DE102016122926A1 - Sensor for providing a physically unclonable function, manufacturing method, identification device and readout system - Google Patents

Abstract

The invention relates to a sensor (3) for providing a physically nonclonable function for an identification device (1), comprising a functional device (6), which comprises a carrier element (8) and a plurality of filling elements arranged on and / or in the carrier element (6) (11), wherein the filling elements (11) are arranged according to a unique arrangement pattern on and / or in the carrier element (8), and with a measuring device (7), at which an electrical quantity can be read out as output of the physically unclonable function, which is given by the arrangement pattern of the filling elements (11) and by a relative position of the filling elements (11) to the measuring device (7), wherein the functional device (6) relative to the measuring device (7) is designed to be movable and at the measuring device ( 7) readable electrical variable depending on the relative position of the filling elements (11) to the measuring device (7).

Description

The present invention relates to a sensor for providing a physically non-clonable function with a functional device which comprises a carrier element and a plurality of filling elements arranged on and / or in the carrier element, wherein the filling elements are arranged according to a unique arrangement pattern on and / or in the carrier element , and with a measuring device, on which an electrical variable is read out as an output of the physically unclonable function, which is given by the arrangement pattern of the filling elements and by a relative position of the filling elements to the measuring device. Moreover, the present invention relates to a method for producing such a sensor. Furthermore, the present invention relates to an identification device with such a sensor. Finally, the present invention relates to a readout system for an identification device.

The interest here is directed to identification devices which are provided in the form of credit cards, debit cards, debit cards, access cards, tags or keys. The use of such an identification device is always associated with a security risk because on such a card many information is stored, which can be easily read as data from the outside. From the prior art cards with a magnetic strip are known, which is usually located on the back of the card and on which the data is stored.

Usually, a personal identification number (PIN) is stored on this magnetic strip in addition to the personal data. The data on these magnetic strips can be read easily by means of commercially available card readers. The protection against criminal abuse is therefore very low.

An improved protection is given by the integration of memory chips in the card. Here the data is stored in an electronic memory. Recognizable are such chips on a special electrode surface, which is usually located on the front of the card. The chip technology is intended to curb the copying and counterfeiting of bank data. The record is safely hidden and the card is checked for authenticity in use. In addition, a PIN is required. Due to its internal structure, the chip offers the possibility to implement additional functions. Furthermore, from the prior art money cards are known, the chips include a built-in microcontroller. This in turn consists of a microprocessor (CPU), a ROM (Read Only Memory), on which the operating system is installed, a RAM (Random Access Memory) as a working memory and an EEPROM (Electrical Erasable And Programmable Read Only Memory) as data storage. The most important tasks of the operating system are the process control, the data transfer, the data management and the execution of cryptographic algorithms. There is a master-slave relationship between the bank terminals and the card, with the terminal assuming the master role and the cash card the slave role. The main task of this role assignment is that the cash card does not reveal any information about itself. Only when the master requests the card with correct commands does the operating system provide the necessary information. To further improve the security of the cards physical and logical measures are taken. The latter are supported by a PIN. Despite complex architecture and cryptography, however, these cards are also not completely secure against unauthorized misuse.

In order to increase the security of the identification device or of the cards, it is necessary to provide uniquely assignable and non-clonable unique items for identifying the card users. In this context, so-called physically unclonable functions (PUF - Physical Unclonable Function) are known from the prior art. These PUFs can be formed in different forms.

The best-known solutions are based on electronic principles. For example, electronic PUFs made of silicon are known, whose electronic circuits usually have tiny deviations. These non-reproducible deviations make the circuit unique. For this reason, such circuits are also referred to as a "chip fingerprint". The effort to produce such PUFs in large numbers, however, is relatively high.

To reduce the cost, physically unclonable functions are known which are based on optical principles. This describes the EP 2 722 191 A1 an identity card having a card body and a physically non-mimickable function disposed within the card body. The physically non-imitable function comprises first and second light-influencing layers, the identity card further comprising a light source for emitting light to the first light-influencing layer and the second light-influencing layer, and an optical sensor for measuring light from the first light-influencing layer and the second light-influencing layer light-influencing layer in response to the emitted light.

Disadvantage of the optical process is the complex optical identification technology. For example, an optical window and for unambiguous identification a complex optical analysis technique is needed. In addition, it must also be ensured that the optical window is not impaired by scratches or layers in its properties.

Moreover, from the prior art, physically unclonable functions are known which are provided by a sensor. For example, describes the US 2014/0162464 A1 a security device having a physically unclonable function comprising a first and a second graphene layer. Through these two graphene layers, different structures such as a resistor, a capacitor, a transistor, a diode or the like can be provided. Non-cloneable functions can be provided by their measurable properties through the two graphene layers.

Furthermore, the describes US 8 622 310 B2 a token containing a physically unclonable function. The physically unclonable function comprises a capacitor with a dielectric material, which is arranged at least in regions between the electrodes of the capacitor. In the dielectric material, electrically conductive particles are randomly arranged. The conductive particles are formed from a phase change material that is changeable between a first structural state having a first conductivity and a second structural state having a second conductivity.

