VERIFICATION OF AN ARTICLE PROVIDED WITH A SECURITY ELEMENT

Abstract

A method for verifying an object is furnished with a security element in which the security element is manufactured in a multi-step method with register variations and contains in a check field an individual characteristic feature of the security element in the form of a superimposition of at least two areal regions. The check field of the security element is optically captured by a camera, the area proportions of the superimposed and not superimposed areal regions are determined and from it a check value for the individual characteristic feature of security element is formed and compared with a reference check value, on which a verification result for the object furnished with the security element is created.

Claims

1.-20. (canceled)

21. A method for verifying an object furnished with a security element in which the security element is manufactured in a multi-step method with register variations and contains in a check field an individual characteristic feature of the security element in the form of a superimposition of at least two areal regions, which are generated upon the manufacture of the security element in different manufacturing steps with register variations, wherein in the method the check field of the security element is optically captured by a camera, the area proportions of the superimposed and/or not superimposed areal regions are determined and from it a check value for the individual characteristic feature of the security element is formed, the formed check value is compared with a reference check value, and on the basis of the comparison result, a verification result for the object furnished with the security element is created.

22. The method according to claim 21, wherein the reference check value is formed upon or after the manufacture of the security element, or upon or after the furnishing of the object with the security element, by determining the area proportions of the superimposed and/or not superimposed areal regions and forming therefrom the reference check value.

23. The method according to claim 21, wherein the reference check value is stored in a database together with an individual marking of the security element and/or the object and is queried from the database for comparison with the formed check value.

24. The methods according to claim 21, wherein the reference check value is present in particular in encrypted or encoded form in the security element or in the object furnished with the security element and is read in for comparison with the formed check value.

25. The method according to claim 21, wherein the check field of the security element is optically captured by a smartphone camera and the determination of the area proportion and the forming of the check value is effected through a software program running on the smartphone.

26. The method according to claim 21, wherein the verification method is carried out in a check field, which contains a superimposition of three, four or more areal regions, which are generated upon the manufacture of the security element in different manufacturing steps with register variations.

27. The method according to claim 21, wherein the verification method is carried out in a check field whose areal regions are generated at least partly by printing methods.

28. The method according to claim 21, wherein the verification method is carried out in a check field whose areal regions are formed at least partly by applications, or by elements or windows on the applications.

29. The method according to claim 21, wherein the verification method is carried out in a check field whose areal regions are formed at least partly by planar laser cuttings, watermarks, laser markings, ink-jet inscriptions or toner-based methods.

30. The method according to claim 21, wherein the verification method is carried out in a check field whose areal regions consist respectively of a multiplicity of small print elements.

31. The method according to claim 30, wherein the check field has several partial regions in which the relative locations of the respective print elements are displaced relative to each other.

32. The method according to claim 21, wherein the verification method is carried out in a security element which is integrated in the object.

33. A verification system for the carrying out of the method according to claim 21, having an object furnished with a security element in which the security element is manufactured in a multi-step method with register variations and contains in a check field an individual characteristic feature of the security element in the form of a superimposition of at least two areal regions, which are generated upon the manufacture of the security element in different manufacturing steps with register variations and a checking apparatus for the verification of the object, having a camera for the optical capture of the check field of the security element, an evaluation unit for determining the area proportions of the superimposed and not superimposed areal regions and for forming a check value for the individual characteristic feature of the security element therefrom, and means for comparing the formed check value with a reference check value and for creation of a verification result on the basis of the comparison result.

34. The verification system according to claim 33, wherein the checking apparatus contains means for capturing an encoded reference check value, for decoding the captured reference check value and for comparing the formed check value with the decoded reference check value.

35. The verification system according to claim 33, wherein the verification system comprises a database, in which are deposited for the security elements respectively a reference check value together with an individual marking of the security element and/or the object, and that the checking apparatus contains means for querying the reference check value or the comparison result of check value and reference check value from the database on the basis of the individual marking of the security element and/or the object.

36. The verification system according to claim 33, wherein the checking apparatus is a bank-note processing machine or a smartphone.

37. Security element for a verification system according to claim 33 which is manufactured in a multi-step method with register variations and contains in a check field an individual characteristic feature of the security element in the form of a superimposition of at least two areal regions which are generated upon the manufacture of the security element in different manufacturing steps with register variations.

