Authentication of data transmitted in a digital transmission system

• US 20040125959A1
• Filed: 04/16/2003
• Published: 07/01/2004
• Est. Priority Date: 04/03/2000
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Poulain, Philippe, Beuque, Jean-Bernard Gerard Maurice
• Granted Patent: US 7,437,561 B2
• Time in Patent Office: Days
• US Class Current: 380/279
• CPC Class Codes: H04L 2209/601 Broadcast encryption
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/3268 using certificate validation, registration, distribution or revocation, e.g. certificate revocation list [CRL]
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/235 Processing of additional data, e.g. scrambling of additional data or processing content descriptors
• CPC Class Codes: H04N 21/2362 Generation or processing of Service Information [SI]
• CPC Class Codes: H04N 21/2541 Rights Management protecting software against unauthorised usage in a vending or licensing environment G06F21/10; security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/26613 for generating or managing keys in general key distribution for secret or secure communication involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP] H04L9/083; network support of key management H04L63/06; key management for network security in communication control or processing H04W12/04
• 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 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/63345 by transmitting keys key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 21/6433 Digital Storage Media - Command and Control Protocol [DSM-CC]
• 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 7/1675 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 of authenticating data transmitted in a digital transmission system, in which the method comprises the steps, prior to transmission, of determining at least two encrypted values for at least some of the data, each encrypted value being determined using a key of a respective encryption algorithm, and outputting said at least two encrypted values with said data.

Claims

1. A method of authenticating data transmitted in a digital transmission system, said method comprising the steps, prior to transmission, of:

determining at least two encrypted values for at least some of the data, each encrypted value being determined for the same data using a key of a respective encryption algorithm; and

outputting said at least two encrypted values with said data.

2. A method according to claim 1, wherein said data comprises a key.

3. A method according to claim 2, wherein said data comprises at least one digital certificate containing a public key of an encryption algorithm for processing data.

4. A method according to claim 3, wherein said data comprises at least one digital root certificate containing a public key of an encryption algorithm for processing data.

5. A method according to claim 3 or claim 4, wherein said at least one digital certificate comprises a digital signature calculated using a private key of the encryption algorithm of the public key contained in that certificate.

6. A method according to any preceding claim, wherein said data comprises an identifier of a revoked public key.

7. A method according to claim 6, wherein said identifier comprises an identifier of a digital certificate containing said revoked public key.

8. A method according to claim 7, wherein said identifier comprises an identifier of a digital root certificate containing said revoked public key.

9. A method according to any of claims 6 to 8, wherein said data comprises a plurality of said identifiers, each identifier identifying a respective revoked public key.

10. A method according to any preceding claim, wherein each algorithm is asymmetric.

11. A method according to any preceding claim, wherein each encrypted value corresponds to a digital signature calculated using a private key of a respective encryption algorithm, each signature being processable using a public key of said encryption algorithm.

12. A method according to claim 11, comprising the step of outputting, with each signature, an identifier of the public key to be used to process that signature.

13. A method according to any preceding claim, wherein the data and encrypted values are output for transmission to a receiver/decoder.

14. A method according to any preceding claim, wherein said data and said encrypted values are received by a receiver/decoder, wherein each encrypted value is processed using a key of said respective encryption algorithm, and each subsequently resulting value is compared with said at least some of the data to authenticate said at least some of the data.

16. A method according to claim 14 or claim 15, wherein said received data is rejected if at least one of the subsequently resulting values is different from said at least some of the data.

17. A method according to any preceding claim, wherein said data and said at least two encrypted values are organised in a data file.

18. A method according to claim 17, wherein said data file comprises an indication of the minimum number of encrypted values to be stored with said data in the subsequently generated data file.

19. A method according to claim 18, wherein said data file is received by a receiver/decoder, wherein the number of encrypted values stored in said data file is compared with said minimum number, and said data file is rejected if the number of encrypted values stored in said data file is less than said minimum number.

20. A method according to any of claims 17 to 19, wherein said data file is output in a data module.

21. A method according to claim 20, wherein a module encrypted value for at least some of the data in said module is calculated using a key of a transmitter encryption algorithm and output in said data module.

22. A method according to claim 21, wherein said data module is received by a receiver/decoder, wherein said module encrypted value is processed using a key of a transmitter encryption algorithm, and the subsequently resulting value is compared with said at least some of the data in said module to authenticate said at least some of the data in said module.

23. A method according to any of claims 20 to 22, wherein said encrypted value for at least some of the data in said module corresponds to a digital signature calculated using a private key of a transmitter encryption algorithm and processable using a public key of said transmitter encryption algorithm.

