FR3035819A1 - AUTHENTICABLE PAPER SMARTPHONE - Google Patents

Abstract

The present invention relates to a security document authentiable by a code formed of colored dots randomly distributed and visible to the naked eye in natural light, characterized in that: - the colored dots are of heterogeneous dimensions, - the colored dots are formed by revealing a pre-existing network of granules introduced by papermaking into or on the surface of the document, which granules consist of aggregates of elementary particles of smaller sizes, which network of granules is visually undetectable before the revelation to produce the colored dots, - the revelation of the colored dots occurs in a step subsequent to the introduction of the granules, by means of a dedicated apparatus or by a known printing process, - the revelation of the colored dots makes it possible to produce a reference signature unique document that can be extracted, encrypted asymmetrically and intro on the document in the form of a printed code, which code can be read by a suitable apparatus during a subsequent authentication step.

Description

The invention relates to a security document that can be authenticated by a code consisting of colored dots randomly distributed and visible to the naked eye in natural light. In the field of security documents, it is known to use elements introduced into the mass of paper to protect the writings from attempts to falsify, it is also known to use elements that can be authenticated in order to avoid counterfeiting and to reveal certain origin of the document, such authenticatable elements are for example watermarks, fluorescent fibers, holograms or various markers. For many years security documents were represented by banknotes, passports, checks, stamps and, more generally, documents of significant value, because of the explosion of counterfeiting almost 10% of global commerce the field of security is moving towards the protection of brands and consumer products. There is indeed a wide field that affects all goods intended for the public for which it is important to authenticate the origin in a certain way. Counterfeiting in the field of pharmaceuticals and food poses critical public health problems, the need for protection of goods is very important and these products must be able to be authenticated directly by consumers at the point of sale.

To ensure this protection security specialists have developed authentication means using secure printed codes affixed to labels or on the packaging of the product to be secured, such processes are described extensively and are for example indicated in US 7,684,088 to Alpvision, in WO 03005634 or in EP 789,480 to Eastman Kodak, there have been registered more than 260 patents in the last fifteen years in the field of product traceability and more than 5,000 in the field of authentication. The solutions proposed to date are essentially related to the printing of a secure code containing protected information that can be read by a software adapted to verify its authenticity or transmitted remotely to a database to compare the printed code with that stored in a database. This type of security is very weak because the computer codes can either be cracked or be acquired by counterfeiters who have 40 significant financial means.

