WO2017084380A1 - 一种量子通信方法和装置 - Google Patents

一种量子通信方法和装置 Download PDF

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Publication number
WO2017084380A1
WO2017084380A1 PCT/CN2016/091808 CN2016091808W WO2017084380A1 WO 2017084380 A1 WO2017084380 A1 WO 2017084380A1 CN 2016091808 W CN2016091808 W CN 2016091808W WO 2017084380 A1 WO2017084380 A1 WO 2017084380A1
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information
unit
quantum
signal
optical signal
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PCT/CN2016/091808
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English (en)
French (fr)
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苏长征
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华为技术有限公司
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
    • H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords

Definitions

  • Embodiments of the present invention relate to the field of quantum communication, and in particular, to a quantum communication method and apparatus.
  • Encryption is one of the important means to ensure information security.
  • AES Advanced Encryption Standard
  • TDEA Triple Data Encryption Algorithm
  • RSA Message-Digest Algorithm
  • MD5 Message-Digest Algorithm
  • SHA Secure Hash Algorithm
  • the existing classical encryption system is based on computational complexity. With the advancement of mathematics and the continuous improvement of computer speed, the existence of its existence is deciphered, and it is not absolutely reliable.
  • the classical cryptosystem only one time and one secret have unconditional security, and it requires a random number key of the same length as the encrypted data. How to generate a large number of random number keys has always been a problem, so one time and one secret has not been practically applied.
  • QKD Quantum Key Distribution
  • QKD specifically uses the quantum state as the information unit, and uses some principles of quantum mechanics to transmit and protect information.
  • the two sides of the communication use the quantum state as the information carrier, and use the quantum mechanical principle to transmit through the quantum channel to establish between the two parties. Shared key. Its security is ensured by the "Heisenberg uncertainty relationship” and “single quantum non-reproducible theorem” in quantum mechanics or the quantum properties such as coherence and non-locality of entangled particles.
  • the transmitting device (Alice) arranges the information to be transmitted into one large number, and then uses another large number as a key, and transmits the product of the two large numbers to the receiving device (Bob) through the classical channel.
  • Bob divides the product of the two large numbers received by the key, which is the information that Alice wants to pass. Both Alice and Bob need to have the same large number as the key for encryption and decryption.
  • the process of generating such a key is called quantum key distribution.
  • the above quantum key distribution process specifically refers to Alice transmitting quantum information and negotiation information to Bob, and Bob generates a key according to the quantum information and the negotiation information sent between Alice and Bob.
  • FIG. 1 exemplarily shows a structural diagram of a one-way encrypted transmission QKD system.
  • Alice 101 and Bob 102 are included in the QKD system, and Alice includes a main control unit 103, a quantum transmitter 104, a synchronous clock transmitter 105, a negotiation information transceiver 106, and a service information transmitter 107.
  • the Bob includes a main control unit 108 and a quantum receiver. 109.
  • Alice sends quantum information to Bob's quantum receiver through a quantum transmitter, so that Bob obtains the original quantum key from the quantum information.
  • Alice sends a synchronous clock signal to Bob's synchronous clock receiver via a synchronous clock transmitter to enable Bob to synchronize with Alice's clock.
  • both Alice and Bob's negotiation information transceivers are used to transmit information that needs to be exchanged between Alice and Bob during the key generation post-processing phase of Alice and Bob's master control unit. Specifically, it refers to a series of processing on the information input to the quantum transmitter and the information output by the quantum receiver, such as: measurement basis, error estimation, error correction, private amplification, and the like.
  • the transmitting device needs to include three transmitters and one transceiver
  • the receiving device needs to include three receivers and one transceiver
  • the structure of the transmitting device and the receiving device is complicated.
  • Embodiments of the present invention provide a quantum communication method and apparatus for simplifying the structure of a transmitting device and a receiving device, and reducing the number of channels between the transmitting device and the receiving device.
  • Embodiments of the present invention provide a quantum communication method, including the following steps:
  • the digital signal processing DSP unit of the transmitting device determines, according to the signal transmission indication information, information that is currently required to be output, wherein the information to be output is quantum information or classical information, and the quantum information and the classical information are time-division multiplexed;
  • the optical signal generating unit of the transmitting device performs spectral processing on the generated optical pulse signal to obtain a first optical signal and a second optical signal; wherein the first optical signal is used to carry quantum information and classical information; the second optical signal is The light intensity signal of the second light signal is greater than the light intensity of the first light signal;
  • the DSP unit of the transmitting device adjusts an attenuation value output by the attenuation unit of the transmitting device according to information currently required to be output; the DSP unit of the transmitting device sends the information to the transmitting device according to information currently required to be output.
  • the modulation unit inputs a modulation signal corresponding to the information to be output;
  • the attenuating unit of the transmitting device attenuates the first optical signal according to the adjusted attenuation value, and the modulating unit of the transmitting device modulates the attenuated first optical signal according to the input modulation signal; Or the modulation unit of the transmitting device modulates the first optical signal according to the input modulation signal, and the attenuation unit of the transmitting device pairs the modulated first optical signal according to the adjusted attenuation value. Attenuate;
  • a polarization coupling unit in the transmitting device couples the attenuated and modulated first optical signal and the second optical signal to obtain a coupled optical signal, and transmits the coupled optical signal number.
  • the optical signal output by the transmitting device includes time-division multiplexed quantum information and classical information, thereby avoiding the need in the prior art to separately transmit quantum information and classical information through two channels, simplifying the structure of the transmitting device and the receiving device. Reduce the number of channels between the transmitting device and the receiving device.
  • the quantum information is an optical random sequence having quantum characteristics including an original quantum key
  • the classical information is information including any one or more of negotiation information, service information, and a synchronization clock signal.
  • any one or any of the negotiation information, the service information, and the synchronization clock signal and the quantum information can be transmitted through the first optical signal sent by the quantum transmitter, thereby avoiding sending by using multiple transmitters separately.
  • the above several kinds of information simplifies the structure of the transmitting device and the receiving device for quantum communication, and reduces the number of channels between the transmitting device and the receiving device.
  • the signaling indication information includes time-division multiplexed first sending indication information and second sending indication information;
  • the DSP unit of the sending device determines the information that needs to be output according to the signal sending indication information, and specifically includes:
  • the DSP unit of the sending device receives, by the DSP unit of the sending device, the first sending indication information, determining that the information that needs to be output is quantum information; and the DSP unit of the sending device receiving the second sending indication information, The DSP unit of the transmitting device determines that information currently required to be output is classic information.
  • the transmitting device can accurately determine whether the information currently required to be output is classic information or quantum information according to the first sending indication information and the second sending indication information, and further can process according to the information currently required to be output, thereby improving the accuracy of data processing. Sex.
  • the DSP unit of the sending device adjusts the attenuation value output by the attenuating unit of the sending device according to the information that is currently required to be output, and specifically includes:
  • the DSP unit of the transmitting device determines that the information that needs to be output is quantum information
  • the attenuation value output by the attenuation unit of the transmitting device is adjusted to be below a first threshold;
  • the DSP unit of the transmitting device When determining that the information that needs to be output is the classic information, adjusting the attenuation value output by the attenuation unit of the sending device to a second threshold or more; wherein the first threshold The value is less than the second threshold.
  • the first optical signal can be attenuated into an optical signal for carrying quantum information and an optical signal for carrying classical information, and time-division multiplexing of the carried quantum information and classical information is realized.
  • the DSP unit of the sending device inputs a modulation signal corresponding to the information that needs to be output to the modulation unit of the sending device according to the information that is currently required to be output, and specifically includes:
  • the modulation signal input by the DSP unit of the transmitting device to the modulation unit of the transmitting device is a random sequence
  • the modulation signal input by the DSP unit of the transmitting device to the modulation unit of the transmitting device is classic information.
  • the information to be output is quantum information
  • the random sequence is modulated on the optical signal.
  • the classical information is modulated on the optical signal, so that the quantum information and the classical information are simultaneously It is carried on an optical signal and realizes time division multiplexing of quantum information and classical information on the optical signal.
  • the modulating unit includes a first modulator, and a second modulator coupled to the first modulator;
  • the modulation signal input by the DSP unit of the sending device to the modulation unit of the sending device is a random sequence, and specifically includes:
  • a modulation sequence input by the DSP unit of the transmitting device to the first modulator and the second modulator of the transmitting device is a random sequence
  • the modulation signal input by the DSP unit of the sending device to the modulation unit of the sending device is classic information, and specifically includes:
  • a modulation signal input by the DSP unit of the transmitting device to the first modulator of the transmitting device is classical information
  • a modulated signal input to the second modulator is classical information or a DC level
  • the modulated signal input by the DSP unit of the transmitting device to the first modulator of the transmitting device is classical information or a DC level, and the modulated signal input to the second modulator is classical information.
  • Embodiments of the present invention provide a quantum communication method, including the following steps:
  • the data signal processing DSP unit of the receiving device determines the information that needs to be received according to the signal receiving indication information, wherein the information that needs to be received is quantum information or classic information, and the quantum information and the classical information are time-division multiplexed;
  • the polarization splitting unit of the receiving device processes the received optical signal to obtain a first optical signal and a second optical signal
  • the DSP unit of the receiving device inputs a modulation signal to a modulation unit of the receiving device according to information currently required to be received;
  • the modulating unit of the receiving device modulates the received second optical signal according to the input modulation signal
  • the coupling unit of the receiving device performs interference processing on the modulated second optical signal and the first optical signal to obtain a processed optical signal
  • the DSP unit of the receiving device recovers the quantum information and the classic information from the processed optical signal according to the information currently required to be received.
  • the successful reception of the optical signal carrying the quantum information and the classical information by the quantum receiver is realized, and the quantum information and the classical information can be recovered according to the received optical signal, and the structure of the transmitting device and the receiving device is simplified. , reducing the number of channels between the transmitting device and the receiving device.
  • the quantum information is an optical random sequence having quantum characteristics including an original quantum key
  • the classical information is information including any one or more of negotiation information, service information, and a synchronization clock signal.
  • any one or any of the negotiation information, the service information, and the synchronization clock signal and the quantum information can be successfully received by the quantum receiver, thereby avoiding the case of using multiple receivers to separately receive the above information.
  • Simplified transmitting device and receiving device for quantum communication The structure reduces the number of channels between the transmitting device and the receiving device.
  • the signal receiving indication information includes first receiving indication information and second receiving indication information that are time division multiplexed;
  • the DSP unit of the receiving device determines the information that needs to be received according to the signal receiving indication information, and specifically includes:
  • the DSP unit of the receiving device receives the first receiving indication information, the DSP unit of the receiving device determines that information currently needed to be received is quantum information; and the DSP unit of the receiving device receives The second receiving indication information, the DSP unit of the receiving device determines that the information that needs to be received currently is classic information.
  • the receiving device can accurately determine whether the information currently required to be output is classic information or quantum information according to the first sending indication information and the second sending indication information, and further can process according to the information currently required to be output, thereby improving the accuracy of data processing. Sex.
  • the DSP unit of the receiving device inputs a modulation signal to a modulation unit of the receiving device according to the information that is currently required to be received, and specifically includes:
  • the modulated signal input by the DSP unit of the receiving device to the modulation unit of the receiving device is a random sequence; the receiving When the DSP unit of the device determines that the information currently needed to be received is quantum information, the modulation signal input by the DSP unit of the receiving device to the modulation unit of the receiving device is a DC level. In this way, the separation of the classical information and the quantum information in the subsequent steps can be successfully achieved.
  • the DSP unit of the receiving device recovers the quantum information and the classic information from the processed optical signal according to the information that is currently required to be received, and specifically includes:
  • the DSP unit of the receiving device outputs a gain value to a balanced receiver unit of the receiving device according to information currently required to be received; the balanced receiver unit converts the input processed optical signal into an electrical signal And using the gain value to perform gain control on the converted electrical signal such that the amplitude of the electrical signal after performing the gain control falls within a preset range; the DSP unit of the receiving device performs the gain control Quantum information and classical information are recovered from the electrical signal.
  • the optical signals carrying the quantum information and the classical information with different amplitudes can be successfully transmitted to the DSP unit of the receiving device, thereby enabling the DSP unit to recover the quantum information and the classical information from the electrical signals after the gain control.
  • the DSP unit of the receiving device recovers the quantum information and the classic information from the processed optical signal according to the information that is currently required to be received
  • the DSP unit further includes:
  • the DSP unit of the receiving device sends the classic information and the quantum information to a main control unit of the receiving device; the main control unit of the receiving device performs according to the classic information and quantum information. Process to determine the final quantum key. In this way, the receiving device can successfully determine the final quantum key, and then encrypt the information to be encrypted according to the quantum key.
  • An embodiment of the present invention provides a transmitting apparatus for quantum communication, including:
  • the digital signal processing DSP is configured to determine the information that needs to be output according to the signal transmission indication information; adjust the attenuation value output by the attenuation unit according to the information currently required to be output; input and output to the modulation unit according to the information currently required to be output a modulated signal corresponding to the information; wherein the information to be output is quantum information or classical information, and the quantum information and the classical information are time-division multiplexed;
  • An optical signal generating unit configured to perform spectral processing on the generated optical pulse signal to obtain a first optical signal and a second optical signal;
  • the attenuation unit is configured to attenuate the input optical signal according to the adjusted attenuation value
  • the modulating unit is configured to modulate the input optical signal according to the input modulation signal
  • a polarization coupling unit configured to couple the first optical signal that is attenuated after being attenuated, or that is modulated and then attenuated, and the second optical signal to obtain a coupled optical signal, and send the coupled optical signal .
  • the optical signal output by the transmitting device includes time-division multiplexed quantum information and classical information, thereby avoiding the need in the prior art to separately transmit quantum information and classical information through two channels, simplifying the structure of the transmitting device and the receiving device. Reduce the number of channels between the transmitting device and the receiving device.
  • the quantum information is an optical random sequence having quantum properties including an original quantum key
  • the classic information is information including any one or more of negotiation information, service information, and synchronization clock signals.
  • the signaling indication information includes time-division multiplexed first sending indication information and second sending indication information;
  • the DSP is specifically configured to:
  • Receiving the second sending indication information determining that the information currently required to be output is classic information.
  • the DSP is specifically configured to:
  • the first threshold is smaller than the second threshold.
  • the DSP is specifically configured to:
  • the modulated signal input to the modulation unit is a random sequence
  • the modulated signal input to the modulation unit is classical information.
  • the modulating unit includes a first modulator, and a second modulator coupled to the first modulator;
  • the DSP is specifically configured to:
  • the modulated signals input to the first modulator and the second modulator are random sequences
  • the DSP is specifically configured to:
  • the modulated signal input to the modulation unit is classical information
  • the modulated signal input to the first modulator is classical information
  • the modulated signal input to the second modulator is classical information or a DC level
  • the modulated signal input to the modulation unit is classical information
  • the modulated signal input to the first modulator is classical information or a direct current level
  • the modulated signal input to the second modulator is classical information
  • the attenuation unit is:
  • a first optical switch receiving the first optical signal, a first fixed attenuator coupled to the first optical switch, and a second optical switch coupled to the first fixed attenuator;
  • a first optical splitter receiving the first optical signal, a second fixed attenuator coupled to the first optical splitter, and a third optical switch coupled to the second fixed attenuator;
  • a fourth optical switch that receives the first optical signal, a third fixed attenuator that is coupled to the fourth optical switch, and a second optical splitter that is coupled to the third fixed attenuator.
  • An embodiment of the present invention provides a receiving apparatus for quantum communication, including:
  • the data signal processing DSP is configured to determine, according to the signal receiving indication information, information currently needed to be received, and input a modulation signal to the modulator according to the information currently required to be received; and according to the information currently required to be received, from the processed optical signal Recovering quantum information and classical information; wherein the information to be received is quantum information or classical information, and the quantum information and the classical information are time-division multiplexed;
  • a polarization beam splitting unit configured to process the received optical signal to obtain a first optical signal and a second optical signal
  • the modulator is configured to modulate the received second optical signal according to the input modulation signal
  • a coupling unit configured to perform interference processing on the modulated second optical signal and the first optical signal to obtain a processed optical signal.
  • the successful reception of the optical signal carrying the quantum information and the classical information by the quantum receiver is realized, and the quantum information and the classical information can be recovered according to the received optical signal, and the structure of the transmitting device and the receiving device is simplified. , reducing the number of channels between the transmitting device and the receiving device.
  • the quantum information is a random sequence of light having quantum properties including an original quantum key
  • the classic information is information including any one or more of negotiation information, service information, and synchronization clock signals.
  • the signal receiving indication information includes first receiving indication information and second receiving indication information that are time division multiplexed;
  • the DSP is specifically configured to:
  • Receiving the first receiving indication information determining that the information that needs to be received currently is quantum information
  • Receiving the second receiving indication information determining that the information that needs to be received currently is classic information.
  • the DSP is specifically configured to:
  • the modulated signal input to the modulator is a random sequence
  • the modulated signal input to the modulator is at a DC level.
  • the DSP is specifically configured to:
  • the balanced receiver unit is configured to convert the input processed optical signal into an electrical signal, and perform gain control on the converted electrical signal by using the gain value, so that the electrical signal after the gain control is performed
  • the amplitude is within the preset range.
  • the DSP is further configured to:
  • the processor is configured to perform post processing according to the classical information and the quantum information to determine a final quantum key.
