BG64427B1 - Method for marking and authenticating an object - Google Patents

Abstract

The invention concerns a method for marking (A, B) and authenticating (C) an object (10) comprising the combination of two different data (K, N) mutually linked by means of a given arbitrary correspondence and use for authenticating the object at least one of the two data (K) being intrinsically undetectable by an observer, the scanning of the two data and the verification of their mutual correspondence being performed during authentication of the object. The method is characterised in that the two data are non-random and said undetectable information is materialized by means interacting with the structure of the object.

Description

Technical field

The invention relates to a method for marking and verifying the authenticity of an object.

The invention relates to items that can be falsified. In this sense, it is applied in a particularly appropriate way, and not only to documents of a certain value - banknotes, checks, stamps, identity documents / passports / or for which it is important to establish authenticity (debit cards, legal acts, lottery tickets), etc.

BACKGROUND OF THE INVENTION

There are many types of means of affixing markings on valuable objects, which marking is preferably not detectable by the naked eye and which enables the authenticity of the object to be controlled by appropriate means (encrypted characters, light marking).

In order to reduce the risk of counterfeiting, items have been created and are known to contain two related information, one of which is imperceptible to the naked eye.

EP A 609 937 describes a check containing a marked area, reproducing in a manner invisible to the eye, one visible check information (batch number or other). Decryption with a machine allows you to determine whether the content in the marked area is identical to the information that is visible.

The rapid spread of improvements to image analysis and decryption software makes that solution accessible to counterfeiters who can reproduce it as soon as they discover the code that will allow them to decrypt the information in the marked area. Such reproduction will also be facilitated by the fact that the technique of invisible marking is readily accessible to the forger immediately after decryption of the code.

GB A 2 252 270 describes a credit card or phonecard containing visible information in one first zone and hidden information (such as covered with opaque plastic tape) in the second zone. The authenticity of such a card can be ascertained by revealing only one hidden information, and because of the uniqueness of the disclosure, this is not a suitable solution in the numerous cases where the authentication of the item must be repeated repeatedly (as is the case with banknotes, for example).

From FR 2 765 014, the protection of a document is known by printing a number written visibly and combined into one solid memory with information on the distribution of magnetic filaments in the document.

The disadvantage of this solution is that the placement of the magnetic filaments in the object is arbitrary and it is not possible to use coding in the desired sequences.

Other safeguards are also known that can be used for related documents. BUS5818019ce describes means for protecting a lottery ticket document by means of a type of selectively applied conductive ink, which creates an electrical circuit.

One of the disadvantages of this solution is that it is quite complicated to use. In addition, the conductive ink is simply applied to the surface of the paper, so it is necessary to provide safeguards, which increases the cost of protecting the document. Finally, it is difficult to foresee the use of information to protect such a document, such as banknotes, because of the complexity and value they have.

SUMMARY OF THE INVENTION

It is an object of the invention to allow objects to be provided with very secure means of verifying their authenticity.

It is another object of the invention to further enable the desired marking sequences to be carried out on a batch of articles to be protected.

It is another object of the invention to further enable the marking to be carried out in a simple and economical manner.

The preferred but not the only aspects of the process according to the invention are the following. It also contains the development of third information, which is encoded using a certain algorithm whose data is two-arbitrary information. The method also includes integrating the subject matter with said third information. In addition, at least one non-observable information for the observer is materialized in variable relief so as to form a three-dimensional non-observable code for the observer on or in the object.

At least one non-observable information for the observer is materialized by applying a variable density ink to form a three-dimensional non-observable observer code on or in the object.

The information inaccessible to the observer contains one combination of a number of zones, the density of the ink applied to each zone being variable. In addition, the density of the applied ink in each printing area may be equal to one first density, enclosed between 10 and 25 μ, or to a second density, enclosed between 30 and 60 μ. At least one inaccessible to the observer information contains at least one embossed printed part, in particular with fine engraving.

Ink includes a substance having a physical, chemical or biological property, measurable and proportional to the amount or density of the integrated substance on or in the article. The property is mechanical, magnetic, electrical or optical.