It is also known to use so-called authenticatable elements in the form of markers introduced randomly on the surface of the labels so as to produce a unique signature of the document, which signature can be encoded, there are many variants of this document. concept, for example a bubble code as described in EP 1 252 616 Novatec is introduced by means of a polymer matrix on a label, various markers such as those reported in US 9 010 638 Bilcare, W02012157009 by Claudio Selva , W02009073463 of Honeywell International, EP 1 990 779 of CSEM, JP2007112059 of Fuji or EP 2 10 781 363 of Dai Nippon Printing, are affixed to the surface of the documents, which after image analysis or mapping of a particular physical element , such as for example magnetism, are then encoded to be verified by means of a specific apparatus. This latter concept of authentication is more robust with respect to counterfeiting than the simple affixing of a printed code, however this method has several disadvantages, the first being that the method of securing by affixing the marker and the code is likely to be captured by mafias because there is virtually no robust technological protection in the chain of security, the second is that authentication requires a very specific equipment, usually expensive, and therefore not accessible to a wide audience of consumers. More effective solutions from the point of view of the possibility of combating counterfeiting have been proposed by papermakers who have significant technological protection because counterfeiters can not obtain a paper machine to produce false documents, in particular also because the number of security manufacturers in the world is very small and the document distribution chain is very protected. Because of this essential technological protection of the security elements such as the watermark and the introduction of authentication elements in the dough itself, as the security fibers, although known since the nineteenth century, are still used and are essential elements of protection, always robust despite the number of years of use. Thus, with the aim of producing documents which can be authenticated by means of elements introduced into the thickness of the substrate and producing a unique signature of the document which can be encoded and traced, several solutions have been proposed: In GB 2 324 065 it has been described the use of capsules of different sizes introduced into the mass of a plastic or on the surface of a document in aerosol form, two categories of particles are used for authentication. The encodable part of the document being a strip comprising the elements to be mapped. This document does not describe the possibility of using granules consisting of aggregates of elementary particles that can be revealed by a reagent or a solvent, in fact this system does not allow to affix the code at any place the document or authenticate it in any other way than by the code affixed. In EP 1 716 003 it has been proposed to map and encode fluorescent fibers invisible to the eye. Other documents also mention the use of fibers or fluorescent particles, for example in a nonlimiting manner: JP6008679, JP8147434, JP8260394, this authentication method is problematic because the reader of the code must be equipped with a specific lighting, generally 10 ultraviolet, which is not available conventionally on devices accessible to all audiences, such as smartphones. In FR 2 890 666 it is described the creation of randomly distributed gas bubbles in a paperboard substrate during its manufacture whereas the document FR 2 425 937 of the same company mentions the use of metal fibers, in both situations. the encoding of the signature proposed by the document must be read with a device specifically developed for this purpose. EP 656 607, EP 625 766 and EP 632 398 describe the use of magnetic elements to form an encodable random frame, again the apparatus is very specific and not available on a large scale. The present invention is fundamentally different from the closest state of the art represented by the following documents: FR 2 970 716 of the Applicant describes a tamper-resistant paper which comprises particle clusters capable of reacting with solvents However, this document does not indicate that the paper must be revealed on a specific area to produce a dot code that can be read by a suitable device, preferably a smartphone. The object of document FR 2 970 716 is to produce an unfalsifiable document and therefore a blank paper throughout its lifetime and for its use, the presence of black dots on such a paper is considered as a defect producing a dispute in customers. The present invention, which consists in realizing document authentication by anyone wishing to check a paper, or a product at the end of the chain before purchase, by means of a Smartphone or a device dedicated to authentication, is distinctly different. of the application described in FR 2 970 716. The document EP 1 716 289 describes the introduction into a paper of boards that can be treated tamper-proof so as to produce a coloration in the case of an attempted fraud, however this device is fundamentally different from the invention in that the boards are not aggregates of elementary particles, they are of uniform sizes and are not intended to reveal a point code, which could not be obtained on a reduced size because the boards are of sizes too big compared to the surface desirable for the realization of the code, they would not allow nc not a satisfactory encoding. As in the paper described by patent FR 2 970 716, the document marketed must be white. All the aforementioned documents employing markers all have the disadvantage of requiring a specific detection tool not accessible to a wide audience of consumers, it is well known in the field of authentication that the cost and ease of implementation of authentication are the key criteria for the application to grow and be used. It should also be noted that for all the systems known to date from the point of view of the consumer user, for example a customer in a supermarket who wishes to verify that a product is genuine, there is no device allowing to verify the authenticity on the spot by a simple and reliable means, which proposes to realize the invention. The invention therefore aims to solve the main difficulties mentioned above by proposing a robust authentication means, requiring an apparatus available from a large number of consumers, the authenticatable document being very difficult to counterfeit because of the protection technological contribution brought by the use of the paper machine for the realization of the document and the difficulty to reproduce the colored dot code as realized.

The present invention thus relates to a security document authentiable by a code formed of colored dots randomly distributed and visible to the naked eye in natural light, characterized in that: - the colored dots are of heterogeneous dimensions, - the colored dots are formed by the revelation of a pre-existing network of granules introduced by papermaking into the document or on its surface, which granules consist of aggregates of elementary particles of smaller sizes, which network of granules is undetectable visually before the revelation in order to produce the colored dots, the revelation of the colored dots takes place in a step subsequent to the introduction of the granules by means of a dedicated apparatus or by a known printing process, the revelation of the colored dots makes it possible to produce unique reference signature of the extractable document, asymmetric encrypted The code can be read by a suitable apparatus in a subsequent authentication step.

