Method and apparatus for embedding authentication information within digital data

• US 6,047,374 A
• Filed: 05/26/1999
• Issued: 04/04/2000
• Est. Priority Date: 12/14/1994
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Barton, James M.
• Primary Examiner(s): Peeso, Thomas R.
• Application Number:
  US09/320,317
• Time in Patent Office: 314 Days
• Field of Search: 713/150, 713/160, 713/161, 713/187, 713/201, 380/37, 380/42, 380/28
• US Class Current: 713/150
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 1/0057 Compression invariant watermarking
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• CPC Class Codes: G06T 2201/0083 whereby only watermarked image required at decoder, e.g. source-based, blind, oblivious
• CPC Class Codes: G06T 2201/0203 whereby the image with embedded watermark is reverted to the original condition before embedding, e.g. lossless, distortion-free or invertible watermarking
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• 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 1/32154 Transform domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/32277 Compression
• CPC Class Codes: H04N 1/4486 using digital data encryption
• 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 21/8358 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 2201/327 which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3281 Encryption; Ciphering
• 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

Arbitrary digital information is embedded within a stream of digital data, in a way that avoids detection by a casual observer and that allows a user to determine whether the digital data have been modified from their intended form. The embedded information may only be extracted as authorized and may be used to verify that the original digital data stream has not been modified.

Claims

1. A method for extracting a bit string of information from a digital data block which includes the bit string of information and digital data comprising a digital representation of an object, the bit string of information encoding knowledge of interest to a receiver of the digital data block, comprising the steps of:

a) providing a digital data block having digital representation data comprising a digital representation of an object and a bit string of information embedded and encrypted therein, said bit string of information encoding knowledge of interest to a receiver of the digital data block and having been encrypted according to a predetermined encryption process and embedded according to a predetermined embedding process so that said bit string is not readily noticeable when said digital data block is converted into a non-digital form;

b) processing said digital data block having said bit string embedded and encrypted therein by both a de-embedding step and a decryption step to segregate said bit string from said digital representation data in said digital data block, said de-embedding step being the inverse of said predetermined embedding process and said decryption step being the inverse of said predetermined encryption process; and

c) retrieving said segregated bit string of information encoding knowledge of interest to a receiver of said digital data block.

2. The method of claim 1, wherein said bit string of information includes meta-data about said digital representation data;

wherein said step of processing includes extracting said meta-data from said digital data block; and

wherein said step of retrieving said segregated bit string includes separately retrieving said meta-data.

3. The method of claim 1, wherein said bit string includes a digital signature for said digital representation data;

wherein said step of processing includes extracting said digital signature from said digital data block; and

wherein said step of retrieving includes separately retrieving said digital signature.

4. The method of claim 3, wherein said digital signature is generated based on said digital representation data.

5. The method of claim 4, wherein said digital signature is calculated according to a predetermined digital signature calculation technique;

wherein said step of providing a digital data block includes the step of appending digital data indicative of said predetermined digital signature calculation technique to said bit string of information;

wherein said step of processing includes extracting said digital data indicative of said predetermined digital signature calculation technique from said digital data block; and

wherein said step of retrieving includes separately retrieving said digital data indicative of said digital signature calculation technique.

6. The method of claim 3, wherein said digital signature comprises a first digital signature;

and wherein said step of providing a digital data block includes generating said first digital signature based on said digital representation data, and embedding and encrypting said first digital signature in said digital data block; and

wherein said method further includes the step of generating a second digital signature based on said digital data block after said step of processing to segregate said bit string from said digital representation data in said digital data block, and comparing said first digital signature to said second digital signature for identifying a match of said first and second digital signatures.

7. The method of claim 6, wherein said first digital signature is calculated according to a predetermined digital signature calculation technique;

and wherein said step of providing a digital data block includes the step of appending digital data indicative of said predetermined digital signature calculation technique to said bit string of information.

8. The method of claim 7, wherein said step of retrieving said segregated bit string of information includes retrieving said digital data indicative of said predetermined digital signature calculation technique.

9. The method of claim 6, wherein said first digital signature is calculated according to a predetermined digital signature calculation technique;

wherein said step of providing a digital data block includes the step of appending digital data indicative of said predetermined digital signature calculation technique to said bit string of information; and

wherein said step of generating said second digital signature includes calculating said second digital signature according to said predetermined digital signature calculation technique.

10. The method of claim 9, wherein said step of retrieving said segregated bit string of information includes retrieving said digital data indicative of said predetermined digital signature calculation technique, and wherein said step of calculating said second digital signature includes using said retrieved digital data indicative of said predetermined digital signature calculation technique to calculate said second digital signature.

11. The method of claim 6, further including the step of authenticating said digital representation data if said first digital signature matches said second digital signature.