  • the digital signal processing (DSP) unit of the transmitting device determines the information that needs to be output according to the signal sending indication information, wherein the information to be output is quantum information or classical information, and the quantum information Time division multiplexing with classic information;
  • the optical signal generating unit of the transmitting device performs spectral processing on the generated optical pulse signal to obtain a first optical signal and a second optical signal; and the DSP unit of the transmitting device adjusts the attenuation value of the attenuation unit output of the transmitting device according to the information currently required to be output.
  • the DSP unit of the transmitting device inputs a modulation signal corresponding to the information to be output to the modulation unit of the transmitting device according to the information currently required to be output; the attenuation unit of the transmitting device attenuates the first optical signal according to the adjusted attenuation value, and transmits
  • the modulating unit of the device modulates the attenuated first optical signal according to the input modulation signal; or the modulating unit of the transmitting device modulates the first optical signal according to the input modulation signal, and the attenuation unit of the transmitting device is configured according to the adjusted
  • the attenuation value attenuates the modulated first optical signal; the polarization coupling unit in the transmitting device couples the attenuated and modulated first optical signal and the second optical signal to obtain the coupled optical signal, and after transmitting and coupling Light signal.
  • the optical signal output by the transmitting device includes time-division multiplexed quantum information and classical information, thereby avoiding the need in the prior art to separately transmit quantum information and classical information through two channels, simplifying the structure of the transmitting device and the receiving device. Reduce the number of channels between the transmitting device and the receiving device.
  • FIG. 1 is a schematic structural diagram of a one-way encrypted transmission QKD system provided in the background art
  • 2a is a schematic structural diagram of a system applicable to a quantum communication method according to an embodiment of the present invention
  • 2b is a schematic structural diagram of a system applicable to a quantum communication method according to an embodiment of the present invention.
  • FIG. 3 is a schematic flowchart of a quantum communication method implemented by a transmitting apparatus according to an embodiment of the present invention
  • 3a is a schematic structural diagram of a transmitting apparatus for quantum communication according to an embodiment of the present invention.
  • 3b is a schematic structural diagram of a quantum communication device according to an embodiment of the present invention.
  • 3c is a schematic structural diagram of another quantum communication device according to an embodiment of the present invention.
  • FIG. 3 is a schematic structural diagram of another quantum communication device according to an embodiment of the present invention.
  • 3e is a schematic diagram of a specific working process of a main control unit and a DSP unit of a transmitting device, and a main control unit and a DSP unit of a receiving device according to an embodiment of the present invention
  • FIG. 3 is a schematic diagram of a specific working process of a main control unit and a DSP unit of a transmitting apparatus, and a main control unit and a DSP unit of a receiving apparatus according to an embodiment of the present disclosure;
  • Figure 3g is another possible implementation of Figure 3a
  • FIG. 3 is a timing diagram of a signal sent by a transmitting apparatus according to an embodiment of the present invention.
  • FIG. 3 is a timing diagram of a signal transmitted by a receiving apparatus according to an embodiment of the present invention.
  • FIG. 4 is a schematic flowchart of a quantum communication method implemented by a receiving apparatus according to an embodiment of the present invention
  • FIG. 5 is a schematic structural diagram of a transmitting apparatus for quantum communication according to an embodiment of the present invention.
  • FIG. 6 is a schematic structural diagram of a receiving apparatus for quantum communication according to an embodiment of the present invention.
  • a quantum channel and a classical channel are included between the transmitting device and the receiving device in the embodiment of the present invention.
  • the transmitting device and the receiving device can communicate via a quantum channel and a classic channel.
  • FIG. 2 is a schematic diagram showing a system structure of a quantum communication method according to an embodiment of the present invention.
  • FIG. 2b is a schematic diagram showing another system structure applicable to the quantum communication method provided by the embodiment of the present invention.
  • the node A includes only the transmitting device 2101, and the node B includes only the receiving device 2102.
  • This system architecture is called a one-way system architecture.
  • the transmitting device 2101 at the node A receives the input service information, and encrypts the service information using the final quantum key to obtain an encrypted signal, and transmits the encrypted signal to the receiving device 2102 through the classical channel and the quantum channel.
  • the receiving device 2102 After receiving the encrypted signal, the receiving device 2102 performs the decryption process using the same final quantum key, decrypts and outputs the service information, and transmits the device to the transmitting device through the classical channel. 2101 sends a message.
  • the service is usually two-way, such as voice, video call, and the like.
  • each node needs encryption and decryption processing, and each node needs a QKD system accordingly.
  • the node A includes a transmitting device 2201 and a receiving device 2203.
  • the node B includes a receiving device 2202 and a transmitting device 2204.
  • the transmitting device 2201 and the receiving device 2202 are a pair, and the transmitting device 2204 and the receiving device 2203 are a pair.
  • This system architecture is called a two-way system architecture.
  • a plurality of information transmission modes can be implemented in the system architecture, and the pair of the transmitting device 2201 and the receiving device 2202 are introduced as an example, for example:
  • the transmitting device 2201 at the node A receives the input service information, and encrypts the service information by using the final quantum key to obtain an encrypted signal, and sends the encrypted signal to the receiving device 2202 at the node B through the classical channel or the time division multiplexed quantum channel.
  • the encrypted signal After receiving the encrypted signal, the receiving device 2202 performs the decryption process using the same final quantum key, and decrypts and outputs the service information. In a first mode, the receiving device 2202 transmits information to the transmitting device 2201 through the classical channel.
  • the receiving device 2202 transmits the service information that needs to be sent to the transmitting device 2201 to the transmitting device 2204 of the node B, and the transmitting device 2204 encrypts the service information using the final quantum key to obtain an encrypted signal.
  • the classic channel between the transmitting device 2204 and the receiving device 2203, or the time division multiplexed quantum channel, is sent to the receiving device 2203.
  • the receiving device 2203 After receiving the encrypted signal, the receiving device 2203 performs the decryption process using the same final quantum key. The information is decrypted and output to the transmitting device 2201.
  • the receiving device may feed back information to the sending device by using the above or other manners.
  • only the transmitting device is limited to how to send information to the receiving device, and/or the receiving device receives the information sent by the sending device. How to deal with it later, and the manner in which the receiving device transmits information to the transmitting device by what way is not specifically limited.
  • any one of the terms “sending device, receiving device” includes but is not limited to a base station, a station controller, an access point (AP), or any other type.
  • An interface device that can operate in a wireless environment.
  • QKD technology includes discrete variable quantum key distribution (Discrete Variable-Quantum Key Distribution, referred to as DV-QKD) and Continuous Variable-Quantum Key Distribution (CV-QKD).
  • DV-QKD discrete Variable-Quantum Key Distribution
  • CV-QKD Continuous Variable-Quantum Key Distribution
  • CV-QKD is more widely used in engineering because it does not need to operate at low temperature single photon detectors, and thus embodiments of the present invention are preferably applicable to CV-QKD technology.
  • the quantum communication method provided by the embodiment of the present invention is mainly used to implement quantum key distribution of a transmitting device and a receiving device.
  • the quantum key is used to encrypt classic information and enhance the security of the classical information transfer process.
  • the classic information in the embodiment of the present invention may be information such as voice, image, video, data, and the like that need to be transmitted securely.
  • FIG. 3 shows a quantum communication method implemented by a transmitting apparatus according to an embodiment of the present invention, which includes the following steps:
  • Step 301 The DSP unit of the sending device determines the information that needs to be output according to the signal sending indication information, wherein the information to be output is quantum information or classical information, and the quantum information and the classical information are time-division multiplexed; that is, quantum information and classical information. Sent at intervals of time;
  • Step 302 The optical signal generating unit of the transmitting device performs spectral processing on the generated optical pulse signal to obtain a first optical signal and a second optical signal.
  • the first optical signal is used to carry quantum information and classical information; the second optical signal is obtained.
  • the light intensity signal of the first light signal is greater than the light intensity of the first light signal;
  • Step 303 the DSP unit of the transmitting device adjusts the attenuation value output by the attenuation unit of the transmitting device according to the information that needs to be outputted at present; the DSP unit of the transmitting device adjusts the attenuation value output by the attenuation unit of the transmitting device according to the information that is currently required to be output; The DSP unit of the device inputs a modulation signal corresponding to the information to be output to the modulation unit of the transmitting device according to the information currently required to be output;
  • Step 304 The attenuation unit of the transmitting device attenuates the first optical signal according to the adjusted attenuation value, and the modulation unit of the transmitting device modulates the attenuated first optical signal according to the input modulation signal; or the modulation unit of the transmitting device
  • the first optical signal is modulated according to the input modulation signal, and the attenuation unit of the transmitting device attenuates the modulated first optical signal according to the adjusted attenuation value;
  • Step 305 The polarization coupling unit in the transmitting device couples the attenuated and modulated first optical signal and the second optical signal to obtain a coupled optical signal, and transmits the coupled optical signal.
  • the light source of the transmitting device generates a periodic light pulse driven by the periodic electric pulse signal generated by the electric pulse signal generating unit, and the light pulse is divided into light intensity by the spectroscopic processing of the optical splitter.
  • the two optical signals are respectively a first optical signal and a second optical signal, wherein the optical intensity of the second optical signal is greater than the optical intensity of the first optical signal.
  • the second optical signal having a large light intensity that is, the associated local oscillation signal, is directly input to one end of the polarization coupler; the first optical signal having a small light intensity is input to the attenuation unit or the modulation unit.
  • the positions of the attenuation unit and the modulation unit are mutually interchangeable. That is, the first optical signal may first pass through the attenuation unit, and the first optical signal output from the attenuation unit enters the modulation unit, and then the first optical signal that is attenuated and modulated is transmitted through the polarization coupling unit. Or the first optical signal may first pass through the modulating unit, and the first optical signal outputted from the adjusting unit enters the fading unit, and then the modulated and attenuated first optical signal is sent out through the polarization coupling unit.
  • the first optical signal is first introduced through the fading unit and then through the modulating unit. The first optical signal passes through the modulating unit and then passes through the fading unit, and the first optical signal passes through the fading unit and then passes through the modulating unit. The method is similar and will not be described again.
  • the quantum information is an optical random sequence having quantum properties including an original quantum key.
  • the transmitting device needs to transmit the quantum information, the transmitting device sends a random sequence of light having quantum characteristics, and the receiving device can only receive the light having the quantum characteristic due to loss in the transmission process. Part of the content in the random sequence. Thereafter, the transmitting device and the receiving device determine the original quantum key from the random sequence of light having quantum properties received by the receiving device.
  • the classic information is information including any one or more of negotiation information, business information, and synchronization clock signals.
  • the negotiation information includes: causing the transmitting end to generate an original quantum key according to the quantum information, and further generating information of the final quantum key according to the original quantum key.
  • the post-processing stage can be, for example, a processing stage such as a measurement base stage, a bit error estimation stage, an error correction stage, and a private amplification stage.
  • Synchronous clock signal includes receiving device The clock is recovered, and the transmitting device is made to hold the clock information.
  • the service information is information that the user needs to send to the transmitting device through the receiving device when the user performs a certain service.
  • FIG. 3 is a schematic structural diagram of a transmitting apparatus for quantum communication provided by an embodiment of the present invention
  • FIG. 3b exemplarily shows a receiving apparatus for quantum communication provided by an embodiment of the present invention. Schematic diagram of the structure used to perform the above steps. The method provided by the embodiment of the present invention will be described below with reference to the apparatus shown in FIG. 3a and FIG. 3b.
  • the transmitting device 3201 provided by the embodiment of the present invention includes a first main control unit 3203, an optical signal generating unit 3205, an attenuating unit 3206, a first modulating unit 3207, a transmitting device DSP unit 3208, and a polarization coupling unit 3209 of the transmitting device.
  • the receiving device 3202 includes a second main control unit 3204 of the receiving device, a polarization splitting unit 3210, a second modulating unit 3211, a coupling unit 3212, a balanced receiver unit 3213, and a receiving device DSP unit 3214.
  • the first main control unit, the second main control unit, the first modulation unit, the second modulation unit, the DSP unit of the transmitting device, and the DSP unit of the receiving device and the likes appearing in similar nouns
  • the first "second” is used only for differentiation and does not have a limiting meaning.
  • FIGS. 3a and 3b can be implemented in various embodiments.
  • An optional embodiment is provided in the embodiment of the present invention, as shown in FIG. 3c and FIG. 3d, and FIG. 3c and FIG. 3d exemplarily show FIG. 3a.
  • FIG. 3c and FIG. 3d exemplarily show FIG. 3a.
  • the optical signal generating unit 3205 of the transmitting device 3201 includes an electrical pulse signal generating unit 3301, a light source 3302 for generating an optical signal connected to the electrical pulse signal generating unit, and a beam splitter 3303 connected to the light source 3302. .
  • the attenuation unit 3206 is connected to the beam splitter 3303.
  • Attenuation unit 3206 can be implemented in a variety of implementations. In Figures 3c and 3d, attenuation unit 3206 is comprised of light adjustable attenuator 3304.
  • the first modulation unit 3207 can include a first modulator 3305 coupled to the optically adjustable attenuator 3304 and a second modulator 3306 coupled to the first modulator 3305.
  • the transmitting device DSP unit 3208 is composed of a first DSP 3310.
  • the first DSP 3310 is connected to the optically adjustable attenuator 3304, the first modulator 3305 and the second modulator 3306.
  • the first DSP 3310 inputs the attenuation value to the optically adjustable attenuator 3304.
  • a modulator 3305 inputs the modulated signal and inputs a modulated signal to the second modulator 3306.
  • Polarization coupling unit 3209 includes a first polarization component coupled to second modulator 3306
  • the optical device 3307 has a first Faraday mirror 3308 connected to the first polarization beam splitter 3307 and a first polarization coupler 3309 connected to the first polarization beam splitter 3307.
  • the polarization splitting unit 3210 of the receiving device 3202 includes a dynamic polarization controller 3311 that receives an optical signal, and a second polarization beam splitter 3312 that is coupled to the dynamic polarization controller 3311.
  • the second modulation unit 3211 includes a third modulator 3313 coupled to the second polarization beam splitter 3312.
  • the coupling unit 3212 includes a third polarization beam splitter 3315 connected to the third modulator 3313, a second Faraday mirror 3316 connected to the third polarization beam splitter 3315, and a coupler 3317 connected to the third polarization beam splitter 3315.
  • the balanced receiver unit 3213 includes a balanced receiver 3318 coupled to a coupler 3317.
  • the receiving device DSP unit 3214 includes a second DSP 3319 coupled to the balanced receiver 3318 and the third modulator 3313.
  • the transmitting device DSP unit 3208 includes at least a first DAC connected to the optically adjustable attenuator 3304 and a second analog to digital converter (Analog-to-Digital Converter) connected to the first modulator 3305. , abbreviated as ADC), and a third DAC connected to the second modulator 3306, and three selectors.
  • ADC Analog-to-Digital Converter
  • the receiving device DSP unit 3214 includes at least a fourth DAC connected to the third modulator, an ADC connected to the balanced receiver, and a Root Meam Square (RMS) root mean square device connected to the ADC and the balanced receiver, and a plurality of Selector.
  • RMS Root Meam Square
  • the light source of the transmitting device generates a periodic light pulse driven by the periodic electrical pulse signal generated by the electrical pulse signal generating unit; the light pulse passes through the beam splitter, and further It is divided into two optical signals with different light intensity levels.
  • One of the light intensity is the second optical signal, that is, the accompanying local oscillator signal, and the associated local oscillator signal is directly input to one end of the polarization coupler.
  • the light intensity output by the optical splitter is a first optical signal for carrying quantum information and classical information
  • the first optical signal is input to the attenuation unit for attenuation, and the first light is attenuated.
  • the signal is modulated by a modulation unit. The process is described in detail below.
  • the first main control unit of the transmitting device generates signaling indication information.
  • the signaling indication information includes first transmission indication information and second transmission indication information that are time division multiplexed.
  • the DSP unit of the sending device receives the first sending indication information, and determines that the information that needs to be output is quantum information.
  • the DSP unit of the sending device receives the second sending indication information, and the DSP unit of the sending device determines that the information that needs to be output is Classic information.
  • the first sending indication information and the second sending indication information may be sent at intervals, for example, sending the first sending indication information from the first minute to the fifth minute, and sending the second sending indication in the fifth minute to the tenth minute.
  • the first transmission indication information is sent from ten minutes to fifteenth minutes. Or, for example, the first sending indication information is sent from the first minute to the fifth minute, the second sending indication information is sent in the fifth minute to the twelfth minute, and the second sending indication information is sent in the twelve minutes to the fifteenth minute.
  • the length of time for sending the first sending indication information and the second sending indication information, and the interval of sending can be freely adjusted.
  • the first sending indication information and the second sending indication information may be implemented by sending a high low level, such as a high level indicating the first sending indication information and a low level indicating the second sending indication information.
  • the DSP unit of the transmitting device determines that the information that needs to be output is quantum information
  • the attenuation value output by the attenuation unit of the transmitting device is adjusted to be below the first threshold, and the DSP unit of the transmitting device determines the current requirement.
  • the attenuation value of the attenuation unit output of the transmitting device is adjusted to be greater than or equal to a second threshold, wherein the first threshold is smaller than the second threshold.
  • the intensity of the obtained first optical signal is lower than the intensity of the optical quantum signal in the continuous variable quantum key distribution process.
  • the optical signal is converted into a photon quantum signal for carrying quantum information.
