition, the laser pointer transmitting device (456, 457, 455) is replaced by the laser pointer receiving device (1606, 699). The 18 thus represents a single photon receiving device 3417.

19 equals to 6 with the difference that the 1603 is replaced by the 1411. In addition, the laser pointer receiving device (1606, 699) is replaced by the laser pointer transmitting device (456, 457, 455). The 19 thus represents a single photon transmission device 3601.

20 is equivalent to 9 , wherein the single photon transmitting device 2601 or 3601 is now in the vehicle 802 and the single photon receiving device 2471 or 3471 is now in the car key.

The above description is not exhaustive and does not limit this disclosure to the examples shown. Other variations to the disclosed examples may be understood and practiced by those of ordinary skill in the art given the drawings, disclosure, and claims. The indefinite article "a" or "an" and its inflections do not exclude a plurality, while mentioning a definite number of elements does not exclude the possibility that there may be more or fewer items. A single entity may perform the functions of multiple elements recited in the disclosure, and conversely, multiple elements may perform the function of one entity. Numerous alternatives, equivalents, variations, and combinations are possible without departing from the scope of the present disclosure.
Unless otherwise stated, all features of the present invention can be freely combined with one another. This applies to the entire document presented here. Unless otherwise stated, the features described in the description of the figures can also be freely combined with the other features as features of the invention. A limitation of individual features of the exemplary embodiments to the combination with other features of the exemplary embodiments is expressly not intended. In addition, physical features of the device can also be reworded as method features and method features can be reworded as physical features of the device. Such a reformulation is thus automatically disclosed.
In the foregoing detailed description, reference is made to the accompanying drawings. The examples in the specification and drawings should be considered as illustrative and not limiting on the specific example or element described. Several examples can be derived from the foregoing description and/or the drawings and/or the claims by modifying, combining or varying certain elements. Furthermore, examples or elements that are not literally described can be derived from the description and/or the drawings by a person skilled in the art.

Reference List

100

Single photon receiver for a polarization modulated single photon beam

102

polarization direction modulated stream of single photons

149

second signal path

150

first signal path

152

receive path

163

non-polarizing first beamsplitter

176

second single photon detector

177

first single photon detector

178

fourth single photon detector

179

third single photon detector

184

second polarizing beam splitter

187

second signal path

188

λ/4 plate

189

rotated second signal path

190

third polarizing beam splitter

201

single photon transmission device

236

first single photon source

237

second single photon source

238

third single photon source

239

fourth single photon source

283

first beam splitter

284

second beam splitter

288

λ/4 plate

290

third beam splitter

336

first single photon source

337

second single photon source

338

third single photon source

339

fourth single photon source

344

first pinhole

345

second pinhole

401

single photon transmission device

402

internal data bus

403

Read/write memory RAM

404

writable non-volatile memory

405

non-volatile read-only memory such as ROM

406

non-volatile, writable and/or non-writable manufacturer memory

407

Cryptographic Accelerator

408

Vendor Storage Firewall

411

CRC module (Cyclic Redundancy Check)

412

Clock generator module (English Clock Driver, CLK)

413

timer module

414

Safety monitoring and control circuit

415

Quantum Random Number Generator (QRNG) based on quantum processes

416

microcontroller core

417

Data interface, in particular one or more universal asynchronous receiver transmitters (UART) for supporting high-speed serial data;

421

Basic clock generator (CLK)

422

reset circuit

423

Power supply or Vcc circuit with voltage regulator

424

ground circuit

425

input/output circuit

426

wireless and/or wired data interface

427

respective connection of the wired or wireless data transmission path, for example connection of the respective antenna of a respective wireless interface 426

428

data transmission channel

429

Control device for the single photon sources 436, 437, 438, 439,440

430

Control line with which the control device 429 for the single photon sources 436, 437, 438, 439, 440 controls an adjustable voltage regulator 442

431

first control line for the first current source 463 of the first single photon source 436

432

second control line for the second current source 463 of the second single photon source 437