12. The method of claim 11, wherein said digital representation data in said digital data block comprises compressed digital data, and wherein said method further includes the step of decompressing said compressed digital data after said step of authenticating said digital representation data.

13. The method of claim 1, wherein said bit string of information includes both meta-data about said digital representation data and a digital signature for said digital representation data;

wherein said step of processing said digital data block includes processing said digital data block to segregate said meta-data and said digital signature from said digital data block; and

wherein said step of retrieving includes separately retrieving said meta-data and said digital signature.

14. The method of claim 1, wherein said step of providing a digital data block includes appending digital data indicative of said predetermined encryption process to said bit string of information;

and wherein said step of processing includes extracting said digital data indicative of said predetermined encryption process from said digital data block, and performing said decryption step based on said extracted digital data indicative of said predetermined encryption process.

15. The method of claim 1, wherein said step of providing a digital data block comprises encrypting said bit string of information according to said predetermined encryption process to provide an encrypted bit string, and embedding said encrypted bit string in said digital data block according to said predetermined embedding process;

and wherein said step of processing said digital data block includes first performing said de-embedding step and thereafter performing said decryption step.

16. The method of claim 1, wherein said step of providing a digital data block includes calculating an error correction code for said bit string of information for correcting a possible error, and appending said error correction code to said bit string;

and wherein said step of processing said digital data block further includes extracting said error correction code from said digital data block and using said extracted error correction code to correct any errors in said segregated bit string of information.

17. The method of claim 1, wherein said bit string includes authentication information for authenticating said digital representation data;

wherein said step of processing said digital data includes processing said digital data block to extract said authentication information; and

wherein said step of retrieving includes separately retrieving said authentication information.

18. The method of claim 17, wherein said authentication information comprises at least one or more of a serial number, an identification tag, an authentication tag, and a digital signature.

19. The method of claim 17, wherein said authentication information includes copy authentication information.

20. The method of claim 1, wherein portions of said digital representation data are modified when said bit string of information is embedded according to said predetermined embedding process;

and wherein said step of providing a digital data block includes compressing said portions of said digital representation data to provide a compressed representation of said portions, and appending said compressed representation to said bit string prior to said bit string being encrypted and embedded in said digital data block.

21. The method of claim 20, wherein said step of processing said digital data block includes extracting said compressed representation from said digital data block;

wherein said step of retrieving includes decompressing said compressed representation extracted from said digital data block to provide a decompressed representation; and

wherein said method further includes replacing the portions of said digital data block that were modified when said bit string was embedded with said decompressed representation.

22. The method of claim 1, wherein said bit string includes at least one of restoration information and authentication information;

and wherein said method further includes the step of performing at least one of a restoring step and an authentication step on said digital data block in accordance with said segregated bit string of information retrieved by said step of retrieving.

23. The method of claim 1, wherein said step of providing a digital data block further includes the step of compressing said digital representation data;

and wherein said method further includes the step of decompressing said digital data block after said step of retrieving said segregated bit string of information.

24. The method of claim 1, wherein said step of providing a digital data block includes compressing said digital representation data and said bit string of information prior to said bit string being encrypted and embedded in said digital data block;

and wherein said step of retrieving includes decompression of said digital data block to provide decompressed digital representation data and said bit string of information.

25. The method of claim 1, wherein said step of providing a digital data block includes compressing said bit string of information prior to said bit string being encrypted and embedded in said digital data block;

and wherein said step of retrieving includes decompressing said segregated bit string of information.

26. The method of claim 1, wherein said bit string is embedded in a pseudo-random distribution fashion.

27. The method of claim 1, wherein said digital representation data is based upon audio digital data which is representative of an audio object.

28. The method of claim 1, wherein said digital representation data is based upon image digital data which is representative of an image.

29. The method of claim 28, wherein said digital representation data comprises a JPEG image.

30. The method of claim 28, wherein said digital representation data comprises a MPEG image.

31. A method for retrieving digital representation data from a digital data block which includes the digital representation data and a bit string of information embedded and encrypted therein, the bit string of information encoding knowledge of interest to a receiver of the digital data block, the method comprising the steps of:

a) providing a digital data block having digital representation data comprising a digital representation of an object and a bit string of information embedded and encrypted therein, said bit string of information encoding knowledge of interest to a receiver of the digital data block and having been encrypted according to a predetermined encryption process and embedded according to a predetermined embedding process so that said bit string is not readily noticeable when said digital data block is converted into a non-digital form;

b) processing said digital data block having said bit string embedded and encrypted therein by both a de-embedding step and a decryption step to segregate said bit string from said digital representation data in said digital data block, said de-embedding step being the inverse of said predetermined embedding process and said decryption step being the inverse of said encryption process;

c) retrieving said segregated bit string of information encoding knowledge of interest to a receiver of said digital data block; and

d) retrieving said digital representation data from said digital data block having said bit string segregated therefrom.