38. An object, in particular value document, security paper, identification card or branded article having a security element according to claim 37.

39. A checking apparatus for a verification system according to claim 33, having a camera for the optical capture of the check field of the security element, an evaluation unit for determining the area proportions of the superimposed and not superimposed areal regions and for forming a check value for the individual characteristic feature of the security element therefrom, and means for comparing the formed check value with a reference check value and for creating a verification result on the basis of the comparison result.

40. A computer program product which has machine-readable program commands for a control unit of a data-processing apparatus which cause the latter to execute a method according to claim 21.

Description

[0065] Further embodiment examples as well as advantages of the invention will be explained hereinafter with reference to the figures, in whose representation a rendition that is true to scale and to proportion has been dispensed with in order to increase the clearness.

[0066] There are shown:

[0067] FIG. 1 in schematic representation, a bank note having a security element in the form of a check field printed on the bank note,

[0068] FIG. 2 a detail view of the check field of FIG. 1,

[0069] FIG. 3 a schematic representation of the components involved in the verification of the bank note of FIG. 1,

[0070] FIG. 4 a check field consisting of several partial regions having print elements displaced relative to each other,

[0071] FIG. 5 a check field integrated in the graphic design of a bank note, and

[0072] FIG. 6 a design in which a check field is present in a separate security element which is applied onto a cashbox to be secured.

[0073] The invention will now first be explained by the example of the verification of a bank note with the help of a smartphone. FIG. 1 shows for this purpose a schematic representation of a bank note 10 having a security element in the form of check field 12 imprinted on the bank note 10. The check field 12 shown in detail in FIG. 2 is part of the bank note 10 and was generated together with the other print elements on the bank-note substrate upon the manufacture of the bank note 10. In other designs, the check field can, however, also be present on a separate security element, for example a transfer element, which is applied to a bank note or other object to be secured.

[0074] For checking the authenticity, the bank note 10 having the check field 12 can simply be captured optically in the hereinafter described manner with a smartphone camera and verified with the help of a check app installed on the smartphone.

[0075] In the process, the bank note 10 and the check field 12 are generated in a multi-step method with register variations. For example, the denomination number 14-A was applied to the bank note 10 in the screen printing method, a portrait 16-A in the intaglio printing method, and a serial number 18 in letterpress. Simultaneously with the denomination number 14-A, a first checkered pattern 14-B (in FIG. 2 tight hatching) was generated in the check field 12 by screen printing, as shown more precisely in the detail representation of the check field 12 in FIG. 2. In a separate printing step, a second checkered patterns 16-B (in FIG. 2 wide hatching) in the intaglio printing was generated in the check field 12 simultaneously with the portrait 16-A. Because of the generation of the elements 14-A/14-B or 16-A/16-B in respectively separate operations with different manufacturing methods, the unavoidable register variations occur in the process which lead to an offset of the two checkered patterns 14-B, 16-B in the check field 12.

[0076] The present inventors have now recognized that these unavoidable register variations of the different manufacturing processes can serve as a kind of fingerprint for the identification of a certain security element or a certain bank note.

[0077] For estimating, one can assume, for example, that the manufacturing steps involved in the generation of the check field 12 have respectively register variations of 1 mm in mutually orthogonal directions (hereinafter designated as x and y direction). The maximally allowed variation amounts to, for example, 1.5 mm. A typical smartphone camera with nominally 6 megapixels has a resolution of 28482136 pixels.

[0078] When, using such a camera, an area is recorded which contains at least the check field 12 and the serial number 18, for example, with a receiving area of 120 mm90 mm, a point density of about 600 dpi or a resolution of 42 m results. In two manufacturing steps there therefore result in every direction 2000 m/40 m=50 distinguishable locations, thus altogether 50.sup.2=2,500 different combinations of register variations. If three manufacturing steps are rendered in the check field 12, already 6,250,000 possibilities result.

[0079] If an areal region is present, for example in a security thread whose insertion location can vary in transverse direction by 3 mm, thus the number of the possibilities can again be multiplied by 6000 m/40 m=150. For a security thread having a well recognizable subject, the location can also be employed in the longitudinal direction and thus further increase the number of the possible combinations.