The advantages of the invention over the prior art described above are numerous: The document can be intended both for a consumer application for labels affixed to products and for a security application. such as checks, passports and identity documents, visas, stamps, etc ... Securing by the technological protection of papermaking is very robust and the security chain is manageable because the number of papermakers and security printers is limited.

10 Smartphone authentication requires no cost for the verification hardware, which is already widespread. Data encryption is also very robust due to the use of asymmetric code and because it is not necessary to access a remote database to compare the signature of the document to be authenticated. with the reference signature. In addition to the above elements, there is also an economic advantage in that the granules represent a very small additional cost on the final product and that they can be introduced by a known papermaking technology, and that the code can be revealed by a device. a traditional process that requires little or no investment in the secure document production chain. Other features and advantages of the invention will emerge from the description which follows. Figure 1 schematically shows the method of marking the paper.

Figure 2 schematically illustrates the authentication method. The invention relates to a code formed of colored dots randomly distributed and visible to the naked eye in natural light, that is to say that no apparatus is necessary to visualize the code of points revealed, however, and it is a peculiarity of the invention, the colored dots are of small sizes, which are less than 500 p, preferentially less than 200 p, and still more favorably less than 150 p. The colored dots are of heterogeneous sizes, ranging between just perceptible to the eye, ie of the order of 50 μ, up to 500 μ, of dissymmetrical shapes and they appear visually weakly contrasted, these specificities being particularly appreciable in order to avoid counterfeiting because it is not possible to reproduce such characteristics by a printing process.

The colored dots are preferably black or in dark color to facilitate image analysis. Since, moreover, the points are advantageously located in the fibrous network of the paper during its manufacture, the colored dots are distributed three-dimensionally in the structure of the substrate, which is also a means of verifying the authenticity of the document. Indeed it can be detected by means of a magnifying glass or a binocular that large dots included in the thickness of the paper are covered with fibers and that colored dots closer to the surface or on the surface thereof are more visible. Colored dots of large sizes can also be viewed by transvision for low weight documents. According to the invention the colored dots are formed by the revelation of a pre-existing network of granules introduced by paper into the document or on its surface, which granules consist of aggregates of elementary particles of smaller sizes, which network of granules being undetectable visually before revelation to produce colored dots. The granules can be of different categories: It is proposed to use granules which are formed of aggregates of large sizes, of more than 50 μ, of a color identical to or similar to that of the substrate, which can be revealed by a chemical reagent brought by the surface of the document during the revelation step, which granules are contained in the fibrous part of the document. Such granules consist for example of agglomerated particles of manganese salts precipitated in water insoluble forms, agglomerates with binders of small elementary particles consisting of phthalein derivatives or various organic reactants, and more general by any reactive compound insoluble in water and likely to develop a coloration under the action of a chemical reagent. Typically the elementary particles have sizes smaller than 20 percent. It is also proposed to use granules formed of aggregates of sizes smaller than 150 p with colored elementary particles, which granules can be revealed by a solvent brought by the surface of the document during the developing step, which granules 35 being contained in the fibrous part of the document or in contact with it. Such granules are for example described in document FR 2 970 716 of the applicant. By bringing to the surface of the document or to its contact it should be understood that the granules can be brought by a coating or coating paper process but also in a glue applied between a film and a paper or by a varnish affixed on a paper, although the contribution of granules by the surface is less favorable for the protection of the document. Typically the elementary particles have sizes smaller than 20 p.