  • the obtained first optical signal is used to carry the classic information.
  • the selector of the transmitting device determines whether the information currently required to be output is quantum information, and if so, the DSP unit of the transmitting device sets the output value of the first DAC to increase The degree of attenuation of the first optical signal; if not, the DSP unit of the transmitting device sets the output value of the first DAC to reduce the degree of attenuation of the first optical signal.
  • the modulation signal input by the DSP unit of the transmitting device to the modulation unit of the transmitting device is a random sequence
  • the DSP unit of the transmitting device determines
  • the information currently required to be output is classic information
  • the modulated signal input by the DSP unit of the transmitting device to the modulation unit of the transmitting device is classical information.
  • the random sequence can be a Gaussian random sequence or a discrete random sequence.
  • the modulating unit includes: a first modulator, and a second modulator connected to the first modulator; and the modulated signal input by the DSP unit of the transmitting device to the modulating unit of the transmitting device is a random sequence, specifically
  • the modulation signal input by the DSP unit of the transmitting device to the first modulator and the second modulator of the transmitting device is a random sequence;
  • the modulated signal input by the DSP unit of the transmitting device to the modulation unit of the transmitting device is classical information, specifically a transmitting device.
  • the modulated signal input by the DSP unit to the first modulator of the transmitting device is classical information
  • the modulated signal input to the second modulator is classical information or a DC level
  • the modulation of the DSP unit of the transmitting device to the modulation unit of the transmitting device is classical information, specifically, the modulated signal input by the DSP unit of the transmitting device to the first modulator of the transmitting device is classical information or a DC level, and the modulated signal input to the second modulator is classical information.
  • the first optical signal output by the modulation unit includes quantum information and classical information, and the quantum information and the classical information are time-division multiplexed, that is, the quantum information and the classical information are transmitted at intervals.
  • the time interval of the quantum information and the classic information is the same as the corresponding time interval in the first transmission indication information and the second transmission indication information in the signal transmission indication information.
  • the modulated first optical signal outputted by the modulation unit of the transmitting device enters the other end of the first polarization coupler, and is polarization-multiplexed and coupled with the second optical signal to obtain polarization multiplexing and coupling.
  • the coupled optical signal is finally output to the fiber.
  • the local oscillator signal leaks to the quantum channel of the first optical signal, thereby generating a large interference, in order to increase the local oscillator signal.
  • the isolation from the first optical signal is usually delayed by a first polarization beam splitter, a first Faraday mirror and a length of optical fiber, such that the first optical signal and the associated local oscillator signal are staggered in timing. Therefore, the isolation between the two is increased, and the interference of the local light signal with the first optical signal is reduced.
  • Fiber length The degree may be determined according to a specific application scenario, and is not limited in the embodiment of the present invention.
  • the main control unit of the transmitting device is configured to generate a random sequence, classic information, and is also used to perform post-processing of the transmitting device to generate a transmitting device quantum key.
  • the transmitting device main control unit further includes other parts required by the QKD system, such as a communication interface, a modulator control interface, a destination signaling point code (DPC) control interface, a performance detection and a report alarm interface, A true random sequence generator, etc., will not be described in detail herein.
  • the attenuation unit in the above method is implemented by multiple implementations, and the attenuation unit is:
  • a first optical switch that receives the first optical signal, a first fixed attenuator coupled to the first optical switch, and a second optical switch coupled to the first fixed attenuator;
  • a first optical splitter that receives the first optical signal
  • a second fixed attenuator that is coupled to the first optical splitter
  • a third optical switch that is coupled to the second fixed attenuator
  • a fourth optical switch that receives the first optical signal, a third fixed attenuator that is coupled to the fourth optical switch, and a second optical splitter that is coupled to the third fixed attenuator.
  • the first optical switch is a 1:2 optical switch
  • the second optical switch is a 2:1 optical switch.
  • FIG. 3g exemplarily shows another possible implementation manner of FIG. 3a.
  • the attenuation unit in FIG. 3g is a first optical switch that receives a first optical signal, and a first fixed attenuator that is connected to the first optical switch.
  • the first beam splitter and the second beam splitter may be a 1:2 splitter.
  • the data signal processing DSP unit of the receiving device determines, according to the signal receiving indication information, the information that needs to be received, wherein the information to be received is quantum information or classic information, and The quantum information and the classical information are time-division multiplexed; the polarization splitting unit of the receiving device processes the received optical signal to obtain a third optical signal and a fourth optical signal; and the DSP unit of the receiving device sends the received information to the receiving device according to the information currently needed to be received.
  • the modulation unit inputs a modulation signal; the modulation unit of the receiving device modulates the received fourth optical signal according to the input modulation signal; and the coupling unit of the receiving device performs interference processing on the modulated fourth optical signal and the third optical signal,
  • the processed optical signal is obtained; the DSP unit of the receiving device recovers the quantum information and the classical information from the processed optical signal according to the information currently required to be received.
  • the fourth optical signal is a channel local oscillator signal that is separated by the optical signal received by the receiving device
  • the third signal is a signal that carries the quantum information and the classical information that is separated by the optical signal received by the receiving device.
  • the light intensity of the fourth light signal is greater than the light intensity of the third light signal.
  • the optical signal received by the receiving device enters a dynamic polarization controller of the receiving device, and the dynamic polarization controller is configured to adjust the polarization state of the optical signal of the control input in real time, so that the optical signal output from the dynamic polarization controller to the polarization beam splitter is When splitting, the third optical signal is completely output from one end of the polarization beam splitter, and the third optical signal, that is, the local light signal is completely output from the other end.
  • the baseband oscillating signal is subjected to measurement base modulation via a third modulator.
  • the third modulator is modulated under the control of the DSP unit of the receiving device.
  • the second main control unit of the receiving device generates signal receiving indication information.
  • the signal receiving indication information includes first receiving indication information and second receiving indication information that are time division multiplexed.
  • the data signal processing DSP unit of the receiving device determines the information that needs to be received according to the signal receiving indication information, and specifically includes:
  • the DSP unit of the receiving device determines that the information that needs to be received is quantum information; and the DSP unit of the receiving device receives the second receiving indication information, the DSP unit of the receiving device determines the current The information that needs to be received is classic information.
  • the DSP unit of the receiving device inputs the modulation signal to the modulation unit of the receiving device according to the information that is currently required to be received, and specifically includes:
  • the modulated signal input by the DSP unit of the receiving device to the modulation unit of the receiving device is a random sequence; and the DSP unit of the receiving device determines that the information currently needed to be received is quantum information.
  • the modulated signal input by the DSP unit of the receiving device to the modulation unit of the receiving device is at a DC level.
  • the modulated fourth optical signal output by the third modulator passes through a device similar to the transmitting device, that is, the third optical signal is delayed by the third polarization beam splitter and the second Faraday mirror to ensure input to the coupler.
  • the third signal and the fourth optical signal are aligned in time series.
  • the coupling unit enters the coupling unit, and the coupling unit performs interference processing on the modulated second optical signal and the first optical signal to obtain a processed optical signal.
  • the coupling unit is a 2:2 coupler, and the two outputs of the coupler are respectively connected Balance the input ends of the receiver.
  • the interference processing is specifically an optical interferometry technique.
  • laser a high-intensity coherent light source
  • the ability of digital integrated circuits such as computers to acquire and process data from interferometers has greatly improved, and the application of single-mode fibers has increased the effective optical path in experiments and still remains low.
  • Noise, fiber optic interferometry technology has developed rapidly. Further, with the development of electronic technology, it is no longer necessary to observe the interference fringes generated by the interferometer, and the phase difference of the coherent light can be directly measured.
  • the DSP unit of the receiving device outputs a gain value to the balanced receiver unit of the receiving device according to the information currently required to be received; the balanced receiver unit converts the processed optical signal input through the coupling unit into an electrical signal, and The gain value is used to perform gain control on the converted electrical signal such that the amplitude of the electrical signal after the gain control is within a preset range.
  • the processed optical signal received by the balanced receiver includes quantum information and classical information spaced in time, that is, the balanced receiver needs to receive the quantum information of the weak light and the classic information of the strong light in a time-sharing manner, and the DSP of the receiving device allows The dynamic range of the input electrical signal is limited, so the gain signal of the optical signal input to the DSP needs to be controlled by the balanced receiver.
  • the preset range of the gain value is the range of the amplitude of the electrical signal allowed by the DSP.
  • the DSP of the receiving device includes an ADC for sampling and detecting the input electrical signal of the balanced receiver, an RMS module for detecting the amplitude of the input signal, and the output of the RMS module is used to adjust the gain of the amplifier inside the balanced receiver. So that the amplitude of the signal input to the ADC remains the same.
  • the DSP unit of the receiving device when indicating that the quantum information is received, and the quantum information is an optical random sequence having a quantum characteristic including the original quantum key, cuts the output signal to the quantum signal measuring unit for data processing, and the processing is completed.
  • the data is called original quantum information, and the original quantum information is output to the main control unit for post processing of the receiving device.
  • the DSP unit of the receiving device processes the electrical signal after the gain control according to the information currently needed to be received.
  • the receiving device DSP unit recovers the quantum information from the electrical signal after the gain control;
  • the receiving device detects and recovers the synchronous clock from the classic information and performs clock holding.
  • the synchronous clock signal is a synchronous clock signal processed by all signals of the receiving device, and then the receiving device DSP unit performs gain control.
  • the classic information is recovered from the electrical signal.
  • the receiving device DSP unit also recovers the synchronous clock based on the received signal.
  • the DSP unit of the receiving device recovers the quantum information and the classic information from the processed optical signal according to the information currently needed to be received
  • the DSP unit of the receiving device sends the classic information and the quantum information to the main control of the receiving device.
  • the unit, the main control unit of the receiving device performs post processing according to the classical information and the quantum information to determine the final quantum key.
  • the main control unit of the receiving device performs post-processing of the receiving device based on the recovered classic information and quantum information and the synchronous clock, and restores the final quantum key of the receiving device.
  • the master unit of the receiving device is further configured to generate a random sequence for outputting the fourth DAC of the DSP unit of the receiving device to the third modulator.
  • the receiving device main control unit also includes other parts of the QKD system, such as communication interface, modulator control interface, DPC control interface, performance detection and reporting alarm interface, true random sequence generator, etc. Said.
  • FIG. 3h exemplarily shows a timing chart in which signals are transmitted from respective units of the transmitting device
  • FIG. 3i exemplarily shows a timing chart in which signals are transmitted from respective units of the receiving device.
  • the main control unit of the transmitting device sends a signal transmission indication information, where the signal transmission indication information includes first transmission indication information and second transmission indication information.
  • the first sending indication information is information indicating that the current output needs to be quantum information
  • the second sending indication information is information indicating that the current output needs to be classic information.
  • the first transmission indication information is a high level
  • the second transmission indication information is a low level.
  • the main control unit of the transmitting device starts at time t0 and continuously transmits the first transmission indication information, and continues to transmit to (t0+T1), starts at (t0+T1) and continues to transmit the second transmission indication information.
  • Starting at (t0+T1+T2) and continuously transmitting the first transmission indication information starting at (t0+2 ⁇ T1+T2) and continuously transmitting the second transmission indication information, at (t0+2 ⁇ T1+2 ⁇ T2)
  • Starts and continuously transmits the first transmission indication information starts at the time of (t0+3 ⁇ T1+2 ⁇ T2) and continuously transmits the second transmission indication information, and so on.
  • t0, T1 and T2 can be any value.
  • the attenuation value output by the transmitting device DSP to the attenuation unit outputs a high voltage in the high-level corresponding region of the signal transmission indication information to increase the attenuation value, that is, when the signal transmission indication information is high level, the attenuation value in FIG. 3h is corresponding.
  • High level portion; a low level corresponding region in which the signal is sent The low voltage is output to reduce the attenuation value, that is, when the signal transmission indication information is low level, it corresponds to the low level portion of the attenuation value in FIG. 3h.
  • the modulation signal output from the transmitting device DSP to the first modulator outputs a random sequence 1 in a high-level corresponding region of the signal transmission instruction information, and outputs a DC level in a low-level corresponding region of the signal transmission instruction information.
  • the modulation signal output from the transmitting device DSP to the second modulator outputs a random sequence 2 in a high-level corresponding region of the signal transmission instruction information, and outputs classic information in a low-level corresponding region of the signal transmission instruction information.
  • Both random sequence 1 and random sequence 2 can be Gaussian random sequences or discrete random sequences.
  • the optical signal output by the transmitting device outputs a quantum signal carrying the quantum information in the high-level corresponding region of the signal transmission instruction information as shown in FIG. 3h, and the signal transmission indication is performed.
  • the low-level corresponding area of the information outputs a classic signal carrying classic information. That is to say, the transmitting device transmits an optical signal that is time-division multiplexed with the quantum information and the classical information, that is, the information transmitted by the transmitting device is time-multiplexed information of the quantum information and the classical information, and the quantum information and the classical information are transmitted at intervals.
  • the main control unit of the receiving device sends a signal receiving indication information, where the signal receiving indication information includes first receiving indication information and second receiving indication information.
  • the first receiving indication information is that the information that needs to be received is quantum information
  • the second receiving indication information is information indicating that the information that needs to be received is classic information.
  • the first receiving indication information is a high level
  • the second receiving indication information is a low level.
  • the main control unit of the receiving device starts at time t1 and continuously receives the first receiving indication information, and continues to receive (t1+T1), starts at (t1+T1) and continues to receive the second receiving indication information, Starting at (t1+T1+T2) and continuously receiving the first reception indication information, starting at (t1+2 ⁇ T1+T2) and continuously receiving the second reception indication information, at (t1+2 ⁇ T1+2 ⁇ T2) starts and continuously receives the first reception indication information, starts at the time of (t1+3 ⁇ T1+2 ⁇ T2) and continuously receives the second reception indication information, and so on.
  • t1, T1 and T2 can be any value.
  • the modulation signal outputted by the receiving device DSP to the third modulator outputs a random sequence in a high-level corresponding region of the signal transmission indication information, and outputs a direct sequence in a low-level corresponding region of the signal transmission indication information.
  • Stream level After the receiving device undergoes a series of operations such as modulation and coupling, the receiving device recovers the classic information from the classical signal carrying the classic information, and recovers the original quantum key from the quantum signal carrying the quantum information. As shown in FIG. 3h, the information recovered by the receiving device returns the original quantum key in the high-level corresponding region of the signal transmission instruction information, and the transmitting device recovers the classic information in the low-level corresponding region of the signal transmission instruction information.
  • quantum information, negotiation information, and synchronous clock information can be transmitted through an optical fiber or a wavelength channel only by time-multiplexing quantum information and classical information, without increasing hardware cost and reducing generation. Cost, and the method is simple and efficient.
  • the DSP unit of the sending device determines the information that needs to be output according to the signal sending indication information, wherein the information to be output is quantum information or classic information, and the quantum information and the classical information.
  • the optical signal generating unit of the transmitting device performs spectroscopic processing on the generated optical pulse signal to obtain a first optical signal and a second optical signal; and the DSP unit of the transmitting device adjusts the attenuation unit of the transmitting device according to the information currently required to be output.
  • the output attenuation value; the DSP unit of the transmitting device inputs a modulation signal corresponding to the information to be output to the modulation unit of the transmitting device according to the information currently required to be output; the attenuation unit of the transmitting device pairs the first optical signal according to the adjusted attenuation value.
  • the modulation unit of the transmitting device modulates the attenuated first optical signal according to the input modulation signal; or the modulation unit of the transmitting device modulates the first optical signal according to the input modulation signal, and the attenuation unit of the transmitting device is configured according to According to the adjusted attenuation value, the modulated number Attenuating optical signal; transmitting means for polarization coupling unit and the attenuated first optical signal modulation, and a second optical signal coupling, to give the coupled optical signal, and transmits the optical signal coupling.
  • the optical signal output by the transmitting device includes time-division multiplexed quantum information and classical information, thereby avoiding the need in the prior art to separately transmit quantum information and classical information through two channels, simplifying the structure of the transmitting device and the receiving device. Reduce the number of channels between the transmitting device and the receiving device.
  • FIG. 4 is a schematic flow chart showing a quantum communication method according to an embodiment of the present invention.
  • an embodiment of the present invention provides a quantum communication method, including the following steps:
  • Step 401 The data signal processing DSP unit of the receiving device receives the indication information according to the signal, Determining information currently needed to be received, wherein the information to be received is quantum information or classical information, and quantum information and classical information are time-division multiplexed;
  • Step 402 The polarization splitting unit of the receiving device processes the received optical signal to obtain a first optical signal and a second optical signal.
  • Step 403 The DSP unit of the receiving device inputs a modulation signal to the modulation unit of the receiving device according to the information currently needed to be received;
  • Step 404 The modulation unit of the receiving device modulates the received second optical signal according to the input modulation signal.
  • Step 405 The coupling unit of the receiving device performs interference processing on the modulated second optical signal and the first optical signal to obtain a processed optical signal.
  • Step 406 The DSP unit of the receiving device recovers the quantum information and the classic information from the processed optical signal according to the information currently needed to be received.
  • the quantum information is a random sequence of light having quantum properties including an original quantum key
  • the classic information is information including any one or more of negotiation information, business information, and synchronization clock signals.
