Uniquely Linking Security Elements in Identification Documents

• US 20100135524A1
• Filed: 05/28/2009
• Published: 06/03/2010
• Est. Priority Date: 07/17/2003
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Durst, Robert T. JR., Jones, Robert L., Kenen, Leo M.
• Granted Patent: US 8,321,350 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06K 19/06046 Constructional details
• CPC Class Codes: G06K 19/08 using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G07D 7/0032 using holograms
• CPC Class Codes: G07D 7/0034 using watermarks
• CPC Class Codes: G07D 7/0053 involving markings added to a pattern, e.g. interstitial points
• CPC Class Codes: G07D 7/01 Testing electronic circuits therein
• CPC Class Codes: G07D 7/2016 using feature extraction, e.g. segmentation, edge detection or Hough-transformation
• CPC Class Codes: G07F 7/005 Details or accessories

Abstract

We provide techniques for uniquely linking security elements in identification documents. In one implementation we provide a digital watermark embedded on, and a smartcard chip embedded in, an identification document. The smart card chip includes a hash or a reduced-bit representation of the digital watermark, while the digital watermark includes a hash of information stored on the smartcard chip. In another implementation we cross-correlate encryption keys carried by various machine-readable features on an identification document. In still another implementation, we embed biometric information, which is stored in smartcard electronic circuitry, with a digital watermark. In one case the watermark is reversible, so that it can be removed to yield unmarked biometric information. In another case the watermark is fragile, to reveal whether the biometric information has been subjected to a transformation. In yet another implementation, we provide a jurisdictional indicator on an identification document. The jurisdictional indicator helps in decoding a digital watermark on the identification document.

Claims

1. A method of verifying a document with a smart card chip comprising:

computing a hash of a digital watermark to be embedded in the document;

storing the hash in the smart card chip;

computing a hash of data stored in the smart card chip; and

embedding the hash of the data stored in the smart card chip in a digital watermark on the document.

2. The method of claim 1 wherein a list of hashes of separate digital watermarks on the document are stored in the smart card chip.

3. The method of claim 1 wherein the hash is randomized before being stored in the smart card chip.

4. A computer readable medium on which is stored instructions for performing the method of claim 1.

5. The method of claim 1 wherein the digital watermark is embedded in a optically variable device.

6. The method of claim 5 wherein the optically variable device comprises a Kinegram®

.

10. A computer readable medium on which is stored instructions for performing the method of claim 1.

7. A method of verifying integrity of a document comprising:

capturing an image scan of the document, including a scan of an optically variable device;

extracting a digital watermark from the image to check the integrity of the optically variable device;

comparing information in the digital watermark with information in another security element captured in the image; and

extracting a printer or issuer identifier from the image to check the source of the document.

8. The method of claim 7 wherein the digital watermark is embedded in an image conveyed by the optically variable device.

9. The method of claim 7 wherein the digital watermark carries data or attribute information about the optically variable device which is used to verify the integrity of the optically variable device.

11. A method of verifying a document comprising:

extracting a public key from a machine readable feature on the document;

extracting a message payload from another machine readable feature on the document, the message payload being encrypted by a private key that forms part of a public-private key pair with the public key; and

using the public key to de-scramble the message payload.

12. The method of claim 11 wherein at least one of the machine readable features is an optically variable device.

13. The method of claim 11 wherein at least one of the machine readable features is a digital watermark.

14. The method of claim 11 wherein the message payload is a digital watermark message payload, and the public key is stored in a machine readable optically variable device.

15. A document comprising:

a substrate; and

an optically variable device attached to the substrate, the optically variable device having a diffraction pattern that conveys a first image at a first orientation of the document, and a second image at a second orientation of the document, wherein the first and second images form a figure ground reversal enabling visual verification of the document.

16. The document of claim 15 wherein at least one of the images carries an embedded digital watermark.

17. The document of claim 15 wherein the relationship between the first and second images is used to verify the integrity of the document.

18. The document of claim 17 wherein the relationship is automatically compared and verified by machine-reading.

19. A document having a smart card chip, the smart card chip carrying a digital watermark used to authenticate the data stored on the smart card chip.

20. The document of claim 19 wherein the digital watermark is embedded in data stored in the smart card chip.

21. The document of claim 20 wherein the data comprises an image.

22. The document of claim 20 wherein the data comprises a biometric of the bearer of the document.

23. The method of claim 20 wherein the digital watermark is reversible such that it can be substantially removed from the host data in which it is embedded to restore the host data.

24. The method of claim 20 wherein the digital watermark is reversible such that it can be perfectly removed from the host data in which it is embedded to restore the host data.

25. The method of claim 20 wherein the digital watermark is designed to be lost or degraded when subjected to a transformation.

26. A method of verifying a document, the document comprising optical memory having first information stored therein and a digital watermark carrying second information, said method comprising:

reading the optical memory to obtain the first information, wherein the first information is related to the digital watermark; and

using at least the first information, extracting the digital watermark embedded in the document to obtain the second information.

27. The method of claim 26, wherein said reading step comprises optically capturing at least a portion of the optical memory and at least a portion of the digital watermark using the same optical sensor.