Such physically unclonable functions, which are provided by a sensor, basically have the disadvantage that they can be read out, for example, with a corresponding evaluation device. Thus, the required security can not be guaranteed.

It is an object of the present invention to provide a solution as an identification device of the type mentioned in a simple manner can be made safer. In addition, a corresponding readout system for reading the identification device should be provided.

This object is achieved by a sensor, by a method, by an identification device and by a readout system with the features according to the respective independent claims. Advantageous developments of the present invention are the subject of the dependent claims.

A sensor according to the invention serves to provide a physically unclonable function for an identification device. The sensor comprises a functional device which comprises a carrier element and a plurality of filling elements arranged on and / or in the carrier element, wherein the filling elements are arranged according to a unique arrangement pattern on and / or in the carrier element. In addition, the sensor comprises a measuring device, on which an electrical variable can be read out as the output of the physically unclonable function, which is given by the arrangement pattern of the filling elements and by the relative position of the filling elements to the measuring device. In this case, the functional device is designed to be movable relative to the measuring device. Furthermore, the readable on the measuring device electrical size depends on the relative position of the filling elements to the measuring device.

The sensor can be used in an identification device, such as a cash card, a debit card, a credit card, an access card, a smart card, a tag or a key card. With the sensor, a physically unclonable function (PUF - Physical Unclonable Function) can be provided. The sensor comprises the carrier element and a plurality of filling elements which in particular influence the electrical and / or magnetic properties of the carrier element. These filling elements may preferably be embedded in the carrier material. Alternatively or additionally, it can be provided that the filling elements are arranged on a surface of the carrier element. The filling elements are arbitrarily or randomly arranged in and / or on the carrier element. The arrangement of the filling elements on and / or in the carrier element is unklonbar or not duplicatable. Furthermore, the sensor comprises the measuring device, on which the electrical variable is readable, which describes the functional device. In particular, the electrical variable describes the arrangement of the filling elements to one another and / or the relative position of the filling elements to the measuring device. The electrical quantity which can be read out at the measuring device represents the output of the physically unclonable function. This output can also be called a response. The physically unclonable function can be fed with an input or a so-called challenge. Such input may be provided, for example, by an electrical signal applied to or impressed on the measuring device.

According to one essential aspect of the present invention, it is provided that the functional device and in particular the carrier element of the functional device at least partially relative to the measuring device is designed to be movable. The functional device can thus be moved relative to the measuring device. For example, if an external field acts on the sensor, the support member may be deformed and / or displaced. In particular, it is provided that the measuring device is designed to be stationary and the functional device is designed as a movable part, which moves in dependence on the external field or an external action relative to the measuring device. In addition, it can be provided that at least a part of the functional device or of the carrier element moves relative to the measuring device. This has the effect that the filling elements, which are arranged on and / or in the carrier element, also move relative to the measuring device. Thereby, the relative position of at least some of the filling elements is changed to the measuring device in dependence on the external field or the external influence. In this way, the electrical size can be read on the measuring device, which is dependent on the field, which acts on the sensor. Thus, the output of the physically unclonable function is dependent on the previously determined external influence on the sensor. An access code or identification may be provided by reading out the electrical quantity for the predetermined external action or the predetermined field acting on the sensor. Since the electrical quantity for this predetermined external influence is not known and can not be read out, a particularly secure physically unclonable function can be provided by means of the sensor.

Preferably, the functional device is movable relative to the measuring device by means of an electric field, magnetic field and / or gravitational field acting on the sensor, and the electrical variable readable at the measuring device is dependent on the electric field, the magnetic field and / or the gravitational field. The functional device can thus be moved relative to the measuring device, that a predetermined external field acts on the sensor. For this purpose, for example, serve an influencing device, by means of which a predetermined field which acts on the sensor, can be provided or influenced. For example, the functional device may be moved by applying an external electric field to the sensor. This electric field may have a predetermined electric field strength and / or a predetermined direction. This is particularly suitable if the filling elements have electrically conductive particles. Alternatively or additionally, the functional device can be moved by applying a magnetic field to the outside of the sensor. This magnetic field may also have a predetermined magnetic field strength, a predetermined magnetic flux density and / or a predetermined direction. This is particularly suitable when the filling elements comprise magnetically conductive or magnetic particles. Furthermore, it can be provided that it is influenced how the gravitational field or the weight force acts on the sensor. For example, the sensor can be moved or aligned accordingly. It is preferably provided that the sensor is inclined by a predetermined inclination angle. Furthermore, it can be provided that the sensor is accelerated in a predetermined manner. Thus, there are different external effects that can act on the sensor to move the functional device relative to the measuring device. These outer fields, which act on the sensor, can also be combined. This allows the physically unclonable function to be set in different ways.

Preferably, the readable on the measuring device electrical variable is dependent on a tilt of the sensor. In other words, the sensor is designed as a physical tilt sensor. When the sensor is tilted by a predetermined inclination angle, the support member is deformed and / or displaced due to gravity. The movement of the carrier element or of the functional device as a consequence of gravity depends on the current inclination of the sensor. Preferably, the functional device is designed as a movable part, which moves in dependence on the inclination of the sensor relative to the measuring device. Thereby, the relative position of at least some of the filling elements is changed to the measuring device in dependence on the inclination of the sensor. In this way, the electrical size can be read on the measuring device, which is dependent on the current inclination of the sensor. Thus, the output of the physically unclonable function depends on the current position of the sensor. An access code or an identification may be provided by reading out the electrical quantity for a predetermined inclination or a predetermined inclination angle.

