Equipment employing watermark-based authentication function

• US 6,804,376 B2
• Filed: 03/28/2002
• Issued: 10/12/2004
• Est. Priority Date: 01/20/1998
• Status: Expired due to Fees

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B., Gustafson, Ammon E.
• Primary Examiner(s): Patel, Jayanti K.
• Application Number:
  US10/113,818
• Publication Number:
  US 20020176600A1
• Time in Patent Office: 929 Days
• Field of Search: 382/100, 382/135, 382/112, 382/232, 382/312, 358/1.18, 358/3.28, 375/240.21, 380/202, 380/203, 380/28, 380/54, 713/176
• US Class Current: 382/100
• CPC Class Codes: B29C 45/1418 the inserts being deformed or preformed, e.g. by the injection pressure
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: G06Q 30/02 Marketing; Price estimation or determination; Fundraising
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• CPC Class Codes: G06T 2207/30144 Printing quality
• CPC Class Codes: G06T 7/0002 Inspection of images, e.g. flaw detection
• 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: H04N 1/00002 Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for error detection, error correction or monitoring in digital computers or digital computer components G06F11/00
• CPC Class Codes: H04N 1/00005 relating to image data
• CPC Class Codes: H04N 1/00037 Detecting, i.e. determining the occurrence of a predetermined state H04N1/00031 takes precedence
• CPC Class Codes: H04N 1/00092 relating to the original or to the reproducing medium, e.g. imperfections or dirt detecting properties of a sheet H04N1/00681
• CPC Class Codes: H04N 1/00973 from a remote device, e.g. receiving via the internet instructions input to a computer terminal
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 1/32219 involving changing the position of selected pixels, e.g. word shifting, or involving modulating the size of image components, e.g. of characters H04N1/32224 takes precedence
• CPC Class Codes: H04N 1/32229 with selective or adaptive application of the additional information, e.g. in selected regions of the image H04N1/32213 takes precedence
• CPC Class Codes: H04N 1/32261 in binary data H04N1/32256 takes precedence
• CPC Class Codes: H04N 1/32304 Embedding different sets of additional information
• CPC Class Codes: H04N 1/32309 in colour image data
• CPC Class Codes: H04N 1/3232 Robust embedding or watermarking
• CPC Class Codes: H04N 1/32331 : Fragile embedding or watermarking
• 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 2201/3239 : using a plurality of different authentication information
• 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

Abstract

Image, video, or audio data is encoded with both a frail and a robust watermark. The two watermarks respond differently to different forms of processing (e.g., copying the object may render the frail watermark unreadable), permitting an original object to be distinguished from a processed object. Appropriate action can then taken in response thereto.

Claims

1. Electronic equipment including an authentication function, the equipment including a steganographic watermark detector that checks sampled data for the presence of first and second steganographic watermarks, the first watermark being relatively frail and the second watermark being relatively robust, the equipment determining that the sampled data is authentic only if both watermarks are present.

2. The equipment of claim 1 wherein operation of the equipment is controlled in a first manner if both watermarks are present, and is controlled in a second, different, manner if only one of the first and second steganographic watermarks is present.

3. The equipment of claim 2, wherein the watermarking of at least the first watermark is effected by slight alterations to the sampled data'"'"'s color.

4. The equipment of claim 3, wherein the first watermark degrades with distortion, the distortion comprising at least scanning and reprinting.

5. A cash-accepting automatic teller machine that determines whether tendered cash is authentic, according to claim 1.

6. Electronic equipment including an authentication function, the authentication function includes a steganographic watermark detector that checks sampled data for the presence of first and second steganographic watermarks, wherein the sampled data corresponds to a printed document, and wherein an original printed document includes first and steganographic watermarks cooperating in an expected manner to evidence authenticity of the original printed document, said electronic equipment determines that the printed document is an original printed document only if both watermarks are present and if the watermarks evidence the expected cooperation.

7. The electronic equipment of claim 6, wherein the expected cooperation comprises a relationship of relative robustness between the first and second watermarks.

8. A method to differentiate copies of an original document from the original document, wherein the original document includes a first digital watermark and a second digital watermark, said method comprising:

obtaining a first metric based on a comparison of the first and second digital watermarks in the original document;

reading the first and second watermarks from a copy of the original document and comparing the watermarks to obtain a second metric; and

using differences between said first and second metrics to differentiate an original document from a copy of the original document.