[0080] With reference to FIG. 2 the register variations of the manufacturing steps screen printing (elements 14-A, 14-B) and intaglio printing (elements 16-A, 16-B) lead to an offset of both checkered patterns 14-B, 16-B which can be quantified, for example, by the area proportions of the superimposed and not superimposed areal regions 20, 22, 24, 26. As is recognizable in FIG. 2, there arise first areal regions 20 from the offset of the two checkered patterns 14-B, 16-B, in which only the printing ink of the screen printing step 14-B is present, second areal regions 22 in which only the printing ink of the intaglio printing step 16-B is present, third areal regions 24 in which the printing ink of the screen printing step and the printing ink of the intaglio printing step superimpose, and fourth areal regions 26 in which neither of the two printing inks are present. The relative area proportions of the areal regions 20 to 26 depend on concretely on the register variations occurred upon the manufacture of the bank note 10, hence from these a check value can be derived which represents a measure individual and characteristic for the bank note 10.

[0081] As is evident from the above estimate, the number of possible register variation combinations at the current resolution of smartphone cameras for two production steps is usually still too low to be able to make a clear identification of a bank note. Nevertheless, the number of the possibilities is already so large that in spite of the simple check with a smartphone, upon a positive verification an authentic bank note can be inferred with high probability. If a greater number of manufacturing steps is included, the number of register variation combinations can also be sufficient for an unambiguous identification of a bank note.

[0082] The check value derived from the relative area proportions can be captured upon or immediately after the manufacture of the bank note 10, for example upon the quality control of the bank notes, for the first time and be deposited together with the serial number 18 of the bank note 10 as a reference check value in a database 34 (FIG. 3). In the database 34, the serial number 18 is then linked to a certain relative area proportion of the areal regions 20-26 in the check field 12 of the bank note 10. As explained above, in the process the assignment does not necessarily have to be unambiguous for meaningful verification.

[0083] For the verification, the bank note 10 is then photographed, as shown in FIG. 3, by a user with the camera of his or her smartphone 30 (reference sign 32), and thereby the check field 12 and the serial number 18 optically captured. A check app running on the smartphone 30 can, on the one hand, read out the serial number 18 of the bank note 10 via an OCR module and, on the other hand, determine the area proportions 20-26 in the check field 12 via an image-processing module and therefrom form the check value for bank note 10.

[0084] The check app then sets up a connection 36 from the smartphone 30 to the database 34 and transfers the serial number 18 and the formed check value. In the database 34, the transferred check value is compared with the reference check value stored there for the serial number 18 and the comparison result is transferred back to the check app via the connection 36. This displays the result of the authenticity check, for example, in the display 38 and can give, for reinforcement, also an acoustic feedback about the successful or failed verification. In a variant, the database can also transfer the stored reference check value to the check app and the comparison of the formed check value with the reference check value can be performed in the check app itself.

[0085] Alternatively or additionally, the reference check value can, after its first-time capture, also be applied in encrypted form to the bank note 10, for example in the form of a bar code 28 arranged beside the check field 12. For verification, the bank note 10 can then be photographed by a user with the camera of his or her smartphone 30 and thereby the check field 12 be optically captured together with the bar code 28. The check app executed on the smartphone 30 then establishes via the image-processing module the area proportions 20-26 in the check field 12, forms therefrom the check value for bank note 10, reads the bar code 28 and decrypts the reference check value encoded thereby. The established check value is compared with the decrypted reference check value and the result of the authenticity check is displayed in the display 38 and is outputted, where applicable, also acoustically.

[0086] For the sake of simpler representation, a superimposition of only two areal regions is shown in FIG. 2, it will, however, be appreciated that in practice also a superimposition of three, four or more areal regions is possible and also often expedient because of the greater number of combination possibilities. Correspondingly, there are more possibilities of combination for the area overlaps than those stated in FIG. 2.

[0087] For the determination of the check value, the image captured by the camera of the smartphone is advantageously preprocessed in the above-described manner. Then, for example, a histogram can be formed in which the pixel frequencies of different colors or gray levels are determined. Further threshold values can be formed in different gradations or different color channels and the obtained pixel numbers again be determined, similar to a histogram. Further statistical methods of image processing which correlate different fields, for example via correlations with each other, can be also applied.

[0088] As shown in FIG. 4, a check field 40 can also consist of several partial regions 42, 44, 46, wherein the relative locations of the print elements 48-R, 48-G, 48-B of the individual print processes are displaced in the different partial regions relative to each other to make a particularly good evaluation of the area proportions of the superimposed and not superimposed areal regions possible. For example, it can be difficult to exactly determine the relative area proportions if the register variation of two areal regions of a bank note lies near zero, since hardly any non-superimposed areal regions then exist.

