WO2014090804A1

WO2014090804A1 - Method for securing a document comprising printed information and corresponding document

Info

Publication number: WO2014090804A1
Application number: PCT/EP2013/076088
Authority: WO
Inventors: Olivier Akli; Yolanda Varuhaki
Original assignee: Gemalto Sa
Priority date: 2012-12-12
Filing date: 2013-12-10
Publication date: 2014-06-19
Also published as: EP2743893A1

Abstract

The invention concerns, in particular, a method for securing a document (10) comprising printed information, called reference information, said method consisting of: - signing the digital representation of said reference information with a cryptographic key in order to obtain signed information; - forming a set of information including the signed information; - converting the set of information into a first machine-readable code (12); - printing the first code (12) on the document (10).

Description

Method of securing a document comprising printed information and corresponding document

The field of the invention is that of the securing of documents comprising printed information, this security having the purpose of combating the falsification of printed information.

Many documents (administrative or official, for example) contain important information that it is desirable to protect against falsification. For example, an identity card, passport, driver's license, registration card, check, pay slip, bank statement, diploma, birth certificate, deed or document A medical receipt (such as a medical prescription or certificate), an electricity receipt, includes printed information, subsequently referred to as "reference information", which may be more or less easily forged by a malicious person. This reference information is for example a name, a first name, a date, a number, an address, a photograph or the name of a medicine.

The falsification of one or more of these reference information may in particular allow an identity theft. In the case of a medical prescription, changing the name of a drug or the amount of prescription drugs can also have serious health consequences. Falsification of the information printed on a diploma can also lead to illegal access to a job.

As mentioned in patent EP-727,316 B1, the means used by the falsifiers are numerous and include solvent-type chemical agents, scraping and scrubbing means, which are intended to delete or erase certain information printed on a document to replace them. by others, such as for example, for a check, a sum and / or the beneficiary.

In order to detect on the document itself an attempt to falsify, special inks, such as magnetic inks, can be used to, for example, enter the C7 code (7-stick coded magnetic characters) of the check number. on the check itself. However, a falsifier may obtain this special ink and, after having removed by scratching or scrubbing the old information, may print another code on the check. It is also known to protect a document using guiiloches or to provide a complex and dense background pattern. Although this means partly dissuades and / or makes it difficult and tedious to delete and copy the underlying motive, it is not entirely reliable, given the obstinacy and patience of certain falsifiers.

It is also known from patent application WO 95/02512 to coat the paper support layer with a coloring layer containing microcapsules capable of breaking under the effect of pressure during printing / writing to release a coloring substance capable of reacting with a reagent also incorporated in the coloring layer. Such papers, called carbonless papers, are used in a bundle comprising a first sheet of plain paper as an original and one or more additional sheets as a duplicate. However, this paper is relatively fragile, because of the extreme sensitivity of the coloring layer, which requires taking great care when handling paper to avoid friction, creators of untimely inscriptions.

It was also proposed to electronically sign a document, such as a PDF document. However, this solution only applies to electronic documents and not to printed documents.

Finally, it was proposed to protect documents, such as passports, using a secure chip with the same information as printed. A comparison of the data read in the chip with the printed data makes it possible to detect a modification of the printed information. However, this solution requires a chip for storing the information to be protected (the reference information) and a specific reader.

The present invention is intended to overcome these disadvantages.

More specifically, one of the objectives of the invention is to provide a method of securing a document containing reference information, very inexpensive and secure, allowing anyone to verify the authenticity of this document.

This objective, as well as others that will appear later, is achieved by a method of securing a document comprising printed information, called reference information, which method comprises: - sign the digital representation of the reference information by a cryptographic key to obtain signed information;

- constitute a set of information including the signed information;

converting the set of information into a first machine-readable code; - print the first code on the document.

The reference information is preferably letters, figures, a photograph or a handwritten signature.

In one implementation mode, the cryptographic key is a secret key.

In a second mode of implementation, the cryptographic key is a private key.

The document is preferably a passport, an identity card or a printed document.