24. A method according to any preceding claim, wherein said digital transmission system is a digital broadcast system.

15. A method of authenticating data transmitted in a digital transmission system, said method comprising the steps of:

receiving said data and at least two encrypted values determined for at least some of the data, each encrypted value being determined using a key of a respective encryption algorithm;

storing a plurality of keys;

processing each encrypted value using a stored key of said respective encryption algorithm; and

comparing each subsequently resulting value with said at least some of the data to authenticate said at least some of the data.

25. Apparatus for authenticating data to be transmitted in a digital transmission system, said apparatus comprising:

means for determining at least two encrypted values for at least some of the data, each encrypted value being determined for the same data using a key of a respective encryption algorithm; and

means for outputting said at least two encrypted values with said data.

26. Apparatus according to claim 25, wherein said data comprises a key.

27. Apparatus according to claim 26, wherein said data comprises at least one digital certificate containing a public key of an encryption algorithm for processing data.

28. Apparatus according to claim 27, wherein said data comprises at least one digital root certificate containing a public key of an encryption algorithm for processing data.

29. Apparatus according to claim 27 or claim 28, wherein said at least one digital certificate comprises a digital signature calculated using a private key of the encryption algorithm of the public key contained in that certificate.

30. Apparatus according to any of claims 25 to 29, wherein said data comprises an identifier of a revoked public key.

31. Apparatus according to claim 30, wherein said identifier comprises an identifier of a digital certificate containing said revoked public key.

32. Apparatus according to claim 31, wherein said identifier comprises an identifier of a digital root certificate containing said revoked public key.

33. Apparatus according to any of claims 30 to 32, wherein said data comprises a plurality of said identifiers, each identifier identifying a respective revoked public key.

34. Apparatus according to any of claims 25 to 33, wherein each algorithm is asymmetric.

35. Apparatus according to claim 34, wherein each encrypted value corresponds to a digital signature calculated using a private key of a respective encryption algorithm, each signature being processable using a public key of said encryption algorithm.

36. Apparatus according to claim 35, wherein said output means is adapted to output, with each signature, an identifier of the public key to be used to process that signature.

37. Apparatus according to any of claims 25 to 36, comprising means for organising said data and said at least two encrypted values in a data file.

38. Apparatus according to claim 37, wherein said data file comprises an indication of the minimum number of encrypted values to be output with said data in the subsequently generated data file.

39. A system for authenticating data transmitted in a digital transmission system, said system comprising apparatus as claimed in any of claims 25 to 38.

40. A system as claimed in claim 39, further comprising a receiver/decoder comprising means for receiving said data and said encrypted values, means for processing each encrypted value using a key of said respective encryption algorithm, and means for comparing each subsequently resulting value with said at least some of the data to authenticate said at least some of the data.

47. A system for authenticating data transmitted in a digital transmission system, said system comprising apparatus as claimed in any of claims 25 to 38 and a receiver/decoder as claimed in any of claims 41 to 46.

41. A receiver/decoder comprising:

means for receiving a data file comprising data and at least two encrypted values determined for at least some of the data, each encrypted value being determined using a key of a respective encryption algorithm;

means for storing a plurality of keys;

means for processing each encrypted value using a stored key of said respective encryption algorithm; and

means for comparing each subsequently resulting value with said at least some of the data to authenticate said at least some of the data.

42. A receiver/decoder according to claim 41, comprising means for rejecting said data file if at least one of the subsequently resulting values is different from said at least some of the data.

43. A receiver/decoder according to claim 41 or claim 42, wherein each encrypted value corresponds to a digital signature calculated using a private key of a respective encryption algorithm, said processing means being adapted to process each signature using a stored public key of said encryption algorithm.

44. A receiver/decoder according to claim 43, wherein each stored public key is contained in a respective digital certificate stored in said storage means.

45. A receiver/decoder according to claim 44, wherein said processing means is adapted to process each signature value using a public key contained in a stored digital certificate identified by an identifier transmitted with that signature value.

46. A receiver/decoder according to any of claims 41 to 45, comprising means for revoking a stored key according to an identifier of that stored key contained within said data.

48. A signal comprising data and at least two encrypted values determined for at least some of the data, each encrypted value being determined for the same data using a key of a respective encryption algorithm.

49. A method of authenticating data substantially as herein described with reference to the accompanying drawings.

50. Apparatus for authenticating data substantially as herein described with reference to the accompanying drawings.

51. A receiver/decoder substantially as herein described with reference to the accompanying drawings.

52. A system for authenticating data substantially as herein described.

53. A signal substantially as herein described with reference to the accompanying drawings.