Watermark system

• US 7,007,165 B1
• Filed: 04/07/2000
• Issued: 02/28/2006
• Est. Priority Date: 05/02/1999
• Status: Expired due to Term

• Current Assignee: Synamedia Limited
• Original Assignee: NDS Limited (Cisco Systems, Inc.)
• Inventors: Tsuria, Yossef
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Abrishamkar, Kaveh
• Application Number:
  US09/544,704
• Time in Patent Office: 2,153 Days
• Field of Search: 713/176, 382/232, 382/100, 380/269, 380/54, 380/201, 380/203, 380/217
• US Class Current: 713/176
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/16 Program or content traceability, e.g. by watermarking
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• CPC Class Codes: G06T 2201/0064 for copy protection or copy management, e.g. CGMS, copy only once, one-time copy
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00884 involving a watermark, i.e. a barely perceptible transformation of the original data which can nevertheless be recognised by an algorithm
• CPC Class Codes: G11B 20/00913 based on a spread spectrum technique
• CPC Class Codes: H04N 1/32288 Multiple embedding, e.g. cocktail embedding, or redundant embedding, e.g. repeating the additional information at a plurality of locations in the image
• CPC Class Codes: H04N 1/32304 Embedding different sets of additional information
• CPC Class Codes: H04N 2005/91335 the copy protection signal being a watermark
• CPC Class Codes: H04N 21/4325 by playing back content from the storage medium reproduction of recorded television signals H04N5/76; reproduction of recorded television signals H04N9/79
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 7/162 Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing

Abstract

A method for examining an electronic representation of an item for a watermark, the method including examining at least a first electronic representation of an item for a watermark in accordance with a first watermark definition, receiving a signal indicating that a second watermark definition is to be used for examining electronic representations, and examining at least a second electronic representation of an item for a watermark in accordance with the second watermark definition.

Related apparatus and methods are also provided.

Claims

1. A method for examining an electronic representation of an item for a watermark, the method comprising:

examining at least a first electronic representation of an item for a watermark in accordance with a first watermark definition;

receiving a signal indicating that a second watermark definition is to be used for examining electronic representations; and

examining at least a second electronic representation of an item for a watermark in accordance with the second watermark definition, and not examining the item for a watermark in accordance with the first watermark definition.

2. A method according to claim 1 and also comprising:

controlling access to at least the second electronic representation based, at least in part, on a result of the examining at least a second electronic representation step.

3. A method according to claim 1 and wherein the first electronic representation and the second electronic representation are identical.

4. A method according to claim 1 and wherein the signal comprises a representation of the second watermark definition.

5. A method according to claim 1 and also comprising:

retrieving the second watermark definition from a storage device in response to the received signal.

6. A method according to claim 1 and also comprising computing the second watermark definition in response to the received signal.

7. A method according to claim 1 and wherein the first watermark definition and the second watermark definition each comprises an indication of a location, within each electronic representation to be examined, at which a watermark, if present, is to be found.

8. A method according to claim 1 and wherein the first watermark definition and the second watermark definition each comprises an indication of a watermarking method according to which each electronic representation to be examined is to be examined for a watermark.

9. A method according to claim 1 and wherein the signal comprises authentication information for establishing that the signal originates from an authentic source, and

the receiving step also includes:

verifying the authentication information to determine whether the authentication information is correct and rejecting the received signal if the authentication information is determined to be incorrect, thereby causing the first watermark definition to continue to be used for examining if the authentication information is incorrect.

10. A watermark examiner for examining an electronic representation of an item for a watermark, the examiner comprising:

a watermark definition store operative to store a watermark definition;

watermark examination apparatus operatively associated with the watermark definition store and operative to examine an electronic representation of an item for a watermark in accordance with the watermark definition stored in the watermark definition store; and

a watermark definition signal receiver operative to receive a signal indicating that a new watermark definition is to be used for examining electronic representations and to store the new watermark definition in the watermark definition store.

wherein, after the watermark definition signal receiver stores the new watermark definition in the watermark definition store, the watermark examination apparatus examines in accordance with the new watermark definition and not in accordance with a watermark definition previously stored in the watermark definition store.

11. A watermark examiner according to claim 10 and wherein the watermark definition comprises an indication of a location, within each electronic representation to be examined, at which a watermark, if present, is to be found.

12. A watermark examiner according to claim 10 and wherein the watermark definition comprises an indication of a watermarking method according to which each electronic representation to be examined is to be examined for a watermark.

13. A watermark examiner according to claim 10 and wherein the signal comprises a representation of the second watermark definition.

14. A watermark examiner according to claim 10 and wherein the watermark examiner also comprises a watermark storage memory for storing at least one watermark definition, and

the watermark definition signal receiver is operative to retrieve the new watermark definition from the watermark storage memory in response to the received signal.

15. A watermark examiner according to claim 10 and wherein the watermark definition signal receiver is also operative to compute the second watermark definition in response to the received signal.

16. A watermark examiner according to claim 10 and wherein the signal comprises authentication information for establishing that the signal originates from an authentic source, and

the watermark definition signal receiver also includes:

signal verification apparatus operative to verify the authentication information to determine whether the authentication information is correct and to reject the received signal if the authentication information is determined to be incorrect, thereby causing the fist watermark definition to continue to be used for examining if the authentication information is incorrect.