In an advantageous mode of implementation, the method according to the invention also consists in printing on the document a second code readable by a machine corresponding to the reference information.

In another embodiment, complementary to the above, the invention also proposes to print on the document a third machine readable code comprising at least one identifier of the cryptographic key.

Advantageously, the third code comprises the public key for decrypting the first code.

The invention also relates to a document comprising printed information, called reference information, this document comprising a first code readable by a machine, the first code comprising the reference information signed by a cryptographic key.

Other features and advantages of the invention will appear on reading the following description of an embodiment of the invention, given by way of illustration and not limitation, and the appended figures in which:

FIG. 1 represents a model of driving license comprising printed reference information as well as a code according to the present invention;

- Figure 2 shows schematically an implementation of the method according to the invention. Fig. 1 shows a model of a driving license comprising printed reference information as well as a code according to the present invention.

A model of a driving license, for example in the form of a plastic card 10, conventionally includes the photo 1 1 of its holder, his name (in point 1), his name (in point 2), his date and place of birth (in point 3), its date of obtaining the permit (in point 4a), the date of validity of the permit (in point 4b), the name of the city which issued the permit (in point 4c) , the license number (point 5) and the signature of the holder (point 6).

The information from points 1 to 5 are printed characters, the signature being printed information. At least some of these characters or printed information, generically referred to as reference information, are information that the invention proposes to secure against modification, for example following a theft of the driving license.

For this purpose, considering for example that we want to secure the surname, first name and license number (points 1, 2 and 5), the invention proposes to secure this reference information by signing (actually in signing their digital representation) by a cryptographic key K (key only in possession of the issuer of the driving license 10) to obtain information signed IS.

We will have:

(SAMPLE SUSAN BO72RRE2155, K) -> IS

with IS = sig (K, SAMPLE SUSAN BO72RRE2155)

The IS signed information is, in a first mode of implementation, converted into a first code readable by a machine. This code is here a QR code referenced 12. The QR code is simply printed on the license 10 during its manufacture.

The verification of the integrity of the permit 10 (verification that it has not been falsified) can for example be carried out during a roadside check by a police officer: he scans, with the help of a terminal (for example using a mobile phone, a PDA or a smartphone) the QR code 12. A dedicated application installed in its terminal includes (or downloads, for example via the Internet, in a signature scheme by shared key - PKI) the paired decryption key Kd with the key K used to sign the reference information. After decryption, the police officer can visually compare the reference information printed on the allowed 10 with those from decryption. Thus, if a malicious person had to change the name, first name or license number, there would be no identity between the printed reference information and those derived from the decryption.

The malicious person can not modify the QR code 12 since it does not have the key of the body that manufactured the permit 10, this key being confidential.

The reference information may be letters and / or numbers and / or a photograph.

As regards the signature keys K and Kd decryption, they can be identical (in a secret key scheme) but they are preferably different (public key scheme). Indeed, a secret key signature scheme is only safe if the secret key is not revealed. This can not be guaranteed if the secret key is present in the terminals of the persons authorized to carry out authenticity checks of documents. On the other hand, if the signature key is a private key, anyone can decrypt the QR code 12 using the associated public key. Key diversification schemes are also possible.

The invention also proposes, on an ancillary basis, printing on the document 10 a second code 13 readable by a machine corresponding to the reference information. In this case, there is no signature of the reference information which is simply converted into the code 13.

Finally, the invention proposes to print on the document 10 a third code 14 readable by a machine comprising at least one identifier of the cryptographic key used to sign this reference information. The identifier is for example the version of the key, or why not, in a PKI scheme, the decryption key Kd. The person wishing to verify that the document 10 has not been forged can then simply scan the code 14 (to reconstitute the public key) before scanning the code 12 to verify the authenticity of the reference information. The code 14 may comprise the decryption key or a link to this decryption key.

When a secret key scheme is used, it is possible to send to the issuer of the license 10 the signed information for it to decipher and retransmitted to the person who checks the document 10. The code 14 then includes a simple link (Internet address) to a site of the issuer of the document 10.

