PL238366B1 - Electronic seal and method of verifying the electronic seal - Google Patents

Abstract

The electronic seal (SL) has two sensitive contact surfaces (SS1, SS2)—the first (SS1) on the bottom and the second (SS2) on the top of the seal (SL). It also includes a communication module in the form of a radio-frequency identifier (RFID), a true random number generator (TRNG), and a physically unclonable function (PUF) system with sensitive electronic components (EE) located on both sensitive contact surfaces (SS1, SS2). The communication module (RFID) is connected to the physically unclonable function (PUF) system and the true random number generator (TRNG). The electronic seal (SL) contacts the first protected object (OB1) with its entire bottom surface and the second protected object (OB2) with its entire top sensitive contact surface (SS2). Both surfaces are bonded to the surfaces of these objects (OB1, OB2) using a strong adhesive layer (SGL).

Description

Description of the invention

The subject of the invention is an electronic seal, in particular to be placed on objects, documents, packages or products.

From Japanese Patent Application Publication No. JP2O18081512, an electronic seal is known containing an RFID communication module with an antenna coil for wireless communication, which has been partially placed on the surface of the laminate using a conductive adhesive characterized by brittleness. Breaking the seal results in damage to the antenna, which results in no radio communication with the seal.

From the international patent application publication no. WO2009157032, an electronic seal is known containing an electronic tape composed of: a protective coating, a conductive tape, an intermediate insulating layer, an insulating surface contact and resistance strips. In order to check the seal, the following parameters are measured: resistance, capacity and inductance, in terms of their changes. Random codes are also written on the tape and in the seal, which are erased when an intrusion is detected.

The disadvantages of known electronic seals are: the lack of sensitivity to the features of the protected object, the inability to ensure the authenticity of the protected object and the possibility of replacing the protected objects, or the separation of the protected object from the electronic seal or the security element of the electronic seal.

From the publication of the Chinese patent application No. CN102265395, a system of physically non-clonable functions (PUF) is known, in which a conductive material of suitable granularity is spread over an insulator layer under which there are many electrical contacts of the electronic system. The electronic circuit uses measurements of capacitance and resistance values between the conductive layer and contacts or between selected contacts. The surface structure of the system causes these values to be random but repeatable, which ensures the functionality of the PUF system.

It is known from the patent literature, e.g. from the patent description US2008256600 (A1), a device containing a system of physically non-cloned PUF functions, consisting of an integrated circuit covered with a sensor matrix, which is covered with a layer of heterogeneous dielectric, which allows for the measurement of capacitance with different values, where the measured capacitance values form a unique key pattern, and also equipped with an RFID communication module, the entire device may be in the form of a label for easy attachment to the objects to be secured. The disadvantage of this solution is that the unique key pattern is created on the basis of internal measurements in a system of physically non-cloned PUFs.

Arrays of physically non-cloning functions are generally used to attach them to protected objects or to ensure the authenticity of electronic circuits in which arrays of physically non-clonable functions are contained. However, the disadvantage of known systems of physically non-clonable functions is that they can only ensure authenticity with respect to their own system. Arrangements of physically non-cloning functions are not electronic seals, except with respect to themselves when they are also a protected object.

From the publication of the Polish patent application No. P.422486, a generator of physically uncopyable cryptographic keys is known, which has a chaotic arrangement. The chaotic system has two ring generators with switched propagation paths, the outputs of which are connected to the phase detector inputs, the output of which is connected to the control inputs of ring generators with switched propagation paths through the controller and to the output of the chaotic system. The output of the chaotic circuit is connected to the output of the generator of physically non-copied cryptographic keys through a recording-comparing circuit. The generator has an input connected simultaneously to the initialization inputs of the switched propagation path ring generators and to one input of a recorder-comparer, the second input of which is connected to the output of the second switched propagation path ring generator.

From Chinese Patent Application Publication No. CN105978552A, a chaotic system is known which comprises two frequency generating circuits, each consisting of four MOS transistors, and an active non-linear circuit consisting of three MOS transistors.

From the publication of the Chinese patent application No. CN107623567A, a chaotic system with a constant spectrum of the Lapunov exponent is known, which includes a signal source module, a linear module, a module

PL 238 366 B1 of a partial linear function and a modulus of negative resistance. The signal source module is connected with the linear module and the negative resistance module, the partial linear function module is connected with the linear module, and the negative resistance module is connected with the linear module.

Known in the art chaotic systems substantially amplify microscopic differences providing a repeatable result of the operation, without the possibility of calculating or discovering the differences on the basis of the result.

The invention solves the problem of ensuring the authenticity of the protected object.