[0089] To remedy this, in one or several partial regions the print elements 48-R, 48-G, 48-B are arranged offset relative to each other such that with perfect register they do not cover each other completely. This is illustrated in FIG. 4 by the example of print elements which represent three basic color pixels 48-R, 48-G, 48-B of an RGB print. In each of the partial regions 42, 44, 46, three basic color pixels 48-R, 48-G, 48-B are arranged in a different relative location to each other, so that the register variations of three color channels in each partial region 42, 44, 46 affect the superimposed and not superimposed area proportions of the print elements differently and thus make the determination of the individual characteristic check value for the check field 40 more reliable. For example, a partial check value can be formed for each partial region 42, 44, 46 and the partial check values can be summarized by adding up or multiplying to an overall check value.

[0090] A check field does not have be present on the document as a separate field, it can also be integrated into the graphic design of the document, as is illustrated with the help of check field 50 of FIG. 5. In the shown embodiment example, a bank note 10 contains in a partial region a graphic 52 in the form of a tree applied in intaglio printing having apples of different color, namely having green apples generated in the simultaneous printing 56 and having red apples generated in the block print 58. The check field 50 contains a green apple 56, a red apple 58 and a part 54 of the leaf structure of the tree. Since all three print elements were manufactured in different prints using different manufacturing methods, they have individual characteristic register variations which can be captured in the check field 50 in the above-described manner with the help of a smartphone camera 30 and be compared with a reference check value.

[0091] In the process, the user does not need to know the presence or the position of check field 50 in graphic design 52. It suffices when the user records the entire bank note or at least the design 52 with his or her smartphone camera 30, because the check app knows the position of the check field 50 and its properties to be checked. Should the recording quality be insufficient or the check field 50 be recorded incompletely, the check app can generate an error message and request a renewed recording, where applicable, with an indication of the region to be recorded.

[0092] FIG. 6 shows a further embodiment example in which a check field of the above-described kind is present in a separate security element 60 which is applied to an object to be secured, such as a cashbox 62. The cashboxes 62 shown in the embodiment example in FIG. 6 is filled, closed and the cover gap 64 is sealed with the security element 60. Then the check field of the security element 60 is photographed, for example with the camera of a smartphone 30 (reference sign 32) and a check value for the security element 60 is established by an app in the above-described manner. Further, an identification number 66 of the cashbox 62 is either inputted or likewise captured with the camera. The app then sets up a connection 36 to a database 34 and transfers the identification number 66 and the formed check value for the security element 60 employed for safeguarding. The transferred check value is then deposited in the database 34 as a reference check value for the identification number 66 and thereby the security element 60 is linked with the cashbox 62 to be secured.

[0093] After the transport of the cashbox 62, the receiver can first check whether the security element 60 is intact and then verify that the security element 60 actually belongs to the identification number 66 of the cashbox 62. For this purpose, he or she merely has to photograph the check field of the security element 60 with the camera of his or her smartphone and input the identification number 66 of the cashbox 62 or likewise photograph it. The app then forms the check value for the security element 60, establishes, where applicable, the identification number 66 via an OCR module, then sets up a connection to the database 34 and transfers the identification number 66 and the formed check value. In the database 34, the transferred check value is compared with the reference check value stored there as to the identification number 66 and the comparison result is transferred back to the smartphone app which communicates the success or failure of the verification to the receiver.

LIST OF REFERENCE SIGNS

[0094] 10 Bank note [0095] 12 Check field [0096] 14-A Denomination number [0097] 14-B First checkered pattern [0098] 16-A Portrait [0099] 16-B Second checkered pattern [0100] 18 Serial number [0101] 20, 22, 24, 26 Areal regions [0102] 28 Bar code [0103] 30 Smartphone [0104] 32 Photographic capture [0105] 34 Database [0106] 36 Connection [0107] 40 Check field [0108] 42, 44, 46 Partial regions [0109] 48-R, 48-G, 48-B Print elements [0110] 50 Check field [0111] 52 Graphic [0112] 54 Part of the leaf structure [0113] 56 Green apples [0114] 58 Red apples [0115] 60 Security element [0116] 62 Cash box [0117] 64 Cover gap [0118] 66 Identification number