Tamper-resistant authentication techniques for identification documents

• US 20060171558A1
• Filed: 12/19/2005
• Published: 08/03/2006
• Est. Priority Date: 07/31/1998
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B., Alattar, Adnan M.
• Granted Patent: US 7,239,734 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 1/005 Robust watermarking, e.g. average attack or collusion attack resistant
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0083 whereby only watermarked image required at decoder, e.g. source-based, blind, oblivious
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/187 Frequency domain transformation; Autocorrelation
• CPC Class Codes: G07B 1/00 Machines for printing and issuing tickets printing mechanisms per se B41; output mechanisms of digital computers G06C11/00
• CPC Class Codes: G07B 11/00 Apparatus for validating or cancelling issued tickets
• CPC Class Codes: G07C 2209/41 with means for the generation of identity documents
• CPC Class Codes: G07C 9/257 electronically G07C9/26 takes precedence
• CPC Class Codes: G07C 9/27 with central registration
• CPC Class Codes: G07D 7/0034 using watermarks
• CPC Class Codes: G07D 7/004 using digital security elements, e.g. information coded on a magnetic thread or strip
• CPC Class Codes: G07D 7/005 Testing security markings invisible to the naked eye, e.g. verifying thickened lines or unobtrusive markings or alterations
• CPC Class Codes: G07D 7/20 Testing patterns thereon G07D7/004, G07D7/005 take precedence
• CPC Class Codes: G07D 7/202 using pattern matching
• CPC Class Codes: H04L 2209/608 Watermarking
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04N 1/32149 Methods relating to embedding, encoding, decoding, detection or retrieval operations
• CPC Class Codes: H04N 1/32352 Controlling detectability or arrangements to facilitate detection or retrieval of the embedded information, e.g. using markers for decoding, detection or retrieval operations H04N1/32149 and subgroups take precedence
• CPC Class Codes: H04N 2201/3205 : of identification information, e.g. name or ID code H04N2201/3209 takes precedence
• CPC Class Codes: H04N 2201/3207 : of an address
• CPC Class Codes: H04N 2201/3226 : of identification information or the like, e.g. ID code, index, title, part of an image, reduced-size image
• CPC Class Codes: H04N 2201/3233 : of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/327 : which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3271 : Printing or stamping
• CPC Class Codes: Y10S 283/902 : Anti-photocopy

Abstract

The present invention provides methods and systems that are helpful authentication of physical and electronic documents like financial documents and identification documents. Steganographic indicia plays a role in some of our implementations. In other implementations we bind design features to a user or to a document. In still other implementations we provide authentication methods to evaluate security documents.

Claims

1. A method comprising:

selecting a set of data from at least one of a photograph and information, wherein the information and photograph are carried by a physical document, the document further including a design;

reducing the selected set of data to a first number; and

altering characteristics of the design according to the first number,

wherein evidence of the altered design characteristics is found through analysis of data corresponding to the altered design characteristics in both a spatial domain and a frequency domain, and

wherein the evidence in either of the spatial domain or the frequency domain provides an authentication clue.

2. The method according to claim 1, wherein the design comprises at least one of a group of concentric circles and a plurality of parallel lines.

3. The method of claim 2 wherein said altering characteristics of the design comprises adjusting spacing between adjacent circles or lines according to the first number.

4. The method of claim 3 wherein said reducing comprises hashing the selected set of data.

5. The method of claim 3 wherein said reducing comprises hashing the selected set of data to obtain a result, and offsetting a predetermined number with the result to yield the first number.

6. The method of claim 2 wherein spatial domain evidence comprises a spatial spacing distance between adjacent circles or between parallel lines.

7. The method of claim 6 wherein frequency domain evidence comprises a circle radius when the design comprises the concentric circles and a frequency point located an identifiable distance from a DC component frequency point when the design comprises the parallel lines.

8. A method to authenticate the document of claim 1, said method comprising:

selecting the set of data from the photograph or information carried by the document;

reducing the selected set of data to the first number; and

comparing the first number with the characteristics of the design.

9. The method of claim 8 wherein the comparing comprises:

analyzing characteristics of the document design in a frequency domain;

converting the first number to an expected radius or distance;

comparing the expected radius or distance with the frequency domain characteristics; and

determining that the document is authentic when the expected radius or distance coincides with the frequency domain characteristics.

10. The method of claim 8 wherein the comparing comprises:

in a spatial domain analyzing a spacing between lines or circles of the design;

comparing the spacing with the first number; and

determining that the document is authentic when the spacing coincides with the first number.

11. The method of claim 1 firther comprising embedding a digital watermark in the document, the digital watermark including a key identifying the set of data.

12. A method comprising:

optically capturing image data corresponding to a physical document;

transforming the optically captured image data into a frequency domain;

comparing frequency characteristics of the transformed image to predetermined frequency characteristics that are associated with a first document type, and if the characteristics coincide, determining that the document is of the first document type; and

if the characteristics do not coincide,

comparing the frequency characteristics of the transformed image to predetermined frequency characteristics that are associated with a second document type, and if the characteristics coincide, determining that the document is of the second document type.

13. The method of claim 12, wherein the frequency domain characteristics comprise a radius.

14. The method of claim 12, wherein the frequency domain characteristics comprise a horizontal distance from a DC component response to a frequency point.

15. The method of claim 14 wherein the frequency domain characteristics further comprise an angle formed between a line from the origin to the frequency point and a horizontal axis.

16. A method comprising:

accessing a data repository including a library,

obtaining a graphic or image from the library of graphics or images, wherein the graphic or image comprises a plural-bit identifier steganographically embedded therein;

once obtained, applying the steganographically embedded image to a security document, the plural-bit identifier providing information associated with an authorized bearer of the security document or with the security document.

17. An security document produced according to claim 16.

18. The method of claim 16 wherein the security document comprises at least one of photo-identification document and a financial instrument.

19. The method of claim 16 wherein the plural-bit number is uniquely associated with a document printer or assembler.

20. The method of claim 16 further comprising adjusting the graphic or image according to a representation of information carried by the security document.