The electrical variable, which can be read out at the measuring device, preferably describes a capacitance between the functional device and the measuring device. The sensor is thus preferably designed as a capacitive sensor. The filling elements, which are arranged in and / or on the carrier element, are in particular electrically conductive filling elements. Due to the unique arrangement pattern of these electrically conductive filling elements, the capacitance between the functional device and the measuring device can be influenced. Furthermore, the capacity is influenced by the relative position of the filling elements or the functional device to the measuring device. This is again depending on the field currently acting on the sensor. Due to the arrangement of the filling elements according to the unique arrangement pattern, each sensor is an original and identifiable as such. The identification is carried out by measuring the capacitance of the sensor or by measuring the voltage as a function of the external field, which acts on the sensor. In addition, the capacity measurement offers the advantage that it can be carried out in a simple and cost-effective manner. In addition, the measurement of the capacity can be performed with the required accuracy.

It can also be provided that the electrical variable, which is readable at the measuring device, describes a magnetic field which is provided by the functional device. In this case, for example, magnetic particles or elements may be arranged in and / or on the carrier element as the filling elements. In this case, the measuring device may have a sensor for measuring the magnetic field.

According to one embodiment, the measuring device has a substrate element, on which at least one transmitting electrode and at least one receiving electrode are arranged, wherein for reading the electrical variable, an influencing of an alternating electric field between the at least one transmitting electrode and the at least one receiving electrode can be determined by at least one region of the functional device is. The substrate element of the measuring device can be provided for example by a printed circuit board. At least one transmitting electrode, on which an electrical alternating voltage can be applied, is arranged on this substrate element. Between the transmitting electrode and the receiving electrode, an alternating electric field is formed. In this case, the transmitting electrode and the receiving electrode are designed such that at least a part or a region of the functional device is located in the alternating field. By influencing the alternating electric field by the functional device, the capacitance between the measuring device and the functional device can be determined. For example, an alternating current can be measured at the receiving electrode. This allows a simple and reliable determination of the capacity or the electrical size.

According to a further embodiment, the measuring device has a first substrate element and a second substrate element, and the functional device is arranged between the first substrate element and the second substrate element. In other words, the measuring device is formed in two parts. In particular, it can be provided that the first substrate element, the second substrate element and the functional device are arranged substantially parallel to each other. The functional device or the carrier element of the functional device can be substantially plate-shaped. Preferably, the carrier element is designed as a membrane. In particular, the functional device is arranged between the first substrate element and the second substrate element such that the carrier element can deform or move between the first substrate element and the second substrate element. At least one transmitting element and at least one receiving element are arranged on the first substrate element. Also on the second substrate element at least one transmitting element and at least one receiving element are arranged. Thus, on the one hand, the capacitance between the first substrate element and the functional device and, on the other hand, the capacitance between the second substrate element and the functional device can be determined. In this way, a differential capacitance measurement can be made possible. This allows a particularly accurate determination of the capacity as electrical variable.

The carrier element is preferably formed from an elastic material, in particular a polymer, and / or the carrier element is designed as a membrane. As already explained, the carrier element can be formed at least in regions as a membrane or comprise a membrane. Depending on the external field, which acts on the sensor, the deflection of the membrane and thus also the capacitance between the functional device and the measuring device, which is arranged fixed to the functional device, changes. The support member may be made of a polymer. For example, the carrier element may be made of a natural rubber or a silicone. In particular, the carrier element can be made of the material PDMS (polydimethylsiloxane).

This can be provided in a simple and inexpensive way, a support member. The base material for the production can be provided, for example, in the liquid state and then the base material can be cured. In addition, the filling elements can be embedded in this base material in a simple manner. By selecting the base material, the mechanical properties of the carrier element can be determined. For curing, the liquid base material can be introduced into a corresponding mold. Thus, any shapes can be realized in a simple and reliable manner.

In a further embodiment, the filling elements of the functional device are electrically conductive particles for influencing a electrical conductivity of the functional device, designed as magnetic conductive particles for influencing a magnetic conductivity of the functional device and / or as mass elements for influencing a deformation of the carrier element. As the filling elements, the functional device may comprise electrically conductive particles which are provided, for example, by soot or metal dusts. Alternatively or additionally, the functional device may have magnetic or magnetically conductive particles as the filling elements. The distribution of these electrically and / or magnetically conductive particles in the carrier element can be homogeneous, but also inhomogeneous. In addition, the functional device may have, as the filling elements, mass elements which influence the deformation of the carrier element or the membrane in the field acting externally on the sensor. Such mass elements can be provided for example by metal balls, in particular steel balls. The mass elements may preferably also be electrically or magnetically conductive. In this case, the diameter of the mass elements is significantly higher compared to a diameter of the electrically and / or magnetically conductive particles. The diameter of the mass elements is in particular less than or equal to the thickness of the membrane or of the carrier element. The number and distribution of the mass elements across the membrane surface is also preferably stochastic. It can also be provided that mass elements with different diameters are used.

