Method and apparatus for supporting broadcast efficiency and security enhancements

• US 20070286422A1
• Filed: 05/26/2006
• Published: 12/13/2007
• Est. Priority Date: 05/26/2006
• Status: Active Grant

• Current Assignee: Rambus Inc.
• Original Assignee: Syphermedia International, Inc. (Verimatrix SA)
• Inventors: Cocchi, Ronald P., McKee-Clabaugh, Frances C.
• Granted Patent: US 7,970,138 B2
• Time in Patent Office: Days
• US Class Current: 380/239
• 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 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 method and apparatus for providing conditional access to media programs is described. An exemplary method comprising the steps of transmitting media information encrypted according to a control word (CW) to a receiver station, transmitting entitlement management information (EMI) to the receiver station, the EMI comprising a service bitmap, and transmitting entitlement control information (ECI) to the receiver station, the entitlement control information including the control word (CW) encrypted according to a key (K) and an index to an element of the service bitmap, wherein the control word (CW) is decrypted by the receiver stations according to a value of the indexed element of the service bitmap.

Claims

1. A method for providing conditional access to media programs, comprising the steps of:

transmitting media information encrypted according to a control word (CW) to a receiver station;

transmitting entitlement management information (EMI) to the receiver station, the EMI comprising a service bitmap; and

transmitting entitlement control information (ECI) to the receiver station, the entitlement control information including the control word (CW) encrypted according to a key (K) and an index to an element of the service bitmap;

wherein the control word (CW) is decrypted by the receiver station according to a value of the indexed element of the service bitmap.

2. The method of claim 1, wherein the media information, the EMI and the ECI are transmitted in a single time division multiple access (TDMA) data stream.

3. The method of claim 1, wherein the service bitmap comprises an array of elements, each element of the array of elements associated with at least one media service and comprising a bit.

4. The method of claim 1, wherein the service bitmap comprises an array of elements, each element of the array of elements associated with at least one media program and comprising a bit.

5. The method of claim 1, wherein:

the EMI further comprises an expiration and the EMI is signed according to a signature transmitted with the EMI.

6. The method of claim 1, wherein:

the entitlement management information (EMI) is transmitted in an entitlement management message (EMM); and

the entitlement control information (ECI) is transmitted in an entitlement control message (ECM).

7. The method of claim 1, wherein the ECM further comprises access condition information and the access control information and the control word (CW) are together encrypted according to the key (K).

8. The method of claim 1, wherein the key (K) is derived at least in part from the service bitmap.

9. The method of claim 8, wherein the key (K) transmitted with the ECI is derived at least in part from the service bitmap, and the receiver station regenerates the key (K) using the service bitmap transmitted with the EMI.

10. The method of claim 1, further comprising the step of

generating a processed second key (K2′

) from a second key (K2), the service bitmap, and the key (K);

transmitting the processed second key (K2′

) to the receiver station; and

wherein the receiver station regenerates the control word (CW) using the service bitmap and the processed second key (K2′

).

11. The method of claim 10, wherein the receiver station regenerates the control word (CW) using the service bitmap and the processed second key (K2′

) by performing steps comprising the steps of;

regenerating the key (K) and the second key (K2) from the processed second key (K2′

) and the service bitmap;

the receiver station regenerates the control word (CW) from the regenerated key (K) and the regenerated second key (K2).

12. The method of claim 11, wherein the receiver station regenerates the control word (CW) using the regenerated key (K) and the regenerated second key (K2) by performing steps comprising:

regenerating the key (K) and the second key (K2);

combining the regenerated key (K) and the regenerated second key (K2) to produce the control word (CW).

13. The method of claim 11, wherein the control word (CW) is encrypted according to an intermediate key (K_I) generated from the key (K) and the second key (K2);

and wherein the receiver station regenerates the control word (CW) using the regenerated key (K) and the regenerated second key (K2) by performing steps comprising;

combining the regenerated key (K) and the regenerated second key (K2) to regenerate the intermediate key (K_I); and

decrypting the encrypted control word (CW) using the regenerated intermediate key (K_I).