  • the signal receiving indication information includes first receiving indication information and second receiving indication information that are time division multiplexed;
  • the DSP unit of the receiving device determines the information that needs to be received according to the signal receiving indication information, and specifically includes:
  • the DSP unit of the receiving device determines that the information that needs to be received currently is quantum information
  • the DSP unit of the receiving device determines that the information currently needed to be received is classic information.
  • the DSP unit of the receiving device inputs the modulation signal to the modulation unit of the receiving device according to the information that is currently required to be received, and specifically includes:
  • the modulated signal input by the DSP unit of the receiving device to the modulation unit of the receiving device is a random sequence
  • the modulated signal input by the DSP unit of the receiving device to the modulation unit of the receiving device is a DC level.
  • the DSP unit of the receiving device recovers the quantum information and the classic information from the modulated first optical signal according to the information that is currently required to be received, and specifically includes:
  • the DSP unit of the receiving device outputs a gain value to the balanced receiver unit of the receiving device according to the information currently required to be received;
  • the balanced receiver unit converts the input processed optical signal into an electrical signal, and performs gain control on the converted electrical signal using the gain value, so that the amplitude of the electrical signal after performing the gain control falls within a preset range;
  • the DSP unit of the receiving device recovers the quantum information and the classical information from the electrical signal after the gain control.
  • the DSP unit of the receiving device recovers the quantum information and the classic information from the processed optical signal according to the information that is currently required to be received
  • the DSP unit further includes:
  • the DSP unit of the receiving device transmits the classic information and the quantum information to the main control unit of the receiving device;
  • the main control unit of the receiving device performs post processing based on the classical information and the quantum information to determine the final quantum key.
  • the data signal processing DSP unit of the receiving device determines the information that needs to be received according to the signal receiving indication information, wherein the information to be received is quantum information or classical information, and the quantum information And the classical information time division multiplexing; the polarization splitting unit of the receiving device processes the received optical signal to obtain the first optical signal and the second optical signal; and the DSP unit of the receiving device modulates the receiving device according to the information currently needed to be received.
  • the unit inputs a modulation signal; the modulation unit of the receiving device modulates the received second optical signal according to the input modulation signal; and the coupling unit of the receiving device performs interference processing on the modulated second optical signal and the first optical signal to obtain a processing The subsequent optical signal; the DSP unit of the receiving device recovers the quantum information and the classical information from the processed optical signal according to the information currently required to be received. In this way, the successful reception of the optical signal carrying the quantum information and the classical information by the quantum receiver is realized, and the quantum information and the classical information can be recovered according to the received optical signal, and the transmitting device and the receiving device are simplified. Structure, reducing the number of channels between the transmitting device and the receiving device.
  • FIG. 5 is a schematic structural diagram of a transmitting apparatus for quantum communication according to an embodiment of the present invention.
  • an embodiment of the present invention provides a transmitting apparatus for quantum communication, where the transmitting apparatus 5201 includes a transmitting apparatus DSP5208, an attenuating unit 5206, a modulating unit 5207, and a polarization coupling unit 5209, and optionally, an optical signal generating unit. 5205 and processor 5203 of the transmitting device:
  • the digital signal processing DSP is configured to determine the information that needs to be output according to the signal transmission indication information; adjust the attenuation value output by the attenuation unit according to the information currently required to be output; input and output to the modulation unit according to the information currently required to be output a modulated signal corresponding to the information; wherein the information to be output is quantum information or classical information, and the quantum information and the classical information are time-division multiplexed;
  • An optical signal generating unit configured to perform spectral processing on the generated optical pulse signal to obtain a first optical signal and a second optical signal;
  • An attenuation unit configured to attenuate the input optical signal according to the adjusted attenuation value
  • a modulating unit configured to modulate the input optical signal according to the input modulation signal
  • the polarization coupling unit is configured to couple the first optical signal that is attenuated after the attenuation, or the first optical signal that is modulated and then attenuated, and the second optical signal to obtain the coupled optical signal, and send the coupled optical signal.
  • the attenuation unit is:
  • a first optical switch that receives the first optical signal, a first fixed attenuator coupled to the first optical switch, and a second optical switch coupled to the first fixed attenuator;
  • a first optical splitter that receives the first optical signal
  • a second fixed attenuator that is coupled to the first optical splitter
  • a third optical switch that is coupled to the second fixed attenuator
  • a fourth optical switch that receives the first optical signal, a third fixed attenuator that is coupled to the fourth optical switch, and a second optical splitter that is coupled to the third fixed attenuator.
  • the modulation unit is one or more modulators.
  • the optical signal generating unit may be a circuit, a light source that generates an electrical pulse signal, which are sequentially connected, And beam splitter.
  • the polarization coupling unit is composed of a polarization beam splitter, a Faraday mirror, and a polarization coupler.
  • the quantum information is a random sequence of light having quantum properties including an original quantum key
  • the classic information is information including any one or more of negotiation information, business information, and synchronization clock signals.
  • the signaling indication information includes first transmission indication information and second transmission indication information that are time division multiplexed;
  • DSP specifically for:
  • the DSP is specifically used to:
  • the first threshold is less than the second threshold.
  • the DSP is specifically used to:
  • the modulated signal input to the modulation unit is a random sequence
  • the modulated signal input to the modulation unit is classical information.
  • the modulating unit comprises a first modulator and a second modulator connected to the first modulator;
  • DSP specifically for:
  • the modulated signals input to the first modulator and the second modulator are all random sequences
  • DSP specifically for:
  • the modulated signal input to the modulation unit is classical information
  • the modulated signal input to the first modulator is classical information
  • the modulated signal input to the second modulator is classical information or a DC level
  • the modulated signal input to the modulation unit is classical information
  • the modulated signal input to the first modulator is classical information or a direct current level
  • the modulated signal input to the second modulator is classical information
  • the DSP unit of the sending device determines the information that needs to be output according to the signal sending indication information, wherein the information to be output is quantum information or classic information, and the quantum information and the classical information.
  • the optical signal generating unit of the transmitting device performs spectroscopic processing on the generated optical pulse signal to obtain a first optical signal and a second optical signal; and the DSP unit of the transmitting device adjusts the attenuation unit of the transmitting device according to the information currently required to be output.
  • the output attenuation value; the DSP unit of the transmitting device inputs a modulation signal corresponding to the information to be output to the modulation unit of the transmitting device according to the information currently required to be output; the attenuation unit of the transmitting device pairs the first optical signal according to the adjusted attenuation value.