In another embodiment of the invention, the printed code is obtained from information including the signed information. This means that the signed information is concatenated with other information, for example with the data to identify the signature key used or a link to this signature key (that to obtain the code 14 in Figure 1) and / or with the printed information (reference information or all printed information),

It is also possible to generate as many codes as there is reference information.

It is also possible to protect the photograph 11 of the holder of the document 10 by the mechanism explained above, as well as the signature (point 6).

A handwritten signature and a photograph can therefore also constitute reference information, the essential being that they are in a digital format (for example jpeg or gif) when editing the document. After printing the image (photograph and / or signature), its digital representation is signed (with or without other information to protect) and converted into a machine readable code, which code is then printed on the document. This guarantees an impossible falsification (not detectable) of a photograph or a signature.

The codes presented so far are QR codes but any type of code can be used (Aztec, Maxicode, Datamatrix, Code One, ...), preferably two-dimensional, the important thing is that the information we want to protect integrity are signed by a key only in the possession of the issuer of the document on which this information is printed.

The document is not necessarily a driver's license and may be a passport, an identity card or any printed document, for example a diploma, a medical prescription, etc.

The invention also makes it possible to verify the integrity of a document transmitted by e-mail or by fax, as long as the printed code or codes are not altered.

The invention also relates to a document comprising reference information, this document also comprising a first code readable by a machine, the first code comprising the reference information signed by a cryptographic key, this first code being obtained according to the method of the invention.

Figure 2 shows schematically an implementation of the method according to the invention.

The reference information to be protected against forgery, denoted 20, is converted by an algorithm 21 into a code 13 (previously called second code) printed on the document 10. Here, the integrity of the holder's handwritten signature 22 is also guaranteed. of the document 10 by signing this handwritten signature by the cryptographic key (secret or preferentially private) of the authority from which the document 10 emanates. The resulting code is referenced 23 and also printed on the document 10.

The authority signature 24 is also used to sign the reference information and the handwritten signature of the holder of the document 10. This signed set is converted to obtain the first code 12 which is printed on the document 10.

Finally, the identifier 25 of the authority signature is converted by the algorithm 21 to obtain the third code 14 which is printed on the document 10.

The invention makes it possible to guarantee the integrity of the information printed on a document, by encrypting this information and coding it in the form of a machine-readable code. The method is very simple to implement and the verification of the printed information (name, date, photograph, signature, ...) can be performed from any mobile terminal including an application dedicated to the recognition of codes ( QR for example) and decryption of a cryptographic signature key.

Claims

claims

1. Method for securing a document (10) comprising printed information, called reference information, characterized in that it consists of:

- Sign the digital representation of said reference information by a cryptographic key to obtain signed information;

- constitute a set of information including said signed information;

converting said set of information into a first code (12) readable by a machine;

- printing said first code (12) on said document (10)

- Printing on said document (10) a second code (13) readable by a machine corresponding to the digital representation of said reference information.

2. Method according to claim 1, characterized in that said reference information is letters.

3. Method according to claim 1, characterized in that said reference information is numbers.

4. Method according to claim 1, characterized in that said reference information is a photograph.

5. Method according to claim 1, characterized in that said reference information is a handwritten signature.

6. Method according to one of claims 1 to 5, characterized in that said cryptographic key is a secret key.

7. Method according to one of claims 1 to 5, characterized in that said cryptographic key is a private key.

8. Method according to one of claims 1 to 7, characterized in that said document (10) is a passport, an identity card or a printed document.

9. Method according to one of claims 1 to 8, characterized in that it also consists in printing on said document a third code (14) readable by a machine comprising at least one identifier of said cryptographic key.

10. The method of claim 9, characterized in that said third code (14) comprises the public key for decrypting said first code (12).

1 1. Document (10) comprising printed information, called reference information, characterized in that it comprises a first code (12) readable by a machine, said first code (12) comprising the digital representation of said reference information signed by a key cryptographic and in that it comprises a second code (13) readable by a machine corresponding to the digital representation of said reference information.