433

third control line for the third current source 463 of the third single photon source 438

434

fourth control line for the fourth current source 462 of the fourth single-photon source 439

435

fifth control line for the fifth current source 463 of the fifth single-photon source 440, which controls the polarized fifth illuminant 464 of the fifth single-photon source 440

436

first single photon source

437

second single photon source. The second single photon source includes a polarized second illuminant 464 and a second current source 463

438

third single photon source. The third single photon source includes a polarized third illuminant 464 and a third current source 463

439

fourth single photon source. The fourth single photon source includes a polarized fourth illuminant 464 and a fourth current source 463

440

fifth single photon source. The fifth single photon source includes a polarized fifth illuminant 464 and a fifth current source 463

441

Supply voltage line of the single photon sources 436 to 440

442

Power supply for the single photon sources 436 to 440

443

supply voltage line

444

First pinhole

445

second pinhole

446

first lens

447

second lens

448

first beam splitter of the transmission path

449

Beam path of the transmitter up to the first beam splitter or mirror 448

450

Beam path of the transmitter from the first beam splitter or mirror 448 to the photodetector 451

451

Photodetector 451

452

QKD coupling beam

453

Received signal of the photodetector 451

454

Evaluation circuit of the photodetector 451

455

Laser pointer device

456

Voltage supply for the laser pointer laser diode 459

457

Control device for the current source 460 of the laser pointer diode 459

459

Laser pointer diode

460

Laser pinter diode 459 power source

461

Projection optics of the laser pinter device

462

Laser pointer beam for aligning the single-photon transmission device 401, 471, for example a car key

463

Power source of the single photon source of the single photon sources 436 to 440

464

Lamps of the single photon source of the single photon sources 436 to 440

465

HMI interface (HMI=Human Machine Interface)

466

input terminal

467

Buttons or switches or other mechanical input devices

468

Biometric Sensor

469

Optical output element, for example one or more lamps or a screen for signaling to a user

470

Actuator, for example an electromechanical vibration means

471

single photon transmission device

601

Single photon receiving device, in particular for a car

602

internal data bus

603

Read/write memory RAM

604

writable non-volatile memory

605

non-volatile read-only memory

606

non-volatile, writable and/or non-writable manufacturer memory

607

Cryptographic Accelerator

608

Vendor Storage Firewall

611

CRC module (Cyclic Redundancy Check)

612

Clock generator module (English Clock Driver, CLK)

613

timer module

614

Safety monitoring and control circuit

615

Quantum Random Number Generator (QRNG) based on quantum processes

616

microcontroller core

617

Data interface, in particular one or more Universal Asynchronous Receiver Transmitters (UART) for supporting high-speed serial data

621

Basic clock generator (CLK)

622

reset circuit

623

Power supply or Vcc circuits with voltage regulator

624

ground circuit

625

input/output circuit

626

wireless and/or wired data interface

627

respective antenna of the respective wireless interface 626

643

supply voltage line

672

Evaluation circuit for the received signals 673 to 676 of the single photon detectors 677 to 680 for differently polarized single photons

673

first received signal of the first single photon detector 677 for horizontally polarized single photons

674

second received signal of the second single photon detector 678 for vertically polarized single photons

675

third received signal of the third single photon detector 679 for +45° polarized single photons

676

fourth received signal of the fourth single photon detector 680 for -45° polarized single photons

677

first single photon detector for horizontally polarized single photons, for example a first SPAD diode

678

second single photon detector for vertically polarized single photons 678, for example a second SPAD diode

679

third single photon detector for +45° polarized single photons, for example a third SPAD diode

680

fourth single photon detector for -45° polarized single photons, for example a fourth SPAD diode

681

Receiving optics for the QKD coupled beam 452

682

Beam path for the individual photons of the QKD coupled beam 452 between receiving optics for the QKD coupled beam 452 and non-polarizing beam splitter 683