  • the modulation unit of the transmitting device modulates the attenuated first optical signal according to the input modulation signal; or the modulation unit of the transmitting device modulates the first optical signal according to the input modulation signal, and the attenuation unit of the transmitting device is configured according to According to the adjusted attenuation value, the modulated number Attenuating optical signal; transmitting means for polarization coupling unit and the attenuated first optical signal modulation, and a second optical signal coupling, to give the coupled optical signal, and transmits the optical signal coupling.
  • the optical signal output by the transmitting device includes time-division multiplexed quantum information and classical information, thereby avoiding the need in the prior art to separately transmit quantum information and classical information through two channels, simplifying the structure of the transmitting device and the receiving device. Reduce the number of channels between the transmitting device and the receiving device.
  • FIG. 6 is a schematic structural diagram of a receiving apparatus for quantum communication according to an embodiment of the present invention.
  • an embodiment of the present invention provides a receiving apparatus for quantum communication.
  • the receiving apparatus 6202 includes a receiving apparatus DSP6214, a modulator 6211, and optionally, a balanced receiver unit 6213, a coupling unit 6212, and a polarization splitting unit. 6210.
  • the processor 6204 of the receiving device includes a receiving apparatus DSP6214, a modulator 6211, and optionally, a balanced receiver unit 6213, a coupling unit 6212, and a polarization splitting unit. 6210.
  • the processor 6204 of the receiving device includes a receiving apparatus DSP6214, a modulator 6211, and optionally, a balanced receiver unit 6213, a coupling unit 6212, and a polarization splitting unit. 6210.
  • the DSP is configured to determine, according to the signal receiving indication information, information currently needed to be received, and input a modulation signal to the modulator according to the information currently needed to be received; and recover the quantum information from the processed optical signal according to the information currently needed to be received.
  • Classic information wherein the information to be received is quantum information or classical information, and quantum information and classical information are time-division multiplexed;
  • a polarization beam splitting unit configured to process the received optical signal to obtain a first optical signal and a second optical signal
  • a modulator for modulating the received second optical signal according to the input modulation signal
  • a coupling unit configured to perform interference processing on the modulated second optical signal and the first optical signal to obtain a processed optical signal.
  • the balanced receiver unit can be a balanced receiver.
  • the coupling unit may be composed of a coupler, a polarization beam splitter, and a Faraday mirror.
  • the polarization splitting unit may be composed of a dynamic polarization controller and a polarization beam splitter.
  • the quantum information is a random sequence of light having quantum properties including an original quantum key
  • the classic information is information including any one or more of negotiation information, business information, and synchronization clock signals.
  • the signal receiving indication information includes first receiving indication information and second receiving indication information that are time division multiplexed;
  • DSP specifically for:
  • Receiving the first receiving indication information determining that the information currently needed to be received is quantum information
  • the DSP is specifically used to:
  • the modulated signal input to the modulator is a random sequence
  • the modulated signal input to the modulator is a DC level.
  • the DSP is specifically used to:
  • the balanced receiver unit is configured to convert the input processed optical signal into an electrical signal, and perform gain control on the converted electrical signal by using a gain value, so that the amplitude of the electrical signal after performing the gain control belongs to a preset range. within.
  • the DSP is also used to:
  • a processor for post processing based on classical information and quantum information to determine a final quantum key For post processing based on classical information and quantum information to determine a final quantum key.
  • the data signal processing DSP unit of the receiving device determines the information that needs to be received according to the signal receiving indication information, wherein the information to be received is quantum information or classical information, and the quantum information And the classical information time division multiplexing; the polarization splitting unit of the receiving device processes the received optical signal to obtain the first optical signal and the second optical signal; and the DSP unit of the receiving device modulates the receiving device according to the information currently needed to be received.
  • the unit inputs a modulation signal; the modulation unit of the receiving device modulates the received second optical signal according to the input modulation signal; and the coupling unit of the receiving device performs interference processing on the modulated second optical signal and the first optical signal to obtain a processing The subsequent optical signal; the DSP unit of the receiving device recovers the quantum information and the classical information from the processed optical signal according to the information currently required to be received. In this way, the successful reception of the optical signal carrying the quantum information and the classical information by the quantum receiver is realized, and the quantum information and the classical information can be recovered according to the received optical signal, and the structure of the transmitting device and the receiving device is simplified. , reducing the number of channels between the transmitting device and the receiving device.
  • embodiments of the present invention can be provided as a method, or a computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.
  • a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.
  • the computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device.
  • the apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.
  • These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device.
  • the instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

Abstract

本发明实施例涉及量子通信领域，尤其涉及一种量子通信方法和装置，用于减少发送装置和接收装置之间的信道数量。本发明实施例中，发送装置的DSP单元根据信号发送指示信息，确定当前需要输出的信息，需要输出的信息为时分复用的量子信息或经典信息，DSP单元根据当前需要输出的信息，调整衰减单元输出的衰减值，并向调制单元输入与需要输出的信息对应的调制信号；衰减单元根据调整后的衰减值对光信号进行衰减，调制单元根据输入的调制信号对光信号进行调制，偏振耦合单元将经过衰减和调制的第一光信号，以及第二光信号进行耦合，得到并发送耦合后的光信号。如此，减少发送装置和接收装置之间的信道数量。

Description

一种量子通信方法和装置
本申请要求在2015年11月20日提交中国专利局、申请号为201510810459.2、发明名称为“一种量子通信方法和装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明实施例涉及量子通信领域，尤其涉及一种量子通信方法和装置。
背景技术
随着网络技术的快速发展，大量敏感信息需要通过网络传输，人们需要对敏感信息进行保护以免丢失或遭到攻击。加密是保障信息安全的重要手段之一。对于经典通信，当前最常用的加密技术是用复杂的数学算法来改变原始信息，如高级加密标准(Advanced Encryption Standard，简称AES)、三重数据加密算法(Triple Data Encryption Algorithm，简称TDEA)、RSA、消息摘要算法第五版(Message-Digest Algorithm，简称MD5)、安全散列算法(Secure Hash Algorithm，简称SHA)等等。
现有经典加密体系是建立在计算复杂度基础之上的，随着数学的进步和计算机速度的不断提升，其存在被破译的可能，并非绝对可靠。经典密码体制中，只有一次一密具有无条件安全性，它要求有与被加密数据相同长度的随机数密钥。而如何产生大量的随机数密钥一直是个难题，所以一次一密并没有得到实际应用。量子密钥分配(Quantum Key Distribution，简称QKD)技术的出现解决了这个难题。
QKD具体是以量子态作为信息单元，利用量子力学的一些原理来传输和保护信息，通常把通信双方以量子态为信息载体，利用量子力学原理，通过量子信道传输，在保密通信双方之间建立共享密钥。其安全性是由量子力学中的“海森堡测不准关系”及“单量子不可复制定理”或纠缠粒子的相干性和非局域性等量子特性来保证的。
量子通信的方案具体如下：
发送装置(Alice)将要传送的信息编排为一个大数，再用另一个大数作为密钥，将该两大数的乘积通过经典信道传递给接收装置(Bob)。Bob将接收到的两个大数的乘积除于密钥，即得到Alice所要传递的信息。上述Alice和Bob都需要拥有一段相同的大数做为加密、解密的密钥。产生这样的密钥过程称为量子密钥分配。
上述量子密钥分配过程具体是指Alice向Bob发送量子信息和协商信息，Bob根据量子信息以及Alice与Bob之间所发送的协商信息，生成密钥。
现有技术中，通过量子信道发送量子信息，通过经典信道发送协商信息。量子信道(Quantum Channel)具体是指单模光纤(Single ModeOptical Fiber)或自由空间。经典信道具体是指传统的物理信道。如图1所示，图1示例性示出了一个单向加密传送QKD系统的结构示意图。
QKD系统中包括Alice101和Bob102，Alice中包括主控单元103、量子发送机104、同步时钟发送机105、协商信息收发机106、业务信息发送机107，Bob中包括主控单元108、量子接收机109、同步时钟接收机110、协商信息收发机111、业务信息接收机112。Alice通过量子发送机向Bob的量子接收机发送量子信息，以使Bob根据量子信息获得原始量子密钥。Alice通过同步时钟发送机向Bob的同步时钟接收机发送同步时钟信号，以使Bob实现与Alice的时钟同步。Alice通过协商信息收发机与Bob的协商信息收发机之间相互发送和接收协商信息，以使Alice和Bob根据协商信息从原始量子密钥中确定出最终量子密钥。Alice通过业务信息发送机向Bob发送业务信息，以使Bob获取最终需要得到的信息。该过程中，Alice和Bob的协商信息收发机均用于传输在Alice和Bob的主控单元进行密钥生成后处理阶段所产生的需要在Alice和Bob之间进行交互的信息，后处理阶段阶段具体是指对输入到量子发送机的信息和量子接收机输出的信息进行的一系列处理，比如：对测量基、误码估计、纠错、私密放大等。
从上述过程中可看出，现有技术中QKD系统中发送装置与接收装置之间 需包括四条信道，发送装置需要包括三个发送机和一个收发机，接收装置需要包括三个接收机和一个收发机，发送装置和接收装置的结构复杂。
综上所述，亟需一种量子通信方法及装置，用于简化发送装置和接收装置的结构，减少发送装置和接收装置之间的信道数量。
发明内容
本发明实施例提供一种量子通信方法及装置，用于简化发送装置和接收装置的结构，减少发送装置和接收装置之间的信道数量。
本发明实施例提供一种量子通信方法，包括以下步骤：
发送装置的数字信号处理DSP单元根据信号发送指示信息，确定当前需要输出的信息，其中，需要输出的信息为量子信息或经典信息，且所述量子信息和所述经典信息时分复用；
所述发送装置的光信号产生单元对产生的光脉冲信号进行分光处理，得到第一光信号和第二光信号；其中，第一光信号用于承载量子信息和经典信息；第二光信号为随路本振光信号；第二光信号的光强度大于第一光信号的光强度；
所述发送装置的所述DSP单元根据当前需要输出的信息，调整所述发送装置的衰减单元输出的衰减值；所述发送装置的所述DSP单元根据当前需要输出的信息，向所述发送装置的调制单元输入与需要输出的信息对应的调制信号；
所述发送装置的所述衰减单元根据调整后的衰减值对所述第一光信号进行衰减，所述发送装置的所述调制单元根据输入的调制信号对衰减后的第一光信号进行调制；或者，所述发送装置的所述调制单元根据输入的调制信号对所述第一光信号进行调制，所述发送装置的所述衰减单元根据根据调整后的衰减值对调制后的第一光信号进行衰减；
所述发送装置中的偏振耦合单元将经过衰减和调制的第一光信号，以及所述第二光信号进行耦合，得到耦合后的光信号，并发送所述耦合后的光信 号。
如此，发送装置输出的光信号包括时分复用的量子信息和经典信息，因此避免了现有技术中需要通过两个信道分别发送量子信息和经典信息的方式，简化发送装置和接收装置的结构，减少发送装置和接收装置之间的信道数量。
可选地，所述量子信息为包括原始量子密钥的具有量子特性的光随机序列；所述经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。如此，则可将协商信息、业务信息和同步时钟信号中的任一项或任几项与量子信息均通过量子发送机所发送的第一光信号发送出去，避免了使用多个发送机分别发送上述几种信息的情况，简化了用于量子通信的发送装置和接收装置的结构，减少发送装置和接收装置之间的信道数量。