14. The method of claim 11, wherein

the receiver station regenerates the control word (CW) using the key (K) and the second key (K2) by performing steps comprising:

regenerating the key (K) and the second key (K2);

combining the key (K) and the second key (K2) to produce a first control value (CV1); and

combining the first control value (CV1) and a second control value (CV2) to generate the control word (CW);

wherein the second control value (CV2) is generated as a combination of the control word (CW) and a combination of the key (K) and the second key (K2) before transmission to the receiver station.

15. An apparatus for providing conditional access to media programs, comprising:

means for transmitting media information encrypted according to a control word (CW) to a receiver station;

means for transmitting entitlement management information (EMI) to the receiver station, the EMI comprising a service bitmap; and

means for transmitting entitlement control information (ECI) to the receiver station, the entitlement control information including the control word (CW) encrypted according to a key (K) and an index to an element of the service bitmap;

wherein the control word (CW) is decrypted by the receiver station according to a value of the indexed element of the service bitmap.

16. The apparatus of claim 15, wherein the media information, the EMI and the ECI are transmitted in a single time division multiple access (TDMA) data stream.

17. The apparatus of claim 15, wherein the service bitmap comprises an array of elements, each element of the array of elements associated with at least one media service and comprising a bit.

18. The apparatus of claim 15, wherein the service bitmap comprises an array of elements, each element of the array of elements associated with at least one media program and comprising a bit.

19. The apparatus of claim 15, wherein:

the EMI further comprises an expiration and the EMI is signed according to a signature transmitted with the EMI.

20. The apparatus of claim 15, wherein:

the entitlement management information (EMI) is transmitted in an entitlement management message (EMM); and

the entitlement control information (ECI) is transmitted in an entitlement control message (ECM).

21. The apparatus of claim 15, wherein the ECM further comprises access condition information and the access control information and the control word (CW) are together encrypted according to the key (K).

22. The apparatus of claim 15, wherein the key (K) is derived at least in part from the service bitmap.

23. The apparatus of claim 22, wherein the key (K) transmitted with the ECI is derived at least in part from the service bitmap, and the receiver station regenerates the key (K) using the service bitmap transmitted with the EMI.

24. The apparatus of claim 15, further comprising the step of

means for generating a processed second key (K2) from a second key (K2), the service bitmap, and the key (K);

and

means for transmitting the processed second key (K2′

) to the receiver station;

wherein the receiver station regenerates the key (K) using the service bitmap and the processed second key (K2′

).

25. The apparatus of claim 24, wherein:

the receiver station regenerates the key (K) and the second key (K2) from the processed second key (K2′

) and the service bitmap; and

the receiver station regenerates the control word (CW) from the regenerated key (K) and the regenerated second key (K2).

26. The apparatus of claim 25, wherein the receiver station regenerates the control word (CW) using the regenerated key (K) and the regenerated second key (K2) by regenerating the key (K) and the second key (K2) and combining the regenerated key (K) and the regenerated second key (K2) to produce the regenerated control word (CW).

27. The apparatus of claim 25, wherein:

the control word (CW) is encrypted by an intermediate key (K_I); and

the receiver station regenerates the control word (CW) using the regenerated key (K) and the regenerated second key (K2) by regenerating the key (K) and the second key (K2), combining the regenerated key (K) and the regenerated second key (K2) to regenerate the intermediate key (K_I), and decrypting the encrypted control word using the regenerated intermediate key (K_I).

28. The apparatus of claim 25, wherein:

the receiver station regenerates the control word (CW) using the regenerated key (K) and the second key (K2) by regenerating the key (K) and the second key (K2), combining the key (K) and the second key (K2) to produce a first control value (CV1), and combining the first control value (CV1) and a second control value (CV2) to generate the control word (CW); and

wherein the second control value (CV2) is generated as a combination of the control word (CW) and a combination of the key (K) and the second key (K2) before transmission to the receiver station.

29. An apparatus for providing conditional access to media programs, comprising:

a first encryptor for encrypting media information according to a control word (CW);

a second encryptor for encrypting the control word according to a key (K);

a processor for generating entitlement management information (EMI), including a service bitmap and for generating entitlement control information (ECI) including the encrypted control word (CW) and an index to an element of the service bitmap; and

a transmitter for transmitting the entitlement management information (EMI) in a first message and for transmitting the entitlement control information (ECI) in a second message; and

wherein the control word (CW) is decrypted by the receiver station according to a value of the indexed element of the service bitmap.