It can also be envisaged to use granules formed of aggregates of large size, greater than 50 μm, of a color identical or similar to that of the substrate, with elementary particles of small size, typically less than 20 μm. p, little or not colored, which can form a color under the action of a powerful light such as a laser or under the action of a particular radiation, such as for example ultraviolet. It is also proposed to use granules which are formed of aggregates of large size, of more than 50, of a color identical to or close to that of the substrate, which can be revealed by heat, the granules introduced into the paper structure consisting of aggregates made with elementary particles of small sizes, typically less than 20 p, agglomerated with a binder, which granules are insoluble in water.

Advantageously according to the invention the granules consist of aggregates comprising one or more pigments assembled by a binder of acrylic type, ethyl cellulose, styrene butadiene, acrylic styrene or cellulose derivatives, more advantageously still the granules, after formation, are insoluble. in water so as to be introduced without any problem into the pulp. According to the invention, the revelation of the colored dots occurs at a stage subsequent to the introduction of the granules, by means of a dedicated apparatus or by a known printing process. According to the invention, the revelation of the colored dots is preferably effected by application of a reagent or solvent so as to produce a unique reference signature of the extractable document, asymmetrically encrypted and introduced on the document in the form of a printed code, which code can be read by an adapted apparatus during a subsequent authentication step.

The method for revealing the colored dots and the marking of the paper are preferably carried out at the security papermaker who has manufactured the substrate or at an approved security printer, the revelation is advantageously carried out only on the area that it is desired to be able to authenticate. . The substrate being processed in its entirety the site of the revelation 35 can be chosen in any part of the document, which presents a great advantage for the realization of various documents. If the revelation is carried out by the papermaker, a specific material allowing the disclosure and the printing of the code must be used, it may for example be an ink jet printer projecting a solvent or a reagent 40 solubilized for the revelation of the paper. If a printer is responsible for the revelation, a traditional printing process for simultaneously transferring a reagent liquid or a solvent is possible. Subsequently, after extraction of the signature and encryption, an impression is affixed to the document before it is broadcast. The step of marking the paper is schematized more precisely in FIG. 1, which indicates in step 1 the step of revealing the colored dots, in the step 5 of image acquisition and in the step of printing. these three stages correspond to material actions. After image acquisition in step 2, a software phase allows the extraction of the image to be analyzed referenced 4, the creation of a reference signature 5 and the encryption 6 of this information by means of a private key 10 in order to achieve asymmetric encryption of the generated code. Once this encryption has been generated, the software part communicates with the printing part 3 for affixing the code and leads to the marked paper. After the development of the colored dots in the marking step the paper is printed and used either to produce identity documents, passports, visas, stamps or various documents conventionally known in the field of security, or labels intended to be affixed to all consumer products, in a conventional manner. When the label is printed with the usage data it is affixed to the destination products. The stores are then supplied in the usual way with the labeled products and the consumers can verify the authenticity of the products using a smartphone comprising the authentication application. Figure 2 schematically describes the authentication of the secure document at the end of the chain, by the consumer himself or by an approved controller 25 in the case of official documents. It is important to note that the authentication is provided by a Smartphone with the appropriate application but it can also be performed by a specific device for this purpose at a place of control, for example in an airport, a customs or on a terminal verification installed in the 30 store distribution products, or even on an automatic cash register as it is currently developing in supermarkets. The paper authentication is described in FIG. 2. When the marked paper is to be checked a first image recovery step 7 is performed by the verifier, a signature of the document is extracted in step 8 after extracting the paper. zone to be analyzed, then a hardware image acquisition step code 9 is operated, and decryption 10 by a public key to obtain the reference signature recorded on the document in the printing step 3. L The application installed on the apparatus finally performs a comparison between the obtained signature and the reference signature and determines whether the document is authentic or not.

