EP2279083A2

EP2279083A2 - Method for producing a security feature on a flat substrate

Info

Publication number: EP2279083A2
Application number: EP09734654A
Authority: EP
Inventors: Martin Schmitt-Lewen; Bernd Vosseler; Karl-Heinz Walther; Soner Akkaya
Original assignee: Heidelberger Druckmaschinen AG
Current assignee: Heidelberger Druckmaschinen AG
Priority date: 2008-04-23
Filing date: 2009-04-22
Publication date: 2011-02-02
Also published as: CN101564945A; RU2507076C2; DE102009016194A1; US20090274298A1; WO2009130009A2; CN101970244A; WO2009130009A3; KR20110008154A; JP2011520644A; JP2009262559A; RU2010147676A

Abstract

The invention relates to a method for producing a security feature (3) on a flat substrate (1), e.g. on paper or cardboard, particles (7) forming a cryptographic random pattern (4) being applied, preferably strewn, onto the substrate (1). The method according to the invention is characterized in that flexible wire or fiber fragments (7), espeically thin copper wire fragments (7), are applied to the substrate (1) in a feature section (8) that corresponds to the security feature (3). The security feature (3) can be provided with a protective layer (13), e.g. a laminate. The security feature (3) produced according to the invention can be captured in a simple and error-free manner and cryptographically evaluated. It cannot be counterfeited by known typographical methods or only at uneconomic expenses.

Description

Method for producing a security feature on a flat substrate

The present invention relates to methods for producing a security feature on a flat substrate with the respective features of the preamble of claim 1 and 2. Furthermore, the present invention relates to a printed product with a

A security feature having the features of claim 10. Also, the present invention relates to a method of verifying the authenticity of a product having the features of claim 11 and a method of protecting products from counterfeiting having the features of claim 14.

When checking the authenticity of printed products, e.g. Documents or pharmaceutical packaging, various methods are used to produce so-called security features. The security features must - to become mass suitable - be inexpensive to produce and still offer a high degree of reliability in the detection of counterfeiting.

Printed products, in particular original documents and packaging of expensive or sensitive products such as cosmetics or pharmaceutical products, can be protected against counterfeiting in a variety of ways. Often, combinations of elaborate printing methods and print media are used to increase the security against counterfeiting, such. For example, banknote printing (iris printing, guilloche, security papers, threads, tipping colors, transparency and much more). For mass-produced articles such as disposable packaging, however, such combined, expensive and thus mostly expensive processes are not very suitable.

In addition to the production of printing technology security features, systems for the encryption of electronic data based on so-called public-key cryptography have also developed. It uses a pair of related keys, one of which is public (public key), while the other is kept secret (private key). The two keys can be left without

Do not divide additional information apart. A message that has been encrypted with a public key can only be associated with the corresponding one secret keys are decrypted and vice versa. The most common method in this regard is the so-called Rivest-Shamir-Adelman method (RSA). This method is implemented, for example, in the popular software "Pretty Good Privacy" (PGP).

It is known from DE 196 14 174 A1, for the labeling of substances or objects, to use multilayer microparticles, e.g. in paints. The microparticles can not be detected by conventional, inexpensive means.

DE 10 2008 014 322, which has not yet been disclosed at the time of application, describes a method for checking the authenticity of a printed product. In this case, a random feature can be generated for example by defects in cold foil transfer.

According to DE 10 2005 013 962 A1, random fine structures of a printed paper or other printing substrate are evaluated microscopically and used as a so-called fingerprint for the relevant document. This fingerprint can be stored in a database with the manufacturer of the security feature and controlled by database access by the user of the security feature. By comparing the fingerprint found on the product with the fingerprint stored in the database ^^, the authenticity of the present document can be confirmed. Alternatively, the fingerprint can be encrypted with a secret key and applied by the manufacturer of the security feature on the product, for example, be printed. The user of the security feature can verify the fingerprint by decrypting with the public key. A disadvantage of the method described, however, is that both the manufacturer and the user of the security feature must have a respective high-resolution device for receiving the fiber structure of the product. This is not very advantageous for use in the authenticity testing of mass products. The same is found in US 4,423,415. The evaluation of the fine structures is possible only with expensive technical means. DE 103 04 805 A1 describes the application of a random pattern to a product, the reading of the random pattern, the extraction of a so-called "fingerprint" from the random pattern in the form of a data record and the storage of the fingerprint When the product is authenticated, the fingerprint is extracted again from the random pattern and the agreement with the stored fingerprint is checked, for which the random pattern must be recorded with complex technical means with a high resolution range, eg with a microscope encryption, which used secret, ie non-public, keys, both of which are of little use in the authentication of mass-produced products.