683

non-polarizing beam splitter 683

684

second polarizing beam splitter

685

third horizontally polarized stream of single photons

686

fourth vertically polarized single photon stream

687

second single photon stream

688

λ/4 plate and/or polarization rotator

689

rotated second single photon stream

690

third polarizing beam splitter

691

sixth -45° polarized single photon stream

692

Control for driving the exemplary locking device 694

693

Control line for driving the exemplary locking device 694

694

exemplary locking device 694 of the motor vehicle 802

695

Data interface to a higher-level computer unit 697 via a data bus 696 of the car 802

696

Data connection from the data interface 695 of the single photon receiving device to a higher-level computer unit 697 via a data bus 696 of the car 802

697

superordinate computer unit

698

alignment receiver line

699

alignment receiver

701

exemplary integrated circuit for use in automotive QKD systems

702

internal data bus of the QKD integrated circuit 701

703

Read/write memory RAM 703 of the QKD integrated circuit 701

704

writable non-volatile memory of the QKD integrated circuit 701

705

non-volatile, read-only memory of QKD integrated circuit 701, such as ROM

706

non-volatile, writable and/or non-writable QKD integrated circuit manufacturer memory 701

707

QKD integrated circuit cryptographic accelerator 701, such as a DES accelerator and/or an AES accelerator 707

708

QKD IC 701 Vendor Storage Firewall

711

CRC (Cyclic Redundancy Check) module of QKD integrated circuit 701

712

Clock driver (CLK) module of QKD integrated circuit 701

713

Timer module of the 701 QKD integrated circuit

714

Safety monitoring and control circuitry of the 701 QKD integrated circuit

715

QKD integrated circuit 701 quantum process-based true random number generator (QRNG).

716

Microcontroller core of QKD integrated circuit 701

717

Data interface, in particular one or more Universal Asynchronous Receiver Transmitters (UART) for supporting high-speed serial data

721

Base clock generator (CLK) of the QKD integrated circuit 701

722

Reset circuit of QKD integrated circuit 701

723

Power supply or Vcc circuit of QKD integrated circuit 701 with voltage regulators

724

Ground circuit of the QKD integrated circuit 701

725

701 QKD integrated circuit input/output circuit

726

QKD integrated circuit 701 data link

727

respective connection of the wired or wireless data transmission path, for example connection of the respective antenna of a respective wireless interface 726

729

Driving device for the single photon sources 736, 737, 738, 739 of the integrated QKD circuit 701

730

Control line of the integrated QKD circuit 701 with which the control device 729 for the single photon sources 736, 737, 478, 479 controls an adjustable voltage regulator 742

731

first control line of the QKD integrated circuit for the first current source 763 of the first single photon source 736 of the QKD integrated circuit, which controls the polarized first illuminant 764 of the first single photon source 736 of the QKD integrated circuit, with the first control line 731 possibly also status data of the first Single photon source 736 of the QKD integrated circuit reports back to the microcontroller core 716 of the QKD integrated circuit via the driver 729 of the QKD integrated circuit for the single photon sources 736, 737, 738, 739 of the QKD integrated circuit

732

second control line of the QKD integrated circuit for the second current source 763 of the second single-photon source 737 of the QKD integrated circuit, which controls the polarized second illuminant 764 of the second single-photon source 737 of the QKD integrated circuit, the second control line 732 possibly also containing status data of the second Single photon source 737 of the QKD integrated circuit reports back to the microcontroller core 716 of the QKD integrated circuit via the control device 729 of the QKD integrated circuit for the single photon sources 736, 737, 738, 739 of the QKD integrated circuit

733

third control line of the QKD integrated circuit for the third current source 764 of the third single-photon source 738 of the QKD integrated circuit, which controls the polarized third illuminant 764 of the third single-photon source 738 of the QKD integrated circuit, with the third control line 733 possibly also status data of the third Single photon source 738 of the QKD integrated circuit reports back to the microcontroller core 716 of the QKD integrated circuit via the driver 729 of the QKD integrated circuit for the single photon sources 736, 737, 738, 739 of the QKD integrated circuit

