Methods and systems for encoding and protecting data using digital signature and watermarking techniques

• US 8,452,972 B2
• Filed: 12/30/2011
• Issued: 05/28/2013
• Est. Priority Date: 06/08/1999
• Status: Expired due to Fees

• Current Assignee: PLS IV, LLC (Pretium Partners, LLC)
• Original Assignee: Intertrust Technologies Corporation (Fidelio Acquisition Co LLC)
• Inventors: Serret-Avila, Xavier, Boccon-Gibod, Gilles
• Primary Examiner(s): Barron, Jr., Gilberto
• Assistant Examiner(s): ALMEIDA, DEVIN E
• Application Number:
  US13/340,801
• Publication Number:
  US 20120151216A1
• Time in Patent Office: 515 Days
• Field of Search: None
• 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: G06T 1/0071 using multiple or alternating watermarks
• 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 20/00123 the record carrier being identified by recognising some of its unique characteristics, e.g. a unique defect pattern serving as a physical signature of the record carrier
• 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 20/00898 based on a hash function
• CPC Class Codes: H04L 2209/608 Watermarking
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04L 9/3247 involving digital signatures
• 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 1/32208 involving changing the magnitude of selected pixels, e.g. overlay of information or super-imposition H04N1/32219, H04N1/32224 take precedence
• CPC Class Codes: H04N 1/32283 Hashing
• 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 1/32293 Repeating the additional information in a regular pattern
• CPC Class Codes: H04N 1/32304 Embedding different sets of additional information
• CPC Class Codes: H04N 1/3232 Robust embedding or watermarking
• CPC Class Codes: H04N 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• CPC Class Codes: H04N 19/467 characterised by the embedded information being invisible, e.g. watermarking
• CPC Class Codes: H04N 2005/91335 the copy protection signal being a watermark
• 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 21/4627 : Rights management associated to the content security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• 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 2201/3235 : Checking or certification of the authentication information, e.g. by comparison with data stored independently
• 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

Systems and methods are provided for protecting and managing electronic data signals. In one embodiment a strong watermark is inserted in a data signal that is divided into a sequence of blocks, and a digital signature for each block is embedded in the signal via a watermark. The signal is then stored and distributed. When attempts are made to use or access the signal, the signal is checked for the presence of a watermark containing the digital signature for the desired portion of the signal. If the watermark is found, the digital signature is extracted and used to verify the authenticity of the desired portion of the signal. If not found, the signal is checked for the presence of the strong watermark, which if found causes the system to inhibit further use of the signal, and if not found further use of the signal is allowed.

Claims

1. A method for detecting modifications to an electronic file, the method performed by a system comprising a processor and a non-transitory computer-readable-medium storing instructions that when executed by the processor, cause the system to perform the method, the method comprising:

searching the electronic file for the presence of a signature-containing watermark;

if the signature-containing watermark is found;

retrieving a signature from the signature-containing watermark, and

using the signature to verify the authenticity of at least a portion of the electronic file;

if the signature-containing watermark is not found;

searching the electronic file for a second watermark;

if the second watermark is found, determining that that the electronic file has been modified;

if the second watermark is not found, granting a request to use the electronic file.

2. The method of claim 1, wherein the second watermark is a strong watermark.

3. The method of claim 1, wherein the second watermark is relatively more difficult to detect than the signature-containing watermark.

4. The method of claim 1, wherein the signature-containing watermark is included in the at least a portion of the electronic file.

5. The method of claim 1, wherein the electronic file comprises a series of multi-bit samples and the signature-containing watermark includes a quality indicator specifying a number of bits in each multi-bit sample that should be included when using the signature to verify the authenticity of the at least a portion of the electronic file.

6. The method of claim 1, wherein the digital signature comprises an encrypted concatenation of a plurality of hash values, each hash value comprising the hash of a sub-portion of the at least a portion of the electronic file.

7. The method of claim 1, wherein the method further comprises taking at least one defensive action relating to the use of the electronic file based on a determination that the electronic file has been modified.

8. The method of claim 7, wherein the at least one defensive action comprises inhibiting use of the electronic file.

9. A system for detecting modifications to an electronic file, the system comprising:

a processor; and

a non-transitory computer-readable medium storing instructions that when executed by the processor, cause the system to;

search the electronic file for the presence of a signature-containing watermark;

if the signature-containing watermark is found;

retrieve a signature from the signature-containing watermark, and

use the signature to verify the authenticity of at least a portion of the electronic file;

if the signature-containing watermark is not found;

search the electronic file for a second watermark;

if the second watermark is found, determine that that the electronic file has been modified;

if the second watermark is not found, grant a request to use the electronic file.

10. The system of claim 9, wherein the second watermark is a strong watermark.

11. The system of claim 9, wherein the second watermark is relatively more difficult to detect than the signature-containing watermark.

12. The system of claim 9, wherein the signature-containing watermark is included in the at least a portion of the electronic file.

13. The system of claim 9, wherein the electronic file comprises a series of multi-bit samples and the signature-containing watermark includes a quality indicator specifying a number of bits in each multi-bit sample that should be included when using the signature to verify the authenticity of the at least a portion of the electronic file.

14. The system of claim 9, wherein the digital signature comprises an encrypted concatenation of a plurality of hash values, each hash value comprising the hash of a sub-portion of the at least a portion of the electronic file.

15. The system of claim 9, wherein the instructions, when executed by the processor, further cause the system to take at least one defensive action relating to the use of the electronic file based on a determination that the electronic file has been modified.

16. The system of claim 15, wherein the at least one defensive action comprises inhibiting use of the electronic file.

17. A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause a computer system to perform a method for detecting modifications to an electronic file, the method comprising:

searching the electronic file for the presence of a signature-containing watermark;

if the signature-containing watermark is found;

retrieving a signature from the signature-containing watermark, and

using the signature to verify the authenticity of at least a portion of the electronic file;

if the signature-containing watermark is not found;

searching the electronic file for a second watermark;

if the second watermark is found, determining that that the electronic file has been modified;

if the second watermark is not found, granting a request to use the electronic file.

18. The non-transitory computer-readable medium of claim 17, wherein the second watermark is a strong watermark.

19. The non-transitory computer-readable medium of claim 17, wherein the second watermark is relatively more difficult to detect than the signature-containing watermark.

20. The non-transitory computer-readable medium of claim 17, wherein the signature-containing watermark is included in the at least a portion of the electronic file.

21. The non-transitory computer-readable medium of claim 17, wherein the electronic file comprises a series of multi-bit samples and the signature-containing watermark includes a quality indicator specifying a number of bits in each multi-bit sample that should be included when using the signature to verify the authenticity of the at least a portion of the electronic file.

22. The non-transitory computer-readable medium of claim 17, wherein the digital signature comprises an encrypted concatenation of a plurality of hash values, each hash value comprising the hash of a sub-portion of the at least a portion of the electronic file.

23. The non-transitory computer-readable medium of claim 17, wherein the method further comprises taking at least one defensive action relating to the use of the electronic file based on a determination that the electronic file has been modified.

24. The non-transitory computer-readable medium of claim 23, wherein the at least one defensive action comprises inhibiting use of the electronic file.