The object of the invention is a document, such as a banknote, and at least one piece of information inaccessible to the observer is materialized on the document by integrating an intermediate medium into the document.

The intermediate carrier is a coded security thread.

The item is a document such as a banknote, and at least one inaccessible information to the observer is materialized on or in the document embedded in its structure.

At least one subtle observer's information is integrated into one watermark. At least one non-observable information is materialized by integrating into the microcapsule object a fluid containing a product to which one of the properties is measurable. The microcapsules contain dipoles, and the object in which they are integrated has an electromagnetic field that allows the dipoles to be oriented in a specific way.

One of the two involuntary information is physically integrated on or in the object, the other information being linked to another physical medium.

In addition to marking each of the two involuntary information on a physical medium, the method also involves transmitting that information to a central authentication device.

The method involves entering two inadvertent information into a single file (filing cabinet) and, upon authentication, sends a request to the file to verify the correspondence of these two information. Querying the file is accomplished through the means of remote communication.

The method also includes a step of decrypting and transmitting inaccessible information for the observer to an authenticating device. The third information contains one sequence of a number of icons, each belonging to a specific set of icons. The third information is also affixed to the object and is masked in the application of one of the inadvertent information.

Authentication also involves decrypting the third information and verifying its compliance with the two involuntary information. The verification of the compliance of the third information with the two involuntary information triggers local memory associated with an authentication machine and containing the algorithm used to compile the third information. Then, remote communication is triggered with a secure central device to recover the third information by triggering said algorithm.

The item is a confidential document, specifically a debit card or banknote.

Description of the attached figures

Aspects, objectives and advantages of the invention are explained by the following description of preferred embodiments of the invention shown in the accompanying drawings, where:

Figure 1 is a schematic note made according to the invention;

FIG. 2 shows the main steps of the method according to the invention for realizing the banknote of FIG. 1 and establishing its authenticity; FIG.

Figure 3 shows the main steps of the method according to the invention for making a banknote and establishing its authenticity;

Embodiments of the invention

Figure 1 shows the banknote 10, which has a space 12 on its left side. In the embodiment (Fig. 1), the space 12 has the form of a strip covering the entire width of the banknote.

The space 12 is divided into seven zones 121 to 127, adjacent two by two and arranged in series and with the same surface.

Each zone 121 to 127 may or may not be printed so that the space 12 is a visible pattern of the printed and unprinted areas.

The method of printing the formed pattern from the areas of space 12 is as follows. Some areas are printed and others may not be; in particular, the printing areas are selected in such a way that two-dimensional encoding is performed in space 12.

More specifically, according to the invention, the printing of the zones selected in space 12 is carried out by the specific technique of fine engraving, which allows controlling the density of the ink deposited on the banknote.

It is possible, for example, to be applied to selected areas of space 12 or a first density of ink E1 covered, for example, between 10 and 25 μ, or a density E2 covered, for example, between 30 and 60, ensuring that the nominal values of be substantially spaced from each other in order to avoid the appearance of fine print engraving that will interfere with measurements.

In this way, for the realization of the fine engraving on the space 12, a board is laid on it, the surface of which bears in some places against the areas selected for printing, indentations of E1 or E2 depth, filled with ink, to be applied thereto. depth in the selected area of the banknote.

Thus, the two-dimensional motif that is being created is in itself a single coding that can be subtle to the observer or subtle, in the case of very small areas (since the number of zones in each space can be arbitrary).

In addition, an equivalent three-dimensional encoding is also created for one K information, which is physically indistinguishable to the observer, since the difference in ink density between selected zones in space 12 (E1 or E2 and both smaller than 60 μ) is audible only with the help of sophisticated measuring instruments.

The fact that information K is not readily apparent to an observer is closely related to the specific way in which this information is encoded on the banknote, which makes it impossible to read without a machine. In this way, fine-grained coding is more effective than simple coding that can be perceived by the observer, which can be made invisible in a simple way, such as printed information covered by a strip that can be torn off or scratched by the observer. access to information.

