FR3059122B1 - SAFETY DOCUMENT PROVIDED WITH AN ANTENNA - Google Patents

Abstract

The invention relates to a system for verifying the authenticity of a security document (1), comprising on the one hand a set of security documents (1) associated with users, and on the other hand readers (8). ) intended to verify the authenticity of said documents (1), characterized in that each security document comprises a passive antenna (5) having at least a first resonance frequency (F0D) constituting an electromagnetic signature (16) of said document, and in that each reader (8) comprises a measuring loop (13) capable of measuring the electromagnetic signature of a document (1) when it is approached from the reader (8), and an electronic circuit (9) for comparing this electromagnetic signature with a reference electromagnetic signature (F0R) stored in said reader (8) or on said security document (1).

Description

The invention relates to the security of official documents or other official documents, such as passports, identity cards, driving licenses, automobile registration cards, etc.

State of the art

In the current state of the art, the security of official documents without electronic circuits is conditioned by the presence of security reasons printed on the surface of the document, or integrated in one of the constituent layers of the document.

Thus, tactile elements printed on the surface of documents, complex patterns such as guilloches, or holograms difficult to reproduce are used. To verify the authenticity of this type of document, it is usually enough to have a visual examination. Other official documents may include inner layers in which information can be written by means of a laser beam. In this case, the verification of authenticity generally requires additional means, particularly lighting, to be able to verify the information hidden inside the document.

Also more secure documents are known, using pucemicroelectronics to store coded and / or encrypted security information. In the so-called "non-contact" versions of these documents, the chip is connected to an antenna, so as to allow a radio-frequency communication with an external reader without contact.

While smart products are likely to have a higher level of security, they are also more expensive and more complex to manufacture and implement, which is not suitable for all markets. In fact, certain markets would need, for cost reasons, less expensive documents than a microelectronic smart document, while presenting a level of security superior to documents simply provided with a security motif printed on the surface, or integrated into the thickness. of the document.

Goals of the invention

A general object of the invention is therefore to provide security documents which are free from the aforementioned drawbacks.

Another object of the invention is to propose a technical solution that makes it possible to increase the resistance of documents to fraud at a lower cost, that is to say even when they do not have a microelectronic chip.

Another object of the invention is to provide documents whose authenticity can be verified effectively by a simple and inexpensive infrastructure. SUMMARY OF THE INVENTION The subject of the invention is therefore a system for verifying the authenticity of a security document, comprising on the one hand a set of security documents associated with users, and on the other hand readers intended for security purposes. verifying the authenticity of said documents, characterized in that each security document comprises a passive antenna having at least a first resonant frequency (F0D) constituting an electromagnetic signature of said document, and in that each reader comprises a measuring loop able to measure the electromagnetic signature of a document when it is approached from the reader, and an electronic circuit for comparing the electromagnetic signature with a reference electromagnetic signature (For) stored in said reader or on said document.

Thus, when the comparison is positive, the verifier using the system has a reliable and reliable indication that the document presented to the reader is undocumented authentic.

According to an advantageous embodiment of the invention, each system reader also comprises a reported or integrated passive antenna having a second resonance frequency (Fol) so that when the passive antenna of the document and the passive antenna of the reader are coupled between them, they present a complex resonance frequency F (old) having several resonance peaks and constituting a complex electromagnetic signature of said document.

According to the invention, each reader comprises signaling means for indicating, according to the result of the comparison made by the reader, the fact that the security document presented is an authentic document, and in the event ofcontrary, the fact that the document presented is a fake.

Advantageously, said signaling means are LED display means, or sound means.

In an even safer version of the system according to the invention, each document comprises, in addition to its passive antenna having a resonance frequency (Fod), an encoded graphic representation of said resonance frequency (F0D), and each reader further comprises a sensor optical and a microcontroller for reading and decoding said graphical representation.

The graphical representation of the resonance frequency (F0D) of the documents is for example a QR code.

