Elementary stream partial encryption

• US 20030081776A1
• Filed: 01/02/2002
• Published: 05/01/2003
• Est. Priority Date: 06/06/2001
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Inventors: Candelore, Brant L.
• Granted Patent: US 7,124,303 B2
• Time in Patent Office: Days
• US Class Current: 380/200
• CPC Class Codes: H04N 21/23476 by partially encrypting, e.g. encrypting the ending portion of a movie
• CPC Class Codes: H04N 21/235 Processing of additional data, e.g. scrambling of additional data or processing content descriptors
• CPC Class Codes: H04N 21/23608 Remultiplexing multiplex streams, e.g. involving modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/2362 Generation or processing of Service Information [SI]
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/23897 by partially encrypting, e.g. encrypting only the ending portion of a movie
• CPC Class Codes: H04N 21/25875 involving end-user authentication restricting access to computer systems by authenticating users using a predetermined code G06F21/33; arrangements for secret or secure communication including means for verifying the identity or authority of a user of the system H04L9/32; networks authentication protocols H04L63/08; authentication in wireless network security H04W12/06
• CPC Class Codes: H04N 21/26606 for generating or managing entitlement messages, e.g. Entitlement Control Message [ECM] or Entitlement Management Message [EMM] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/4181 for conditional access
• CPC Class Codes: H04N 21/42615 involving specific demultiplexing arrangements
• CPC Class Codes: H04N 21/4344 Remultiplexing of multiplex streams, e.g. by modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/4345 Extraction or processing of SI, e.g. extracting service information from an MPEG stream
• CPC Class Codes: H04N 21/4347 Demultiplexing of several video streams
• CPC Class Codes: H04N 21/435 Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream
• CPC Class Codes: H04N 21/43607 Interfacing a plurality of external cards, e.g. through a DVB Common Interface [DVB-CI]
• CPC Class Codes: H04N 21/43853 involving multiplex stream decryption arrangements using cryptography for the use of broadcast information or broadcast-related information H04H60/23
• CPC Class Codes: H04N 21/43856 by partial decryption, e.g. decrypting a multiplex stream that has been partially encrypted
• CPC Class Codes: H04N 21/44055 by partially decrypting, e.g. decrypting a video stream that has been partially encrypted
• CPC Class Codes: H04N 21/4516 involving client characteristics, e.g. Set-Top-Box type, software version or amount of memory available
• CPC Class Codes: H04N 21/454 Content or additional data filtering, e.g. blocking advertisements
• CPC Class Codes: H04N 21/4623 : Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/835 : Generation of protective data, e.g. certificates protecting software against unauthorised usage in a vending or licensing environment G06F21/10
• CPC Class Codes: H04N 7/162 : Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing
• CPC Class Codes: H04N 7/167 : Systems rendering the television signal unintelligible and subsequently intelligible
• 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

An encryption arrangement for multiple encryption of television programs. A system according to embodiments of the present invention multiple encrypts only a portion of the data required for full presentation of a television program to permit coexistence of multiple conditional access encryption systems associated with multiple manufacturer'"'"'s set-top boxes within a single system. In one embodiment, only audio data are encrypted leaving video in the clear. By only encrypting a portion of the program, dramatically less bandwidth is consumed than the alternative of multiple encryption of all program data, thus permitting a larger number of programs to be carried over the same bandwidth while permitting coexistence of multiple conditional access systems in a single cable television system.

Claims

1. A method of encrypting a television signal, comprising:

encrypting an audio portion of the television signal according to a first encryption method to produce a first encrypted audio portion and according to a second encryption method to produce a second encrypted audio portion; and

combining an unencrypted video portion of the television signal with the first and second encrypted audio portion.

2. The method according to claim 1, wherein the television signal is a digital television signal, and wherein the encrypting comprises encrypting packets identified as audio packets.

3. The method according to claim 2, wherein the digital television signal complies with an MPEG standard, and wherein the audio packets are identified for encryption by a packet identifier (PID).

4. The method according to claim 2, wherein the digital television signal complies with a digital satellite service (DSS) transport standard, and wherein the audio packets are identified for encryption by a service channel identifier (SCID)

5. The method according to claim 2, wherein audio packets encrypted according to the first encryption method are assigned a first packet identifier and audio packets encrypted according to the second encryption method are assigned a second packet identifier.

6. The method according to claim 5, wherein the first packet identifier and the second packet identifier are referenced as primary elementary PIDs in a program map table (PMT).

7. The method according to claim 5, wherein the first packet identifier is referenced as a primary elementary PID in a program map table (PMT) and the second packet identifier is referenced as a secondary elementary PID in the program map table (PMT).

8. The method according to claim 5, wherein the first encrypted audio portion and the second encrypted audio portion are distributed over one of a terrestrial broadcast system, a satellite system and a cable system.

9. The method according to claim 8, further comprising distributing system information to provide locating information used to locate the first and second encrypted audio portions.

10. The method according to claim 9, further comprising encrypting the system information.

11. An electronic storage medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a television signal according to claim 1.