In addition, the affixing of the banknote mark is not sufficient, since fine engraving requires interaction with the structure of the banknote. Indeed, this is a requirement of the printing technique, since the printing form covers recesses of varying depths filled with ink, and this form is pressed onto the banknote. In this case, those portions of the banknote which are against the recesses are deformed due to their adhesion to the recesses. A fine engraving thus provides a controlled change in the surface of the banknote and the application of an ink whose density is also controlled.

In the described example (FIG. 1), therefore, an invisible three-dimensional encoding is performed, which is masked in a two-dimensional motif that can be heard.

The areas selected in the space 12 should be sufficiently wide, having regard to the wear of the applied ink with fine engraving and to ensure, despite the manipulations tolerated by the banknote, that a considerable surface of these areas remains covered by the desired ink density. It is also possible to coat the applied ink with a protective film that can be transparent.

As indicated, ink deposition on the surface 12 forms a three-dimensional code K that is not readily apparent to the observer. In this example (FIG. 1) it is possible to print with an ink jet one arbitrary combination of the seven zones 121 to 127 of the surface 12, the number of combinations in this case being equal to 5040. In addition, all areas of the surface 12 may be printed.

Of course, the shape of the two-dimensional motif formed by the printed and non-printed areas of the surface 12 is not limited by the very simplified example shown in Figure 1. These zones can be defined in such a way that the motif is arbitrary since space 12 it is not necessary to have the appearance of a rectangle and can be replaced by a freely chosen arrangement of the areas to be printed with fine engraving, since the said zones do not necessarily represent topologically continuous spaces. Therefore, it is possible to implement multiple three-dimensional combinations for encoding surface areas 12.

It is not possible to implement the described coding for counterfeiting, as equipment and knowledge are required for fine-grained printing.

Banknote 10 also has a space 3 in which second information N is printed with visible signs, which in this example represents the serial number of the banknote (3466 in the example described). Figures 2 and 3 illustrate how the two K and N information associated with the banknote are used for more secure protection when verifying its authenticity.

The method (Fig. 2) covers three main steps:

- stage A, which corresponds to the creation of the three-dimensional code and its printing on the banknote;

- step B, through which an arbitrary dependency (link) is associated, the three-dimensional code, to the serial number of the banknote printed in space 13; thus, steps A and B correspond to the production of the banknote;

- Stage C, which corresponds to the authenticity of the banknote as it is put into circulation.

During step A, proceed to step A1, which involves printing on the banknote the three-dimensional coding described in Figure 1. The coding is carried out in a programmed manner (predetermined coding).

More specifically, it is possible to mark each banknote in a specific batch by a code belonging to the desired sequence that relates to information K. This allows the creation of batches of banknotes, on which information K, on the one hand, and N, on the other, follow every law you want.

It is also possible to use the technique of fine engraving without ink, deforming the embossing of a banknote by applying the shape to its surface; in this case, under the influence of the pressure of the form, the paper reaches the bottom of the recesses of the form and tolerates a controlled deformation without receiving ink. Three-dimensional coding K is obtained by controlled distribution of banknote reliefs.

Stage B consists essentially of four sub-stages:

- in B1, the machine reads the three-dimensional code (whether programmed or arbitrary) and transmits it to a central storage device of the banknote-producing apparatus,

- the serial number of the banknote is printed in B 2 while being stored in the central storage device,

- in B 3 the information K and N is processed by a certain algorithm and the result obtained (which will be called a function of the bijection of K and N and which will be denoted by M) is printed in encrypted form on the note in B 4. The function is printed the bias may be in the designated area or masked inside the serial number printing using very small characters for the bias function.

The bias function can be encrypted in the form of three pictograms, for example alphanumeric characters, each can be one uppercase letter, one lowercase letter or one digit (or 26 + 26 + 10 = 62 character options) since the three characters may be different. In this case, there are 226 920 possible combinations for the function of bias.

In step C, we proceed to step C 1 to establish the authenticity of the banknote by reading the machine of code K, the number N, and the function by M. The machine for establishing the authenticity containing the algorithm that served to produce the function from the bijection, checks the correspondence between information K, N and M, this algorithm is not accessible outside the machine, even for a falsifier who would reach it. This machine can be autonomous, ie not be connected to a central office with information K and N relating to each banknote.