Furthermore, e.g. Known from the production of banknotes to incorporate fluorescent fibers in the paper and to check the authenticity of a banknote with UV light. An individualized examination, i. Testing the authenticity of a unique is not possible in this way.

Against this background, it is an object of the present invention to provide a comparison with the prior art improved method for producing a security feature, which is a simple and inexpensive to manufacture easily (by conventional means, such as camera mobile devices) to be detected and cryptographically simple and error-free evaluation of the security feature. It is further a further or alternative object of the present invention to provide a printed product having improved, i.e., improved, upon the prior art. easy to detect and cryptographically simple and error-free to evaluate

Security feature. It is a further or alternative object of the present invention to provide a process and printed product improved over the prior art which allows for good distinctness, visual and / or haptic, between a true security feature and a mimicked security feature. It is a further or alternative object of the present invention to provide a method for verifying the authenticity of a product which is improved over the prior art and a method for protecting a product To create products against counterfeiting, which make a simple and inexpensive to produce, easily (by conventional means, such as camera mobile devices) to be detected and used cryptographically simple and error-free to evaluate security feature.

These objects are achieved according to the invention by methods having the respective features of claims 1 and 2, by a printed product having the features of claim 10 and by the method having the respective features of claims 11 and 14. Advantageous developments of the invention will become apparent from the accompanying dependent claims and from the description and the accompanying drawings.

An inventive method for producing a security feature on a flat substrate, wherein particles - forming a cryptographic random pattern - are applied to the substrate, characterized in that flexible wire or fiber pieces in a - with the security feature corresponding - feature area applied to the substrate become.

An inventive method for producing a security feature in a flat substrate, wherein particles - forming a cryptographic random pattern - are introduced into the substrate, characterized in that flexible wire or fiber pieces in a - corresponding to the security feature - introduced feature in the substrate become.

For the purposes of this application, the term "flexible" is to be understood as meaning "deformable", in particular "flexible." In this case, both elastic and plastic, both reversible and irreversible deformability can be given in that they can be provided with a curvature along their longitudinal axis (or multiple curves) which is permanently maintained.

The use of wire or fiber pieces allows good distinctness between original and imitation (counterfeit), since the pieces have a characteristic light reflection Due to their 3D structure, they can be recognized as pieces by the naked eye from different angles and the 3D structure can also be felt. In addition, the pieces can overlap and thus create a more complex and even more perceptible 3D structure.

A development of the method according to the invention which is advantageous and therefore preferred on account of the improved detection properties can be distinguished by the fact that plastic or metal wire pieces, in particular copper wire pieces, are applied to the substrate or introduced into the substrate.

A development of the method according to the invention that is advantageous and therefore preferred in terms of simple production can be distinguished by the fact that the wire or fiber pieces are applied to a feature area of the substrate pretreated with adhesive, in particular scattered.

An advantageous because of their robustness and therefore preferred embodiment of the method according to the invention may be characterized in that the wire or fiber pieces with a protective layer, in particular with a laminate, are covered.

An advantageous and therefore preferred due to a simple production

Development of the method according to the invention may be distinguished by the fact that the fiber pieces are transferred to the substrate with a fluid, in particular with printing ink or lacquer.

A refinement of the method according to the invention which is advantageous and therefore preferred in terms of improved protection against counterfeiting can be distinguished by the fact that the wire or fiber pieces have at least one curvature.

Another with regard to an improved protection against counterfeiting and improved detection advantageous and therefore preferred embodiment of the invention

The method can be characterized in that colored or fluorescent wire or fiber pieces are applied to the substrate or introduced into the substrate. A because of their robustness and improved counterfeit protection advantageous and therefore preferred embodiment of the method according to the invention may be characterized in that the wire or fiber pieces are placed in a nonwoven or a film applied to the substrate.

A printed product according to the invention with a security feature is characterized in that the security feature has a flexible piece of wire or fiber applied to a substrate - forming a random pattern.

Within the scope of the invention, a printing material processing machine - e.g. Printing machine, in particular sheet-fed rotary lithographic printing press, or printing finishing machine - to be seen, which are suitable for carrying out one of the above-mentioned methods according to the invention, e.g. by appropriate application devices configured.