This can result in a total of five stochastic factors: the concentration of the electrically and / or magnetically conductive particles, the distribution of the conductive particles, the number of mass elements, the size or the diameter of the mass elements and the distribution of the mass elements. These stochastic factors guarantee a high degree of randomness. This means that there is very unlikely to be another identical sensor. On the other hand, it is virtually impossible to replicate the sensor identically. When different sensors are made, they are physically different and virtually non-clonable. Thus, physically unclonable functions can be reliably provided.

A method according to the invention is used to produce a sensor according to the invention. In this case, the functional device and the measuring device are provided. To provide the functional device, a base material for producing the carrier element in a liquid state is provided. Further, the elements are mixed with the material and then the material is cured. As already explained, the functional device can be manufactured from a polymer and in particular from the material PDMS. This material or base material can be provided in the liquid state. For this purpose, for example, two components of the base material can be mixed. In this liquid base material then the filling elements can be introduced. As the filling elements, electrically conductive particles, magnetic conductive particles and / or mass elements, which are preferably formed by metal balls, are introduced. Subsequently, the base material and the filling elements can be mixed together. The mixing can be carried out such that the filling elements are arranged substantially homogeneously or evenly distributed in the material. Preferably, the filling elements are introduced into the material such that the filling elements are arranged inhomogeneously or unevenly distributed in the material. The mixing results in the unique arrangement pattern of the filling elements in the carrier material. Subsequently, the base material can be introduced together with the filling elements in a mold and cured there. During curing, a crosslinking reaction can take place. Before curing, the base material, in which the filling elements are introduced, be subjected to vacuum, so that, if necessary, air bubbles can be removed from the liquid material.

To produce the measuring device, a printed circuit board can be provided which has at least one metallization layer. The printed circuit board is preferably my relatively thin printed circuit board, which is made in particular of a flexible material. The metallization layer can be structured to provide the transmitting electrodes and / or receiving electrodes. The transmitting electrodes and / or receiving electrodes may be formed on the front side of the printed circuit board. On the back of the circuit board, a planar ground electrode or metallization view may be present. Thus, overall, the sensor can be manufactured in a simple and cost-effective manner.

An identification device according to the invention comprises a sensor according to the invention. The identification device may preferably be in the form of a cash card, a debit card, a smartcard, a tag, an access card or a key (card). The identification device may in particular be designed as a card, which comprises a card body. The sensor can be integrated in this card body. The sensor is manufactured in particular by means of a microtechnical manufacturing process. In particular, the sensor is designed as a microsensor. For example, the sensor may have a height which is less than 0.7 mm, preferably less than 0.5 mm. This makes it possible to integrate the sensor into the card body, which is designed according to ISO standard 7816 and has a thickness of 0.76 mm. The sensor may be arranged in a recess of the card body. The sensor can also be cast in the manufacture of the card body in the material of the card body. In particular, the sensor is arranged in the card body such that the functional device can move relative to the measuring device.

Preferably, the sensor is arranged in and / or on a base body of the identification device such that the sensor can not be removed or removed from the base body in a non-destructive manner. If the identification device is designed as a card, the basic body can be formed by the card body. For example, the sensor may be materially connected to the base body and in particular glued. Thus, it can be prevented that the sensor as a whole can be removed from the main body and thus the structure of the sensor can be examined.

In addition, the identification device may have a microcontroller. This microcontroller may in turn comprise a microprocessor and corresponding memory. Personal data may be stored on these memories. An operating system can be run on this microcontroller. In addition, the identification device may have an interface or an electrode surface for contacting the identification device. This interface can also be electrically connected to the sensor and in particular to the measuring device of the sensor. Thus, it is possible to read the electrical quantity from the measuring device.

An inventive reading system for an identification device according to the invention comprises an influencing device for influencing an electric field, magnetic field and / or gravitational field acting on the identification device. In addition, the readout system comprises an evaluation device for reading out the electrical size of the sensor of the identification device in the case of the electric field, magnetic field and / or gravitational field acting on the identification device or the sensor. The readout system may comprise a terminal which comprises the influencing device and the evaluation device. The terminal may have a corresponding receptacle for the identification device or the card. In this recording, the user or the owner can bring the identification device. With the influencing device, an electric field can then be provided. For this purpose, the influencing device may comprise, for example, electrically conductive plates, on each of which an electrical potential can be applied and between which the identification device can be arranged. Alternatively or additionally, the influencing device may comprise at least one electromagnet or a coil, with which a predetermined magnetic field can be provided. It can also be provided that an areally inhomogeneous electric and / or magnetic field is provided by means of the influencing device. The electric field or magnetic field provided with the influencing device may also change with time. Furthermore, it can be provided that the identification device is moved with the aid of the influencing device or the position of the identification device is changed. Thus, it can be influenced how the gravitational field acts on the sensor. For example, the identification device with the influencing device can be moved to a predetermined position. It can also be provided that the identification device is brought to a predetermined orientation by means of the influencing device. With the influencing device, the identification device can be inclined in particular together with the sensor. It can also be provided that predetermined acceleration is exerted on the identification device by means of the influencing device. The influencing device may comprise, for example, a holding unit for holding the identification device and an actuator for moving the identification device or the holding unit. The identification device and a longitudinal axis and / or a vertical axis can then be tilted with the actuator. The actuator may preferably have a plurality of degrees of freedom with respect to translation and rotation. Thus, for example, the inclination angle can be specified by which the identification device is inclined. Furthermore, trajectories and / or circular paths can be specified, along which the identification device with the influencing device can be moved at least in sections. The functional device of the sensor moves differently as a result of the gravitational field, depending on the orientation or inclination of the sensor. With the influencing device, the field which acts on the sensor can be specified precisely. In addition, different fields, ie the electric field, the magnetic field and / or the gravitational field can be provided and / or combined with the influencing device. The respective fields can also be adjusted by means of the influencing device. By means of the evaluation device, the electrical size or the capacitance of the sensor can be read out. The evaluation device can with the identification device be moved or arranged to be stationary.