30. The apparatus of claim 29, the EMI and the ECI are transmitted in a single time division multiple access (TDMA) data stream.

31. The apparatus of claim 29, wherein the service bitmap comprises an array of elements, each element of the array of elements associated with at least one media service and comprising a bit.

32. The apparatus of claim 29, wherein the service bitmap comprises an array of elements, each element of the array of elements associated with at least one media program and comprising a bit.

33. The apparatus of claim 29, wherein:

the EMI further comprises an expiration and the EMI is signed according to a signature transmitted with the EMI.

34. The apparatus of claim 29, wherein:

the entitlement management information (EMI) is transmitted in an entitlement management message (EMM); and

the entitlement control information (ECI) is transmitted in an entitlement control message (ECM).

35. The apparatus of claim 29, wherein the ECM further comprises access condition information and the access control information and the control word (CW) are together encrypted according to the key (K).

36. The apparatus of claim 29, wherein the key (K) is derived at least in part from the service bitmap.

37. The apparatus of claim 36, wherein the key (K) transmitted with the ECI is derived at least in part from the service bitmap, and the receiver station regenerates the key (K) using the service bitmap transmitted with the EMI.

38. The apparatus of claim 29, further comprising:

a key generator for generating a processed second key (K2′

) from a second key (K2), the service bitmap, and the key (K;

)

a transmitter for transmitting the service map and the processed second key (K2′

) to the receiver station; and

wherein the receiver station regenerates the key (K) using the service bitmap and the processed second key (K2′

).

39. The apparatus of claim 29, wherein:

the receiver station regenerates the key (K) and the second key (K2) from the processed second key (K2′

) and the service bitmap; and

the receiver station regenerates the control word (CW) from the regenerated key (K) and the regenerated second key (K2).

40. The apparatus of claim 29, wherein the receiver station regenerates the control word (CW) using the regenerated key (K) and the regenerated second key (K2) by regenerating the key (K) and the second key (K2) and combining the regenerated key (K) and the regenerated second key (K2) to produce the control word (CW).

41. The apparatus of claim 39, wherein:

the control word (CW) is encrypted by an intermediate key (K_I); and

the receiver station regenerates the control word (CW) using the regenerated key (K) and the regenerated second key (K2) by regenerating the key (K) and the second key (K2), combining the regenerated key (K) and the second key (K2) to regenerate the intermediate key (K_I), and decrypting the encrypted control word using the regenerated intermediate key (K_I).

42. The apparatus of claim 39, wherein:

the receiver station regenerates the control word (CW) using the regenerated key (K) and the regenerated second key (K2) by regenerating the key (K) and the second key (K2), combining the regenerated key (K) and the regenerated second key (K2) to produce a first control value (CV1), and combining the first control value (CV1) and a second control value (CV2) to generate the control word (CW); and

wherein the second control value (CV2) is generated as a combination of the control word (CW) and a combination of the key (K) and the second key (K2) before transmission to the receiver station.

43. A method for providing conditional access to media programs, comprising the steps of:

transmitting media information encrypted according to a control word (CW) to a receiver station;

transmitting entitlement management information (EMI) to the receiver station, the EMI comprising a service bitmap; and

transmitting entitlement control information (ECI) to the receiver station, the entitlement control information including an index to an element of the service bitmap;

wherein the receiver station regenerates the control word (CW) according to a value of the indexed element of the service bitmap.

44. The method of claim 43, wherein the control word (CW) is regenerated at least in part from the service bitmap.

45. The method of claim 44, wherein the ECI is derived at least in part from the service bitmap, and the receiver station regenerates the control word (CW) using the service bitmap transmitted with the EMI.

46. The method of claim 43, wherein a processed second key (K2′

) is generated from a second key (K2), the service bitmap, and the key (K) before transmission to the receiver station, and the method further comprises the step of regenerating the key (K) using the service bitmap and the processed second key (K2′

).

47. The method of claim 46, further comprising the steps of:

regenerating the key (K) and the second key (K2) from the processed second key (K2′

) and the service bitmap; and

regenerating the control word (CW) from the regenerated key (K) and the regenerated second key (K2).