A method according to the invention for checking the authenticity of a product has the following method steps: a signature assigned to the product is recorded, the signature is transferred by decryption into an identifier, a comparison feature is generated from the identifier, and the comparison feature is computer-aided with an image of the Product associated random pattern.

The method according to the invention makes it advantageously possible to check the authenticity of a product, making it possible to use a security feature that is simple to produce and easy to detect (using conventional means, such as camera mobile devices) that is cryptographically simple and error-free to evaluate.

An advantageous because of their ease of use and therefore preferred embodiment of the method can be characterized in that the signature is detected by a camera of a mobile device and that the comparison feature is displayed in the display of the mobile device. An advantageous and therefore preferred development of the method according to the invention, which is advantageous for the user due to the foreseeability of counterfeiting, can be characterized in that the comparison feature in the display of the mobile radio device is superimposed on the image of the random pattern.

A method according to the invention for protecting products against counterfeiting comprises the following method steps: a cryptographic random pattern of flexible wire or fiber pieces is generated, the random pattern is detected by a camera, an identifier is generated from the image of the random pattern, the identifier is encrypted with a secret key a signature is transferred, the random pattern and the signature are applied to the product to be protected, the signature is detected by a camera, the signature is transferred by decryption with a public key in the identifier, from the identifier is a comparison feature is generated, the comparison feature is computer-aided overlaid with a picture of the random pattern and compared.

The method according to the invention makes it advantageously possible to protect products against counterfeiting, whereby a security feature which can be produced easily and inexpensively and can be easily and reliably evaluated by conventional means such as camera mobile telephones is also made available.

The described invention and the described, advantageous developments of the invention are also in combination with each other advantageous developments of the invention. Of particular advantage is the successive application of adhesive, the scattering of pieces of wire, such as copper, and the application of paint or film. Also of particular advantage is the production of a label with a cryptographic random pattern of flexible wire or fiber pieces and with an adjacent, the random pattern representing and encrypted signature in the form of a 2D barcode (data matrix code). The invention as such as well as structurally and / or functionally advantageous developments of the invention are described below with reference to the accompanying drawings with reference to at least one preferred exemplary embodiment. In the drawings, corresponding elements are provided with the same reference numerals.

The drawings show:

Figure 1 is a schematic view of a first embodiment of a security feature produced according to the invention;

Figure 2 is a schematic view of a second embodiment of a security feature produced according to the invention; and

Figures 3a-3e sequence of a preferred embodiment of a method according to the invention for protecting products from counterfeiting.

The inventive security feature on a substrate is essentially based on a special random pattern, which is detected and evaluated after its production according to the invention. into a characteristic vector describing the random pattern and into a - optionally supplemented by further data and (asymmetrically-) encrypted - signature is überfuhrt. The signature produced in this way is likewise applied to the substrate, preferably printed, and serves for the authenticity check in comparison with the random pattern. Thus, e.g. from the decrypted signature, a comparison random pattern or from the random pattern, a comparison signature are calculated. In both cases, therefore, the user must be provided with a key, preferably a public key.

Such a cryptography method is described, for example, in DE 10 2008 014 322, which has not yet been disclosed, for a random pattern produced with cold foil or adhesively bonded particles. DE 10 2008 014 322 is referred to in this application with regard to the disclosed cryptography and evaluation method. The random pattern described in this application forms a cryptographic random pattern, ie a random pattern that can not or only uneconomically mimic and that allows by its special nature, a capture, encryption, decryption and comparison in a simple and error-free manner. It thus serves not only the general counterfeiting and / or manipulation protection, but also the individual product protection, ie individual products can be specifically recognized as counterfeits. In short, a potential counterfeiter would not only have to mimic or create a random pattern of the same kind, but an identical random pattern in order to forge products. A cryptographic random pattern is preferably a random local pattern, ie, a random pattern selectively positioned at a defined, localized location of the substrate and not a random pattern extending substantially over the entire substrate or large areas thereof.

