Selective encryption to enable multiple decryption keys

• US 20030159140A1
• Filed: 12/13/2002
• Published: 08/21/2003
• Est. Priority Date: 01/02/2002
• 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 7,233,669 B2
• Time in Patent Office: Days
• US Class Current: 725/31
• CPC Class Codes: H04L 9/088 Usage controlling of secret information, e.g. techniques for restricting cryptographic keys to pre-authorized uses, different access levels, validity of crypto-period, different key- or password length, or different strong and weak cryptographic algorithms network architectures or network communication protocols for using time-dependent keys in a packet data network H04L63/068
• CPC Class Codes: H04N 21/23476 by partially encrypting, e.g. encrypting the ending portion of a movie
• 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 21/25875 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 21/4344 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 21/43607 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 21/44055 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

A selective encryption method and apparatus consistent with the invention duplicates selected packets in a file or data stream and multiple encrypts the packets using multiple encryption keys. Each encryption key is valid for a specific segment of time so that changes in entitlement keys used for decryption can be made without negatively impacting a customer'"'"'s ability to access content that has been paid for.

Claims

1. A method of selectively encrypting digital video content, comprising;

receiving a plurality of unencrypted packets containing the digital video content;

selecting certain of the packets of a specified type for encryption according to a selection criterion;

encrypting the selected packets using a first encryption key to produce first encrypted packets;

encrypting the selected packets using a second encryption key to produce second encrypted packets; and

replacing the unencrypted packets of the specified packet type with the first encrypted packets and the second encrypted packets in the digital video signal to produce a partially dual encrypted video signal.

2. The method according to claim 1, wherein the first encryption key is valid for a first time segment and the second encryption key is valid for a subsequent time segment.

3. The method according to claim 1, wherein the first encryption key is valid for a first month and the second encryption key is valid for a subsequent month.

4. The method according to claim 1, wherein the packets encrypted under the first and second encryption keys are identified by first and second program identifiers (PIDs).

5. The method according to claim 4, wherein one of the first and second PIDs also identify the unencrypted packets.

6. The method according to claim 4, further comprising generating user private data that identifies valid time periods for the first and second encryption keys by PIDs.

7. The method according to claim 1, further comprising transmitting the selectively encrypted digital video content to a receiver.

8. The method according to claim 1, wherein The method according to claim 1, further comprising storing the selectively encrypted digital video content on an electronic storage medium.

9. The method according to claim 1, carried out on a programmed processor.

10. A computer readable medium storing instructions that, when executed on a programmed processor, carry out the method of selectively encrypting digital video content according to claim 1.

11. The computer readable medium of claim 10, wherein the medium comprises one of an electronic storage medium and a carrier wave.

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

13. A method of decrypting and decoding selectively encrypted digital video content, comprising:

receiving packets of digital video, certain of the packets being unencrypted and certain of the packets being encrypted, wherein certain of the encrypted packets carry data encrypted under a first encryption key and certain other packets carry information encrypted under a second encryption key;

determining which of the encrypted packets are encrypted under a currently valid encryption key;

decrypting the encrypted packets having the currently valid encryption key; and

decoding the unencrypted and decrypted packets to produce a decoded video signal.

14. The method according to claim 13, wherein the packets encrypted under the first and second encryption keys are identified by first and second program identifiers (PIDs).

15. The method according to claim 14, wherein one of the first and second PIDs also identify the unencrypted packets.

16. The method according to claim 14, wherein the determining comprises reading user private data that identifies valid time periods for the first and second encryption keys by PIDs.

17. The method according to claim 13, wherein the first encryption key is valid for a first time period and the second encryption key is valid for a second time period.

18. The method according to claim 13, wherein the first encryption key is valid for a first month and the second encryption key is valid for a second month.

19. The method according to claim 13, carried out on a programmed processor.

20. A computer readable medium storing instructions that, when executed on a programmed processor, carry out the method of decoding selectively encrypted digital video content according to claim 13.

21. The computer readable medium of claim 20, wherein the medium comprises one of an electronic storage medium and a carrier wave.

22. An electronic transmission medium carrying an encrypted digital video signal encrypted by the method according to claim 13.

23. A selective encryption decoder, for decrypting and decoding selectively encrypted digital video content, comprising:

a demultiplexer that receives packets of digital video, certain of the packets being unencrypted and certain of the packets being encrypted under a first encryption key and certain of the packets being encrypted under a second encryption key;

means for determining which of the first and second encryption keys are currently valid;

a decrypter receiving the encrypted packets having the valid encryption key and decrypting the encrypted packets using a valid decryption key to produce decrypted packets; and

a decoder that decodes the unencrypted and decrypted packets to produce a decoded video signal.

24. The decoder according to claim 23, wherein the packets encrypted under the first and second encryption keys are identified by first and second program identifiers (PIDs).