Thus, according to the invention, the adapted apparatus for authentication is a smartphone or an apparatus comprising an image sensor in which the image is processed by a secure application making it possible to decode the signature formed by the colored dots and verify that it corresponds to the encrypted code affixed to the document, which encrypted code corresponding to a pre-recorded reference signature during an earlier printing step. According to the invention, the colored dots after revelation can no longer be modified and form a three-dimensional indelible code, the colored dots being of irregular shapes. In addition, the zone comprising the colored dots appears visually poorly contrasted with respect to the support. By low contrast it should be understood that black colored dots form an area to be analyzed visually perceived in gray by the human eye because of the number and size of the dots.

It is important that there are enough points for the signature of the document to be unique, but not so many that the image analysis can be performed on individualized points, limiting the number of contiguous points, advantageously, the part to be analyzed for forming the signature contains from 50 to 500 points per cm 2 visually perceptible, including in particular of the order of 20% rather large points, ie 10 to 100 points per cm 2 which will preferably be used for the realization of the signature. When the points are in significant numbers the signature can use only 1 to 3% of the visible points, preferably but not exclusively, the larger ones.

The surface of the part revealed with the colored dots which corresponds to the zone to be analyzed can be of variable size without departing from the scope of the invention, a square of 2.56 cm 2 is very suitable for carrying out the signature, dimensions more Smaller or larger are quite usable in relation to the amount of granules incorporated into the paper.

Advantageously according to the invention the security document authenticated by colored dots is also unfalsifiable by the addition of sensitization elements which prevent the modification of the writes, which elements are distributed throughout the entire fibrous structure of the document and are finely dispersed so as to be visually indistinguishable.

Typically the sensitizing elements are soluble in water and introduced by the size press into the paper machine or by the very small particle mass, generally less than 20%. The invention also consists in a method for producing a security document, which can be authenticated by an apparatus comprising an image acquisition device 40, the authentication being carried out by means of a signature obtained with randomly distributed colored dots. , the method being characterized in that it comprises the following steps: a) manufacture of a papermaking substrate with visually non-perceptible granules, which granules consist of aggregates of elementary particles of smaller sizes, which granules being visually undetectable before a revelation step to produce the colored dots, b) transformation of the granules into visible colored dots by application of a reactive agent or a solvent, c) acquisition of the image of the colored dots, extraction of a reference signature and asymmetric encryption of said signature, then retranscription 10 on the document thus formed d a code by a printing method, which code can be read by a suitable software application contained in an apparatus comprising an image acquisition device. The invention also consists in a method of authenticating a document by an apparatus comprising an image acquisition device by means of a signature obtained with randomly distributed color dots, characterized in that it comprises the the following steps: a) producing a papermaking substrate with non-visually perceptible granules, which granules consist of aggregates of smaller sized elementary particles, which granules are visually undetectable before a revelation step to produce the colored dots, b) transformation of the granules into colored dots visible by application of a reagent agent, c) acquisition of the image of the colored dots, extraction of a single reference signature and asymmetric encryption of said signature, then transcription on the document d a code by a printing method, in a marking step, d) verification of the document by acquisition image of the colored dots on the apparatus usable for authentication, extraction of the signature, then image acquisition of the printed code and decryption so as to extract the reference signature, then comparison between the signatures obtained for decision of validation. In a variant, it is also envisaged that the authentication is performed by sending the signatures retrieved by the image acquisition apparatus to a remote secure server, which server contains a database with the signatures of the documents saved and software for performing the validation of received signatures. The sending of signatures can be done by any known means of communication. The encryption of the reference signature is performed asymmetrically according to a known protocol of the RSA encryption type or a cryptography on the elliptic curves, the protection mode of the reference signature and the decryption and comparison protocols of the signatures. known in themselves and conventionally used in various fields. As a variant of the invention, it is envisaged that the final document comprising the colored dots on the zone that has been revealed may be authenticated on another part of the document by the consumer or the approved verifier in several different ways: by the use of a reagent identical to that used for the revelation of the dots, or allowing the same color development, by the addition of a different reagent in the paper operating with a co-reactant contained for example in a specific felt, by any other means already known in the art for its authentication characteristic. As a variant of the invention it is provided that the security document marked with the colored dots is authenticated as previously by an apparatus comprising an image acquisition means but instead that the validation decision is made by the application the signature is sent by any communication system to a remote secure server containing a database having previously registered the reference signature which performs the comparison and the validation decision. This type of verification, although less favorable, may be complementary to the authentication described in the general scope of the invention. It is also contemplated within the scope of the invention to combine the colored dots forming the visible signature with points invisible to the eye and also of large dimensions, perceptible under ultraviolet light or at another wavelength. The colored point code described here is obviously combinable with conventional two-dimensional codes such as QR code or Datamatrix without departing from the scope of the invention.