FIG. 1 shows a schematic view of a first embodiment of a security feature produced according to the invention. A substantially flat substrate 1, preferably of paper, cardboard or plastic (e.g., a paper or cardboard sheet or a plastic label), preferably has a printed area 2, e.g. Text and / or image. The substrate thus preferably forms a printed product, e.g. a product made in lithographic offset printing like packaging. The substrate has a limited spatial extent, preferably limited to an area of about 50 to about 500 square millimeters, e.g. about 20 by 20 millimeters large - security feature 3 on. The security feature comprises a cryptographic random pattern 4 and a signature 5 corresponding thereto. Optionally, the security feature may further comprise a frame 6 which is preferably printed, e.g. in dark or black color, or other marking, e.g. Crosshairs, include. The frame essentially serves as a reference feature in the detection and evaluation of the random pattern. Section A shows the security feature in an enlarged view.

The cryptographic random pattern 4 of the security feature 3 is produced according to the first embodiment of the invention by applying flexible wire or fiber pieces 7, ie wire or fiber material of limited length, to the substrate in a feature area 8 corresponding to the security feature. Both the Wire and fiber pieces are thin and therefore flexible in relation to their respective lengths. Fiber pieces differ from wire pieces essentially by the smaller diameter. The fiber pieces are also referred to as staple fibers. Preferably, about 3 to about 20 pieces are applied.

The flexible wire pieces 7 used are preferably metal wire, but plastic wire can also be used. Particularly preferred is copper wire, e.g. about 50 to 100 micrometers thick, more preferably about 80 micrometers thick, and about 3 to about 30 millimeters long. The cross section is preferably circular. Due to its dimensional stability (essentially invariable

Curvature), robustness against downstream processes, intrinsic color, gloss and its easy recognizability or detectability mediated thereby. At the same time, the optical (and haptic) appearance of metal wire pieces by conventional methods, e.g. with cold foil application, hardly replicate. Overlying pieces of wire also have raised and therefore easily detectable points of intersection and are not prone to clumping.

The flexible fiber pieces 7 used are preferably synthetic fibers (e.g., fibers of natural or synthetic polymers such as nylon, glass, carbon, metal or ceramic fibers), but natural fiber (e.g., vegetable fibers;

Fibers, hair or animal silk, whether or not of human origin; Mineral fibers) are used. Furthermore, threads, i. E. a fiber composite produced from individual fibers (in this application, fibers are also understood to mean such fiber composites).

The production of the security feature 3 shown in FIG. 1 can preferably take place as follows: The feature area 8 is pretreated with an adhesive 9 (for the sake of recognizability only partially and shown as lines), eg UV adhesive, ie by local, restricted to the feature area Application of an adhesive 9 brought into a sticky state. For this purpose, an application device 10 can be used, for example a spraying or rolling device. Then the wire or fiber pieces 7 are sprinkled on the thus pretreated feature area. The scattering can be done, for example, with an air jet or with conveyor belts, generally with an applicator 11. For this purpose, the pieces 7 are dosed from a supply in an air jet and this fanned directed to the feature area 8; or the pieces are transferred from the supply to a conveyor belt whose

Conveyor speed can be varied, and promoted to the feature area. The scattering provides for random spatial distribution and alignment of the pieces within the feature area. In addition, the number of pieces in the feature area is controllable via the pieces supplied per unit of time and per unit area.

It is also possible to stockpile the pieces 7 in the form of a compact and to release them from the pressing by means of a rotating brush or the like and to supply them individually to the substrate 1.

Alternatively, the pieces 7 may also be used exclusively or additionally by a subsequent paint or foil application (by a corresponding device 12), e.g. by a transparent or at least partially transparent laminate 13 (the recognizability because of only partially and shown as lines), fixed and protected against displacement or damage. If, instead, an opaque protective layer is provided, the elevations of the protection caused by the pieces-and preferably made more readily recognizable by coloring-can be detected.

Alternatively, the wire or fiber material may be extruded or advanced and cut to a predetermined or random length. Here, the pieces 7 also a predetermined or random curvature can be impressed.

The wire or fiber pieces 7, or the corresponding materials, may also be dyed, metallized, fluorescent or phosphorescent for ease of detection. Preferably, the pieces have a good optical contrast to the substrate 1, for example dark or black pieces on a light or white substrate. However, according to the method disclosed in DE 10 2008 014 322, the cryptographic random pattern 4 produced in this way is detected in a corresponding manner by the manufacturer instead of the cold foil random pattern disclosed therein in detail and converted into a signature 5 which is applied to the substrate 1 , On the user side, the cryptographic random pattern or the signature can be detected and an authentication comparison can be carried out using an available key. In this case, a mobile device with camera can be used, which detects the macroscopic properties of the random pattern.