734

fourth control line of the QKD integrated circuit for the fourth current source 763 of the fourth single photon source 739 of the QKD integrated circuit, which controls the polarized fourth illuminant 764 of the fourth single photon source 739 of the QKD integrated circuit, with the fourth control line 734 possibly also status data of the fourth Single photon source 739 of the QKD integrated circuit reports back to the microcontroller core 716 of the QKD integrated circuit via the control device 729 of the QKD integrated circuit for the single photon sources 736, 737, 738, 739 of the QKD integrated circuit

736

first single photon source of the QKD integrated circuit 701.

737

second single photon source of the QKD integrated circuit 701

738

third single photon source 738 of the integrated QKD circuit 701

739

fourth single photon source of the QKD integrated circuit 701

741

Supply voltage line of the single photon sources 736 to 739

742

Energy supply for the exemplary four single photon sources 736 to 739 of the integrated QKD circuit 701

743

supply voltage line

751

701 QKD Integrated Circuit Photodetector

753

Received signal of the photodetector 751 of the integrated QKD circuit 701

754

Evaluation circuit of the photodetector 751 of the integrated QKD circuit 701

756

Voltage supply for the laser pointer laser diode 459

757

Control device for the current source 760 of the laser pointer diode 459

760

Laser pinter diode 459 power source

763

respective lighting means of the respective single-photon source of the four single-photon sources 736 to 739, for example

764

respective current source of the respective single photon source of the four single photon sources 736 to 739 of the integrated QKD circuit 701

772

Evaluation circuit for the received signals 773 to 776 of the single photon detectors 777 to 780 for differently polarized single photons. The evaluation circuit receives measured values in the form of signals from the single photon detectors 777 to 780 for differently polarized single photons via said received signals 773 to 776. The evaluation circuit processes these measured values and makes the result of this processing available to the microcontroller core 716 via the internal data bus 702.

773

first received signal of the first single photon detector 777 for horizontally polarized single photons

774

second received signal of the second single photon detector 778 for vertically polarized single photons

775

third received signal of the third single photon detector 779 for +45° polarized single photons

776

fourth received signal of the fourth single photon detector 780 for -45° polarized single photons

777

first single photon detector for horizontally polarized single photons, for example a first SPAD diode

778

second single photon detector for vertically polarized single photons, for example a second SPAD diode

779

third single photon detector for +45° polarized single photons, for example a third SPAD diode

780

fourth single photon detector for -45° polarized single photons, for example a fourth SPAD diode

792

Control for driving the exemplary locking device 694

793

Control line for driving the exemplary locking device 694

795

Data interface to a higher-level computer unit 697 via a data bus 696 of the car 802 or another device in which the integrated QKD circuit 701 is used

798

alignment receiver line

801

Situation when negotiating a QKD key between a car key and a car 802

802

automobile

803

Optical window for the QKD coupling beam 452 in the body of the 802 car

804

802 car door

1011

charging station

1012

charging cable

1013

charging connector

1114

Software update device

1115

data transfer cable

1116

Software update connector

1117

Calculator of software update device 1114

1118

Server of the SW provider

1301

Conical mirror

1407

Car key single photon transmission device 401, 471

1408

Conical mirror or functionally equivalent device for combining the single photon streams of the single photon sources 436 to 440 into a single single photon stream

1409

Identification means for identifying the user

1410

Single photon beams from single photon sources 436 through 440

1411

Receiver module for polarization modulated single photons;

1601

Alignment receiver 699 receiver

1603

Single photon detector system for receiving a polarization modulated single photon signal

1604

first single photon stream

1605

fifth +45° polarized single photon stream

1606

Alignment receiver interface 699

1701

Alignment receiver 699 receiver

1703

Single photon detector system for receiving a polarization modulated single photon signal

1706

Alignment receiver interface 699

1707

Single photon transmission device of the QKD circuit 701, e.g. the car key 401, 471