12. An electronic transmission medium carrying an encrypted television signal encrypted by the method according to claim 1.

13. A method of encrypting a television signal, comprising:

encrypting an audio portion of the television signal according to a first encryption method to produce a first encrypted audio portion; and

combining the first encrypted audio portion with an unencrypted video portion of the television signal to produce a partially encrypted television signal.

14. The method according to claim 13, wherein the television signal is a digital television signal, and wherein the encrypting comprises encrypting packets identified as audio packets.

15. The method according to claim 14, wherein the digital television signal complies with an MPEG standard, and wherein the audio packets are identified for encryption by a packet identifier (PID).

16. The method according to claim 13, further comprising distributing the partially encrypted television signal over one of a cable system and a satellite system.

17. The method according to claim 16, further comprising transmitting system information to provide locating information used to locate the first encrypted audio portion.

18. The method according to claim 17, further comprising encrypting the system information.

19. The method according to claim 13, further comprising partially encrypting the unencrypted video portion of the television signal.

20. An electronic storage medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a television signal according to claim 13.

21. An electronic transmission medium carrying an encrypted television signal encrypted by the method according to claim 13.

22. An encrypted television signal for encrypting a television signal having a clear audio portion and a clear video portion, comprising:

a first encrypted audio portion, comprising the clear audio portion encrypted under a first encryption method;

a second encrypted audio portion, comprising the clear audio portion encrypted under a second encryption method; and

an unencrypted video portion.

23. The encrypted television signal according to claim 22, wherein the television signal is a digital television signal, and wherein the first and second encrypted audio portions comprise encrypted packets identified as audio packets.

24. The encrypted television signal according to claim 23, wherein the digital television signal complies with an MPEG standard, and wherein the first encrypted audio portion is comprised of packets identified by a first packet identifier (PID), and wherein the second encrypted audio portion is comprised of packets identified by a second packet identifier (PID).

25. An encrypted television signal for encrypting a television signal having a clear audio portion and a clear video portion, comprising:

a first encrypted audio portion, comprising the clear audio portion encrypted under a first encryption method; and

an unencrypted video portion.

26. The encrypted television signal according to claim 25, wherein the television signal is a digital television signal, and wherein the first encrypted audio portion comprises encrypted packets identified as audio packets.

27. The encrypted television signal according to claim 26, wherein the digital television signal complies with an MPEG standard, and wherein the first encrypted audio portion is comprised of packets identified by a first packet identifier (PID).

29. The apparatus according to claim 26, wherein the receiver further receives and discards audio packets encrypted under a second encryption algorithm.

28. A television set-top box, comprising:

a receiver receiving a dual partially encrypted television program;

a decrypter that receives encrypted audio packets from the receiver and decrypts the encrypted audio packets, the encrypted audio packets being encrypted under a first encryption algorithm; and

a decoder that receives and decodes the decrypted audio packets, and that receives and decodes unencrypted video packets to produce a television signal suitable for play on a television receiver.

30. A cable system headend, comprising:

a first encryption system that encrypts audio packets using a first encryption algorithm;

a second encryption system that encrypts audio packets using a second encryption algorithm; and

means for distributing a stream of packets over a cable television system, the stream of packets comprising a video packets, audio packets encrypted under the first encryption algorithm, and audio packets encrypted under the second encryption algorithm and system information packets.

31. The apparatus according to claim 30, wherein the video packets are unencrypted.

32. The apparatus according to claim 30, wherein the system information packets are unencrypted.

33. The apparatus according to claim 30, wherein the video packets are partially encrypted.

34. The apparatus according to claim 30, wherein the system information packets are encrypted.

35. A method of decoding a partially encrypted television signal, comprising:

receiving a television signal having an encrypted audio portion and a clear video portion;

decrypting the encrypted audio portion to produce a decrypted audio portion;

decoding the decrypted audio portion and the clear video portion to produce a decoded television signal.

36. The method according to claim 35, wherein the decoded signal is suitable for play on a television set.

37. The method according to claim 35, wherein the encrypted audio portion is identified by a packet identifier (PID) associated with a decryption algorithm used for decrypting the encrypted audio portion.

38. The method according to claim 35, wherein the television signal further comprises a second encrypted audio portion;

and wherein the encrypted audio portion and the second encrypted audio portions are encrypted using two different encryption algorithms.

39. The method according to claim 38, wherein the encrypted audio portion is identified by a first packet identifier (PID) associated with a decryption algorithm used for decrypting the encrypted audio portion;

and wherein the second encrypted audio portion is identified by a second packet identifier (PID) associated with a decryption algorithm used for decrypting the encrypted audio portion.

40. The method according to claim 39, wherein the first PID is a secondary PID and wherein the second PID is a primary PID.

41. The method according to claim 39, wherein the first PID is a primary PID and wherein the second PID is a secondary PID.