32. The method of claim 31, wherein said bit string of information includes meta-data about said digital representation data;

wherein said step of processing includes extracting said meta-data from said digital data block; and

wherein said step of retrieving said segregated bit string includes separately retrieving said meta-data.

33. The method of claim 31, wherein said bit string includes a digital signature for said digital representation data;

wherein said step of processing includes extracting said digital signature from said digital data block; and

wherein said step of retrieving said bit string includes separately retrieving said digital signature.

34. The method of claim 33, wherein said digital signature comprises a first digital signature;

and wherein said step of providing a digital data block includes generating said first digital signature based on said digital representation data, and embedding and encrypting said first digital signature in said digital data block; and

wherein said method further includes the step of generating a second digital signature based on said digital data block after said step of processing to segregate said bit string from said digital representation data in said digital data block, and comparing said first digital signature to said second digital signature for identifying a match of said first and second digital signatures.

35. The method of claim 34, wherein said first digital signature is calculated according to a predetermined digital signature calculation technique;

and wherein said step of providing a digital data block includes the step of appending digital data indicative of said predetermined digital signature calculation technique to said bit string of information.

36. The method of claim 35, wherein said step of retrieving said segregated bit string of information includes retrieving said digital data indicative of said predetermined digital signature calculation technique.

37. The method of claim 34, wherein said first digital signature is calculated according to a predetermined digital signature calculation technique;

wherein said step of providing a digital data block includes the step of appending digital data indicative of said predetermined digital signature calculation technique to said bit string of information; and

wherein said step of generating said second digital signature includes calculating said second digital signature according to said predetermined digital signature calculation technique.

38. The method of claim 37, wherein said step of retrieving said segregated bit string of information includes retrieving said digital data indicative of said predetermined digital signature calculation technique, and wherein said step of calculating said second digital signature includes using said retrieved digital data indicative of said predetermined digital signature calculation technique to calculate said second digital signature.

39. The method of claim 34, further including the step of authenticating said digital representation data if said first digital signature matches said second digital signature.

40. The method of claim 31, wherein said step of providing a digital data block includes appending digital data indicative of said predetermined encryption process to said bit string of information;

and wherein said step of processing includes extracting said digital data indicative of said predetermined encryption process from said digital data block, and performing said decryption step based on said extracted digital data indicative of said predetermined encryption process.

41. The method of claim 31, wherein said step of providing a digital data block includes calculating an error correction code for said bit string of information for correcting a possible error, and appending said error correction code to said bit string;

and wherein said step of processing said digital data block further includes extracting said error correction code from said digital data block and using said extracted error correction code to correct any errors in said segregated bit string of information.

42. The method of claim 31, wherein said bit string includes authentication information for authenticating said digital representation data;

wherein said step of processing said digital data includes processing said digital data block to extract said authentication information; and

wherein said step of retrieving said bit string includes separately retrieving said authentication information.

43. The method of claim 42, wherein said authentication information comprises at least one or more of a serial number, an identification tag, an authentication tag, and a digital signature.

44. The method of claim 43, wherein said authentication information includes copy authentication information.

45. The method of claim 31, wherein portions of said digital representation data are modified when said bit string of information is embedded according to said predetermined embedding process;

and wherein said step of providing a digital data block includes compressing said portions of said digital representation data to provide a compressed representation of said portions, and appending said compressed representation to said bit string prior to said bit string being encrypted and embedded in said digital data block.

46. The method of claim 45, wherein said step of processing said digital data block includes extracting said compressed representation from said digital data block;

wherein said step of retrieving said bit string includes decompressing said compressed representation extracted from said digital data block to provide a decompressed representation; and

wherein said method further includes replacing the portions of said retrieved digital representation data that were modified when said bit string was embedded with said decompressed representation.

47. The method of claim 31, wherein said step of providing a digital data block includes compressing said bit string of information prior to said bit string being encrypted and embedded in said digital data block;

and wherein said step of retrieving includes decompressing said segregated bit string of information.

48. The method of claim 31, wherein said bit string is embedded in a pseudo-random distribution fashion.

49. A method for extracting a bit string of information from a digital data block, the bit string of information having been encrypted according to a predetermined encryption process and then embedded in the digital data block according to a predetermined embedding process, the bit string of information encoding knowledge of interest to a receiver of the digital data block and not being readily noticeable when the digital data block having the bit string embedded and encrypted therein is converted into a non-digital form, the method comprising the steps of:

a) providing said digital data block having said bit string of information encrypted and embedded therein;

b) extracting an encrypted bit string from said digital data block by using an inverse of said predetermined embedding process;

c) decrypting said encrypted bit string by using an inverse of said predetermined encryption process; and

d) retrieving said bit string of information after said decrypting step.