25. The decoder according to claim 24, wherein one of the first and second PIDs also identify the unencrypted packets.

26. The decoder according to claim 24, wherein the means for determining comprises means for reading user private data that identifies valid time periods for the first and second encryption keys by PIDs.

27. The decoder according to claim 23, wherein the first encryption key is valid for a first time period and the second encryption key is valid for a second time period.

28. The decoder according to claim 23, wherein the first encryption key is valid for a first month and the second encryption key is valid for a second month.

29. The decoder according to claim 23, wherein the selectively encrypted digital video content is stored on an electronic storage medium.

30. The decoder according to claim 23, wherein the selectively encrypted digital video content is received from a content provider.

31. The decoder according to claim 23, wherein the decoder forms a part of a television Set-top box.

32. The decoder according to claim 23, implemented using a programmed processor.

33. A selective encryption encoder, comprising:

a packet identifier that identifies packets of a specified packet type;

a packet duplicator that duplicates the identified packets to produce first and second sets of the identified packets; and

a first encrypter for encrypting the selected packets using a first and second encryption key.

34. The encoder according to claim 33, further comprising a program identifier (PID) mapper, and wherein the PID mapper identifies the packets encrypted under the first and second encryption keys by first and second program identifiers (PIDs).

35. The encoder according to claim 34, wherein one of the first and second PIDs also identify the unencrypted packets.

36. The encoder according to claim 34, further comprising a program specific information inserter that identifies valid time periods for the first and second encryption keys by PIDs.

37. The encoder according to claim 33, wherein the first encryption key is valid for a first time period and the second encryption key is valid for a second time period.

38. The encoder according to claim 33, wherein the first encryption key is valid for a first month and the second encryption key is valid for a second month.

39. The encoder according to claim 33, further comprising an electronic storage medium, and wherein the selectively encrypted digital video content is stored on the electronic storage medium.

40. The encoder according to claim 33, further comprising a transmitter, and wherein the selectively encrypted digital video content is transmitted from the transmitter to a receiver.

41. The encoder according to claim 33, residing at a cable system head end.

42. The encoder according to claim 33, implemented using a programmed processor.

43. A television set-top box, comprising:

a receiver receiving a digital television signal comprising;

a plurality of unencrypted packets; and

a plurality of encrypted packets, the encrypted packets being encrypted under first and second encryption keys;

means for determining which of the first and second keys is valid;

a decrypter that decrypts the encrypted packets using a valid decryption key; and

a decoder that decodes the unencrypted packets and the decrypted packets to produce a signal suitable for play on a television set.

44. The television set-top box according to claim 43, further comprising a demultiplexer, and wherein the demultiplexer identifies the packets encrypted under the first and second encryption keys by first and second program identifiers (PIDs).

45. The television set-top box according to claim 44, wherein the means for determining comprises means for reading user private data that identifies valid time periods for the first and second encryption keys by PIDs.

46. The television set-top box according to claim 43, wherein one of the first and second PIDs also identify the unencrypted packets.

47. The television set-top box according to claim 43, wherein the first encryption key is valid for a first time period and the second encryption key is valid for a second time period.

48. The television set-top box according to claim 43, wherein the first encryption key is valid for a first month and the second key is valid for a second month.

49. A computer readable medium that carries instructions that when executed on a programmed processor to facilitate operation of a video receiver device to decrypt and decode a selectively encoded digital video signal wherein the instructions comprise:

a code segment that controls a demultiplexer that receives packets of digital video, certain of the packets being unencrypted and certain of the packets being encrypted under a first encryption key and certain of the packets being encrypted under a second encryption key;

a code segment that determines which of the first and second keys are valid;

a code segment that controls decryption of the encrypted packets under the valid key to produce decrypted packets; and

a code segment that controls decoding the unencrypted and decrypted packets to produce a decoded video signal.

50. The computer readable medium according to claim 49, further comprising a code segment that controls remapping at least one of the first and second encrypted packets to a program identifier PID so that the unencrypted packets and the decrypted packets have a same PID.

51. The computer readable medium according to claim 49, further comprising a segment of code that generates user private data that identifies valid time periods for the first and second encryption keys by PIDs.

52. The computer readable medium of claim 49, wherein the medium comprises one of an electronic storage medium and a carrier wave.

53. A selectively encrypted digital video signal embodied in a carrier wave, comprising:

a stream of packets of video data, wherein the stream of packets when not encrypted represent a segment of video content;

certain of the packets being unencrypted and certain of the packets being encrypted, wherein certain of the encrypted packets are encrypted using a first encryption key and certain of the packets are encrypted using a second encryption key;

a first segment of code that identifies the unencrypted packets by a first packet identifier (PID);

a second segment of code that identifies the packets encrypted under the first encryption key by the first packet identifier (PID).

a third segment of code that identifies the packets encrypted under the second encryption key by a second packet identifier (PID).

54. The selectively encrypted digital video signal according to claim 53, further comprising a segment of code that identifies valid time periods for the first and second encryption keys by PIDs.