The aim of the invention is to ensure a bond between the product and the seal, the breach of which will produce irreversible changes resulting in electronic breaking of the seal.

The essence of the invention lies in the fact that the electronic seal, containing a communication module and a system of physically non-cloning functions connected to it, containing at least one sensitive element whose electrical parameters change the response of this system, has at least one sensitive contact surface attached to at least one protected object. Moreover, at least one sensitive element of the system has an electrical contact connected to it, which is placed directly next to the sensitive contact surface, or at least one sensitive element of the system, which is a sensitive electronic element, is located directly at the sensitive contact surface, thanks to which the connection of the sensitive contact surface with the protected object is it changes the electrical parameters of at least one element of a sensitive system of physically non-cloning functions. The technical effect of the solution is that the breach of the seal against the protected object will produce irreversible changes in parameters in the structure of the system of physically non-clonable functions. Thanks to the solution, a breach of the seal can be detected without the need to constantly monitor and power the seal, and checking it confirms the authenticity of the protected object.

Preferably, at least one electrical contact is brought out to at least one sensitive contact surface and is electrically connected directly to the object to be protected. Thanks to this solution, the parameters of the resistive and impedance connection have an impact on the responses of the system of physically non-cloning functions.

Preferably, at least one electrical contact is led onto at least one sensitive contact surface and is electrically connected directly to the protected object through an insulator. Thanks to this solution, the parameters of the capacitive and inductive connection have an influence on the responses of the system of physically non-cloning functions.

Preferably, at least one sensitive electronic element of the system is placed on at least one sensitive contact surface, and changing the position of the protected object in relation to this element changes the electrical parameters of the system. Bringing the electronic components in the vicinity of the protected object enables their parameters to be changed in the event of a change in the protected object's location, and thus the response of the system of physically non-clonable functions.

The electronic seal is preferably attached to the protected object by means of an adhesive layer. As a result, the impact of accidental, unintentional tampering of the seal is minimized and the effects of detachment or breach of the seal are enhanced.

Preferably, the adhesive layer is electrically conductive. This makes it possible to detect changes in resistance.

Preferably, the insulator is also an adhesive layer electrically insulating at least one electrical contact with respect to the protected object. This makes it possible to detect capacitive changes.

Preferably, the adhesive layer is stronger than the internal structure of the physically non-cloning function system. Thanks to this, the violation or breaking of the seals intensifies changes in the sensitive structure of the system of physically non-clonable functions.

Preferably, the system of physically non-cloning functions comprises a chaotic system. The chaotic system intensively strengthens the microscopic differences that are the initial conditions for the system's operation, which translates into significant changes at the output of this system. As a result, the sensitivity of the system of physically non-clonable functions increases.

The electronic seal preferably comprises a random number generator connected to the communication module. Thanks to this, you can encrypt information with one-time encryption keys.

Preferably, the random number generator is a true random number generator. This makes the encryption keys more unique and reduces the susceptibility to attacks that exploit the periodicity and / or bias of random generators.

Preferably, the communication module is a radio frequency identifier.

PL 238 366 B1

This solution enables communication with the seal in the RFID standard.

Preferably, the communication module is a short range radio module. This solution enables communication with the seal in the NFC standard.

The invention makes it possible to detect a breach of the direct connection between the seal and the surface against which the seal has been placed.

The subject of the invention is presented in the embodiment in the drawing, in which Fig. 1 shows a schematic diagram of a seal with direct connections, Fig. 2 shows a schematic diagram of a seal with insulated connections, Fig. 3 schematically shows the seal from the contact surface side, Fig. 4 shows a schematic diagram of a seal with electronic elements of a system of physically non-cloning functions positioned at the edge of the contact surface, and Fig. 5 is a schematic diagram of a double-sided seal.

The electronic seal in the embodiment illustrated in Fig. 1 comprises a sensitive contact surface SS on the underside of the electronic seal SL, an arrangement of physically non-cloning PUF functions. which contains sensitive EL elements and KT electrical contacts led out on the edge of the sensitive contact surface SS. The KT electrical contacts are connected to the sensitive EL elements of the system of physically non-cloning PUF functions. The electronic SL seal contacts the entire bottom surface with the protected object OB. The electrical contacts of the KT are in contact with the surface of the OB object. The edges of the lower surface of the SL seal were attached to the surface of the OB object with the GL adhesive layer.

The electronic seal shown in Fig. 2 includes a sensitive contact surface SS on the underside of the electronic seal SL, a COM communication module, a random number generator RNG, a system of physically non-cloning PUF functions that includes sensitive EL elements and electrical contacts KT brought out at the edge of the sensitive contact surface SS. The COM communication module is connected to the system of physically non-cloning PUFs and to the random number generator RNG. The KT electrical contacts are connected to the sensitive EL elements of the system of physically non-cloning PUF functions. The electronic SL seal contacts the entire lower surface with the protected object OB through an IR insulator, so that the electrical contacts of the KT do not come into direct contact with the surface of the object OB.