In all cases, whether or not a bias function is calculated, the means of verifying the authenticity of a banknote send only one dichotomous signal, which may have only two values, corresponding respectively to one authentic banknote and one non-authentic banknote.

The method described allows marking whose protection level is extremely high because it combines several strong security features:

- a marking technique that is difficult to access for counterfeiters and makes it completely impossible for observer to encode. The fine engraving which illustrates the example of the banknote of Figure 1 and which is a preferred technique (but not the only one) for realizing the invention, in itself, constitutes an obstacle to counterfeiting because of the knowledge and specific means used, and the three-dimensional motives that this technique allows to be realized can only be read by machine;

- due to the possible numerous combinations for the code K and for the function M, it is potentially impossible for the forger to reveal the calculation algorithm.

In addition, in the case where the algorithm constructs a function from the bijection M, this algorithm is protected in the banknote authentication machine (or as will be seen in another secure device). The algorithm, which is the key to the calculation, is therefore unavailable.

In any case, the dichotomous sign of the response of the controls does not provide any element to allow the correlation between the information contained in the banknote to be revealed.

The steps of the method described above may proceed in a different order. In particular, it is possible to print the N number and save it before printing the K code. It is also possible to print the two information in different places, which further increases the security level of the method.

It is also possible to include in the banknote an indistinguishable code for the observer through other methods that require interaction with the banknote structure itself (or with the object to be marked). In particular, microcapsules containing liquid allowing the coding to be integrated can be integrated into the banknote paper.

In a preferred embodiment, these microcapsules are made of a liquid lacquer comprising magnetic dipoles. After integrating the lacquer into the paper (during paper production or subsequently), the paper is subjected to a non-uniform electromagnetic field with respect to at least one parallel direction on the surface of the banknote (with the distribution of the field values being controlled or not) effect orientation of the liquid dipoles contained in the liquid lacquer. The banknote is then subjected to some irradiation to allow the lacquer to dry (for example, UV rays which cause the lacquer to polymerize) in order to impede the orientation of the dipoles. It is then possible to "read" with a machine the two-dimensional field induced by the dipole distribution. The two-dimensional distribution of this field exactly compiles the coded information K.

The microcapsules may also contain any other product to which one of the specific properties can be detected. This property could be activated, as in the case of dipoles exposed or not in an electromagnetic field (an example of microcapsules containing one or more colorants. In all cases, it is important to have variants of this quality when describing the surface of a banknote , be measurable in order to characterize the K code.

Figure 3 illustrates an embodiment of the method according to the invention, where the function of bijection is not calculated. In this case, steps A1, B2 and B2 are carried out and then:

B31, the central storage device builds an F file for pairs (K, N) for each banknote produced. This creates an arbitrary relationship between information K and N (it does not fit any definition) and which is also fixed in the memory of file F. It should be noted that if a function is constructed from the bijection M, there is also an arbitrary relationship between

K and N, with this ratio being: "K and N are coherent with each other as input data of the algorithm that allows the function M to be determined";

- and the authentication step Cl 1 consists here of reading from the machine the code K and the banknote number N and requesting the file F remotely (by wire connection - for example, telephone or any other known transmission method - radio, etc.). ) in order to verify the correspondence between these two information.

Although the application of the banknote security method is extremely suitable and the fine engraving or integration into the paper of microcapsules are reliable techniques for the three-dimensional marking of objects and documents of value accomplished according to the invention, they do not limit the scope of the invention.

It is possible, for example, to enhance the protection of marking and printing with fine engraving by using to print objects subject to protection which ink containing at least one substance having a special property that can be measured by a machine, such as the measured property is proportional to the density or amount of substance applied to the article.

In this case, code K is read by measuring at each point of the print space of that particular property, the measurement being proportional to the density of the substance present at said point of the object, and therefore to the density of the ink applied at that point ( since the concentration of the substance in the ink is known). A series of measurements at different points in space allows the recovery of a code K equivalent to a three-dimensional code.