From the recorded image, the position of the wire or fiber pieces 7,

Orientation, curvature, crossing points, etc. extracted and the preferably only slightly curved pieces by polygons, preferably with up to about 5 interpolation points, approximated. With 9 bits of data per coordinate of a fulcrum (equivalent to 40 microns accuracy), assumed 10 pieces of wire or fiber and 36 bits of additional format information, the result is a remarkably small total data of only 117 bytes, with which the random pattern 4 can be described with sufficient accuracy.

Alternatively, the wire or fiber pieces introduced into a nonwoven fabric can be applied to the substrate 1. For this purpose, first a colored fleece with the therein, preferably different colored wire or fiber pieces 7, e.g. produced by thermal welding and a piece of this nonwoven feature area 8 is disposed on the substrate 1, e.g. bonded. Example: A few thousand, preferably about 5,000 dark or black fibers (about 20 to 200 millimeters long, about 10 to 100 microns thick, radius of curvature greater about 5 millimeters) in a web of light or white fibers.

Further alternatively, the wire or fiber pieces 7 may be formed in a preferably transparent substrate, e.g. a film introduced or mixed with this and applied to the substrate 1. Thus, e.g. the provided

Plastic granules of the film with the wire or fiber pieces offset and the film is drawn from this material, extruded or cast. The advantage here is that the Scattering and fixing of the pieces can be omitted and instead only the film produced according to the invention in the feature area 8 is applied to the substrate.

A further alternative may provide that the wire or fiber pieces 7 directly into the raw material for the production of a package, e.g. a plastic bottle is introduced, so that the random pattern 4 - preferably only locally - is found in the material of the packaging.

FIG. 2 shows a schematic view of a second embodiment of a security feature produced according to the invention. Section A shows the security feature 3 in an enlarged view. According to this embodiment, fiber pieces 7 are transferred to the substrate 1 with or in a fluid 13 (for the sake of recognizability only partially and as lines), in particular with printing ink or lacquer. In other words, a preferably light-colored printing ink or a transparent varnish is mixed with fiber pieces before being printed. With the fluid thus prepared, the cryptographic random pattern 4 is generated by printing in a separate printing operation (by a corresponding device 1). The fiber pieces used in this case preferably have a recognizable and a good contrast to the fluid and the substrate forming inherent color. In addition, the fiber pieces can advantageously have fluorescence property, so that under UV light improved detection is made possible.

The fiber pieces 7 used may be present as substantially smooth or crimped pieces. In addition, branched individual fiber pieces (typically natural fibers) or fiber composites of essentially unbranched or branched single-fiber pieces can be used.

The printing process can preferably be carried out by using a flexographic printing plate 14 in conjunction with a simplified inking unit, which is not impaired by the fiber pieces, for example, without a grid. By printing the fiber pieces 7 a random positioning and alignment of the pieces is guaranteed. Also in the embodiment according to FIG. 2, the recording and cryptographic evaluation of the random pattern 4 with conventional technology, which is in principle available to every consumer, is made possible, for example with camera mobile devices. Both embodiments have in common, among other things, that the random pattern generated in each case can also be perceived by the naked eye, so that a first authenticity or plausibility check is also possible without any technical aids. Furthermore, both embodiments have in common that the respectively generated random patterns are simple and inexpensive to produce and the respective manufacturing process can be easily integrated into existing printing processes or printing presses.

Figures 3a to 3e show a preferred embodiment of the method according to the invention for protecting products from forgery or manipulation. First, according to FIG. 3a, a pre-produced and preferably provided by a supply roll, preferably about 1 cm ² small, two-dimensional cryptographic random pattern 4 of flexible wire or fiber pieces 7 manufacturer, ie still during the production of the security feature 3, detected by a camera 15 and an image generated thereby or the associated image data of the random pattern 4 is fed to a computer 16.

