METHOD AND SYSTEM FOR PREVENTING REVOCATION DENIAL OF SERVICE ATTACKS

• US 20110197069A9
• Filed: 05/02/2007
• Published: 08/11/2011
• Est. Priority Date: 01/30/2004
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Rodgers, Stephane, Dellow, Andrew
• Granted Patent: US 9,461,825 B2
• Time in Patent Office: Days
• US Class Current: 713/176
• CPC Class Codes: G06F 21/1014 to tokens
• CPC Class Codes: G06F 21/1076 Revocation
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 2209/605 Copy protection
• CPC Class Codes: H04L 2463/062 applying encryption of the keys cryptographic mechanisms or cryptographic arrangements for key distribution using key encryption key H04L9/0822
• CPC Class Codes: H04L 63/0435 wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 63/1458 Denial of Service
• 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

Abstract

Methods and systems for preventing revocation denial of service attacks are disclosed and may include receiving and decrypting a command for revoking a secure key utilizing a hidden key, and revoking the secure key upon successful verification of a signature. The command may comprise a key ID that is unique to a specific set-top box. A key corresponding to the command for revoking the secure key may be stored in a one-time programmable memory, compared to a reference, and the security key may be revoked based on the comparison. The command for revoking the secure key may be parsed from a transport stream utilizing a hardware parser. The method and system may also comprise generating a command for revoking a secure key. The command may be encrypted and signed utilizing a hidden key and may comprise a key ID that is unique to a specific set-top box.

Claims

1. A method for signal processing in a secure communication system, the method comprising:

receiving a command for revoking a secure key;

decrypting said command for revoking said secure key utilizing a hidden key;

verifying a signature of said decrypted command for revoking said secure key; and

revoking said secure key upon successful verification of said signature.

2. The method according to claim 1, wherein said secure key is encrypted.

3. The method according to claim 1, wherein said secure key is signed.

4. The method according to claim 1, wherein said command for revoking said secure key comprises a key ID that is unique to a specific set-top box.

5. The method according to claim 1, wherein said secure key is encrypted using an encryption key that is unique to a specific set-top box.

6. The method according to claim 1, comprising storing a revocation key corresponding to said command for revoking said secure key in a one-time programmable memory.

7. The method according to claim 6, comprising comparing said stored revocation key with a reference.

8. The method according to claim 7, comprising revoking said secure key based on said comparison.

9. The method according to claim 7, wherein said reference is stored in said one-time programmable memory.

10. The method according to claim 1, comprising parsing said command for revoking said secure key from a transport stream.

11. The method according to claim 1, comprising parsing via hardware said command for revoking said secure key from said transport stream.

12. A method for signal processing in a secure communication system, the method comprising:

generating a command for revoking a secure key;

encrypting said generated command for revoking said secure key utilizing a hidden key;

signing said encrypted generated command for revoking said secure key.

13. The method according to claim 12, wherein said generated command for revoking said secure key comprises a key ID that is unique to a specific set-top box.

14. The method according to claim 12, wherein said secure key is encrypted using an encryption key that is unique to a specific set-top box.

15. A system for signal processing in a secure communication system, the system comprising:

one or more circuits for receiving a command that revokes a secure key;

said one or more circuits decrypts said command for revoking said secure key utilizing a hidden key;

said one or more circuits verifies a signature of said decrypted command for revoking said secure key; and

said one or more circuits revokes said secure key upon successful verification of said signature.

16. The system according to claim 15, wherein said secure key is encrypted.

17. The system according to claim 15, wherein said secure key is signed.

18. The system according to claim 15, wherein said command for revoking said secure key comprises a key ID that is unique to a specific set-top box.

19. The system according to claim 15, wherein said secure key is encrypted using an encryption key that is unique to a specific set-top box.

20. The system according to claim 15, wherein said one or more circuits stores a revocation key corresponding to said command for revoking said secure key in a one-time programmable memory.

21. The system according to claim 20, wherein said one or more circuits compares said stored revocation key with a reference.

22. The system according to claim 21, wherein said one or more circuits revokes said secure key based on said comparison.

23. The system according to claim 21, wherein said reference is stored in said one-time programmable memory.

24. The system according to claim 15, wherein said one or more circuits parses said command for revoking said secure key from a transport stream.

25. The system according to claim 15, wherein said one or more circuits parses via hardware, said command for revoking said secure key from said transport stream.

26. A system for signal processing in a secure communication system, the system comprising:

one or more circuits that generates a command for revoking a secure key;

said one or more circuits encrypts said command for revoking said secure key utilizing a hidden key; and

said one or more circuits signs said encrypted generated command for revoking said secure key.

27. The system according to claim 26, wherein said generated command for revoking said secure key comprises a key ID that is unique to a specific set-top box.

28. The system according to claim 26, wherein said secure key is encrypted using an encryption key that is unique to a specific set-top box.