This makes it possible, for example, to apply a fine engraving of an ink containing a known concentration of a substance with a property that may be magnetic, electrical (conductivity or otherwise), optical (visible or not, which can use fluorescent or phosphorescent glow substances), chemical, biological. The code reading means K in this case comprise suitable means for measuring the property exhibited by the substance (for example, a photocamera for a substance having an optical property or magnetic decryption means, an interferometer ultra-high frequency reading device).

If the code reader K allows measurement without contact with the property of the substance contained in the ink (eg in the case of magnetic field measurement), it is also possible to cover the three-dimensional overlay containing the code K with masking agents whose laying it on the document may possibly cause the ink density to be evened out (for example, when covered with a single hologram with a heat press).

Among K code implementation techniques, fine engraving is a particularly suitable method. Any other method which allows the marking of the observer to be indelible, whether embossed or not, and interacting with the structure of the object may also be used according to the invention.

In the example of the banknote, the K code can be implemented in the form of a code that can only be decrypted by a machine and is not readable by the observer. This can be achieved, for example, as follows. The code K is integrated into an intermediate element, such as a security thread, which will also be integrated into the banknote (for example in the production of the banknote) and by integrating the code K inside the banknote structure (in this case the watermark bearing the code K).

In addition, it is possible to realize not only the marking of information K, but also the information N, so that such marking is imperceptible to the observer, the main feature of the invention being to provide two combined information, at least one of which is not detectable for the observer.

It is also possible to realize the invention for any item of value that can be falsified (audio and video CDs, perfumes, medicines, car spare parts, jewelry and branded clothes) and used on different types of media (metal, plastics, glass, fabrics) any method which makes it possible to obtain a mark which may be machine-deciphered but not recognizable to the observer.

According to one embodiment corresponding to the fine engraving example described above, a method will be selected to allow embossed marking in a controlled manner.

In this case, any method can be used to control the variations of fine-print embossing (micrometric embossing) so that these variants can be decrypted by a machine, but indistinguishable to the observer: pattern printing, heliography, mechanical engraving with high precision, chemical, laser engraving).

Some of the incomprehensible information can, as already emphasized, be materialized in any way. Thus, all or part of this information can be realized with uncontrolled relief variants, since the aggregated information is decrypted and stored during object marking.

It should be emphasized that the invention allows not only the protection of the object, but also the tracing of its movement (establishing the road). Indeed, the number of authentication checks is unlimited, and each check has the certainty that it has the original item (banknote or other).

This aspect of the method can be used to combat counterfeiting, in the sense that by making frequent checks it is possible to determine with precision the location and timing of the occurrence of counterfeiting. It is quite obvious that it is possible to affix a label to the objects to be protected according to the invention instead of directly labeling the object.

According to an embodiment of the invention, it is also possible to physically separate the two information K and N: for example, it is possible to mark expensive clocks with one information K and the warranty card of the clock to carry information N as one of the two information is indistinguishable for the observer. During authentication, the decryption of both information on the clock and on the warranty card (or decryption of the bias function, if provided) is carried out. Such a solution increases the level of protection of the method. It is also possible to integrate the two K and N information in different locations, which increases the flexibility of production and the level of protection.

Finally, if a function M is provided, depending on the two information K and N, it may be possible, as already indicated, to provide an individual authentication machine, which provides the algorithm for calculating the function from K and N (for example, the portable terminal into which the algorithm is introduced into the microprocessor board), but it is also possible to store this algorithm in a secure central device, by which the authentication machine can communicate remotely (via translation or radiator) lane link).

It is also possible to provide a mixed formula in which the authentication machine contains a portion of the data which allows the calculation algorithm to be restored, since the machine must communicate with the central device according to a particular protocol in order to obtain additional data, that will allow the recovery of the function from the bijection. Different algorithms may also be provided, thereby creating batches of marked objects, each comprising objects combined by a single algorithm.