The readout system preferably has a server device for determining the electrical field, magnetic field and / or gravitational field influenced by the influencing device and for comparing the electrical variable in the influenced electric field, magnetic field and / or gravitational field with a stored value for the electrical variable. The server device may have a corresponding data memory on which the electrical quantity for predetermined fields acting on the sensor is stored. For this purpose, the electrical size or the capacity for the predetermined fields, which act on the sensor, be detected in advance. For example, capacitance values may be picked up by the sensor on one or more orbits. For example, up to 360 capacity values or multiples thereof can be determined for one revolution. Thus, a fingerprint of the sensor formed by the capacitance values for the different tilt angle can be provided. In addition, the capacitance values for the electrical and / or magnetic fields which act on the sensor can be stored. For example, a capacitance value may describe the electrical capacitance of the sensor at a predetermined inclination, a predetermined electric field acting on the sensor, and / or a predetermined magnetic field acting on the sensor. Thus, there are also numerous variants here to change the electrical size that can be read out on the sensor.

The readout system may further comprise an interrogation unit, with which, for example, a PIN can be queried. It can also be provided that another person-related key, such as the fingerprint or an iris scan be queried. This can be done depending on the level of security. The requested personal data is transmitted to the server device. The server device can then be used to determine stochastic numerical values, which are generated, for example, using a random number generator. These numerical values can describe the specific fields which should affect the sensor. For example, the numerical values can describe electrical and / magnetic fields which are to act on the sensor. Furthermore, these numbers may also describe trajectories or circular paths along which the identification device is moved with the influencing device for setting the specific position, for example the specific angle of inclination. By means of the influencing device, the identification device can then be moved into the specific position. With the evaluation device can then be measured for the predetermined field, which acts on the sensor from the outside, the capacity or the electrical size. The measured values for the electrical quantity can then be transmitted again to the server device, which compares these with the stored values. Depending on the comparison, a release or lock may be transmitted to the terminal.

The preferred embodiments presented with reference to the sensor according to the invention and their advantages apply correspondingly to the method according to the invention, the identification device according to the invention and to the readout system according to the invention.

Further features of the invention will become apparent from the claims, the figures and the description of the figures. The features and feature combinations mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respectively specified combination but also in other combinations or in isolation, without the frame to leave the invention.

• 1 eine Identifizierungsvorrichtung in Form einer Karte, welche einen Sensor zum Bereitstellen einer physikalisch unklonbaren Funktion aufweist;
• 2 eine schematische Darstellung des Sensors in einer geschnittenen Seitenansicht sowie eine Auswertevorrichtung zum Auslesen einer elektrischen Größe des Sensors;
• 3 einen Sensor gemäß einer weiteren Ausführungsform in einer geschnittenen Seitenansicht;
• 4 einen Sensor gemäß einer weiteren Ausführungsform in einer geschnittenen Seitenansicht;
• 5 eine Trajektorie, entlang welcher der Sensor bewegt werden kann, um den Sensor in vorbestimmte Neigungswinkel zu positionieren;
• 6 mögliche Trajektorien, entlang welcher der Sensor bewegt werden kann; und
• 7 ein Auslesesystem für die Identifizierungsvorrichtung in einer schematischen Darstellung.

The invention will now be described with reference to preferred embodiments and with reference to the accompanying drawings. Showing:

• 1 an identification device in the form of a card having a sensor for providing a physically unclonable function;
• 2 a schematic representation of the sensor in a sectional side view and an evaluation device for reading an electrical size of the sensor;
• 3 a sensor according to another embodiment in a sectional side view;
• 4 a sensor according to another embodiment in a sectional side view;
• 5 a trajectory along which the sensor can be moved to position the sensor at predetermined tilt angles;
• 6 possible trajectories along which the sensor can be moved; and
• 7 a readout system for the identification device in a schematic representation.

In the figures, identical and functionally identical elements are provided with the same reference numerals.