42. The method according to claim 35, carried out in an integrated circuit.

43. The method according to claim 35, carried out in an application specific integrated circuit.

44. The method according to claim 35, carried out in a television device.

45. The method according to claim 35, carried out in a television set-top box.

46. A method of decoding a partially encrypted television signal, comprising:

receiving a television signal having a first encrypted audio portion, a second encrypted audio portion and a clear video portion, the first audio portion being identified by a first packet identifier (PID), and the second audio portion being identified by a second PID;

discarding the second encrypted audio portion by PID filtering;

decrypting the first encrypted audio portion to produce a decrypted audio portion; and

decoding the decrypted audio portion and the clear video portion to produce a decoded signal.

47. The method according to claim 46, wherein the decoded signal is suitable for play on a television set.

48. The method according to claim 46, wherein the first PID is a secondary PID and wherein the second PID is a primary PID.

49. The method according to claim 46, wherein the first PID is a primary PID and wherein the second PID is a secondary PID.

50. The method according to claim 46, carried out in an integrated circuit.

51. The method according to claim 46, carried out in an application specific integrated circuit.

52. The method according to claim 46, carried out in a television device.

53. The method according to claim 46, carried out in a television set-top box.

54. A method of encrypting a digital television signal, wherein the television signal includes an elementary data stream and system information (SI), comprising:

encrypting the SI under a first encryption system;

forming a partially encrypted digital television signal comprising;

the elementary data stream in an unencrypted form; and

the SI encrypted under the first encryption system.

55. The method according to claim 54, further comprising encrypting the SI under a second encryption system.

56. The method according to claim 55, wherein the partially encrypted digital television signal further comprises the SI encrypted under the second encryption system.

57. The method according to claim 54, further comprising distributing the partially encrypted television signal over one of the following:

a cable system, a terrestrial broadcast system and satellite system.

58. The method according to claim 57, wherein the encrypted SI information is distributed in a different band than that used to distribute the elementary data stream in the unencrypted form.

59. The method according to claim 54, further comprising distributing the partially encrypted television signal over one of the following:

a cable system, a terrestrial broadcast system and satellite system.

60. The method according to claim 59, wherein the encrypted SI information is distributed in a different band than that used to distribute the elementary data stream in the unencrypted form.

61. An electronic storage medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a digital television signal according to claim 54.

62. An electronic transmission medium carrying an encrypted digital television signal encrypted by the method according to claim 54.

63. A partially encrypted digital television signal, comprising:

an unencrypted elementary data stream; and

system information (SI) encrypted under a first encryption system.

64. The apparatus according to claim 63, further comprising the system information (SI) encrypted under a second encryption system.

65. The apparatus according to claim 64, wherein the unencrypted elementary data stream is modulated to a first frequency band and wherein the encrypted SI is modulated to a second frequency band.

66. The apparatus according to claim 63, wherein the unencrypted elementary data stream is modulated to a first frequency band and wherein the encrypted SI is modulated to a second frequency band.

67. A television set-top box, comprising:

a receiver that receives a television signal comprising content and encrypted system information;

a decrypter that decrypts the system information; and

a decoder that decodes the content.

68. The apparatus according to claim 67, wherein the content is decoded according to the information.

69. The apparatus according to claim 67, wherein the system information includes channel identifier information for identifying the content.

70. The apparatus according to claim 67, wherein the system information is received in an out of band receiver.

71. The apparatus according to claim 68, wherein the system information is received in an in-band receiver.

72. A method of encrypting a television signal, comprising:

encrypting an elementary stream of the television signal according to a first encryption method to produce a first encrypted elementary stream; and

encrypting the elementary stream according to a second encryption method to produce a second encrypted elementary stream.

73. The method according to claim 72, further comprising distributing an unencrypted video portion of the television signal along with the first and second encrypted elementary streams.

74. The method according to claim 72, wherein the television signal is a digital television signal, and wherein the encrypting comprises encrypting packets identified as one of audio elementary stream packets, video elementary stream packets and system information elementary stream packets.

75. The method according to claim 74, wherein the digital television signal complies with an MPEG standard, and wherein the elementary stream packets are identified for encryption by a packet identifier (PID).

76. A method of encrypting a television signal, comprising:

encrypting a selected elementary stream of the television signal according to a first encryption method to produce a first encrypted elementary stream; and

combining the first encrypted elementary stream with at least one unencrypted elementary stream of the television signal to produce a partially encrypted television signal.

77. The method according to claim 76, wherein the television signal is a digital television signal, and wherein the encrypting comprises encrypting packets identified as the selected elementary stream packets.

78. The method according to claim 76, wherein the digital television signal complies with an MPEG standard, and wherein the selected elementary stream packets are identified for encryption by a packet identifier (PID).

79. The method according to claim 76, further comprising distributing the partially encrypted television signal over one of a cable system, a terrestrial broadcast system and a satellite system.

80. The method according to claim 76, wherein the television signal is a digital television signal, and wherein the encrypting comprises encrypting packets identified as one of audio elementary stream packets, video elementary stream packets and system information elementary stream packets.

81. An electronic storage medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a television signal according to claim 76.

82. An electronic transmission medium carrying an encrypted television signal encrypted by the method according to claim 76.