Elementary stream partial encryption

• US 7,124,303 B2
• Filed: 01/02/2002
• Issued: 10/17/2006
• Est. Priority Date: 06/06/2001
• Status: Expired due to Term

• 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: Unger, Robert Allan, Pedlow, JR., Leo M., Mirsky, Gregory, Eyer, Mark Kenneth, Candelore, Brant L.
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Shiferaw, Eleni A.
• Application Number:
  US10/037,914
• Publication Number:
  US 20030081776A1
• Time in Patent Office: 1,749 Days
• Field of Search: 713/193, 713/189
• US Class Current: 713/193
• 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 digital television signal, comprising:

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

combining an unencrypted video portion of the television signal with the first and second encrypted audio portions to produce the encrypted digital television signal; and

transmitting the encrypted digital television signal comprising the unencrypted video portion and the encrypted first and second audio portions.

2. The method according to claim 1, 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 packet identifiers (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 packet identifier (PID) in a program map table (PMT) and the second packet identifier is referenced as a secondary elementary packet identifier (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 combining encrypted system information with the video portion and first and second encrypted audio portions.

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 encrypted television signal stored in electronic transmission readable-medium encrypted by the method according to claim 1.

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

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

encrypting a duplicate of the data representing the audio portion of the television signal according to a second encryption method to produce a second encrypted audio portion;

combining the first encrypted audio portion and the second encrypted audio portion with an unencrypted video portion of the television signal to produce a multiple partially encrypted digital television signal; and

transmitting the multiple partially encrypted digital television signal comprising the unencrypted video portion and the first and second encrypted audio portions.

14. The method according to claim 13, wherein the multiple 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 multiple encryption by a packet identifier (PID).

16. The method according to claim 13, further comprising distributing the multiple partially encrypted television signal over one of a cable system, a terrestrial broadcast 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. A multiple encrypted television signal stored in electronic transmission readable-medium encrypted by the method according to claim 13.

22. A digital television receiver device, comprising:

a receiver receiving a dual partially encrypted television signal, the dual partially encrypted television signal comprising audio packets containing audio data encrypted under a first encryption algorithm and duplicate audio packets containing a duplicate of the audio data encrypted under a second encryption algorithm;

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

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

23. The digital television receiver device according to claim 22, wherein the receiver further receives and discards audio packets encrypted under a second encryption algorithm.

24. A cable system headend, comprising:

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

a second encryption system that encrypts data in duplicates of said audio packets using a second encryption algorithm; and

means for distributing an output stream of packets representing a dual partially encrypted television program over a cable television system, the stream of packets comprising video packets or audio packets encrypted under the first encryption algorithm, and duplicates of said audio packets encrypted under the second encryption algorithm and system information packets.

25. The cable system headend according to claim 24, wherein the video packets are unencrypted.

26. The cable system headend according to claim 24, wherein the system information packets are unencrypted.

27. The cable system headend according to claim 24, wherein the video packets are partially encrypted.

28. The cable system headend according to claim 24, wherein the system information packets are encrypted.

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

receiving a television signal having a multiple encrypted audio portion and a clear video portion, wherein the multiple encrypted audio portion comprises a first encrypted audio portion having audio data encrypted under a first encryption method and a second encrypted duplicate audio portion having a duplicate of said audio data encrypted under a second encryption method;

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 television signal as an output signal.

30. The method according to claim 29, wherein the decoded signal is suitable for play on a television set.

31. The method according to claim 29, wherein the first encrypted audio portion is identified by a first packet identifier (PID) associated with a first decryption algorithm used for decrypting the first encrypted audio portion and the second encrypted audio portion is identified by a second packet identifier (PID) associated with a second decryption algorithm used for decrypting the second encrypted audio portion.

32. The method according to claim 31, wherein the first PID is a secondary PID and wherein the second PID is a primary PID.

33. The method according to claim 31, wherein the first PID is a primary PID and wherein the second PID is a secondary PID.