可选地，所述信号发送指示信息包括时分复用的第一发送指示信息和第二发送指示信息；
所述发送装置的所述DSP单元根据信号发送指示信息，确定当前需要输出的信息，具体包括：
所述发送装置的所述DSP单元接收到所述第一发送指示信息，则确定当前需要输出的信息为量子信息；所述发送装置的所述DSP单元接收到所述第二发送指示信息，则所述发送装置的所述DSP单元确定当前需要输出的信息为经典信息。
如此，发送装置即可根据第一发送指示信息和第二发送指示信息准确确定出当前需要输出的信息为经典信息还是量子信息，进而可根据当前需输出的信息进行处理，提高了数据处理的准确性。
可选地，所述发送装置的DSP单元根据当前需要输出的信息，调整所述发送装置的所述衰减单元输出的衰减值，具体包括：
所述发送装置的所述DSP单元确定当前需要输出的信息为量子信息时，将所述发送装置的所述衰减单元输出的衰减值调整至第一阈值以下；所述发送装置的所述DSP单元确定当前需要输出的信息为经典信息时，将所述发送装置的所述衰减单元输出的衰减值调整至第二阈值以上；其中，所述第一阈 值小于所述第二阈值。
如此，则可将第一光信号衰减为用于承载量子信息的光信号和用于承载经典信息的光信号，且实现所承载的量子信息和经典信息时分复用。
可选地，所述发送装置的所述DSP单元根据当前需要输出的信息，向所述发送装置的所述调制单元输入与需要输出的信息对应的调制信号，具体包括：
所述发送装置的所述DSP单元确定当前需要输出的信息为量子信息时，所述发送装置的所述DSP单元向所述发送装置的调制单元输入的调制信号为随机序列；
所述发送装置的DSP单元确定当前需要输出的信息为经典信息时，所述发送装置的所述DSP单元向所述发送装置的所述调制单元输入的调制信号为经典信息。
如此，则可在需要输出的信息为量子信息时，将随机序列调制在光信号上，当前需要输出的信息为经典信息时，将经典信息调制在光信号上，从而将量子信息和经典信息同时承载于一个光信号上，并实现了量子信息和经典信息在该光信号上的时分复用。
可选地，所述调制单元包括第一调制器，以及与所述第一调制器连接的第二调制器；
所述发送装置的所述DSP单元向所述发送装置的所述调制单元输入的调制信号为随机序列，具体包括：
所述发送装置的所述DSP单元向所述发送装置的所述第一调制器和所述第二调制器输入的调制信号均为随机序列；
所述发送装置的所述DSP单元向所述发送装置的所述调制单元输入的调制信号为经典信息，具体包括：
所述发送装置的所述DSP单元向所述发送装置的所述第一调制器输入的调制信号为经典信息，向所述第二调制器输入的调制信号为经典信息或直流电平；或者
所述发送装置的所述DSP单元向所述发送装置的所述第一调制器输入的调制信号为经典信息或直流电平，向所述第二调制器输入的调制信号为经典信息。
通过该方案，实现了调整单元将随机序列和经典信息调制在第一光信号上的目的。
本发明实施例提供一种量子通信方法，包括以下步骤：
接收装置的数据信号处理DSP单元根据信号接收指示信息，确定当前需要接收的信息，其中，需要接收的信息为量子信息或经典信息，且所述量子信息和所述经典信息时分复用；
所述接收装置的偏振分光单元对接收到的光信号进行处理，得到第一光信号和第二光信号；
所述接收装置的DSP单元根据当前需要接收的信息，向所述接收装置的调制单元输入调制信号；
所述接收装置的所述调制单元根据输入的调制信号对接收到的所述第二光信号进行调制；
所述接收装置的耦合单元对调制后的第二光信号和所述第一光信号进行干涉处理，得到处理后的光信号；
所述接收装置的DSP单元根据当前需要接收的信息，从所述处理后的光信号中恢复出量子信息和经典信息。
如此，则实现了通过量子接收机对承载有量子信息和经典信息的光信号的成功接收，并可根据该接收到的光信号，恢复出量子信息和经典信息，简化发送装置和接收装置的结构，减少发送装置和接收装置之间的信道数量。
可选地，所述量子信息为包括原始量子密钥的具有量子特性的光随机序列；所述经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。如此，则可将协商信息、业务信息和同步时钟信号中的任一项或任几项与量子信息均通过量子接收机成功接收，避免了使用多个接收机分别接收上述几种信息的情况，简化了用于量子通信的发送装置和接收装置 的结构，减少发送装置和接收装置之间的信道数量。
可选地，所述信号接收指示信息包括时分复用的第一接收指示信息和第二接收指示信息；
所述接收装置的所述DSP单元根据信号接收指示信息，确定当前需要接收的信息，具体包括：
所述接收装置的所述DSP单元接收到所述第一接收指示信息，则所述接收装置的所述DSP单元确定当前需要接收的信息为量子信息；所述接收装置的所述DSP单元接收到所述第二接收指示信息，则所述接收装置的所述DSP单元确定当前需要接收的信息为经典信息。
如此，接收装置即可根据第一发送指示信息和第二发送指示信息准确确定出当前需要输出的信息为经典信息还是量子信息，进而可根据当前需输出的信息进行处理，提高了数据处理的准确性。
可选地，所述接收装置的所述DSP单元根据当前需要接收的信息，向所述接收装置的调制单元输入调制信号，具体包括：
所述接收装置的所述DSP单元确定当前需要接收的信息为量子信息时，所述接收装置的所述DSP单元向所述接收装置的所述调制单元输入的调制信号为随机序列；所述接收装置的所述DSP单元确定当前需要接收的信息为量子信息时，所述接收装置的所述DSP单元向所述接收装置的所述调制单元输入的调制信号为直流电平。如此，可成功实现后续步骤中的经典信息和量子信息的分离。
可选地，所述接收装置的DSP单元根据当前需要接收的信息，从所述处理后的光信号中恢复出量子信息和经典信息，具体包括：
所述接收装置的所述DSP单元根据当前需要接收的信息，向所述接收装置的平衡接收机单元输出增益值；所述平衡接收机单元将输入的所述处理后的光信号转换为电信号，并使用所述增益值对转换后的电信号进行增益控制，以使进行增益控制之后的电信号的幅值属于预设范围之内；所述接收装置的所述DSP单元从进行增益控制之后的电信号中恢复出量子信息和经典信息。 如此，可成功将幅值不同的承载量子信息和经典信息的光信号传输至接收装置的DSP单元，进而使DSP单元从进行增益控制之后的电信号中恢复出量子信息和经典信息。
可选地，所述接收装置的DSP单元根据当前需要接收的信息，从所述处理后的光信号中恢复出量子信息和经典信息之后，还包括：
所述接收装置的所述DSP单元将所述经典信息和所述量子信息发送给所述接收装置的主控单元；所述接收装置的所述主控单元根据所述经典信息和量子信息进行后处理，确定出最终量子密钥。如此，可使接收装置成功确定出最终量子密钥，进而根据该量子密钥对待加密的信息进行加密处理。
本发明实施例提供一种用于量子通信的发送装置，包括：
数字信号处理DSP，用于根据信号发送指示信息，确定当前需要输出的信息；根据当前需要输出的信息，调整衰减单元输出的衰减值；根据当前需要输出的信息，向调制单元输入与需要输出的信息对应的调制信号；其中，需要输出的信息为量子信息或经典信息，且所述量子信息和所述经典信息时分复用；
光信号产生单元，用于对产生的光脉冲信号进行分光处理，得到第一光信号和第二光信号；
所述衰减单元，用于根据调整后的衰减值对输入的光信号进行衰减；
所述调制单元，用于根据输入的调制信号对输入的光信号进行调制；
偏振耦合单元，用于对经过先衰减后调制，或者先调制后衰减的第一光信号，以及所述第二光信号进行耦合，得到耦合后的光信号，并发送所述耦合后的光信号。
如此，发送装置输出的光信号包括时分复用的量子信息和经典信息，因此避免了现有技术中需要通过两个信道分别发送量子信息和经典信息的方式，简化发送装置和接收装置的结构，减少发送装置和接收装置之间的信道数量。
可选地，所述量子信息为包括原始量子密钥的具有量子特性的光随机序列；
所述经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。
可选地，所述信号发送指示信息包括时分复用的第一发送指示信息和第二发送指示信息；
所述DSP，具体用于：
接收到所述第一发送指示信息，则确定当前需要输出的信息为量子信息；
接收到所述第二发送指示信息，则确定当前需要输出的信息为经典信息。
可选地，所述DSP，具体用于：
确定当前需要输出的信息为量子信息时，将所述衰减单元输出的衰减值调整至第一阈值以下；
确定当前需要输出的信息为经典信息时，将所述衰减单元输出的衰减值调整至第二阈值以上；
其中，所述第一阈值小于所述第二阈值。
可选地，所述DSP，具体用于：
确定当前需要输出的信息为量子信息时，向所述调制单元输入的调制信号为随机序列；
确定当前需要输出的信息为经典信息时，向所述调制单元输入的调制信号为经典信息。
可选地，所述调制单元包括第一调制器，以及与所述第一调制器连接的第二调制器；
所述DSP，具体用于：
在向所述调制单元输入的调制信号为随机序列时，向所述第一调制器和所述第二调制器输入的调制信号均为随机序列；
所述DSP，具体用于：
在向所述调制单元输入的调制信号为经典信息时，向所述第一调制器输入的调制信号为经典信息，向所述第二调制器输入的调制信号为经典信息或直流电平；或者
在向所述调制单元输入的调制信号为经典信息时，向所述第一调制器输入的调制信号为经典信息或直流电平，向所述第二调制器输入的调制信号为经典信息。
可选地，所述衰减单元为：
光可调衰减器；或者
接收所述第一光信号的第一光开关，与所述第一光开关连接的第一固定衰减器，与所述第一固定衰减器连接的第二光开关；或者
接收所述第一光信号的第一分光器，与所述第一分光器连接的第二固定衰减器，与所述第二固定衰减器连接的第三光开关；或者
接收所述第一光信号的第四光开关，与所述第四光开关连接的第三固定衰减器，与所述第三固定衰减器连接的第二分光器。
本发明实施例提供一种用于量子通信的接收装置，包括：
数据信号处理DSP，用于根据信号接收指示信息，确定当前需要接收的信息，根据当前需要接收的信息，向调制器输入调制信号；根据当前需要接收的信息，从所述处理后的光信号中恢复出量子信息和经典信息；其中，需要接收的信息为量子信息或经典信息，且所述量子信息和所述经典信息时分复用；
偏振分光单元，用于对接收到的光信号进行处理，得到第一光信号和第二光信号；
所述调制器，用于根据输入的调制信号对接收到的所述第二光信号进行调制；
耦合单元，用于对调制后的第二光信号和所述第一光信号进行干涉处理，得到处理后的光信号。
如此，则实现了通过量子接收机对承载有量子信息和经典信息的光信号的成功接收，并可根据该接收到的光信号，恢复出量子信息和经典信息，简化发送装置和接收装置的结构，减少发送装置和接收装置之间的信道数量。
可选地，所述量子信息为包括原始量子密钥的具有量子特性的光随机序 列；
所述经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。
可选地，所述信号接收指示信息包括时分复用的第一接收指示信息和第二接收指示信息；
所述DSP，具体用于：
接收到所述第一接收指示信息，则确定当前需要接收的信息为量子信息；
接收到所述第二接收指示信息，则确定当前需要接收的信息为经典信息。
可选地，所述DSP，具体用于：
确定当前需要接收的信息为量子信息时，向所述调制器输入的调制信号为随机序列；
确定当前需要接收的信息为量子信息时，向所述调制器输入的调制信号为直流电平。
可选地，所述DSP，具体用于：
根据当前需要接收的信息，向平衡接收机单元输出增益值；从进行增益控制之后的电信号中恢复出量子信息和经典信息；
所述平衡接收机单元，用于将输入的所述处理后的光信号转换为电信号，并使用所述增益值对转换后的电信号进行增益控制，以使进行增益控制之后的电信号的幅值属于预设范围之内。
可选地，所述DSP，还用于：
在根据当前需要接收的信息，从所述处理后的光信号中恢复出量子信息和经典信息之后，将所述经典信息和所述量子信息发送给处理器；
所述处理器，用于根据所述经典信息和量子信息进行后处理，确定出最终量子密钥。
本发明实施例中，发送装置的数字信号处理(Digital Signal Processing，简称DSP)单元根据信号发送指示信息，确定当前需要输出的信息，其中，需要输出的信息为量子信息或经典信息，且量子信息和经典信息时分复用； 发送装置的光信号产生单元对产生的光脉冲信号进行分光处理，得到第一光信号和第二光信号；发送装置的DSP单元根据当前需要输出的信息，调整发送装置的衰减单元输出的衰减值；发送装置的DSP单元根据当前需要输出的信息，向发送装置的调制单元输入与需要输出的信息对应的调制信号；发送装置的衰减单元根据调整后的衰减值对第一光信号进行衰减，发送装置的调制单元根据输入的调制信号对衰减后的第一光信号进行调制；或者，发送装置的调制单元根据输入的调制信号对第一光信号进行调制，发送装置的衰减单元根据根据调整后的衰减值对调制后的第一光信号进行衰减；发送装置中的偏振耦合单元将经过衰减和调制的第一光信号，以及第二光信号进行耦合，得到耦合后的光信号，并发送耦合后的光信号。如此，发送装置输出的光信号包括时分复用的量子信息和经典信息，因此避免了现有技术中需要通过两个信道分别发送量子信息和经典信息的方式，简化发送装置和接收装置的结构，减少发送装置和接收装置之间的信道数量。
附图说明
为了更清楚地说明本发明实施例中的技术方案，下面将对实施例描述中所需要使用的附图作简要介绍。
图1为背景技术中提供的一个单向加密传送QKD系统的结构示意图；
图2a为本发明实施例提供的量子通信方法适用的一种系统结构示意图；
图2b为本发明实施例提供的量子通信方法适用的一种系统结构示意图；
图3为本发明实施例提供的发送装置实现的一种量子通信方法流程示意图；
图3a为本发明实施例所提供的一种用于量子通信的发送装置的结构示意图；
图3b为本发明实施例所提供的一种量子通信装置的结构示意图；
图3c为本发明实施例所提供的另一种量子通信装置的结构示意图；
图3d为本发明实施例所提供的另一种量子通信装置的结构示意图；
图3e为本发明实施例所提供的发送装置的主控单元和DSP单元以及接收装置的主控单元和DSP单元的具体工作流程示意图；
图3f为本发明实施例所提供的发送装置的主控单元和DSP单元以及接收装置的主控单元和DSP单元的具体工作流程示意图；
图3g为图3a的另一种可能的实现方式；
图3h为本发明实施例所提供的发送装置发送信号的时序图；
图3i为本发明实施例所提供的接收装置发送信号的时序图；
图4为本发明实施例所提供的接收装置实现的一种量子通信方法流程示意图；
图5为本发明实施例提供的一种用于量子通信的发送装置的结构示意图；
图6为本发明实施例提供的一种用于量子通信的接收装置的结构示意图。
具体实施方式
为了使本发明的目的、技术方案及有益效果更加清楚明白，以下结合附图及实施例，对本发明进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本发明，并不用于限定本发明。
本发明实施例中的发送装置和接收装置之间包括量子信道和经典信道。发送装置和接收装置可通过量子信道和经典信道进行通信。
图2a示例性示出了本发明实施例提供的量子通信方法适用的一种系统结构示意图，图2b示例性示出了本发明实施例提供的量子通信方法适用的另一种系统结构示意图。
如图2a所示，本发明实施例适用的系统架构中节点A仅包括发送装置2101，节点B仅包括接收装置2102。此系统架构称为单向系统架构。节点A处的发送装置2101接收输入的业务信息，使用最终量子密钥对业务信息进行加密过程，得到一个加密信号，通过经典信道和量子信道向接收装置2102发送该加密信号。接收装置2102接收到该加密信号之后，使用相同的最终量子密钥进行解密过程，将该业务信息解密并输出，并通过经典信道向发送装置 2101发送信息。
具体实施中，业务通常是双向的，比如语音、视频通话等业务。在双向进行的业务中，每个节点都需要加密和解密处理，相应地每个节点都需要一套QKD系统。如图2b所示，本发明实施例适用的系统架构中节点A包括发送装置2201和接收装置2203，节点B包括接收装置2202和发送装置2204。发送装置2201和接收装置2202是一对，发送装置2204和接收装置2203是一对。此系统架构称为双向系统架构。该系统架构下可实现多种信息传输方式，以发送装置2201和接收装置2202这一对为例进行介绍，比如：
节点A处的发送装置2201接收输入的业务信息，使用最终量子密钥对业务信息进行加密过程，得到一个加密信号，通过经典信道，或时分复用的量子信道向节点B处的接收装置2202发送该加密信号。接收装置2202接收到该加密信号之后，使用相同的最终量子密钥进行解密过程，将该业务信息解密并输出。方式一，接收装置2202通过经典信道向发送装置2201发送信息。方式二，接收装置2202将需要发送给发送装置2201的业务信息发送给节点B的发送装置2204，发送装置2204将该业务信息使用最终量子密钥对业务信息进行加密过程，得到一个加密信号，通过发送装置2204和接收装置2203之间的经典信道，或时分复用的量子信道发送给接收装置2203，接收装置2203接收到该加密信号之后，使用相同的最终量子密钥进行解密过程，将该业务信息解密并输出给发送装置2201。
上述方式仅仅是举例，接收装置可通过以上或者其它多种方式向发送装置反馈信息，本发明实施例中仅仅限定发送装置如何向接收装置发送信息，和/或接收装置接收到发送装置发送的信息之后如何处理，而对于接收装置通过何种方式何种信道向发送装置发送信息不做具体限定。
本发明实施例中，本发明实施例中，术语“发送装置、接收装置”中的任一个包括但不限于基站、站控制器、接入点(Access Point，简称AP)、或任何其它类型的能够在无线环境中工作的接口装置。
本发明实施例适用于QKD技术。QKD技术包括离散变量量子密钥分配 (Discrete Variable-Quantum Key Distribution，简称DV-QKD)和连续变量量子密钥分配(Continuous Variable-Quantum Key Distribution，简称CV-QKD)。CV-QKD由于其不需要工作于低温的单光子探测器，因而在工程中受到了更广泛的应用，因此本发明实施例优选地适用于CV-QKD技术。
本发明实施例提供的量子通信方法，主要用于实现发送装置和接收装置的量子密钥分配。该量子密钥用于对经典信息进行加密，增强经典信息传递过程的安全性。本发明实施例中的经典信息可以是需要保密传输的语音、图像、视频、数据等等信息。
基于图2a和图2b所示的系统架构，图3示出了本发明实施例提供的发送装置实现的一种量子通信方法，包括以下步骤：
步骤301，发送装置的DSP单元根据信号发送指示信息，确定当前需要输出的信息，其中，需要输出的信息为量子信息或经典信息，且量子信息和经典信息时分复用；即量子信息和经典信息在时间上间隔发送；
步骤302，发送装置的光信号产生单元对产生的光脉冲信号进行分光处理，得到第一光信号和第二光信号；其中，第一光信号用于承载量子信息和经典信息；第二光信号为随路本振光信号；第二光信号的光强度大于第一光信号的光强度；
步骤303，发送装置的DSP单元根据当前需要输出的信息，调整发送装置的衰减单元输出的衰减值；发送装置的DSP单元根据当前需要输出的信息，调整发送装置的衰减单元输出的衰减值；发送装置的DSP单元根据当前需要输出的信息，向发送装置的调制单元输入与需要输出的信息对应的调制信号；
步骤304，发送装置的衰减单元根据调整后的衰减值对第一光信号进行衰减，发送装置的调制单元根据输入的调制信号对衰减后的第一光信号进行调制；或者，发送装置的调制单元根据输入的调制信号对第一光信号进行调制，发送装置的衰减单元根据根据调整后的衰减值对调制后的第一光信号进行衰减；
步骤305，发送装置中的偏振耦合单元将经过衰减和调制的第一光信号，以及第二光信号进行耦合，得到耦合后的光信号，并发送耦合后的光信号。
上述步骤302中,发送装置的光源在电脉冲信号产生单元所产生的周期性电脉冲信号的驱动下，产生周期性的光脉冲，光脉冲经过分光器的分光处理，被分成光强度大小不等的两路光信号，分别为第一光信号和第二光信号，其中第二光信号的光强度大于第一光信号的光强度。之后，光强度大的第二光信号，即随路本振信号直接输入到偏振耦合器一端；光强度小的第一光信号输入到衰减单元或调制单元。
本发明实施例中，上述步骤303中，衰减单元和调制单元的位置可相互调换。也就是说，第一光信号可先经过衰减单元，从衰减单元输出的第一光信号再进入调制单元，之后经过偏振耦合单元将经过衰减和调制的第一光信号发送出去。或者第一光信号可先经过调制单元，从调整单元输出的第一光信号再进入衰减单元，之后经过偏振耦合单元将经过调制和衰减的第一光信号发送出去。以下为了方便介绍，以第一光信号先经过衰减单元再经过调制单元为例进行介绍，第一光信号先经过调制单元再经过衰减单元的方法与第一光信号先经过衰减单元再经过调制单元的方法类似，不再赘述。
本发明实施例中，量子信息为包括原始量子密钥的具有量子特性的光随机序列。具体来说，发送装置在当前需要发送量子信息时，发送装置所发送出的是一个具有量子特性的光随机序列，由于传输过程中有损耗，因此接收装置仅能接收到该具有量子特性的光随机序列中部分内容。之后，发送装置和接收装置从接收装置所接收到的具有量子特性的光随机序列中确定出原始量子密钥。经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。其中，协商信息包括使发送端根据量子信息生成原始量子密钥，进而根据原始量子密钥生成最终量子密钥的信息。具体来说，在发送装置和接收装置的进行密钥生成后处理阶段所产生的需要在发送装置和接收装置之间进行交互的信息。后处理阶段比如可为：对测量基阶段、误码估计阶段、纠错阶段、私密放大阶段等处理阶段。同步时钟信号包括使接收装置 恢复出时钟，进而使发送装置做时钟保持的信息。业务信息为用户执行某项业务时所需要通过接收装置需要向发送装置发送的信息。
图3a示例性示出了本发明实施例所提供的一种用于量子通信的发送装置的结构示意图，图3b示例性示出了本发明实施例所提供的一种用于量子通信的接收装置的结构示意图，用于执行上述步骤。下面结合图3a和图3b所示的装置对本发明实施例所提供的方法进行介绍。
本发明实施例所提供的发送装置3201包括发送装置的第一主控单元3203、光信号产生单元3205、衰减单元3206、第一调制单元3207、发送装置DSP单元3208和偏振耦合单元3209。接收装置3202中包括接收装置的第二主控单元3204、偏振分光单元3210、第二调制单元3211、耦合单元3212、平衡接收机单元3213和接收装置DSP单元3214。