1820

Exemplary SPAD diode for use as a sensor element of a single photon detector

1821

Shallow trench isolation STI of example SPAD diode 1820

1822

Example SPAD diode 1820 anode contact

1823

Cathode contact of the example SPAD diode 1820

1824

Cap oxide or optically transparent insulating layer of the example SPAD diode 1820

1825

highly doped first connection region of a first conductivity type

1826

first doped well of a second conductivity type

1827

second doped well of a second conductivity type

1828

epitaxial layer of a second conductivity type

1829

Base material of the semiconducting monocrystalline wafer, which has a second conductivity type

1830

second doped well of a second conductivity type below the anode contact

1831

highly doped second connection region of a second conductivity type

1832

Insulation, for example an oxide or the like

1833

metal-optical filter

1834

optically transparent slits in the metal-optical filter 1833

1835

incident electromagnetic wave

1950

Metal-optical filter with four metal-optical sub-filters 1951, 1952, 1953, 1954 for a 2x2 SPAD diode array of four SPAD diodes with the polarization filter effect of the metal-optical sub-filters 1951, 1952, 1953, 1954 rotated in 45° steps

1951

first metal-optical sub-filter with vertical polarization direction of the E-field for a first SPAD diode, which is typically arranged under the first metal-optical sub-filter 1951

1952

second metal-optical sub-filter with 45° polarization direction of the E-field for a second SPAD diode, which is typically arranged under the second metal-optical sub-filter 1952 in the semiconductor substrate

1953

third metal-optical sub-filter with horizontal polarization direction of the E-field for a third SPAD diode, which is typically arranged under the third metal-optical sub-filter 1953 in the semiconductor substrate

1954

fourth metal-optical sub-filter with vertical polarization direction of the E-field for a fourth SPAD diode, which is typically arranged under the fourth metal-optical sub-filter 1954 in the semiconductor substrate

1955

another exemplary metal-optical filter

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US5307410 [0010]

Claims (12)

vehicle system with a vehicle and with device parts (401, 601) and wherein at least a first device part is part of the vehicle and wherein the vehicle system comprises a QKD system (401, 601, 452, 428) and wherein at least the first device part exchanges a key for encrypting data using the QKD system (401, 601, 452, 428) with a further second device part of the vehicle system and wherein the first part of the device exchanges encrypted data with the second part of the device at least temporarily using this key. vehicle system claim 1 , wherein the second device part is a car key. vehicle system claim 1 , wherein the second device part is also part of the vehicle. vehicle system claim 1 , wherein the second device part is an infrastructure device. vehicle system claim 1 , wherein the second device part is another vehicle. Vehicle system according to one or more of Claims 1 until 5 , wherein the vehicle is a car or a truck or a special machine or a ship or a ship's hull or a floating body or another mobile device. Vehicle system according to one or more of Claims 1 until 6 , wherein the vehicle system at least at times comprises a polarization-modulated single photon current, in particular a QKD coupling current (452), between the second device part and the first device part, which the second device part exchanges with the first device part. vehicle system claim 7 , wherein the first device part comprises a single-photon receiving device (601) for the polarization-modulated single-photon stream and wherein the second device part comprises a single-photon transmitting device (401) for the polarization-modulated single-photon stream. vehicle system claim 7 or 8th , wherein the first device part comprises a single-photon transmission device (401) for the polarization-modulated single-photon stream and wherein the second device part comprises a single-photon receiving device (601) for the polarization-modulated single-photon stream. Vehicle system according to one or more of Claims 7 until 9 , - wherein the single photon stream is a QKD coupling stream (452). Vehicle system according to one or more of Claims 1 until 10 , wherein the first device part and the second device part have means (1411, 1603) for exchanging a single photon stream, in particular a QKD coupled beam (452). Vehicle system according to one or more of Claims 1 until 11 , wherein the first device part and the second device part have means (455, 699) for aligning a single photon stream, in particular a QKD coupled beam (452).

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