Claims (27)

1. A marking method (A, B) and authentication (C) of a single object (10) comprising the association to the object of two different information (K, N), linked together by arbitrary given correspondence and used to establish authenticity of the object, with at least one of the two information (K) being inaccessible to the observer, the decryption of the two information and the verification of correspondence between them during the authentication of the object, characterized in that the two information is preliminary but selected (K, N) and subtle information is materialized by means that interact with the structure of the object. Method according to claim 1, characterized in that it also comprises the compilation (B3) of third information (M), which is encoded by a particular algorithm whose input data is the two selected information (K, N). Method according to claim 2, characterized in that the process also comprises integrating into the subject (B4) the third information (M). A method according to any one of the preceding claims, characterized in that at least one information (K) that is inaccessible to the observer is materialized by different embossing so as to form a three-dimensional invisible to the observer code on or in the object. . A method according to any one of the preceding claims, characterized in that at least one information (K) that is inaccessible to the observer is materialized by applying an ink of different density to form a three-dimensional code on or in the object, indistinguishable. for the observer. 6. The method of claim 5, wherein said non-observable information (K) comprises a combination of a number of zones (211 to 217), the density of the ink applied in these zones being different. A method according to claim 6, characterized in that the density of the applied ink in each zone (211 to 217) can be equal to a first density in the range of 10 to 25 μ (E 1) and a second density (E2). with thickness from 30 to 60 μ. Method according to one of Claims 5 to 7, characterized in that at least one information (K) that is not readily observable comprises at least one part (211 to 217) embossed, in particular with fine engraving. Method according to one of Claims 5 to 8, characterized in that the ink contains a substance having a physical, chemical or biological property, measurable and proportional to the amount or density of the integrated substance on or in the article. A method according to claim 9, characterized in that said property is mechanical, magnetic, electrical or optical. A method according to any one of the preceding claims, characterized in that the subject is a document, such as a banknote, and that at least one non-observable information is materialized on or in the document by integration into an intermediate medium, which in turn is integrated into document. A method according to claim 11, characterized in that the intermediate carrier is a coded security thread. A method according to any one of the preceding claims, characterized in that the object is a document, such as a banknote, and at least one information inaccessible to an observer is materialized on the document by integration into its structure. A method according to claim 13, characterized in that at least one non-observable information is integrated into a watermark. A method according to any one of the preceding claims, characterized in that at least one non-observable information is materialized by integrating into the object microcapsules with a liquid containing a product whose property is measurable. A method according to claim 15, characterized in that the microcapsules contain dipoles and that the object in which the microcapsules are integrated is subjected to an electromagnetic field that allows the dipoles to be oriented in a specific manner. A method according to any one of the preceding claims, characterized in that one of the involuntary information is physically integrated on or in said subject matter, the other information being associated with a different physical medium. A method according to any one of the preceding claims, characterized in that it comprises simultaneously marking each of the two selected information (K and и) on a physical medium and transmitting this information to a central authentication device. A method according to the preceding claim, characterized in that it comprises the association (B1) of the two selected information (K and Ν) to one file (F) in order to verify the correspondence of the two information. A method according to claim 19, characterized in that the request for the file is performed by means of remote communication means. A method according to one of the preceding claims, characterized in that it comprises a step (B 1) of decrypting and transmitting the non-observable information (K) to a central authentication device. A method according to one of the preceding claims, taken in combination with claim 2, characterized in that the third information (M) comprises a number of pictograms belonging to each batch of pictograms. A method according to claim 22, characterized in that the third information (M) is printed on the object and is masked in one of the printed involuntary information. A method according to any one of the preceding claims, taken in combination with claim 2, characterized in that the authentication also includes decryption of the 5 third information (M) and verification of its correspondence with the two selected information (K, N ), 25. The method of claim 24, wherein the verification of the compliance of the third information (M) with the two selected information (K, N) triggers one local memory coupled to an authentication machine and containing an algorithm used for the development of the third information (M). 26. The method of claim 24, wherein verifying the compliance of the third information (M) with the two selected information (K, N) triggers remote communication with a secure central device to recover this third information by triggering said algorithm . 27. The method of claim 1, wherein the subject is a confidential document and / or security, in particular a banknote or debit card.