Desynchronized fingerprinting method and system for digital multimedia data

• US 20050175224A1
• Filed: 02/11/2004
• Published: 08/11/2005
• Est. Priority Date: 02/11/2004
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Venkatesan, Ramarathnam, Mihcak, Mehmet Kivanc, Kucukgoz, Mehmet
• Granted Patent: US 7,382,905 B2
• Time in Patent Office: Days
• US Class Current: 382/124
• 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

Abstract

A desynchronized fingerprinting method and system for identifying collaborators in the making of illegal copies of digital multimedia products. The desynchronized fingerprinting system and method can be used for both audio and video applications. The method and system include an embedding feature and a detection and extraction feature. A different and unique key is assigned to each buyer of a copy of the digital data. The embedding feature includes applying a pseudo-random transformation to selected embedding regions. The key for the pseudo-random transform is user-specific. These regions are chosen by using a secure multimedia hash function. The detection and extraction feature includes a brute-force search in the key space of the buyers. If one of the keys is likely enough, then it can be said that that user was been involved in the production of an illegal copy.

Claims

1. A computer-implemented method for desynchronized fingerprinting of digital data, comprising:

selecting embedding regions in the digital data for embedding fingerprints;

selecting desynchronization regions in the digital data for desynchronizing copies of the digital data from each other;

performing random desynchronization for each of the desynchronization regions to randomly vary a width of each of the desynchronization regions; and

embedding fingerprints at each of the embedding regions to produce desynchronized fingerprinted digital data.

2. The computer-implemented method of claim 1, further comprising randomly selecting the embedding regions and desynchronization regions.

3. The computer-implemented method of claim 1, further comprising using a master key and a hash function to randomly select the embedding regions.

4. The computer-implemented method of claim 3, further comprising finding and storing hash values for each of the embedding regions.

5. The computer-implemented method of claim 1, further comprising using a master key to randomly select the desynchronization regions.

6. The computer-implemented method of claim 1, wherein performing random desynchronization for each of the desynchronization regions further comprises using a master key to randomly compute a width for each of the desynchronization regions such that the width varies between the copies of the digital data.

7. The computer-implemented method of claim 1, further comprising generating multiple copies of the digital data and fingerprinting each copy.

8. The computer-implemented method of claim 1, further comprising embedding a unique secret key at each of the embedding regions.

9. A computer-readable medium having computer-executable instructions for performing the computer-implemented method recited in claim 1.

10. A computer-readable medium having computer-executable instructions for desynchronized fingerprinting of digital multimedia data, comprising:

generating multiple copies of the digital multimedia data;

randomly selecting embedding regions within each copy;

randomly selecting desynchronization regions within each copy;

computing a random width for each of the desynchronization regions such that a width of each of the desynchronization regions varies between the multiple copies; and

embedding information at each of the embedding regions to produce desynchronized fingerprinted copies of the digital multimedia data.

11. The computer-readable medium of claim 10, wherein randomly selecting embedding regions further comprises using a pseudo-random operator and a master key.

12. The computer-readable medium of claim 11, wherein the pseudo-random operator is a hash function.

13. The computer-readable medium of claim 10, further comprising finding and storing hash values for each of the embedding regions.

14. The computer-readable medium of claim 10, wherein randomly selecting desynchronization regions further comprises using a master key.

15. The computer-readable medium of claim 10, wherein computing a random width for each of the desynchronization regions further comprises using a master key for computing a random width and changing the width accordingly.

16. The computer-readable medium of claim 10, wherein embedding information at each of the embedding regions further comprises embedding unique copy information and a unique secret key.

17. The computer-readable medium of claim 16, further comprising cataloging the unique copy information such that each of the multiple copies is associated with a specific entity.

18. The computer-readable medium of claim 16, further comprising associating the unique copy information with the unique secret key.

19. The computer-readable medium of claim 18, wherein the unique information is number of a specific one of the multiple copies.

20. The computer-readable medium of claim 17, further comprising:

extracting the unique copy information from an illegal copy of the digital multimedia data; and

determining from the unique copy information the identities of entities involved in the production of the illegal copy.

21. A process for detecting and extracting fingerprints from digital data, comprising:

determining embedding regions within the digital data;

using a plurality of secret keys to perform watermark detection on each of the embedding regions; and

detecting identification information associated with a secret key.

22. The process as set forth in claim 21, further comprising computing multiple hash values of the digital data and determining the embedding regions using the multiple hash values.

23. The process as set forth in claim 21, further comprising extracting collaborator information from the identification information.

24. The process as set forth in claim 23, further comprising constructing a list of collaborators from the collaborator information representing a list of persons who collaborated in producing the digital data.

25. One or more computer-readable media having computer-readable instructions thereon which, when executed by one or more processors, cause the one or more processors to implement the method of claim 21.

26. A desynchronized fingerprinting system for desynchronized fingerprinting of copies of an original digital multimedia product, comprising:

an embedding module for using a random desynchronization process and a plurality of secret keys to embedding fingerprints in each copy of the product; and

a detection and extraction module for detecting the embedded fingerprints using the plurality of secret keys and extracting collaborator information from the fingerprints to identify collaborators in the production of an illegal copy of the digital multimedia product.

27. The desynchronized fingerprinting system as set forth in claim 26, wherein the embedding module further comprises an embedding region selector for randomly selecting embedding regions in each copy of the product in which to embed fingerprints.

28. The desynchronized fingerprinting system as set forth in claim 26, wherein the embedding module further comprises a desynchronization region selector for randomly selecting desynchronization regions in which to apply intentional desynchronization.

29. The desynchronized fingerprinting system as set forth in claim 28, wherein the embedding module further comprises a random desynchronization module for randomly selecting and applying a width of the desynchronization regions such that each width of a desynchronization region is different between each copy of the product.