Watermarking in an encrypted domain

• US 20070110237A1
• Filed: 07/07/2006
• Published: 05/17/2007
• Est. Priority Date: 07/07/2005
• Status: Active Grant

• Current Assignee: Verance Corporation
• Original Assignee: Verance Corporation
• Inventors: Petrovic, Rade, Tehranchi, Babak
• Granted Patent: US 8,781,967 B2
• Time in Patent Office: Days
• US Class Current: 380/201
• CPC Class Codes: G06T 1/0035 Output size adaptive watermarking
• CPC Class Codes: G06T 2201/0053 Embedding of the watermark in the coding stream, possibly without decoding; Embedding of the watermark in the compressed domain
• CPC Class Codes: H04N 1/32149 Methods relating to embedding, encoding, decoding, detection or retrieval operations
• CPC Class Codes: H04N 1/32272 Encryption or ciphering
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• 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 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

Methods, apparatus and systems for embedding auxiliary information in encrypted host signals are provided. The present invention enables secure application of digital watermarks at any point in the transmission and/or distribution of digital content by enabling the insertion of a plurality of digital watermarks, without the knowledge of the encryption/decryption keys, into a digital host content that has been encrypted with an encryption key. The embedded watermarks persist throughout the content subsequent to the decryption of the content. The disclosed techniques are applicable to content that has been encrypted using a variety of different encryption techniques and algorithms, including stream ciphers, block ciphers, symmetric and asymmetric encryption algorithms. These methods are further adapted to enable the insertion of watermarks into a content that is compressed prior to encryption.

Claims

1. A method for embedding auxiliary information symbols in an encrypted host content signal, comprising:

encrypting a first version of a host content signal embedded with a first logical value to produce a first encrypted signal;

encrypting a second version of the host content signal embedded with a second logical value to produce a second encrypted signal; and

combining a first set of segments from said first encrypted signal with a second set of segments from said second encrypted signal in a pre-defined manner to produce a composite encrypted host content with embedded auxiliary information.

2. The method of claim 1, wherein said first and second encrypted signals are encrypted in accordance with at least one of:

a stream cipher,

a block cipher,

a symmetric encryption algorithm, and

an asymmetric encryption algorithm.

3. The method of claim 1, wherein said first and second encrypted signals are in a compressed format.

4. The method of claim 1, wherein said combining is performed without the use of the encryption or decryption keys.

5. The method of claim 1, wherein the embedded auxiliary information persists throughout the host content after decryption of said composite encrypted host content.

6. The method of claim 1, wherein said pre-defined manner identifies an entity or a transaction.

7. The method of claim 1, wherein said encrypting of the first and second versions of the host content signal occurs at a pre-processing center and said combining occurs at a user location.

8. The method of claim 1, wherein said host content signal comprises at least one of audio, video, text, or programming information.

9. A method for embedding auxiliary information symbols in an encrypted host content signal, comprising:

encrypting a first version of an original host content signal embedded with a first logical value to produce a first encrypted signal;

producing a second signal comprising information corresponding to said first logical value and a second logical value embedded in the host content signal; and

combining a first set of segments from said first encrypted signal with a second set of segments from said second signal in a pre-defined manner to produce a composite encrypted host content with embedded auxiliary information.

10. The method of claim 9, wherein said first encrypted signal is encrypted in accordance with at least one of:

a stream cipher,

a block cipher,

a symmetric encryption algorithm, and

an asymmetric encryption algorithm.

11. The method of claim 9, further comprising at least one of compressing, encrypting, and scrambling said second signal.

12. The method of claim 9, wherein said pre-defined manner identifies an entity or a transaction.

13. The method of claim 9, wherein said host content signal comprises at least one of audio, video, text, or programming information.

14. The method of claim 9, wherein:

said host content signal is in a compressed format;

said encrypting comprising encrypting of the compressed host content signal embedded with a first logical value; and

said second signal comprises information corresponding to said first and second logical values embedded in the compressed host content signal.

15. A method for embedding auxiliary information symbols in an encrypted host content signal, comprising:

encrypting the host content signal to produce an unmarked encrypted host content signal;

producing a first signal comprising information corresponding to a first logical value embedded in the host content signal;

producing a second signal comprising information corresponding to a second logical value embedded in the host content signal;

selecting a first set of segments from said first signal;

selecting a second set of segments from said second signal;

combining said first set and said second set of segments with said unmarked encrypted host content in a predefined manner to produce a composite encrypted host content with embedded auxiliary information.

16. The method of claim 15, wherein said unmarked encrypted host content signal is encrypted in accordance with at least one of:

a stream cipher,

a block cipher,

a symmetric encryption algorithm, and

an asymmetric encryption algorithm.

17. The method of claim 15, further comprising at least one of compressing, encrypting, and scrambling said first or second signal.

18. The method of claim 15, wherein:

said host content signal is in compressed format;

said encrypting comprising encrypting of the compressed host content signal; and

said first and second signals comprise information corresponding to first and second logical values embedded in the compressed host content signal, respectively.

19. The method of claim 15, wherein said first and second signals are transmitted to a user premises, and combined with the unmarked encrypted host content signal that resides at said user premises.

20. The method of claim 15, wherein said pre-defined manner identifies an entity or a transaction.

21. The method of claim 15, wherein said host content signal comprises at least one of audio, video, text, and programming information.

22. A method for embedding auxiliary information symbols in a compressed and encrypted host content signal, comprising:

encrypting a first version of a compressed host content signal embedded with a first logical value to produce a first encrypted signal;

producing a second signal comprising information corresponding to said first logical value and a second logical value embedded in the compressed host content signal; and

combining a first set of segments from said first encrypted signal with a second set of segments from said second signal in a pre-defined manner to produce a composite encrypted host content with embedded auxiliary information.

23. The method of claim 22, wherein said first encrypted signal and said second signal comprise a matching signal interval.

24. The method of claim 23, wherein said combining occurs within said matching signal interval.

25. The method of claim 22, wherein said first encrypted signal comprises a partially encrypted signal.

26. The method of claim 22, wherein additional meta data corresponding to said first encrypted signal and said second signal are produced to facilitate said combining.

27. The method of claim 22, wherein said first encrypted signal is encrypted in accordance with at least one of:

a stream cipher,

a block cipher,

a symmetric encryption algorithm, and

an asymmetric encryption algorithm.

28. The method of claim 22, wherein said pre-defined manner identifies an entity or a transaction.

29. The method of claim 22, wherein said host content signal comprises at least one of audio, video, text, and programming information.

30. A method for embedding auxiliary information into an encrypted host signal, comprising:

receiving a first signal comprising an encrypted first version of a host signal,

receiving a second signal comprising information related to first and second logical values embedded in a second version of said host signal;

combining at least portions of said second signal with said first signal in a pre-defined manner to produce a composite encrypted host signal with embedded auxiliary information.

31. A method for embedding auxiliary information into an encrypted host signal, comprising:

receiving an information signal corresponding to first and second logical values embedded into a first version of the host signal from a pre-processing center; and

combining said information signal with an encrypted second version of the host signal in a pre-defined manner to produce a composite encrypted host signal with embedded auxiliary information.