1 shows an identification device 1 according to an embodiment of the present invention in a schematic representation. The identification device 1 is presently designed as a card, for example as a cash card, debit card, credit card, access card, key card or the like. The identification device 1 or the card comprises a card body 2 which has a thickness of 0.76 mm, a length of 85 mm and a width of 54 mm according to ISO standard 7816 can have. The card body 2 may be formed for example of a plastic. In addition, the identification device comprises 1 a sensor 3 which is in the card body 2 is integrated. With the sensor 3 can be provided - as explained in more detail below - a physically unclonable function (Physical Unclonable Function). This physically unclonable function serves to identify a user of the identification device 1 or the map.

Furthermore, the identification device comprises 1 a microcontroller 4 which is also in the card body 2 is integrated. This microcontroller 4 in turn consists of a microprocessor and a memory on which an operating system is stored. Furthermore, the microcontroller 4 have a working memory and a data memory. Furthermore, the identification device comprises 1 an interface 5 or an electrode surface, by means of which the identification device 1 can be electrically contacted. Here is the interface 5 electrically with the sensor 3 and the microcontroller 4 connected.

2 shows a sensor 3 according to a first embodiment in a sectional side view. The sensor 3 includes a functional device 6 as well as a measuring device 7 , The functional device 6 comprises a carrier element 8th which is formed of an elastic material. For example, the carrier element 8th of a rubbery material such as a natural rubber or PDMS (polydimethylsiloxane) or similar materials. The carrier element 8 is present at least partially as a membrane 9 educated. Furthermore, the carrier element comprises 8th a holding area 10 , which compared to the membrane 9 has a greater layer thickness. The membrane 9 is at the holding area 10 clamped or held. The membrane 9 and the holding area 10 are integrally formed in the present example.

In addition, the functional device includes 6 a plurality of filling elements 11. As filling elements 11 includes the functional device 6 in the present case, electrically conductive particles 12 , which in the support element 8th are introduced. Through the particles 12 can be achieved that the functional device 6 becomes electrically conductive. The particles 12 For example, carbon black particles may be present in the carrier element 8th are introduced. The amount of soot is arbitrarily adjustable, but always below a value at which the mechanical cohesion of the membrane is lost. The distribution of the particles 12 in the membrane 9 can be homogeneous, but also inhomogeneous. Instead of carbon black, other conductive materials such as metal dusts may be used. Alternatively or additionally, it may be provided that the functional device 6 as the filling elements 11 having magnetically conductive particles.

Furthermore, the functional device comprises 6 as filling elements 11 Mass elements 13. The mass elements 13 show in comparison to the particles 12 a much larger diameter. The diameter of the mass elements 13 is less than or equal to the thickness of the membrane 9 , The mass elements 13 For example, they may be formed by metal balls, in particular steel balls. In the present case, the mass elements 13 different diameters. It can also be provided that the mass elements 13 each having the same diameter. Here is the distribution of the particles 12 and / or the mass elements 13 within the carrier element 8th stochastically.

The measuring device 7 can be formed by a printed circuit board. The measuring device 7 comprises a substrate element 14 which may be formed of a dielectric material. On a top 15 of the substrate element 14 , which of the functional device 6 facing, the measuring device 7 at least one transmitting electrode 16 and a receiving electrode 17 on. The transmitting electrode 16 and the receiving electrode 17 can be done by structuring the metallization on top 15 to be provided. Furthermore, the measuring device comprises 7 on a back 18 of the substrate element 14 a metallization layer 19 ,

The sensor 3 is designed as a capacitive sensor. The measuring device forms 7 a stationary part of the sensor 3 and the functional device 6 forms a movable part of the sensor 3 , The functional device 6 and in particular the membrane 9 are elastically formed and deforms depending on a field, which from the outside to the sensor 3 acts. Due to the deformation of the diaphragm 9, the capacitance between the functional device changes 6 and the measuring device 7 , which as an electrical variable at the measuring device 7 can be read out.

For reading the capacity of the sensor 3 can the sensor 3 with an evaluation device 20 be connected, which is shown schematically in the present case. The evaluation device 20 includes a voltage source 21 , by means of which an electrical AC voltage V can be provided. The voltage source 21 is with the transmitting electrode 16 electrically connected. Further, the metallization 19 of the sensor 3 with a ground connection 22 connected. The evaluation device 20 further comprises a current-voltage converter, which is formed by an operational amplifier 23 and the impedance Z. The ground connection 22 is further connected to a positive input of the operational amplifier 23 connected. The negative input of the operational amplifier 23 is electrically connected to the receiving electrode 17 connected. Between the transmitting electrode 16 and the receiving electrode 17 an alternating electric field is generated in which a part of the membrane 9 located. The alternating electric field is through the membrane 9 affected. This results at the receiving electrode 17 a current I. This current can be converted by the current-voltage converter in the voltage V ₀ . This voltage V ₀ represents an electrical quantity representing the capacitance of the sensor 3 describes.