In an advantageous embodiment of the documents of the system, the tracks of the passive antenna of the documents and the QR code are made on a single and same metal layer integrated in the thickness of the document, and protected by external layers. Other features and advantages of the invention will appear from the reading of the detailed description and the accompanying drawings in which: FIG. 1 represents an exploded perspective view of a document according to the invention, in the format of a card; Figure 2 shows a card reader in schematic form; FIG. 3 represents the frequency response of the reader alone, equipped with an antenna, the frequency response of a single card according to the invention, equipped with an antenna, and the frequency response of the system constituted by the reader of FIG. 2 and the map of Figure 1; FIG. 4 represents a card variant according to the invention, provided with an antenna and a QR code; FIG. 5 represents a functional flowchart of the test software executed by the reader for the card test according to FIG. 1, without QR code; FIG. 6 represents a functional flowchart of the test software executed by the reader for the card test according to FIG. 4, with a QRcode on the cards tested.

detailed description

FIG. 1 shows a security document 1, in the format of a plastic card having dimensions conforming to the ISO 7816-1 standard. Of course, this form factor is only a practical example; The document form is absolutely not limiting of the scope of the invention.

Most existing security documents are plastic cards simply having on the outer layers printed information relating to the issuer of the card, and graphic informationrelative to the cardholder, for identification. The information in the card is intended to be read either by a human controller or by a scanner-type acquisition device connected to a scanning system and processing the information read. In this context, these cards are very simple and have neither microelectronic chip nor antenna.

The principle of the invention consists on the contrary in providing security documents, for example cards 1 such as that of FIG. 1, with a passive antenna 5 intended to interact with an antenna of a card reader. The antenna 5 of the card is not arbitrary, it is chosen to have a particular electromagnetic signature, especially a particular and calibrated resonant frequency.

For the rest of the talk, we will consider that the electromagnetic signature of an antenna is represented in a simplified way by its resonant frequency. We will therefore associate a given resonance frequency with a given type of card. Thus, all the cards or documents issued by a given authority, will have a unique resonant frequency.

In a basic version of the invention, the card readers of the system, such as the reader 8 shown diagrammatically in FIG. 2, will be equipped with a microcontroller 9 provided with a memory (not shown) in which a frequency value of reference resonance denoted For, corresponding to that of the authentic documents used in the system. The readers 8 also include a measurement coil 13 of the resonant frequency of a document that a user will approach the reader. The measurement of the antenna resonant frequency 5 of the document 1 is transmitted in the microcontroller 8 to a circuit comparing the resonance frequency detected from the card with the reference resonance frequency FOr stored in memory. Finally, the readers 8comprise signaling means (optical, sound, etc.), such as for example the LEDs 11, 12, to signal the result of the comparison to the system user and indicate that a given test document corresponds to a authentic document or to a falsified document.

It is therefore easy to understand that the specific antenna 5 integrated in each document 1 increases the resistance of the document to falsification, since a fraudster will have the means to retrofit a fake document, with an antenna having the same electromagnetic signature, the same resonant frequency as the authentic documents.

However, the integration of such an antenna 5 into a document remains within the reach of networks of structured fraudsters equipped with hardware for copying desantennas.

We must go further. For this purpose, a slightly more advanced version of the invention provides for also equipping the readers 8 with a specific passive antenna 14, also called a de-tuning antenna, having its own characteristic resonant frequency. In this case, when approaching the reader 8 a document 1 according to the inventionand provided with its own antenna 5, we obtain a system of two antennas 5, 14couplés them, and having a complex electromagnetic signature 17, as shown in Figure 3, including in particular two or more resonance patterns that can be detected by the measuring coil 13 of the reader.

As shown in FIG. 3, suppose that the antenna 14 of the reader 8 has a resonant frequency 16 slightly less than 13 MHz, and that the antenna 5 of the document 1 has a resonant frequency 17 slightly greater than 13 MHz. Then the antennas system 5, 14 coupled to each other will have an electromagnetic signature 18, having two resonance peaks, for example around 11 and 16 Mhz. Again, the electromagnetic signature expected from the pair of antennas 5, 14 is stored in the memory of the reader 8, and for each new documentapproché of the reader, it will compare the memorized electromagnetic signature, with the electromagnetic signature detected for the system constituted by passive antenna 14 of the reader coupled with the passive antenna 5 of the new document to be tested.