48. The method of claim 47, wherein the step of regenerating the control word (CW) using the regenerated key (K) and the regenerated second key (K2) comprises the steps of:

combining the regenerated key (K) and the second key (K2) to produce the control word (CW).

49. The method of claim 47, wherein the control word (CW) is encrypted according to an intermediate key (K_I) generated from the key (K) and the second key (K2);

and wherein the step of regenerating the control word (CW) using the regenerated key (K) and the regenerated second key (K2) comprises the steps of;

combining the regenerated key (K) and the regenerated second key (K2) to produce the regenerated intermediate key (K_I); and

decrypting the encrypted control word (CW) using the regenerated intermediate key (K).

50. The method of claim 47, wherein

the step of regenerating the control word (CW) using the key (K) and the second key (K2) comprises the steps of:

regenerating the key (K) and the second key (K2);

combining the key (K) and the second key (K2) to produce a first control value (CV1);

adn

combining the first control value (CV1) and a second control value (CV2) to generate the control word (CW);

wherein the second control value (CV2) is generated as a combination of the control word (CW) and a combination of the key (K) and the second key (K2) before transmission to the receiver station.

51. An apparatus for providing conditional access to media programs, comprising:

means for transmitting media information encrypted according to a control word (CW) to a receiver station;

means for transmitting entitlement management information (EMI) to the receiver station, the EMI comprising a service bitmap; and

means for transmitting entitlement control information (ECI) to the receiver station, the entitlement control information including an index to an element of the service bitmap;

wherein the receiver station regenerates the control word (CW) according to a value of the indexed element of the service bitmap.

52. The apparatus of claim 51, wherein the control word (CW) is regenerated at least in part from the service bitmap.

53. The apparatus of claim 52, wherein the ECI is derived at least in part from the service bitmap, and the receiver station regenerates the control word (CW) using the service bitmap transmitted with the EMI.

54. The apparatus of claim 51, wherein a processed second key (K2) is generated from a second key (K2), the service bitmap, and the key (K) before transmission to the receiver station, and the apparatus further comprises means for regenerating the key (K) using the service bitmap and the processed second key (K2′

).

55. The apparatus of claim 51, further comprising:

means for regenerating the key (K) and the second key (K2) from the processed second key (K2′

) and the service bitmap; and

means for regenerating the control word (CW) from the regenerated key (K) and the regenerated second key (K2).

56. The apparatus of claim 55, wherein the means for regenerating the control word (CW) using the regenerated key (K) and the regenerated second key (K2) comprises:

means for combining the key (K) and the second key (K2) to produce the control word (CW).

57. The apparatus of claim 55, wherein:

the control word (CW) is encrypted according to an intermediate key (K_I) generated from the key (K) and the second key (K2); and

wherein the means for regenerating the control word (CW) using the regenerated key (K) and the regenerated second key (K2) comprises;

means for combining the regenerated key (K) and the regenerated second key (K2) to produce the regenerated intermediate key (K_I); and

means for decrypting the encrypted control word (CW) using the regenerated intermediate key (K_I).

58. The apparatus of claim 55, wherein:

the means for regenerating the control word (CW) using the key (K) and the second key (K2) comprises;

means for regenerating the key (K) and the second key (K2);

means for combining the key (K) and the second key (K2) to produce a first control value (CV1);

means for combining the first control value (CV1) and a second control value (CV2) to generate the control word (CW); and

wherein the second control value (CV2) is generated as a combination of the control word (CW) and a combination of the key (K) and the second key (K2) before transmission to the receiver station.

59. An apparatus for providing conditional access to media programs, comprising:

a first encryptor for encrypting media information according to a control word (CW);

processor for generating entitlement management information (EMI), including a service bitmap and for generating entitlement control information (ECI) including an index to an element of the service bitmap; and

a transmitter for transmitting the entitlement management information (EMI) in a first message and for transmitting the entitlement control information (ECI) in a second message;

wherein the control word (CW) is decrypted by the receiver station according to a value of the indexed element of the service bitmap.

60. The apparatus of claim 59, wherein the control word (CW) is regenerated at least in part from the service bitmap.

61. The apparatus of claim 60, wherein the ECI is derived at least in part from the service bitmap, and the receiver station regenerates the control word (CW) using the service bitmap transmitted with the EMI.