本发明实施例中的“第一主控单元、第二主控单元、第一调制单元、第二调制单元、发送装置的DSP单元和接收装置的DSP单元”，以及类似的名词中出现的“第一”“第二”仅仅用于区分，不具有限定意义。
上述图3a和图3b中各个单元可由多种实现方式，本发明实施例中提供一种可选地实施方式，如图3c和图3d所示，图3c和图3d示例性示出了图3a和3b中各个单元的一种结构示意图。
如图3c和图3d所示，发送装置3201的光信号产生单元3205包括电脉冲信号产生单元3301，连接电脉冲信号产生单元的用于产生光信号的光源3302，连接光源3302的分光器3303组成。衰减单元3206连接分光器3303。衰减单元3206可由多种实现方式，在图3c和图3d中，衰减单元3206由光可调衰减器3304组成。第一调制单元3207可包括与光可调衰减器3304连接的第一调制器3305，以及与第一调制器3305连接的第二调制器3306。发送装置DSP单元3208由第一DSP3310组成，第一DSP3310连接光可调衰减器3304、第一调制器3305和第二调制器3306，第一DSP3310向光可调衰减器3304输入衰减值，向第一调制器3305输入调制信号，向第二调制器3306输入调制信号。偏振耦合单元3209包括与第二调制器3306连接的第一偏振分 光器3307、与第一偏振分光器3307连接的第一法拉第反射镜3308、与第一偏振分光器3307连接的第一偏振耦合器3309。
如图3c和图3d所示，接收装置3202的偏振分光单元3210包括接收光信号的动态偏振控制器3311、与动态偏振控制器3311连接的第二偏振分光器3312。第二调制单元3211包括与第二偏振分光器3312连接的第三调制器3313。耦合单元3212包括与第三调制器3313连接的第三偏振分光器3315、与第三偏振分光器3315连接的第二法拉第反射镜3316、与第三偏振分光器3315连接的耦合器3317。平衡接收机单元3213包括一个与耦合器3317连接的平衡接收机3318。接收装置DSP单元3214包括一个与平衡接收机3318和第三调制器3313连接的第二DSP3319。
图3e和图3f示例性示出了发送装置的主控单元和DSP单元以及接收装置的主控单元和DSP单元的具体工作流程示意图。如图3e和图3f所示，发送装置DSP单元3208至少包括与光可调衰减器3304连接的第一DAC，与第一调制器3305连接的第二模数转换器(Analog-to-Digital Converter，简称ADC)，以及与第二调制器3306连接的第三DAC，以及三个选择器。接收装置DSP单元3214至少包括与第三调制器连接的第四DAC，与平衡接收机连接的ADC，以及与ADC和平衡接收机连接的(Root MeamSquare，简称RMS)均方根装置，以及多个选择器。
下面结合图3a、图3b、图3c、图3d、图3e和3f对通信方法进行详细介绍。
如图3a、图3b、图3c和3d所示，发送装置的光源在电脉冲信号产生单元所产生的周期性电脉冲信号的驱动下，产生周期性的光脉冲；光脉冲经过分光器，进而被分成光强度大小不等的两路光信号。光强度大的一路为第二光信号，即随路本振信号，随路本振信号直接输入到偏振耦合器一端。
如图3a和图3b所示，分光器输出的光强度小的一路为第一光信号，用于承载量子信息和经典信息，第一光信号输入到衰减单元进行衰减，衰减后的第一光信号经过调制单元进行调制。下面对该过程进行详细介绍。
上述步骤301中，具体来说，发送装置的第一主控单元产生信号发送指示信息。可选地，信号发送指示信息包括时分复用的第一发送指示信息和第二发送指示信息。发送装置的DSP单元接收到第一发送指示信息，则确定当前需要输出的信息为量子信息；发送装置的DSP单元接收到第二发送指示信息，则发送装置的DSP单元确定当前需要输出的信息为经典信息。具体来说，第一发送指示信息和第二发送指示信息在时间上可间隔发送，比如第一分钟至第五分钟发送第一发送指示信息，在第五分钟至第十分钟发送第二发送指示信息，在十分钟至第十五分钟发送第一发送指示信息。或者比如第一分钟至第五分钟发送第一发送指示信息，在第五分钟至第十二分钟发送第二发送指示信息，在十二分钟至第十五分钟发送第二发送指示信息。本发明实施例中，第一发送指示信息和第二发送指示信息的发送的时间长度，发送的间隔均可自由调整。第一发送指示信息和第二发送指示信息可通过发送高低电平的方式来实现，比如高电平表示第一发送指示信息，低电平表示第二发送指示信息。
上述步骤302中，可选地，发送装置的DSP单元确定当前需要输出的信息为量子信息时，将发送装置的衰减单元输出的衰减值调整至第一阈值以下，发送装置的DSP单元确定当前需要输出的信息为经典信息时，将发送装置的衰减单元输出的衰减值调整至第二阈值以上，其中，第一阈值小于第二阈值。衰减单元通过第一阈值以下的衰减值对输入的第一光信号进行衰减后，所得到的第一光信号的强度低于连续变量量子密钥分配过程中光量子信号的强度，此时，第一光信号转换为光量子信号，用于承载量子信息。衰减单元通过第二阈值以上的衰减值对输入的第一光信号进行衰减后，所得到的第一光信号用于承载经典信息。
步骤302的具体实现方法如图3e和图3f所示，发送装置的选择器判断当前需要输出的信息是否为量子信息，若是，则发送装置的DSP单元设置第一DAC的输出值，以便增大对第一光信号的衰减程度；若不是，则发送装置的DSP单元设置第一DAC的输出值，以便减小对第一光信号的衰减程度。
上述步骤304中，可选地，发送装置的DSP单元确定当前需要输出的信息为量子信息时，发送装置的DSP单元向发送装置的调制单元输入的调制信号为随机序列，发送装置的DSP单元确定当前需要输出的信息为经典信息时，发送装置的DSP单元向发送装置的调制单元输入的调制信号为经典信息。随机序列可为高斯随机序列或离散随机序列。
具体来说，可选地，调制单元包括第一调制器，以及与第一调制器连接的第二调制器；发送装置的DSP单元向发送装置的调制单元输入的调制信号为随机序列，具体为发送装置的DSP单元向发送装置的第一调制器和第二调制器输入的调制信号均为随机序列；发送装置的DSP单元向发送装置的调制单元输入的调制信号为经典信息，具体为发送装置的DSP单元向发送装置的第一调制器输入的调制信号为经典信息，向第二调制器输入的调制信号为经典信息或直流电平；或者发送装置的DSP单元向发送装置的调制单元输入的调制信号为经典信息，具体为发送装置的DSP单元向发送装置的第一调制器输入的调制信号为经典信息或直流电平，向第二调制器输入的调制信号为经典信息。
通过上述步骤实现了调制单元所输出的第一光信号中包括量子信息和经典信息，且量子信息和经典信息时分复用，即量子信息和经典信息在时间上间隔发送。量子信息和经典信息的时间间隔与信号发送指示信息中的第一发送指示信息和第二发送指示信息中对应的时间间隔相同。
上述步骤306中，如图3e和图3f所示，发送装置调制单元输出的经过调制的第一光信号进入第一偏振耦合器另一端，与第二光信号一起做偏振复用以及耦合，得到耦合后的光信号，最后输出到光纤。该步骤中由于通常的偏振耦合器无法提供足够的偏振隔离度，随路本振光信号会泄露到第一光信号的量子通道，从而产生很大的干扰，为了加大随路本振光信号和第一光信号的隔离度，通常会通过一个第一偏振分光器、第一法拉第反射镜和一段光纤来延迟第一光信号，使得第一光信号和随路本振光信号在时序上错开，从而增加两者的隔离度，减少随路本振光信号对第一光信号的干扰。光纤具体长 度可根据具体应用场景制定，本发明实施例不做限制。
发送装置的主控单元用于生成随机序列、经典信息，还用于进行发送装置后处理，从而生成发送装置量子密钥。发送装置主控单元还包括一个QKD系统所需的其他部分内容，如通信接口、调制器控制接口、目的信令点编码(Destination Point Code，简称DPC)控制接口、性能检测与上报告警接口、真随机序列产生器等，在此不做详述。
可选地，上述方法中的衰减单元由多种实现方式，衰减单元为：
光可调衰减器；或者
接收第一光信号的第一光开关，与第一光开关连接的第一固定衰减器，与第一固定衰减器连接的第二光开关；或者
接收第一光信号的第一分光器，与第一分光器连接的第二固定衰减器，与第二固定衰减器连接的第三光开关；或者
接收第一光信号的第四光开关，与第四光开关连接的第三固定衰减器，与第三固定衰减器连接的第二分光器。
具体来说，第一光开关为1：2光开关，第二光开关为2:1光开关。图3g示例性示出了图3a的另一种可能的实现方式，图3g中衰减单元为接收第一光信号的第一光开关，与第一光开关连接的第一固定衰减器，与第一固定衰减器连接的第二光开关。可选地，第一分光器和第二分光器可为1:2分光器。
发送装置发送出耦合后的光信号之后，可选地，接收装置的数据信号处理DSP单元根据信号接收指示信息，确定当前需要接收的信息，其中，需要接收的信息为量子信息或经典信息，且量子信息和经典信息时分复用；接收装置的偏振分光单元对接收到的光信号进行处理，得到第三光信号和第四光信号；接收装置的DSP单元根据当前需要接收的信息，向接收装置的调制单元输入调制信号；接收装置的调制单元根据输入的调制信号对接收到的第四光信号进行调制；接收装置的耦合单元对调制后的第四光信号和第三光信号进行干涉处理，得到处理后的光信号；接收装置的DSP单元根据当前需要接收的信息，从处理后的光信号中恢复出量子信息和经典信息。
其中，第四光信号为接收装置接收到的光信号被分光出的随路本振信号，第三信号为接收装置接收到的光信号被分光出的承载量子信息和经典信息的信号。第四光信号的光强度大于第三光信号的光强度。
下面对接收装置的方法流程进行详细说明。
接收装置接收到的光信号进入到接收装置的动态偏振控制器中，动态偏振控制器用于实时调整控制输入的光信号的偏振状态，以使从动态偏振控制器输出至偏振分光器的光信号在进行分光时，第三光信号完全从偏振分光器的其中一端输出，第三光信号，即随路本振光信号完全从另外一端输出。
随路本振光信号经过第三调制器进行测量基调制。第三调制器在接收装置的DSP单元的控制下进行调制。可选地，接收装置的第二主控单元产生信号接收指示信息，可选地，信号接收指示信息包括时分复用的第一接收指示信息和第二接收指示信息。可选地，接收装置的数据信号处理DSP单元根据信号接收指示信息，确定当前需要接收的信息，具体包括：
接收装置的DSP单元接收到第一接收指示信息，则接收装置的DSP单元确定当前需要接收的信息为量子信息；接收装置的DSP单元接收到第二接收指示信息，则接收装置的DSP单元确定当前需要接收的信息为经典信息。
可选地，接收装置的DSP单元根据当前需要接收的信息，向接收装置的调制单元输入调制信号，具体包括：
接收装置的DSP单元确定当前需要接收的信息为量子信息时，接收装置的DSP单元向接收装置的调制单元输入的调制信号为随机序列；接收装置的DSP单元确定当前需要接收的信息为量子信息时，接收装置的DSP单元向接收装置的调制单元输入的调制信号为直流电平。
第三调制器输出的经过调制的第四光信号经过与发送装置相类似的装置，即经过第三偏振分光器和第二法拉第反射镜进行第四光信号延迟，以保证在输入到耦合器的第三信号和第四光信号时序上是对齐的。之后进入耦合单元中，耦合单元对调制后的第二光信号和第一光信号进行干涉处理，得到处理后的光信号。可选地，耦合单元为2:2的耦合器，耦合器的两个输出端分别接 平衡接收机的输入两端。
其中，干涉处理具体为光学干涉测量技术。随着激光这一高强度相干光源的发明，计算机等数字集成电路获取并处理干涉仪所得数据的能力大大提升，以及单模光纤的应用增长了实验中的有效光程并仍能保持很低的噪声，光纤干涉测量技术有了快速发展。进一步随着电子技术的发展，不必再去观察干涉仪产生的干涉条纹，而可以对相干光的相位差直接进行测量。
可选地，接收装置的DSP单元在根据当前需要接收的信息，向接收装置的平衡接收机单元输出增益值；平衡接收机单元将通过耦合单元输入的处理后的光信号转换为电信号，并使用增益值对转换后的电信号进行增益控制，以使进行增益控制之后的电信号的幅值属于预设范围之内。由于平衡接收机所接收的处理后的光信号包括在时间上间隔的量子信息和经典信息，即平衡接收机需要分时接收弱光的量子信息和强光的经典信息，而接收装置的DSP允许输入的电信号的动态范围有限，因此需要通过平衡接收机对输入至DSP的光信号进行增益控制。增益值地预设范围为DSP所允许输入的电信号的幅值的范围。具体来说，接收装置的DSP包括一个用于采样检测平衡接收机输入电信号的ADC，一个用于检测输入信号幅值的RMS模块，该RMS模块输出用于调整平衡接收机内部的放大器的增益，使得其输入到ADC的信号幅度保持一致。
可选地，接收装置的DSP单元当指示为接收量子信息，量子信息为包括原始量子密钥的具有量子特性的光随机序列，则将输出信号切到量子信号测量单元进行数据处理，其处理完的数据称为原始量子信息，该原始量子信息输出到主控单元做接收装置后处理。
接收装置的DSP单元根据当前需要接收的信息，对进行增益控制之后的电信号进行处理，当前需要接收量子信息时，接收装置DSP单元从进行增益控制之后的电信号中恢复出量子信息；当前需要接收经典信息时，接收装置从经典信息中检测恢复出同步时钟并做时钟保持，该同步时钟信号是接收装置所有信号处理的同步时钟信号，之后接收装置DSP单元从进行增益控制之 后的电信号中恢复出经典信息。接收装置DSP单元还依据接收到的信号恢复出同步时钟。可选地，接收装置的DSP单元根据当前需要接收的信息，从处理后的光信号中恢复出量子信息和经典信息之后，接收装置的DSP单元将经典信息和量子信息发送给接收装置的主控单元，接收装置的主控单元根据经典信息和量子信息进行后处理，确定出最终量子密钥。
接收装置的主控单元根据恢复出的经典信息和量子信息以及同步时钟，进行接收装置的后处理，恢复出接收装置的最终量子密钥。接收装置的主控单元还用于生成随机序列，用于使接收装置的DSP单元的第四DAC向第三调制器输出。接收装置主控单元还包括一个QKD系统所需的其他部分内容，如通信接口、调制器控制接口、DPC控制接口、性能检测与上报告警接口、真随机序列产生器等，在此不做详述。
为了更加详细描述上述方法流程，图3h示例性示出了发送装置各个单元发送信号的时序图；图3i示例性示出了接收装置各个单元发送信号的时序图。
如图3h所示，在t0时刻，发送装置的主控单元发出信号发送指示信息，信号发送指示信息包括第一发送指示信息和第二发送指示信息。第一发送指示信息为指示当前需要输出的信息为量子信息，第二发送指示信息为指示当前需要输出的信息为经典信息。第一发送指示信息为高电平，第二发送指示信息为低电平。
图3h中，发送装置的主控单元在t0时刻开始并持续发送第一发送指示信息，持续发送至(t0+T1)时，在(t0+T1)时刻开始并持续发送第二发送指示信息，在(t0+T1+T2)时刻开始并持续发送第一发送指示信息，在(t0+2×T1+T2)时刻开始并持续发送第二发送指示信息，在(t0+2×T1+2×T2)时刻开始并持续发送第一发送指示信息，在(t0+3×T1+2×T2)时刻开始并持续发送第二发送指示信息，以此类推。其中，t0、T1和T2可为任意值。
发送装置DSP向衰减单元所输出的衰减值，在信号发送指示信息的高电平对应区域输出高电压，以增大衰减值，即信号发送指示信息为高电平时，对应为图3h中衰减值的高电平部分；在信号发送指示信息的低电平对应区域 输出低电压，以减小衰减值，即信号发送指示信息为低电平时，对应为图3h中衰减值的低电平部分。
发送装置DSP向第一调制器输出的调制信号，在信号发送指示信息的高电平对应区域输出随机序列1，在信号发送指示信息的低电平对应区域输出直流电平。发送装置DSP向第二调制器输出的调制信号，在信号发送指示信息的高电平对应区域输出随机序列2，在信号发送指示信息的低电平对应区域输出经典信息。随机序列1和随机序列2均可为高斯随机序列或离散随机序列。如此，经过上述衰减、调制等一系列的工作之后，发送装置所输出的光信号如图3h所示，在信号发送指示信息的高电平对应区域输出承载量子信息的量子信号，在信号发送指示信息的低电平对应区域输出承载经典信息的经典信号。也就是说发送装置所发送的是量子信息和经典信息时分复用的一个光信号，即发送装置所发送的信息为量子信息和经典信息时分复用的信息，量子信息和经典信息间隔发送。
如图3i所示，在接收装置，需要将输入的时分复用的量子信息和经典信息区别开来，并使用量子信息和经典信息分别进行数据恢复。在t1时刻，接收装置的主控单元发出信号接收指示信息，信号接收指示信息包括第一接收指示信息和第二接收指示信息。第一接收指示信息为指示当前需要接收的信息为量子信息，第二接收指示信息为指示当前需要接收的信息为经典信息。第一接收指示信息为高电平，第二接收指示信息为低电平。
图3i中，接收装置的主控单元在t1时刻开始并持续接收第一接收指示信息，持续接收至(t1+T1)时，在(t1+T1)时刻开始并持续接收第二接收指示信息，在(t1+T1+T2)时刻开始并持续接收第一接收指示信息，在(t1+2×T1+T2)时刻开始并持续接收第二接收指示信息，在(t1+2×T1+2×T2)时刻开始并持续接收第一接收指示信息，在(t1+3×T1+2×T2)时刻开始并持续接收第二接收指示信息，以此类推。其中，t1、T1和T2可为任意值。
接收装置DSP向第三调制器输出的调制信号，在信号发送指示信息的高电平对应区域输出随机序列，在信号发送指示信息的低电平对应区域输出直 流电平。接收装置经过调制、耦合等一系列的工作之后，接收装置从承载经典信息的经典信号中恢复出经典信息，从承载量子信息的量子信号中恢复出原始量子密钥。接收装置所恢复的信息如图3h所示，在信号发送指示信息的高电平对应区域发送装置恢复出原始量子密钥，在信号发送指示信息的低电平对应区域发送装置恢复出经典信息。
本发明实施例中仅仅通过将量子信息和经典信息进行时分复用的方法，即可通过光纤或波长通道实现量子信息、协商信息和同步时钟信息等的传送，不需要增加硬件成本，降低了生成成本，且方法简单高效。
从上述内容可以看出：本发明实施例中，发送装置的DSP单元根据信号发送指示信息，确定当前需要输出的信息，其中，需要输出的信息为量子信息或经典信息，且量子信息和经典信息时分复用；发送装置的光信号产生单元对产生的光脉冲信号进行分光处理，得到第一光信号和第二光信号；发送装置的DSP单元根据当前需要输出的信息，调整发送装置的衰减单元输出的衰减值；发送装置的DSP单元根据当前需要输出的信息，向发送装置的调制单元输入与需要输出的信息对应的调制信号；发送装置的衰减单元根据调整后的衰减值对第一光信号进行衰减，发送装置的调制单元根据输入的调制信号对衰减后的第一光信号进行调制；或者，发送装置的调制单元根据输入的调制信号对第一光信号进行调制，发送装置的衰减单元根据根据调整后的衰减值对调制后的第一光信号进行衰减；发送装置中的偏振耦合单元将经过衰减和调制的第一光信号，以及第二光信号进行耦合，得到耦合后的光信号，并发送耦合后的光信号。如此，发送装置输出的光信号包括时分复用的量子信息和经典信息，因此避免了现有技术中需要通过两个信道分别发送量子信息和经典信息的方式，简化发送装置和接收装置的结构，减少发送装置和接收装置之间的信道数量。
图4示例性示出了本发明实施例提供的一种量子通信方法的流程示意图。
基于相同构思，本发明实施例提供一种量子通信方法，包括以下步骤：
步骤401，接收装置的数据信号处理DSP单元根据信号接收指示信息， 确定当前需要接收的信息，其中，需要接收的信息为量子信息或经典信息，且量子信息和经典信息时分复用；
步骤402，接收装置的偏振分光单元对接收到的光信号进行处理，得到第一光信号和第二光信号；
步骤403，接收装置的DSP单元根据当前需要接收的信息，向接收装置的调制单元输入调制信号；
步骤404，接收装置的调制单元根据输入的调制信号对接收到的第二光信号进行调制；
步骤405，接收装置的耦合单元对调制后的第二光信号和第一光信号进行干涉处理，得到处理后的光信号；
步骤406，接收装置的DSP单元根据当前需要接收的信息，从处理后的光信号中恢复出量子信息和经典信息。
可选地，量子信息为包括原始量子密钥的具有量子特性的光随机序列；
经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。
可选地，信号接收指示信息包括时分复用的第一接收指示信息和第二接收指示信息；
接收装置的DSP单元根据信号接收指示信息，确定当前需要接收的信息，具体包括：
接收装置的DSP单元接收到第一接收指示信息，则接收装置的DSP单元确定当前需要接收的信息为量子信息；
接收装置的DSP单元接收到第二接收指示信息，则接收装置的DSP单元确定当前需要接收的信息为经典信息。
可选地，接收装置的DSP单元根据当前需要接收的信息，向接收装置的调制单元输入调制信号，具体包括：
接收装置的DSP单元确定当前需要接收的信息为量子信息时，接收装置的DSP单元向接收装置的调制单元输入的调制信号为随机序列；
接收装置的DSP单元确定当前需要接收的信息为量子信息时，接收装置的DSP单元向接收装置的调制单元输入的调制信号为直流电平。
可选地，接收装置的DSP单元根据当前需要接收的信息，从调制后的第一光信号中恢复出量子信息和经典信息，具体包括：
接收装置的DSP单元根据当前需要接收的信息，向接收装置的平衡接收机单元输出增益值；
平衡接收机单元将输入的处理后的光信号转换为电信号，并使用增益值对转换后的电信号进行增益控制，以使进行增益控制之后的电信号的幅值属于预设范围之内；
接收装置的DSP单元从进行增益控制之后的电信号中恢复出量子信息和经典信息。
可选地，接收装置的DSP单元根据当前需要接收的信息，从处理后的光信号中恢复出量子信息和经典信息之后，还包括：
接收装置的DSP单元将经典信息和量子信息发送给接收装置的主控单元；
接收装置的主控单元根据经典信息和量子信息进行后处理，确定出最终量子密钥。
从上述内容可以看出：本发明实施例中，接收装置的数据信号处理DSP单元根据信号接收指示信息，确定当前需要接收的信息，其中，需要接收的信息为量子信息或经典信息，且量子信息和经典信息时分复用；接收装置的偏振分光单元对接收到的光信号进行处理，得到第一光信号和第二光信号；接收装置的DSP单元根据当前需要接收的信息，向接收装置的调制单元输入调制信号；接收装置的调制单元根据输入的调制信号对接收到的第二光信号进行调制；接收装置的耦合单元对调制后的第二光信号和第一光信号进行干涉处理，得到处理后的光信号；接收装置的DSP单元根据当前需要接收的信息，从处理后的光信号中恢复出量子信息和经典信息。如此，则实现了通过量子接收机对承载有量子信息和经典信息的光信号的成功接收，并可根据该接收到的光信号，恢复出量子信息和经典信息，简化发送装置和接收装置的 结构，减少发送装置和接收装置之间的信道数量。
图5示例性示出了本发明实施例提供的一种用于量子通信的发送装置的结构示意图。