In the production of the sensor 3 may be a base material for the production of the carrier element 8th be provided in the liquid state. In this liquid material then the filling elements 11 , in particular the electrically conductive particles and the steel balls, are introduced and mixed accordingly with the base material. Subsequently, the mixture of the base material and the filling elements 11 be introduced into a corresponding shape for curing and cured there. The filling elements 11 are then in the carrier element 8th arranged according to a unique arrangement pattern, which can not be replicated. Overall, there are five stochastic factors that determine the capacity of the sensor 3 influence: the concentration of the particles 12 , the distribution of the particles 12 in the carrier element 8th , the number of mass elements 13 , the size or the diameter of the mass elements 13 and the distribution of the mass elements 13 in the carrier element 8th , Thus, a very high degree of randomness is guaranteed, making it almost possible to use the sensor 3 identical replicate. Thus, a physically unclonable function can be provided with the sensor 3. Each sensor is an original and identifiable as such.

3 shows a sensor 3 according to another embodiment in a sectional side view. It can be seen that the measuring device 7 a plurality of transmitting electrodes 16 and a plurality of receiving electrodes 17 having. In each case between a transmitting electrode 16 and a receiving electrode 17 an alternating electric field are provided and in this area a partial capacity can be determined. The transmitting electrodes 16 and receiving electrodes 17 are in particular matrix-like on the substrate element 14 arranged, so the capacity of the sensor 3 can be precisely determined.

4 shows a sensor 3 according to another embodiment in a sectional side view. Here, the measuring device includes 7 in addition to the substrate element 14 or a first substrate element, a second substrate element 14 '. Here are the first substrate element 14 and the second substrate element 14 ' identical construction. On each of the substrate elements 14 . 14 ' are a plurality of transmitting electrodes 16 and a plurality of receiving electrodes 17 arranged. The functional device 6 is between the substrate elements 14 . 14 ' arranged.

In the present case, a first partial capacitance C ₁ is shown schematically, which is between a transmitting electrode 16 and a receiving electrode 17 of the first substrate element 14 can be determined. Furthermore, a second partial capacitance C ₂ is shown schematically, which is between a transmitting electrode 16 and a receiving electrode 17 of the second substrate element 14 ' can be determined. This enables a differential capacitance measurement. When determining the capacity of the sensor 3 can also have capacities of the transmitting electrodes 16 and receiving electrodes 17 be considered to the mass. This allows the capacity of the sensor 3 be determined exactly.

To an identification using the sensor 3 to allow the capacitance values from the sensor 3 for different outer fields that are on the sensor 3 act, recorded. It may be provided that the sensor 3 is moved to affect how the gravitational field on the sensor 3 and in particular the functional device 6 acts. For example, the capacitance values may be from the sensor 3 be recorded for different angles of inclination. For this purpose, the sensor 3 along a predetermined trajectory 24 to be moved. This is schematically in 5 shown. In the present case, the trajectory 24 describes a circular path. To the sensor 3 can move to the specified tilt angle, the sensor 3 for example, with steps of one degree along the trajectory 24 to be moved. Thus, for example, 360 capacity values can be provided. It may also be provided that more than 360 capacity values are recorded. In addition, it may be provided that the sensor 3 along different predetermined trajectories 24 is moved. This is exemplified by 6 illustrates which multiple trajectories 24 shows which are formed as circular paths. The trajectories 24 can also be determined such that they run along sections or regions of the circular paths. The trajectories 24 can also be chosen so that they have a trajectory different from a circular path.

In addition, it may also be provided that the capacitance values of the sensor 3 for different, predetermined electric fields, which on the sensor 3 act, be recorded. Alternatively or additionally, the capacitance values for different magnetic fields applied to the sensor 3 act, be stored.

7 shows a readout system 25 for reading the identification device 1 , The readout system 25 includes a terminal 26 , with a recording 27 into which the identification device 1 can be introduced. The recording 27 is shown here only schematically. Further, the terminal 26 with an interrogator 28 connected, which may be formed depending on a security level. The polling device 28 is used to query a personal key. This can be done by a user of the identification device 1 - For example, by an operator input - be provided. At the polling facility 28 For example, a PIN can be requested. Instead of a PIN, another person-related bowl, such as a fingerprint or the like, can be queried. It can also be done an iris scan.

The personal key is used by the interrogator 28 to a computing device 29 of the terminal 26 transfer. This personal data is then sent to a server device 30 of the readout system 25 transfer. In the server device 30 the data are with a computing device 31 receive. Furthermore, the server device comprises a random number generator 32 , with which stochastic numerical values can be determined. For example, four stochastic numerical values can be determined and by the computing device 31 the server device 30 to the computing device 29 of the terminal 26 be transmitted.

For example, the first number of the four numbers may be a trajectory 24 describe along which the identification device 1 to be moved. The other three numerical values can be alignments of the sensor 3 and in particular describe inclination angle. Alternatively or additionally, the numbers may also describe electrical and / or magnetic fields applied to the sensor 3 or the identification device 1 Act. In the terminal 26 there is an influencing device 33 , which is shown schematically in the present case. With the influencing device 33 can the identification device 1 along the trajectory 24 to be moved. In this case, the identification device 1 be moved in the predetermined orientations and in particular in the predetermined inclination angle. It can also be provided that with the help of the influencing device 33 an electric field and / or a magnetic field is provided, which on the identification device 1 or the sensor 3 acts. At each angle of inclination, electric field and / or magnetic field is then with the evaluation device 20 the capacity value is determined. The capacity value is determined by the evaluation device 20 to the computing device 29 of the terminal 26 and from there to the computing device 31 the server device 30 transfer.

