Uniquely linking security elements in identification documents

• US 8,321,350 B2
• Filed: 05/28/2009
• Issued: 11/27/2012
• Est. Priority Date: 07/17/2003
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Durst, Robert T. Jr.
• Primary Examiner(s): Nigh, James D
• Application Number:
  US12/473,488
• Publication Number:
  US 20100135524A1
• Time in Patent Office: 1,279 Days
• Field of Search: 705/51, 713/176, 283/113, 358/3.28, 162/110
• US Class Current: 705/51
• 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 involving a document that includes a smart card chip, the method comprising:

computing a first hash of a digital watermark message using a hardware processor configured to perform such act;

storing the first hash in the smart card chip;

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

augmenting the digital watermark message with the hash of the data stored in the smart card chip, encoding the augmented digital watermark message into a digital watermark, and embedding the digital watermark in the document.

2. The method of claim 1 wherein hashes of multiple digital watermark messages are stored in the smart card chip.

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

4. The method of claim 1 that includes embedding the augmented digital watermark message in a optically variable device on the document.

5. A document including a substrate and two security elements, one of said security elements comprising a smart card chip conveyed by the substrate, another of said security elements comprising a digital watermark conveyed by the substrate, the digital watermark encoding a message, the smart card chip storing data that includes a hash of said message, the digital watermark also encoding a hash of data stored in the smart card chip, wherein said two security elements convey interdependent data so as to enhance security of the document and enable document authentication.