Depending on the type of surface, in particular depending on its impedance properties, direct electrical connections or insulated connections or mixed connections are selected. In the case of direct electrical connections, depending on the resistive nature of the typical material of the protected object (the conductivity of this material), the internal elements of the system are selected for physically non-cloning functions whose parameter values allow interaction with external parameters. For example, the electronic element of the PUF system can be connected in parallel with a fragment of the surface of the protected object when the surface of the protected object is characterized by high resistance. On the other hand, when the surface of the protected object is characterized by low resistance, a fragment of the surface of the protected object can be used as the electric path of the PUF structure (or be connected in parallel with it).

The sensitive contact surface SS includes a set of electric contacts KT arranged in a matrix, as shown in Fig. 3. The size of the electrical contacts, their density and location, and the number of contacts depend on the nature of the surface of the protected object, in particular on the roughness of the surface of the protected object, internal cohesive graininess the structure of the material of the object and its general impedance properties.

The electronic seal shown in Fig. 4 includes a sensitive SS contact surface on the underside of the SL electronic seal, an NFC short-range radio communication module, a TRNG true random number generator, a physically non-cloning PUF system that includes sensitive EL elements and sensitive electronic EE components located in the near the edge of the sensitive contact surface of the SS. The NFC communication module is connected to an array of physically non-clonable PUFs and a true random number generator TRNG. The electronic SL seal contacts the entire bottom surface with the protected object OB. the edges of the lower face of the SL seal were affixed to the surface of the OB object with the GL adhesive layer, while the sensitive contact surface SS was attached to the surface of the OB object with the strongly bonding SGL adhesive layer.

Alternatively, the electronic seal shown in Fig. 5 includes two sensitive contact surfaces SS1 and SS2 - the first SS1 on the bottom and the second SS2 on the top of the electronic seal SL. The electronic SL seal also includes a communication module in the form of a radio-frequency RFID identifier, a TRNG true random number generator, a physically non-cloning system

The function of a PUF which contains sensitive electronic components EE located near the edges of both sensitive contact surfaces SS1 and SS2. The RFID communication module is connected to an array of physically non-clonable PUFs and a true random number generator TRNG. The electronic seal SL contacts the entire lower surface with the first protected object OB1 and the entire upper sensitive contact surface SS2 with the second protected object OB2. Both surfaces were attached to the surfaces of objects OB1 and OB2 with a strongly bonding SGL adhesive layer.

Many solutions of Physical Unclonable Function (PUF) are based on microscopic differences in electrical parameters of electronic components. These systems are designed in such a way as to ensure sensitivity to the inter-copy dispersion of parameters of the elements that make up this system. Any differences in the geometry of the elements (thickness, length, width), their mutual distance, inhomogeneity of doping, etc., translate into the dispersion of parameters such as: resistance, capacitance, impedance, current efficiency, etc. These differences are used to generate PUF responses inextricably linked with the given an example of the system - importantly, in most cases these parameters are impossible to recognize, and such an attempt would destroy or change the structure of the PUF. The strong PUF (strong PUF) category concerns solutions in which the PUF system generates R responses to C challenges, which are mostly vectors of binary numbers. With a sufficiently large space of challenge vectors and response vectors, the PUF system can perform a function analogous to that of asymmetric cryptography. In addition, such solutions can be used to generate non-copyable cryptographic keys unique to a specific device. These keys are random but repeatable for a given instance. Their significant advantage, in addition to non-copyability, is that these keys are usually not in the system, because they are generated only when they are needed in the system - thanks to this, such solutions are extremely resistant to various types of side-channel attacks. .). The structure of the PUF system includes elements (both electronic and passive) that have no effect (or have a negligible effect) on the result of the system operation, and elements _ (both electronic EE and passive KT), whose electrical parameters affect the result of operation of this system - in particular, these are all the elements related to the reconfiguration of the system in response to the challenges C. So far, intra-systemic differences within the systems have been used, while according to the invention, in addition to intra-systemic features, external features have also been taken into account to generate a PUF response. , occurring due to the immediate proximity of the external object OB, OB1, OB2. Thanks to this, it is possible to implement the SL electronic seal. A particularly advantageous embodiment of the PUF system is a chaotic system, thanks to which the microscopic features of the PUF system are infinitely enhanced. The chaotic system is additionally characterized by the fact that even the manufacturer of electronic circuits is not able to imitate or fabricate the operation of a specific copy.