The computer 16 calculates from the image data a preferably binary characteristic vector or an identifier which contains the data about the by polygons with preferably to about 5 interpolation points approximated wire or fiber pieces. The characteristic vector can be supplemented by further data (so-called additional information, such as manufacturer, product, best-before date, regional code, etc.). Subsequently, the encryption of the characteristic vector is carried out using a secret, ie not public or not provided to the public key. The encrypted characteristic vector is now available as a signature. Consequently, the signature is derived from the identifier and the identifier is derived from the random pattern. The signature can later, ie in the authenticity check, using a corresponding non-secret, ie public or public provided key back into the identifier (back) are transferred. For encryption and decryption can be up Conventional methods are preferred, preferably according to the principle of so-called public key cryptography, again preferably according to the so-called RSA encryption (Rivest-Shamir-Adelman), which is also used for example in the widely used software "Pretty Good Privacy" (PGP) ,

When using RSA encryption, which today is considered the most secure asymmetric cryptography system, the signature is at least as long as the key used for encryption. Today's usual, considered safe key sizes are between about 640 and about 2048 bits. Due to the signature length, it is advantageous to apply the signature in a machine-readable form to the printed product, for example in the form of a one- or preferably two-dimensional coding (2D barcode, data matrix code).

According to FIG. 3 b, the signature 5 produced in this way is supplied by the computer 16 to a printer 17, preferably an inkjet printer, and applied, in particular printed, to the substrate 1, preferably adjacent to the feature area 8. The signature 5 is preferably applied in the form of a two-dimensional coding (2D barcode or data matrix code). The security feature 3 can additionally be provided with a protective layer, for example a laminate, in order to protect the wire or fiber pieces 7 or their positions and the signature from damage.

The security feature 3 is then according to Figure 3c applied to a product to be protected 18, usually a package (examples: pharmaceutical packaging, electronics packaging, etc.) or a label (examples: for clothing, shoes, etc.), preferably glued and the product 18 in the Selling where it is user-side, ie can be checked for authenticity by the seller or the buyer.

The authenticity check is carried out by, according to FIG. 3d, the security feature 3 on the user side is in turn detected by a camera 19. This is preferably a sufficiently resolving camera 19 of a commercially available mobile radio device ("mobile phone") 20 with a display, commercial users, that is to say the sellers, or persons who Instead, it should also be possible to provide professional test equipment with higher resolution and larger displays, by detecting counterfeits through random tests.

A computer / memory located in the mobile device 20 holds the public key ready for decrypting the signature. This public key can (preferably already before) be loaded onto the mobile device via a temporary, preferably encrypted (radio) data connection from a public server, preferably the security feature manufacturer. According to the invention and advantageously not the secret key, but only the public key must be transmitted. By means of this public key, the signature 5 can be decrypted "on-site", ie with the mobile radio device or the test device at the place of storage or sale / purchase.Another advantage of the invention is the fact that the mobile radio device or test device at the moment Since the public key can be previously downloaded from this server, the method can not be connected to the server of the original manufacturer, and the method is therefore also applicable in places where connections are permanently or temporarily not possible Finally, the method according to the invention offers the advantage In particular, it is not necessary to locally provide a comprehensive data collection that contains all the previously captured images of random samples for testing purposes.

As a result of the decryption, the signature 5 is returned to the characteristic vector and this is returned to the image of the cryptographic random pattern 4, the calculated image subsequently serving as the comparison feature 21. The authenticity check ends with the computer-aided checking of the correspondence between the comparison feature 21 and the cryptographic random pattern 4. For this purpose, the comparison feature 21 is preferably displayed on the display 22 of the mobile device 20 and superimposed on the recorded image 23 of the random cryptographic pattern 4. In FIG. 3e, the comparison feature 21 and the image 23 are shown slightly offset for better recognizability. Matching feature 21 and Figure 23 match, so For example, the comparison feature 21 may be displayed in green, otherwise red, for example, to signal the user visually easily recognizable the authenticity or the forgery. In addition, "OK" or a comparably clear optical or acoustic signal can be output with the present authenticity Depending on the result of the authenticity check, the user, eg the potential buyer of the marked product, makes his purchase decision.

With the method described it is easily possible to obtain a counterfeit of a real product, e.g. an original document or a pharmaceutical packaging. A counterfeiter could indeed create a random pattern 4 with wire or fiber pieces 7 and imprint a (random) signature 5. However, since he has no access to the secret key of the original manufacturer, the signature 5 is not properly derived from the random pattern 4. A check, i. generating a comparison feature 21 and comparing it with the random pattern 4 or its image 23 thus unambiguously reveals the counterfeiting and without significant time delay. The reverse way of transferring a signature 5 of an original to forgeries does not lead to success either, since the potential counterfeiter can not deliberately generate the associated random pattern 4.