50. The method of claim 49, wherein said bit string of information includes meta-data about said digital data block, and wherein said step of retrieving said bit string includes separately retrieving said meta-data.

51. The method of claim 49, wherein said bit string includes a digital signature for said digital data block, and wherein said step of retrieving includes separately retrieving said digital signature.

52. The method of claim 51, wherein said digital signature is generated based on said digital data block.

53. The method of claim 51, wherein said digital signature is calculated according to a predetermined digital signature calculation technique;

wherein said step of providing a digital data block includes the step of appending digital data indicative of said predetermined digital signature calculation technique to said bit string of information prior to said bit string being encrypted; and

wherein said step of retrieving includes separately retrieving said digital data indicative of said digital signature calculation technique.

54. The method of claim 51, wherein said digital signature comprises a first digital signature;

and wherein said step of providing a digital data block includes generating said first digital signature based on said digital data block, and encrypting and embedding said first digital signature in said digital data block; and

wherein said method further includes the step of generating a second digital signature based on said digital data block after said step of retrieving said bit string from said digital data block, and comparing said first digital signature to said second digital signature for identifying a match of said first and second digital signatures.

55. The method of claim 54, wherein said first digital signature is calculated according to a predetermined digital signature calculation technique;

and wherein said step of providing a digital data block includes the step of appending digital data indicative of said predetermined digital signature calculation technique to said bit string of information.

56. The method of claim 55, wherein said step of retrieving said bit string of information includes retrieving said digital data indicative of said predetermined digital signature calculation technique.

57. The method of claim 54, wherein said first digital signature is calculated according to a predetermined digital signature calculation technique;

wherein said step of providing a digital data block includes the step of appending digital data indicative of said predetermined digital signature calculation technique to said bit string of information; and

wherein said step of generating said second digital signature includes calculating said second digital signature according to said predetermined digital signature calculation technique.

58. The method of claim 57, wherein said step of retrieving said bit string of information includes retrieving said digital data indicative of said predetermined digital signature calculation technique, and wherein said step of calculating said second digital signature includes using said retrieved digital data indicative of said predetermined digital signature calculation technique to calculate said second digital signature.

59. The method of claim 54, further including the step of authenticating said digital data block if said first digital signature matches said second digital signature.

60. The method of claim 59, wherein digital data block comprises compressed digital data, and wherein said method further includes the step of decompressing said compressed digital data after said step of authenticating said digital data block.

61. The method of claim 49, wherein said bit string of information includes both meta-data about said digital data block and a digital signature for said digital data block, and wherein said step of retrieving includes separately retrieving said meta-data and said digital signature.

62. The method of claim 49, wherein said step of providing a digital data block includes appending digital data indicative of said predetermined encryption process to said bit string after said bit string has been encrypted and prior to said bit string being embedded in said digital data block;

and wherein said step of extracting includes extracting said digital data indicative of said predetermined encryption process from said digital data block, and performing said decrypting step based on said extracted digital data indicative of said predetermined encryption process.

63. The method of claim 49, wherein said step of providing a digital data block includes calculating an error correction code for said bit string of information for correcting a possible error, and appending said error correction code to said bit string prior to said bit string being embedded in said digital data block;

and wherein said step of extracting includes extracting said error correction code from said digital data block and using said extracted error correction code to correct any errors in said encrypted bit string.

64. The method of claim 49, wherein said bit string includes authentication information for authenticating said digital data block;

and wherein said step of retrieving includes separately retrieving said authentication information.

65. The method of claim 64, wherein said authentication information comprises at least one or more of a serial number, an identification tag, an authentication tag, and a digital signature.

66. The method of claim 64, wherein said authentication information includes copy authentication information.

67. The method of claim 49, wherein portions of said digital data block are modified when said bit string is embedded according to said predetermined embedding process;

and wherein said step of providing a digital data block includes compressing said portions of said digital representation data to provide a compressed representation of said portions, and appending said compressed representation to said bit string prior to said bit string being embedded.

68. The method of claim 67, wherein said step of retrieving includes separately retrieving said compressed representation and decompressing said compressed representation to provide a decompressed representation;

and wherein said method further includes replacing the portions of said digital data block that were modified when said encrypted bit string was embedded with said decompressed representation.

69. The method of claim 49, wherein said step of providing a digital data block further includes the step of compressing said digital representation data;

and wherein said method further includes the step of decompressing said digital data block after said step of retrieving said bit string of information.

70. The method of claim 49, wherein said step of providing a digital data block includes compressing said bit string of information prior to said bit string being encrypted;

and wherein said step of retrieving includes decompressing said bit string of information.

71. The method of claim 49, wherein said bit string is embedded in a pseudo-random distribution fashion.

72. The method of claim 49, wherein said digital data block is based upon audio digital data which is representative of an audio object.

73. The method of claim 49, wherein said digital data block is based upon image digital data which is representative of an image.