34. The method according to claim 29, carried out in one of an integrated circuit and a programmable logic device.

35. The method according to claim 29, carried out in one of an application specific integrated circuit and a field programmable gate array.

36. The method according to claim 29, carried out in a television device.

37. The method according to claim 29, carried out in a television set-top box.

38. 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, the second audio portion comprising data that is a duplicate of data contained in the first audio portion when the first and second audio portions are unencrypted;

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 output signal.

39. The method according to claim 38, wherein the decoded signal is suitable for play on a television set.

40. The method according to claim 38, wherein the first PID is a secondary PID and wherein the second PID is a primary PID.

41. The method according to claim 38, wherein the first PID is a primary PID and wherein the second PID is a secondary PID.

42. The method according to claim 38, carried out in an integrated circuit.

43. The method according to claim 38, carried out in one of an application specific integrated circuit and a field programmable gate array.

44. The method according to claim 38, carried out in a television device.

45. The method according to claim 38, carried out in a television set-top box.

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

encrypting data representing a video portion of the television signal according to a first encryption method to produce a first encrypted video portion;

encrypting a duplicate of the data representing said video portion according to a second encryption method to produce a second encrypted video portion;

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

transmitting the encrypted television signal comprising the first and second encrypted video portions and the unencrypted audio portion.

47. The method according to claim 46, wherein the television signal is a digital television signal, and wherein the encrypting comprises encrypting packets identified as video packets.

48. The method according to claim 47, wherein the digital television signal complies with an MPEG standard, and wherein the video packets are identified for encryption by a packet identifier (PID).

49. The method according to claim 47, wherein the digital television signal complies with a digital satellite service (DSS) transport standard, and wherein the video packets are identified for encryption by a service channel identifier (SCID).

50. The method according to claim 47, wherein video packets encrypted according to the first encryption method are assigned a first packet identifier and video packets encrypted according to the second encryption method are assigned a second packet identifier.

51. The method according to claim 50, wherein the first packet identifier and the second packet identifier are referenced as primary elementary packet identifiers (PIDs) in a program map table (PMT).

52. The method according to claim 50, wherein the first packet identifier is referenced as a primary elementary packet identifier (PID) in a program map table (PMT) and the second packet identifier is referenced as a secondary elementary packet identifier (PID) in the program map table (PMT).

53. The method according to claim 50, 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.

54. The method according to claim 53, further comprising distributing system information to provide locating information used to locate the first and second encrypted video portions.

55. The method according to claim 54, further comprising combining encrypted system information with the audio portion and the first and second encrypted video portions.

56. 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 46.

57. An encrypted television signal stored in electronic transmission readable-medium encrypted by the method according to claim 46.

58. A method of multiple encrypting a television signal, comprising:

encrypting data representing a video portion of the television signal according to a first encryption method to produce a first encrypted video portion;

encrypting a duplicate of the data representing said video portion of the television signal according to a second encryption method to produce a second encrypted video portion;

combining the first encrypted video portion and the second encrypted video portion with an unencrypted audio portion of the television signal to produce a multiple partially encrypted television signal; and

transmitting the multiple partially encrypted television signal comprising the first and second encrypted video portions and the unencrypted audio portion.

59. The method according to claim 58, wherein the television signal is a digital television signal, and wherein the multiple encrypting comprises encrypting packets identified as video packets.

60. The method according to claim 59, wherein the digital television signal complies with an MPEG standard, and wherein the video packets are identified for multiple encryption by a packet identifier (PID).

61. The method according to claim 59, further comprising distributing the multiple partially encrypted television signal over one of a cable system, a terrestrial broadcast system and a satellite system.

62. The method according to claim 61, further comprising transmitting system information to provide locating information used to locate the first encrypted video portion.

63. The method according to claim 62, further comprising encrypting the system information.

64. The method according to claim 58, further comprising partially encrypting the unencrypted audio portion of the television signal.

65. 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 58.

66. A multiple encrypted television signal stored in electronic transmission-readable medium encrypted by the method according to claim 58.