Even in the event that the potential counterfeiter comes into possession of one or more security features and applies them to counterfeit or manipulated products, the fraud can be detected if there are indications from the decrypted additional information. For example, the supplemental information may include a product code (that is, a product-related restriction on sales approval), a date of expiration / expiration date (a time restriction on sales approval), a region code / sales territory (ie, a territorial restriction on sales permissibility), or a seller code (that is, a personal restriction of sale), which can make it extremely difficult for the potential counterfeiter to monetize his counterfeits. Example: the decrypted and the user presented additional information indicates that the product P may be offered only by day T in country L by the seller V. If the user finds a deviation between the displayed data P, T, L, V (see Figure 3e) and the data that results directly from the sales situation (which product is offered to him when, where and by whom?), so he can refrain from the purchase.

LIST OF REFERENCE NUMBERS

1 substrate

2 printed area

3 security feature

4 cryptographic random pattern

5 signature

6 frames

7 pieces of wire or fiber

8 feature area

9 glue

10 adhesive application device

11 Wire or fiber piece applicator

12 paint or film application device

13 paint or paint

14 printing device

15 camera

16 computers

17 printer

18 product

19 Camera 0 Mobile device 1 Comparison feature 2 Display 3 Image

Claims

claims

1. A method for producing a security feature on a flat substrate, wherein particles (7) - forming a cryptographic random pattern (4) - on the substrate (1) are applied, characterized in that flexible wire or fiber pieces (7) in a - with the security feature (3) corresponding feature area (8) are applied to the substrate (1).

2. A method for producing a security feature in a flat substrate, wherein particles (7) - a cryptographic random pattern (4) forming - are introduced into the substrate (1), characterized in that flexible wire or fiber pieces (7) in a - with the security feature (3) corresponding feature area (8) are introduced into the substrate (1).

3. The method according to claim 1 or 2, characterized in that plastic or metal wire pieces (7), in particular copper wire pieces (7) applied to the substrate (1) or introduced into the substrate (1).

4. The method according to claim 1, characterized in that the wire or fiber pieces (7) applied to a with adhesive (9) pretreated feature area (8) of the substrate (1), in particular scattered.

5. The method according to claim 1, characterized Porsche Style nzeichnet that the wire or fiber pieces (7) with a protective layer (13), in particular with a laminate (13), are covered.

6. The method according to claim 1, dadu rch in that the fiber pieces (7) with a fluid (13), in particular with printing ink (13) or paint (13) are transferred to the substrate (1).

7. The method according to claim 1 or 2, dadu rch gekennzeichn et, that the wire or fiber pieces (7) have at least one curvature.

8. The method according to claim 1 or 2, characterized Porsche Style nzeichnet that colored or fluorescent wire or fiber pieces (7) applied to the substrate (1) or introduced into the substrate (1).

9. The method according to claim 1, characterized et et, that the wire or fiber pieces (7) placed in a nonwoven or a film on the substrate (1) are applied.

10. printed product with a security feature, wherein the security feature (3) on a substrate (1) applied - a random pattern (4) forming - flexible wire or fiber pieces (7).

11. A method of verifying the authenticity of a product, wherein

a signature associated with the product (18) is detected (5),

- The signature (5) is transferred by decryption in an identifier, from the identifier, a comparison feature (21) is generated, and the comparison feature (21) computer-aided compared with an image (23) of the product (18) associated random pattern (4) becomes.

12. The method according to claim 11, characterized dadu rch, in that the signature (5) is detected by a camera (19) of a mobile radio device (20) and that the comparison feature (21) is displayed in the display (22) of the mobile radio device (20).

13. Method according to claim 12, wherein the comparison feature (21) in the display (22) of the mobile radio device (20) is superimposed on the image (23) of the random pattern (4).

14. A method of protecting products against counterfeiting, wherein

- a cryptographic random pattern (4) of flexible wire or fiber pieces (7) is generated,

the random pattern (4) is detected by a camera (15),

- an identifier is generated from the image of the random pattern (4),

the identifier is transferred with a secret key into a signature (5),

the random pattern (4) and the signature (5) are applied to the product to be protected,

the signature (5) is detected by a camera (19),

the signature (5) is transferred by decryption with a public key into the identifier,

- a comparison feature (21) is generated from the identifier,

- The comparison feature (21) computer-aided superimposed on an image (23) of the random pattern (4) and compared.