Flexible printed circuits have been known for years in the art and on the market, which, in a way, offer little possibilities for the realization of electronic seals. On the other hand, the technologies of flexible integrated circuits, which are flexible like flexible printed circuits, are relatively new. The technologies of such flexible integrated circuits are characterized by a very small scale of integration (very large size of electronic components), so that many complex implementations (such as asymmetric cryptography algorithms) often exceed the capabilities of these technologies. Another disadvantage of flexible integrated circuits is the lack of memory (FLASH or RAM), which makes it impossible to save and change cryptographic keys. Therefore, cryptographic implementations are impossible or very difficult. According to the invention, a solution is proposed that does not require memory in an electronic circuit, and is also not complex in implementation. What's more, the dimensions of flexible integrated circuits (the form of a thin flexible foil) allow for sealing objects of all sizes (e.g. confirming the authenticity of banknotes or a stamp on a paper envelope of a letter).

A disadvantage of many electronic seals is that they require a continuous power supply, which is used, for example, to monitor a security circuit for a breach. Moreover, in the event of a power failure, once it has been restored, it is often impossible to determine whether the safety circuit was interrupted during the power failure. The solution according to the invention makes it possible to verify that the seal has not been tampered with in relation to its condition registered at the beginning, after the seal is applied. Moreover, when using RFID or NFC communication technology, the seal is de-energized most of the time. Energy is induced in the seal only while the seal is being checked.

PL 238 366 B1

The possibilities of applying the invention are provided in ensuring the originality of products, in securing the integrity of objects or their elements, in counterfeiting products and in counterfeiting documents, in particular in RFID or NFC tags made in the technologies of integrated circuits with a low scale of integration and without memory or permanent storage. power source.

Claims (13)

Patent claims 1. An electronic seal (SL) containing a communication module (COM) and an attached physically non-cloning function (PUF) system containing at least one sensitive element (EL) whose electrical parameters alter the response of this system (PUF), characterized in that it has at least one sensitive contact surface (SS, SS1, SS2) connected to at least one protected object (OB, OB1, OB2), and at least one sensitive element (EL) of the system (PUF) has an electrical contact (KT) connected to it, which is directly adjacent to the sensitive contact surface (SS), or at least one sensitive element (EL) of the system (PUF), which is a sensitive electronic element (EE), is located directly at the sensitive contact surface (SS, SS1, SS2), so that the connection of the sensitive contact surface (SS, SS1, SS2) with the protected object (OB, OB1, OB2) changes the electrical parameters of at least one sensitive element (EL, EE) system u physically non-clonable functions (PUFs). 2. An electronic seal according to claim 3. The apparatus of claim 1, characterized in that at least one electrical contact (KT) is brought out to at least one sensitive contact surface (SS) and is electrically connected directly to the object to be protected (OB). 3. An electronic seal according to claim 3. The apparatus of claim 1, characterized in that at least one electrical contact (KT) is brought out to at least one sensitive contact surface (SS) and is electrically connected directly to the protected object (OB) through an insulator (IR). 4. An electronic seal according to claim The method of claim 1, characterized in that at least one sensitive electronic element (EE) of the system (PUF) is placed on at least one sensitive contact surface (SS, SS1, SS2), the change of the position of the protected object (OB, OB1, OB2) in relation to this element (EE) changes the electrical parameters of the system (PUF). 5. An electronic seal according to any of the claims from 1 to 4, characterized in that it is attached to the protected object (OB, OB1, OB2) by means of an adhesive layer (GL). 6. An electronic seal according to claim 5. The adhesive of claim 5, wherein the adhesive layer (GL) is electrically conductive. 7. An electronic seal according to claim 1 3. The insulator according to claim 3, characterized in that the insulator (IR) is simultaneously an adhesive layer electrically insulating at least one electrical contact (KT) with respect to the protected object (OB). 8. An electronic seal according to any of the claims characterized in that the adhesive layer (GL) is stronger than the internal structure of the system of physically non-cloning functions (PUF). 9. An electronic seal according to any of the claims The composition of any of the preceding claims 1 to 8, characterized in that the system of physically non-cloning functions (PUF) comprises a chaotic system. 10. An electronic seal according to any one of the claims 1 to 10. characterized in that it comprises a random number generator (RNG) connected to the communication module (COM). 11. An electronic seal according to claim 1; The method of claim 10, wherein the random number generator (RNG) is a true random number generator (TRNG). 12. An electronic seal according to any one of the claims 1 to 12. characterized in that the communication module (COM) is a radio frequency identifier (RFID). 13. An electronic seal as claimed in any one of the claims 1 to 13. from 1 to 12, characterized in that the communication module (COM) is a short-range radio module (NFC).