On a data store 34 the server device are the capacitance values for different ones on the sensor 3 acting gravitational fields, magnetic fields and / or electric fields previously for the sensor 3 were determined, stored. The computing device 31 can store the stored values from the datastore 34 query and compare with the measured capacity values. If there is a match, the access is released. Otherwise, a lock occurs. This is shown schematically by the arrow 35 shown. The dashed lines describe here 36 the input at the terminal 26 as well as the transmission to the server device 30 , The dotted lines 37 describe the determination of the stochastic numerical values used by the server device 30 to the terminal 26 or the influencing device 33 be transmitted. The solid lines 38 describe the transmission of the capacitance values from the terminal 26 to the server device 30 ,

By using the identification device 1 that with the readout system 25 a high level of security can be provided. Neither the data-simulating chip on the identification device will help 1 still the knowledge of the PIN continues when the identification device 1 is faked. The from the server device 30 certain random numbers are purely stochastic and inaccessible. Therefore, it does not do anything to explore the data, because at the next use of the identification device 1 other stochastic preselected server data output and thus others on the sensor 3 Acting fields or capacity values are queried. Only if the sensor 3 is modeled identically, the data access would be possible. But this is due to the multiple stochastic structure of the sensor 3 most likely prevented.

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• EP 2722191 A1 [0007]
• US 2014/0162464 A1 [0009]
• US 8622310 B2 [0010]

Cited non-patent literature

• ISO standard 7816 [0039]

Claims (12)

Sensor (3) for providing a physically unclonable function for an identification device (1), comprising a functional device (6) which comprises a carrier element (8) and a plurality of filling elements (11) arranged on and / or in the carrier element (6) in that the filling elements (11) are arranged according to a unique arrangement pattern on and / or in the carrier element (8), and with a measuring device (7) on which an electrical quantity can be read out as output of the physically unclonable function, which is determined by the arrangement pattern the filling elements (11) and by a relative position of the filling elements (11) is given to the measuring device (7), characterized in that the functional device (6) is designed to be movable relative to the measuring device (7) and at the measuring device (7 ) readable electrical variable depending on the relative position of the filling elements (11) to the measuring device (7). Sensor (3) after Claim 1 , characterized in that the functional device (7) is movable relative to the measuring device by means of an electric field, magnetic field and / or gravitational field acting on the sensor (3) and the electrical variable readable at the measuring device (7) depends on the electric field , the magnetic field and / or the gravitational field. Sensor (3) after Claim 1 or 2 , characterized in that the readable on the measuring device electrical quantity is dependent on an inclination of the sensor (3). Sensor (3) according to one of the preceding claims, characterized in that the electrical variable, which is readable at the measuring device (7), describes a capacitance between the functional device (6) and the measuring device (7). Sensor (3) according to one of the preceding claims, characterized in that the measuring device (7) has a substrate element (14) on which at least one transmitting electrode (16) and at least one receiving electrode (17) are arranged, wherein for reading the electrical variable an influence of an alternating electric field between the at least one transmitting electrode (16) and the at least one receiving electrode (17) can be determined by at least one region of the functional device (6). Sensor (3) after Claim 5 , characterized in that the measuring device has a first substrate element (14) and a second substrate element (14 ') and the functional device (6) between the first substrate element (14) and the second substrate element (14') is arranged. Sensor (3) according to one of the preceding claims, characterized in that the carrier element (8) is formed from an elastic material, in particular a polymer, and / or the carrier element (8) is designed as a membrane (9). Sensor (3) according to one of the preceding claims, characterized in that the filling elements (11) of the functional device (6) as electrically conductive particles (12) for influencing an electrical conductivity of the functional device (6), as magnetically conductive particles for influencing a magnetic Conductivity of the functional device (6) and / or as mass elements (13) for influencing a deformation of the carrier element (8) are formed. Method for producing a sensor (3) according to one of Claims 1 to 8th in which the functional device (6) and the measuring device (7) are provided, wherein for providing the functional device (6) a base material for producing the carrier element (8) in a liquid state is provided, the filling elements (11) are inhomogeneous with the base material or mixed homogeneously and the mixture of the base material and the filling elements (11) is cured. Identification device (1) with a sensor (3) according to one of Claims 1 to 8th , wherein the identification device (1) is designed in particular as a cash card, credit card, access card or key. Readout system (25) for an identification device (1) according to Claim 8 with an influencing device (33) for influencing an electric field, magnetic field and / or gravitational field acting on the identification device (1) and with an evaluation device (20) for reading out the electrical size of the sensor (3) of the identification device (1) on the identification device (1) acting electric field, magnetic field and / or gravitational field. Readout system (25) after Claim 11 , characterized in that the readout system (25) comprises a server device (30) for determining the electric field, magnetic field and / or gravitational field influenced by the influencing device (33) and for comparing the electrical variable in the influenced electric field, magnetic field and / or or gravitational field with a stored value for the electrical quantity.

Images