Digital watermark key generation

• US 20060013395A1
• Filed: 05/26/2005
• Published: 01/19/2006
• Est. Priority Date: 07/01/2004
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Brundage, Trent J., Brunk, Hugh L.
• Granted Patent: US 8,140,848 B2
• Time in Patent Office: Days
• US Class Current: 380/255
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• CPC Class Codes: G10L 19/018 Audio watermarking, i.e. embedding inaudible data in the audio signal
• CPC Class Codes: H04L 9/0816 Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
• CPC Class Codes: H04L 9/0819 Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s) network architectures or network communication protocols for key distribution in a packet data network H04L63/062
• 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 1/32154 Transform domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/32272 Encryption or ciphering
• 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 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/26613 for generating or managing keys in general key distribution for secret or secure communication involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP] H04L9/083; network support of key management H04L63/06; key management for network security in communication control or processing H04W12/04
• 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 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/3269 of machine readable codes or marks, e.g. bar codes or glyphs
• CPC Class Codes: H04N 2201/3281 Encryption; Ciphering
• CPC Class Codes: H04N 2201/3284 for error correction

Abstract

The present invention relates to message encoding. In a first implementation, a message is provided. The message is transformed by a secret key. The secret key is generated by providing a plural-bit seed. The seed is randomized and then error correction encoded. We prefer tail-biting convolutional encoding for our error correction encoding. The encoded seed forms a secure key, which is used to transform the message prior to embedding.

Claims

1. A digital watermark key generation method, the key providing security for a plural-bit message, said method comprising:

providing a plural-bit seed;

randomizing the plural-bit seed; and

encoding the randomized plural-bit seed with convolutional encoding, the encoded seed comprising a key.

2. The method of claim 1 further comprising transforming an independent message with the key.

3. The method of claims 2 further comprising steganographically embedding the transformed message in media.

4. The method of claim 1, wherein the convolutional encoding comprises tail-biting convolutional encoding.

5. The method of claim 4 further comprising transforming an independent message with the key.

6. The method of claims 5 further comprising steganographically embedding the transformed message in media.

16. Logic gates formed in a silicon structure to perform the method recited in claim 1.

17. Logic gates formed in a silicon structure to perform the method recited in claim 2.

18. Logic gates formed in a silicon structure to perform the method recited in claim 3.

19. Logic gates formed in a silicon structure to perform the method recited in claim 5.

7. A method of providing information to transform a plural-bit message for steganographic encoding, said method comprising:

providing a unique plural-bit number;

altering the unique plural-bit number;

error correction encoding the altered plural-bit number, wherein the error correction encoded, altered plural-bit number comprises information for transforming an independent message.

8. The method of claim 7, wherein the error correcting comprises convolutional encoding.

9. The method of claim 8 wherein the convolutional encoding comprises tail-biting encoding.

10. The method of claim 7 further comprising transforming the message in media.

11. The method of claim 8 further comprising transforming the message in media.

12. The method of claim 9 further comprising transforming the message in media.

13. The method of claim 10 wherein, prior to transformation, the message comprises error correction encoding.

14. The method of claim 11 wherein, prior to transformation, the message comprises error correction encoding.

15. The method of claim 12 wherein, prior to transformation, the message comprises error correction encoding.

20. Logic gates formed in a silicon structure to perform the method recited in claim 9.

21. A method of generating a secure key for use with machine-readable indicia, said method comprising:

obtaining a unique identifier representing an entity or client;

altering the unique identifier in a random or pseudo-random manner;

error correction encoding the altered unique identifier; and

transforming a plural-bit message with the error correction encoded altered unique identifier to produce a secure key.

22. The method of claim 21 wherein the machine-readable indicia comprises steganographic encoding.

23. The method of claim 21 wherein the error correction encoding comprises convolution encoding.

24. Logic gates formed in a silicon structure to perform the method recited in claim 21.