As the electromagnetic signature 18 of the antenna system 5, 14 is more complex than in the previous case with a single antenna 5 located on the document, it becomes more difficult to replicate fraudulently, but this is possible with the appropriate means.

In a slightly safer version of the system according to the invention, the documents 1 and the readers 8 are still equipped as previously with specific antennas 5, 14, but there is added in addition to the reader a secret mathematical processing unit to further complicate more electromagnetic scintillation of the antenna system consisting of the passive antenna14 of the reader coupled with the passive antenna 5 of a document.

For example, the reader software will calculate a resonant frequency FOf by a treatment of the type: FOf = A.Fol + B.Fod where A and B are integer or non-integer parameters, and F0L and F0d respectively represent the resonance frequency of the passive antenna 14 of the reader, and the resonant frequency of the passive antenna 5 of the document.

Of course, the same treatment has been applied before the reference resonance frequencies of the reader and an authentic document, in order to store in memory the expected target value.

As can be seen, in order to be able to obtain a falsified document presenting the electromagnetic signature 17, in particular the good resonance frequencies, it will now be necessary to have the resonance frequency 16 of the emulator 8, that of an authentic document 5, and the parameters A, B of the secret operation performed in the reader.

According to a preferred and even more secure variant of the invention, each security document 1 provided with its antenna 5 will comprise, as shown in FIG. 4, a coded graphic representation of the electromagnetic signature of its antenna 5, in particular its resonant frequency. . And each reader 8 will be equipped with means for reading this coded graphic representation when the document 1 is approached to the reader 8, for the decoder and for comparing it with the reference resonance frequency 17 expected and stored in the reader's memory. In this case, a passive antenna 14 can be dispensed with on each reader, but the readers will have, as shown schematically in FIG. 2, an optical sensor 10 for reading the coded graphic representation 15 disposed on the card.

In practice, the coded graphic representation of the value of the resonance frequency of the antenna of a document will for example consist of a QR code printed on one of the layers 2, 3, 4, 6, 7 of the card. This kind of decode is very difficult to replicate. But other coded graphic representations, such as 2D bar codes, are conceivable.

Depending on the location of the QR code or equivalent, it may be useful for the plastic layers located above the QR code to be transparent, or have a transparent window, to facilitate the reading of the QR code by the optical sensor 10 of the reader 8.

In order to further increase system security, the resonance frequency values stored in a QR Code can be matched by digital protection in terms of authenticity, integrity or confidentiality. For example, for authenticity and integrity, the data in the QR code is pre-digitally signed using an asymmetric private key provided by the issuer of the document. To verify the signature, you must obtain the corresponding public key certificate from the entity that generated and certified the asymmetric key.

For confidentiality, the data is encrypted with a symmetric key provided by the issuer of the document. To decipher the QR code, it is necessary to use the keystone which is distributed, as is well known in the technical state.

In an advantageous embodiment of the invention, the tracks of the antenna 5 of the document 1 and the QR code 15 will be made on a single and integrated metal layer in the thickness of the document during the manufacture thereof. Thus any manipulation of the antenna 5 and the QR code 15 will become visible.

Preferably, the reader comprises visual signaling means or indicators of the result of the comparison between the value of the resonant frequency of the tested document and the reference value stored in the reader. These means take for example the shape of a green LED 11 to indicate that the document presented is authentic, and a red LED 12 to indicate that the document presented is a forgery.

FIG. 5 shows the functional flowchart of the reader test software 8 in the case where the documents tested 1 do not have a coded graphic representation of their resonant frequency. In this case, the switch 8 goes into a waiting loop 20 of a card to be tested, and when a card 1 arrives near the reader 8, the reader measures its resonant frequency F 0 and then reads the electromagnetic fingerprint. FOr reference stored in the reader's memory. At 23, the microcontroller 9 of the reader 8 compares the measured resonance frequency with the reference resonance frequency stored in memory. In case of equality of the two resonant frequencies, the document 1presented is deemed authentic, which is for example signaled 24 by turning on the green LED. In the opposite case, the document 1 presented is reputedly authentic, which is for example indicated by the lighting of the red LED.