基于相同构思，本发明实施例提供一种用于量子通信的发送装置，发送装置5201包括发送装置DSP5208、衰减单元5206、调制单元5207和偏振耦合单元5209，可选地，还包括光信号产生单元5205和发送装置的处理器5203：
数字信号处理DSP，用于根据信号发送指示信息，确定当前需要输出的信息；根据当前需要输出的信息，调整衰减单元输出的衰减值；根据当前需要输出的信息，向调制单元输入与需要输出的信息对应的调制信号；其中，需要输出的信息为量子信息或经典信息，且量子信息和经典信息时分复用；
光信号产生单元，用于对产生的光脉冲信号进行分光处理，得到第一光信号和第二光信号；
衰减单元，用于根据调整后的衰减值对输入的光信号进行衰减；
调制单元，用于根据输入的调制信号对输入的光信号进行调制；
偏振耦合单元，用于对经过先衰减后调制，或者先调制后衰减的第一光信号，以及第二光信号进行耦合，得到耦合后的光信号，并发送耦合后的光信号。
可选地，衰减单元为：
光可调衰减器；或者
接收第一光信号的第一光开关，与第一光开关连接的第一固定衰减器，与第一固定衰减器连接的第二光开关；或者
接收第一光信号的第一分光器，与第一分光器连接的第二固定衰减器，与第二固定衰减器连接的第三光开关；或者
接收第一光信号的第四光开关，与第四光开关连接的第三固定衰减器，与第三固定衰减器连接的第二分光器。
可选地，调制单元为一个或多个调制器。
可选地，光信号产生单元可为依次连接的产生电脉冲信号的电路、光源、 和分光器。
可选地，偏振耦合单元由偏振分光器、法拉第反射镜和偏振耦合器组成。
发送装置的一种可能的实现方式如图3c所示。
可选地，量子信息为包括原始量子密钥的具有量子特性的光随机序列；
经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。
可选地，信号发送指示信息包括时分复用的第一发送指示信息和第二发送指示信息；
DSP，具体用于：
接收到第一发送指示信息，则确定当前需要输出的信息为量子信息；
接收到第二发送指示信息，则确定当前需要输出的信息为经典信息。
可选地，DSP，具体用于：
确定当前需要输出的信息为量子信息时，将衰减单元输出的衰减值调整至第一阈值以下；
确定当前需要输出的信息为经典信息时，将衰减单元输出的衰减值调整至第二阈值以上；
其中，第一阈值小于第二阈值。
可选地，DSP，具体用于：
确定当前需要输出的信息为量子信息时，向调制单元输入的调制信号为随机序列；
确定当前需要输出的信息为经典信息时，向调制单元输入的调制信号为经典信息。
可选地，调制单元包括第一调制器，以及与第一调制器连接的第二调制器；
DSP，具体用于：
在向调制单元输入的调制信号为随机序列时，向第一调制器和第二调制器输入的调制信号均为随机序列；
DSP，具体用于：
在向调制单元输入的调制信号为经典信息时，向第一调制器输入的调制信号为经典信息，向第二调制器输入的调制信号为经典信息或直流电平；或者
在向调制单元输入的调制信号为经典信息时，向第一调制器输入的调制信号为经典信息或直流电平，向第二调制器输入的调制信号为经典信息。
从上述内容可以看出：本发明实施例中，发送装置的DSP单元根据信号发送指示信息，确定当前需要输出的信息，其中，需要输出的信息为量子信息或经典信息，且量子信息和经典信息时分复用；发送装置的光信号产生单元对产生的光脉冲信号进行分光处理，得到第一光信号和第二光信号；发送装置的DSP单元根据当前需要输出的信息，调整发送装置的衰减单元输出的衰减值；发送装置的DSP单元根据当前需要输出的信息，向发送装置的调制单元输入与需要输出的信息对应的调制信号；发送装置的衰减单元根据调整后的衰减值对第一光信号进行衰减，发送装置的调制单元根据输入的调制信号对衰减后的第一光信号进行调制；或者，发送装置的调制单元根据输入的调制信号对第一光信号进行调制，发送装置的衰减单元根据根据调整后的衰减值对调制后的第一光信号进行衰减；发送装置中的偏振耦合单元将经过衰减和调制的第一光信号，以及第二光信号进行耦合，得到耦合后的光信号，并发送耦合后的光信号。如此，发送装置输出的光信号包括时分复用的量子信息和经典信息，因此避免了现有技术中需要通过两个信道分别发送量子信息和经典信息的方式，简化发送装置和接收装置的结构，减少发送装置和接收装置之间的信道数量。
图6示例性示出了本发明实施例提供的一种用于量子通信的接收装置的结构示意图。
基于相同构思，本发明实施例提供一种用于量子通信的接收装置，接收装置6202包括接收装置DSP6214、调制器6211，可选地，还包括平衡接收机单元6213、耦合单元6212、偏振分光单元6210、接收装置的处理器6204：
DSP，用于根据信号接收指示信息，确定当前需要接收的信息，根据当前需要接收的信息，向调制器输入调制信号；根据当前需要接收的信息，从处理后的光信号中恢复出量子信息和经典信息；其中，需要接收的信息为量子信息或经典信息，且量子信息和经典信息时分复用；
偏振分光单元，用于对接收到的光信号进行处理，得到第一光信号和第二光信号；
调制器，用于根据输入的调制信号对接收到的第二光信号进行调制；
耦合单元，用于对调制后的第二光信号和第一光信号进行干涉处理，得到处理后的光信号。
可选地，平衡接收机单元可为平衡接收机。
可选地，耦合单元可由耦合器、偏振分光器和法拉第反射镜组成。
可选地，偏振分光单元可由动态偏振控制器和偏振分光器组成。
接收装置的一种可能的实现方式如图3d所示。
可选地，量子信息为包括原始量子密钥的具有量子特性的光随机序列；
经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。
可选地，信号接收指示信息包括时分复用的第一接收指示信息和第二接收指示信息；
DSP，具体用于：
接收到第一接收指示信息，则确定当前需要接收的信息为量子信息；
接收到第二接收指示信息，则确定当前需要接收的信息为经典信息。
可选地，DSP，具体用于：
确定当前需要接收的信息为量子信息时，向调制器输入的调制信号为随机序列；
确定当前需要接收的信息为量子信息时，向调制器输入的调制信号为直流电平。
可选地，DSP，具体用于：
根据当前需要接收的信息，向平衡接收机单元输出增益值；从进行增益控制之后的电信号中恢复出量子信息和经典信息；
平衡接收机单元，用于将输入的处理后的光信号转换为电信号，并使用增益值对转换后的电信号进行增益控制，以使进行增益控制之后的电信号的幅值属于预设范围之内。
可选地，DSP，还用于：
在根据当前需要接收的信息，从处理后的光信号中恢复出量子信息和经典信息之后，将经典信息和量子信息发送给处理器；
处理器，用于根据经典信息和量子信息进行后处理，确定出最终量子密钥。
从上述内容可以看出：本发明实施例中，接收装置的数据信号处理DSP单元根据信号接收指示信息，确定当前需要接收的信息，其中，需要接收的信息为量子信息或经典信息，且量子信息和经典信息时分复用；接收装置的偏振分光单元对接收到的光信号进行处理，得到第一光信号和第二光信号；接收装置的DSP单元根据当前需要接收的信息，向接收装置的调制单元输入调制信号；接收装置的调制单元根据输入的调制信号对接收到的第二光信号进行调制；接收装置的耦合单元对调制后的第二光信号和第一光信号进行干涉处理，得到处理后的光信号；接收装置的DSP单元根据当前需要接收的信息，从处理后的光信号中恢复出量子信息和经典信息。如此，则实现了通过量子接收机对承载有量子信息和经典信息的光信号的成功接收，并可根据该接收到的光信号，恢复出量子信息和经典信息，简化发送装置和接收装置的结构，减少发送装置和接收装置之间的信道数量。
本领域内的技术人员应明白，本发明的实施例可提供为方法、或计算机程序产品。因此，本发明可采用完全硬件实施例、完全软件实施例、或结合软件和硬件方面的实施例的形式。而且，本发明可采用在一个或多个其中包含有计算机可用程序代码的计算机可用存储介质(包括但不限于磁盘存储器、CD-ROM、光学存储器等)上实施的计算机程序产品的形式。
本发明是参照根据本发明实施例的方法、装置(系统)、和计算机程序产品的流程图和/或方框图来描述的。应理解可由计算机程序指令实现流程图和/或方框图中的每一流程和/或方框、以及流程图和/或方框图中的流程和/或方框的结合。可提供这些计算机程序指令到通用计算机、专用计算机、嵌入式处理机或其他可编程数据处理装置的处理器以产生一个机器，使得通过计算机或其他可编程数据处理装置的处理器执行的指令产生用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的装置。
这些计算机程序指令也可存储在能引导计算机或其他可编程数据处理装置以特定方式工作的计算机可读存储器中，使得存储在该计算机可读存储器中的指令产生包括指令装置的制造品，该指令装置实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能。
这些计算机程序指令也可装载到计算机或其他可编程数据处理装置上，使得在计算机或其他可编程装置上执行一系列操作步骤以产生计算机实现的处理，从而在计算机或其他可编程装置上执行的指令提供用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的步骤。
尽管已描述了本发明的优选实施例，但本领域内的技术人员一旦得知了基本创造性概念，则可对这些实施例作出另外的变更和修改。所以，所附权利要求意欲解释为包括优选实施例以及落入本发明范围的所有变更和修改。
显然，本领域的技术人员可以对本发明进行各种改动和变型而不脱离本发明的精神和范围。这样，倘若本发明的这些修改和变型属于本发明权利要求及其等同技术的范围之内，则本发明也意图包含这些改动和变型在内。

Claims (25)

  1. 一种量子通信方法，其特征在于，包括以下步骤：
    发送装置的数字信号处理DSP单元根据信号发送指示信息，确定当前需要输出的信息，其中，需要输出的信息为量子信息或经典信息，且所述量子信息和所述经典信息时分复用；
    所述发送装置的光信号产生单元对产生的光脉冲信号进行分光处理，得到第一光信号和第二光信号；
    所述发送装置的所述DSP单元根据当前需要输出的信息，调整所述发送装置的衰减单元输出的衰减值；所述发送装置的所述DSP单元根据当前需要输出的信息，向所述发送装置的调制单元输入与需要输出的信息对应的调制信号；
    所述发送装置的所述衰减单元根据调整后的衰减值对所述第一光信号进行衰减，所述发送装置的所述调制单元根据输入的调制信号对衰减后的第一光信号进行调制；或者，所述发送装置的所述调制单元根据输入的调制信号对所述第一光信号进行调制，所述发送装置的所述衰减单元根据根据调整后的衰减值对调制后的第一光信号进行衰减；
    所述发送装置中的偏振耦合单元将经过衰减和调制的第一光信号，以及所述第二光信号进行耦合，得到耦合后的光信号，并发送所述耦合后的光信号。
  2. 如权利要求1所述的方法，其特征在于，所述量子信息为包括原始量子密钥的具有量子特性的光随机序列；
    所述经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。
  3. 如权利要求1或2所述的方法，其特征在于，所述信号发送指示信息包括时分复用的第一发送指示信息和第二发送指示信息；
    所述发送装置的所述DSP单元根据信号发送指示信息，确定当前需要输 出的信息，具体包括：
    所述发送装置的所述DSP单元接收到所述第一发送指示信息，则确定当前需要输出的信息为量子信息；
    所述发送装置的所述DSP单元接收到所述第二发送指示信息，则所述发送装置的所述DSP单元确定当前需要输出的信息为经典信息。
  4. 如权利要求1至3任一权利要求所述的方法，其特征在于，所述发送装置的DSP单元根据当前需要输出的信息，调整所述发送装置的所述衰减单元输出的衰减值，具体包括：
    所述发送装置的所述DSP单元确定当前需要输出的信息为量子信息时，将所述发送装置的所述衰减单元输出的衰减值调整至第一阈值以下；
    所述发送装置的所述DSP单元确定当前需要输出的信息为经典信息时，将所述发送装置的所述衰减单元输出的衰减值调整至第二阈值以上；
    其中，所述第一阈值小于所述第二阈值。
  5. 如权利要求1至4任一权利要求所述的方法，其特征在于，所述发送装置的所述DSP单元根据当前需要输出的信息，向所述发送装置的所述调制单元输入与需要输出的信息对应的调制信号，具体包括：
    所述发送装置的所述DSP单元确定当前需要输出的信息为量子信息时，所述发送装置的所述DSP单元向所述发送装置的调制单元输入的调制信号为随机序列；
    所述发送装置的DSP单元确定当前需要输出的信息为经典信息时，所述发送装置的所述DSP单元向所述发送装置的所述调制单元输入的调制信号为经典信息。
  6. 如权利要求5所述的方法，其特征在于，所述调制单元包括第一调制器，以及与所述第一调制器连接的第二调制器；
    所述发送装置的所述DSP单元向所述发送装置的所述调制单元输入的调制信号为随机序列，具体包括：
    所述发送装置的所述DSP单元向所述发送装置的所述第一调制器和所述 第二调制器输入的调制信号均为随机序列；
    所述发送装置的所述DSP单元向所述发送装置的所述调制单元输入的调制信号为经典信息，具体包括：
    所述发送装置的所述DSP单元向所述发送装置的所述第一调制器输入的调制信号为经典信息，向所述第二调制器输入的调制信号为经典信息或直流电平；或者
    所述发送装置的所述DSP单元向所述发送装置的所述第一调制器输入的调制信号为经典信息或直流电平，向所述第二调制器输入的调制信号为经典信息。
  7. 一种量子通信方法，其特征在于，包括以下步骤：
    接收装置的数据信号处理DSP单元根据信号接收指示信息，确定当前需要接收的信息，其中，需要接收的信息为量子信息或经典信息，且所述量子信息和所述经典信息时分复用；
    所述接收装置的偏振分光单元对接收到的光信号进行处理，得到第一光信号和第二光信号；
    所述接收装置的DSP单元根据当前需要接收的信息，向所述接收装置的调制单元输入调制信号；
    所述接收装置的所述调制单元根据输入的调制信号对接收到的所述第二光信号进行调制；
    所述接收装置的耦合单元对调制后的第二光信号和所述第一光信号进行干涉处理，得到处理后的光信号；
    所述接收装置的DSP单元根据当前需要接收的信息，从所述处理后的光信号中恢复出量子信息和经典信息。
  8. 如权利要求7所述的方法，其特征在于，所述量子信息为包括原始量子密钥的具有量子特性的光随机序列；
    所述经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。
  9. 如权利要求7或8所述的方法，其特征在于，所述信号接收指示信息包括时分复用的第一接收指示信息和第二接收指示信息；
    所述接收装置的所述DSP单元根据信号接收指示信息，确定当前需要接收的信息，具体包括：
    所述接收装置的所述DSP单元接收到所述第一接收指示信息，则所述接收装置的所述DSP单元确定当前需要接收的信息为量子信息；
    所述接收装置的所述DSP单元接收到所述第二接收指示信息，则所述接收装置的所述DSP单元确定当前需要接收的信息为经典信息。
  10. 如权利要求9所述的方法，其特征在于，所述接收装置的所述DSP单元根据当前需要接收的信息，向所述接收装置的调制单元输入调制信号，具体包括：
    所述接收装置的所述DSP单元确定当前需要接收的信息为量子信息时，所述接收装置的所述DSP单元向所述接收装置的所述调制单元输入的调制信号为随机序列；
    所述接收装置的所述DSP单元确定当前需要接收的信息为量子信息时，所述接收装置的所述DSP单元向所述接收装置的所述调制单元输入的调制信号为直流电平。
  11. 如权利要求7至10任一权利要求所述的方法，其特征在于，所述接收装置的DSP单元根据当前需要接收的信息，从所述处理后的光信号中恢复出量子信息和经典信息，具体包括：
    所述接收装置的所述DSP单元根据当前需要接收的信息，向所述接收装置的平衡接收机单元输出增益值；
    所述平衡接收机单元将输入的所述处理后的光信号转换为电信号，并使用所述增益值对转换后的电信号进行增益控制，以使进行增益控制之后的电信号的幅值属于预设范围之内；
    所述接收装置的所述DSP单元从进行增益控制之后的电信号中恢复出量子信息和经典信息。
  12. 如权利要求7至11任一权利要求所述的方法，其特征在于，所述接收装置的DSP单元根据当前需要接收的信息，从所述处理后的光信号中恢复出量子信息和经典信息之后，还包括：
    所述接收装置的所述DSP单元将所述经典信息和所述量子信息发送给所述接收装置的主控单元；
    所述接收装置的所述主控单元根据所述经典信息和量子信息进行后处理，确定出最终量子密钥。
  13. 一种用于量子通信的发送装置，其特征在于，包括：
    数字信号处理DSP，用于根据信号发送指示信息，确定当前需要输出的信息；根据当前需要输出的信息，调整衰减单元输出的衰减值；根据当前需要输出的信息，向调制单元输入与需要输出的信息对应的调制信号；其中，需要输出的信息为量子信息或经典信息，且所述量子信息和所述经典信息时分复用；
    光信号产生单元，用于对产生的光脉冲信号进行分光处理，得到第一光信号和第二光信号；
    所述衰减单元，用于根据调整后的衰减值对输入的光信号进行衰减；
    所述调制单元，用于根据输入的调制信号对输入的光信号进行调制；
    偏振耦合单元，用于对经过先衰减后调制，或者先调制后衰减的第一光信号，以及所述第二光信号进行耦合，得到耦合后的光信号，并发送所述耦合后的光信号。
  14. 如权利要求13所述的装置，其特征在于，所述量子信息为包括原始量子密钥的具有量子特性的光随机序列；
    所述经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。
  15. 如权利要求13或14所述的装置，其特征在于，所述信号发送指示信息包括时分复用的第一发送指示信息和第二发送指示信息；
    所述DSP，具体用于：
    接收到所述第一发送指示信息，则确定当前需要输出的信息为量子信息；
    接收到所述第二发送指示信息，则确定当前需要输出的信息为经典信息。
  16. 如权利要求13至15任一权利要求所述的装置，其特征在于，所述DSP，具体用于：
    确定当前需要输出的信息为量子信息时，将所述衰减单元输出的衰减值调整至第一阈值以下；
    确定当前需要输出的信息为经典信息时，将所述衰减单元输出的衰减值调整至第二阈值以上；
    其中，所述第一阈值小于所述第二阈值。
  17. 如权利要求13至16任一权利要求所述的装置，其特征在于，所述DSP，具体用于：
    确定当前需要输出的信息为量子信息时，向所述调制单元输入的调制信号为随机序列；
    确定当前需要输出的信息为经典信息时，向所述调制单元输入的调制信号为经典信息。
  18. 如权利要求17所述的装置，其特征在于，所述调制单元包括第一调制器，以及与所述第一调制器连接的第二调制器；
    所述DSP，具体用于：
    在向所述调制单元输入的调制信号为随机序列时，向所述第一调制器和所述第二调制器输入的调制信号均为随机序列；
    所述DSP，具体用于：
    在向所述调制单元输入的调制信号为经典信息时，向所述第一调制器输入的调制信号为经典信息，向所述第二调制器输入的调制信号为经典信息或直流电平；或者
    在向所述调制单元输入的调制信号为经典信息时，向所述第一调制器输入的调制信号为经典信息或直流电平，向所述第二调制器输入的调制信号为经典信息。
  19. 如权利要求13至18任一权利要求所述的装置，其特征在于，所述衰减单元为：
    光可调衰减器；或者
    接收所述第一光信号的第一光开关，与所述第一光开关连接的第一固定衰减器，与所述第一固定衰减器连接的第二光开关；或者
    接收所述第一光信号的第一分光器，与所述第一分光器连接的第二固定衰减器，与所述第二固定衰减器连接的第三光开关；或者
    接收所述第一光信号的第四光开关，与所述第四光开关连接的第三固定衰减器，与所述第三固定衰减器连接的第二分光器。
  20. 一种用于量子通信的接收装置，其特征在于，包括：
    数据信号处理DSP，用于根据信号接收指示信息，确定当前需要接收的信息，根据当前需要接收的信息，向调制器输入调制信号；根据当前需要接收的信息，从所述处理后的光信号中恢复出量子信息和经典信息；其中，需要接收的信息为量子信息或经典信息，且所述量子信息和所述经典信息时分复用；
    偏振分光单元，用于对接收到的光信号进行处理，得到第一光信号和第二光信号；
    所述调制器，用于根据输入的调制信号对接收到的所述第二光信号进行调制；
    耦合单元，用于对调制后的第二光信号和所述第一光信号进行干涉处理，得到处理后的光信号。
  21. 如权利要求20所述的装置，其特征在于，所述量子信息为包括原始量子密钥的具有量子特性的光随机序列；
    所述经典信息为包括协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。
  22. 如权利要求20或21所述的装置，其特征在于，所述信号接收指示信息包括时分复用的第一接收指示信息和第二接收指示信息；
    所述DSP，具体用于：
    接收到所述第一接收指示信息，则确定当前需要接收的信息为量子信息；
    接收到所述第二接收指示信息，则确定当前需要接收的信息为经典信息。
  23. 如权利要求22所述的装置，其特征在于，所述DSP，具体用于：
    确定当前需要接收的信息为量子信息时，向所述调制器输入的调制信号为随机序列；
    确定当前需要接收的信息为量子信息时，向所述调制器输入的调制信号为直流电平。
  24. 如权利要求20至23任一权利要求所述的装置，其特征在于，所述DSP，具体用于：
    根据当前需要接收的信息，向平衡接收机单元输出增益值；从进行增益控制之后的电信号中恢复出量子信息和经典信息；
    所述平衡接收机单元，用于将输入的所述处理后的光信号转换为电信号，并使用所述增益值对转换后的电信号进行增益控制，以使进行增益控制之后的电信号的幅值属于预设范围之内。
  25. 如权利要求20至24任一权利要求所述的装置，其特征在于，所述DSP，还用于：
    在根据当前需要接收的信息，从所述处理后的光信号中恢复出量子信息和经典信息之后，将所述经典信息和所述量子信息发送给处理器；
    所述处理器，用于根据所述经典信息和量子信息进行后处理，确定出最终量子密钥。
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