Of course, the invention is not limited to the embodiments described and shown by way of example, but it also includes all technical equivalents as well as combinations thereof.

Claims (10)

CLAIMS1- Security document authentiable by a code formed of colored dots randomly distributed and visible to the naked eye in natural light, characterized in that: - the colored dots are of heterogeneous dimensions, - the colored dots are formed by the revelation a pre-existing network of papermaking granules introduced into the document or on its surface, which granules consist of aggregates of elementary particles of smaller sizes, which network of granules is visually undetectable before the revelation to produce the colored dots, the revelation of the colored dots takes place in a step subsequent to the introduction of the granules, by means of a dedicated apparatus or by a known printing method, the revelation of the colored dots makes it possible to produce a unique reference signature of the document can be extracted, encrypted asymmetrically and introduced on the document ent in the form of a printed code, which code can be read by a suitable apparatus during a subsequent authentication step. 2- security document according to claim 1 wherein the granules are formed of aggregates of large sizes, greater than 50 p, of a color identical to or close to that of the substrate, which can be revealed by a chemical reagent brought by the surface of the document during the revelation step, which granules are contained in the fibrous portion of the document. 3- security document according to claim 1 wherein the granules are formed of aggregates of sizes less than 150 p comprising colored elementary particles, which granules can be revealed by a solvent brought by the surface of the document during the step of revelation, which granules are contained in the fibrous part of the document or in contact with it. 4- security document according to claim 1 wherein the granules consist of aggregates comprising one or more pigments assembled by a binder of acrylic type, ethyl cellulose, styrene butadiene, acrylic styrene or cellulose derivatives. 3035819 13 5- security document according to claim 1 wherein the colored dots after revelation can no longer be modified and form a three-dimensional indelible code, the colored dots being irregular in shape. The security document of claim 1 wherein the colored dots are smaller than 200p. 7- security document according to claim 1 wherein the security document authenticated by colored dots is also unfalsifiable by the addition of sensitization elements that prevent the modification of the writes, which elements are distributed throughout the structure fibrous of the document and are finely dispersed so as to be visually indistinguishable. 8- security document according to claim 1 wherein the signature is obtained by an area to be analyzed containing from 50 to 500 dots per cm2. 15 9- Method for producing a security document, authenticatable by an apparatus comprising an image acquisition device, the authentication being carried out by means of a signature obtained with randomly distributed colored dots, the method being characterized in it comprises the following steps: a) manufacture of a papermaking substrate with visually imperceptible granules, which granules consist of aggregates of elementary particles of smaller sizes, which granules are visually undetectable before a revealing step to produce the colored dots, b) transformation of the granules into visible colored dots by application of a reagent agent, c) acquisition of the image of the colored dots, extraction of a reference signature and asymmetric encryption of said signature, then retranscription on the document thus formed of a code by a printing process, which code can be read by a software application adapted contained in an apparatus having an image acquisition device. 10- A method of authenticating a document made according to claim 9 by means of an apparatus comprising an image acquisition device characterized in that it comprises the following steps: a) image acquisition of the area of colored dots, b) extraction of the signature of this area, c) image acquisition of the code on the document, 3035819 14 d) decryption of the code to obtain the reference signature e) comparison of the two signatures for decision validation or not of the authenticity of the document.