FIG. 6 shows the functional flow chart of the reader test software 8 in the case where the tested documents comprise at the same time several resonance frequencies Fo, Fo ', Fo "and a graphical representation of these resonant frequencies, for example a The reference electromagnetic signature stored in the reader's memory is then, for example, the sum Fo + Fo '+ Fo "of the resonant frequencies of the authentic cards, and this signature is stored, during the manufacture of the card, both in the graphic representation like the QR code, and in the memory 8.

Thus, to verify the authenticity of a document or an approximate map en20 of the reader, the reader measures at 21 the resonance frequency (s) of the document to be tested, then in 26 he reads the QR code or equivalent situated on the document it calculates at 27 the sum of the resonant frequencies measured, and at 28compare the calculated sum at the read QR code and possibly at the stored signature in the reader's memory 8. In case of correspondence of all the elements, the card is deemed authentic and the Green LED is lit in 24, otherwise the red LED is lit in 25.

It should be noted that in the case where a QR code is used, the reader does not necessarily need to be equipped with a de-tuning antenna 14, since the security level obtained through the use of a QR code is enough.

Advantages of the invention The invention meets the stated goals. Thanks to the invention, it is possible to simply check the authenticity of a regal document, while the security means implemented represent a minimal cost.

In addition, the solution of the invention has great flexibility, since the cards can be customized by country (a resonance frequency per country for example) or by customer. The choice of the resonance frequency of the card can be done at the last moment during the process of manufacturing the card, laser parsing of the tracks of the antenna.

The security is increased compared to a regulatory document without a chip than conventional security means: to hope to counterfeit the document according to the invention, laboratory level knowledge is required.

In addition, any attempt to disable security, such as cutting or changing the card's antenna or removing the QR code, will leave visible damage on the card.

Finally, the lifetime of the security document is very long, since the additional means consist of a simple antenna easy to integrate, without electronic module.

The technique of the invention could also be adapted as complementary security for documents with a chip, even if in this case one would not obtain a security as economical as in the case of documents or cards without chip.

Claims (3)

1 - System for verifying the authenticity of a security document (1), comprising on the one hand a set of security documents (1) associated with users, and on the other hand readers (8) intended to verify the authenticity of said documents (1), each security document (1) comprising a passive antenna (5) having at least a first resonance frequency (F0D) constituting an electromagnetic signature (16) of said document, and each reader (8) comprising a measuring loop (13) capable of measuring the electromagnetic signature of a document (1) when it is approached from the reader (8) andan electronic circuit (9) for comparing this electromagnetic signature with a reference electromagnetic signature (FOr) stored in said reader (8) or said security document (1), characterized in that each reader (8) further comprises a passive antenna (14) having a second resonance frequency (17) so when the passive antenna (5) of the document (1) and the passive antenna (14) of the reader (8) are coupled to each other, they exhibit a complex resonance frequency (18) having several resonance peaks etc constituting an electromagnetic signature of said document. 2 - System according to claim 1, characterized in that each reader (8) comprises signaling means (11,12) for indicating, as a function of the result of the comparison performed by the reader (8), the fact that the security document (1) presented is an authentic document, and if not, the fact that the document presented is a fake. 3 - System according to claim 2, characterized in that said signaling means are LED type of light display means (11,12), or sonmoyens means. 4 - System according to any one of the preceding claims, characterized in that each security document (1) comprises, in addition to its passive antenna (5) having a resonance frequency (F0D), a coded graphic representation (15) of said resonance frequency (F0D), and in that chaquelecteur (8) further comprises an optical sensor (10) and a microcontroller (9) for reading and decoding said graphical representation (15). 5. System according to claim 4, characterized in that the graphical representation (15) of the resonance frequency (F0D) of the documents is a QR code. 6 - System according to claim 5, characterized in that the tracks of the passive antenna ((5) of the document (1) and the QR code are made on a single and even metal layer integrated in the thickness of the document. according to one of claims 4 to 6, characterized in that the coded graphic representation (15) integrates digital protection into authenticity, integrity or confidentiality.