Tamper resistant player for scrambled contents

• US 6,175,925 B1
• Filed: 09/05/1997
• Issued: 01/16/2001
• Est. Priority Date: 06/13/1996
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Graunke, Gary L., Aucsmith, David W., Nardone, Joseph M., Shippy, Keith L., Mangold, Richard P., Maliszewski, Richard L., Pfotenhauer, Jody L.
• Primary Examiner(s): Beausoliel, Jr., Robert W.
• Assistant Examiner(s): Baderman, Scott T.
• Application Number:
  US08/924,167
• Time in Patent Office: 1,229 Days
• Field of Search: 713/200, 713/201, 713/202, 713/189, 713/190-193, 711/164, 380/3, 380/4, 380/9, 380/21, 380/23, 380/25, 380/194-268
• US Class Current: 726/22
• CPC Class Codes: G06F 12/1408 by using cryptography for digital transmission H04L9/00
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/14 against software analysis or reverse engineering, e.g. by obfuscation
• CPC Class Codes: G06F 21/52 during program execution, e.g. stack integrity ; Preventing unwanted data erasure; Buffer overflow
• CPC Class Codes: G06F 21/57 Certifying or maintaining trusted computer platforms, e.g. secure boots or power-downs, version controls, system software checks, secure updates or assessing vulnerabilities
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: G06F 2221/2135 Metering
• CPC Class Codes: G06F 2221/2151 Time stamp
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00

Abstract

In one apparatus, a group of plain text and obfuscated cells of programming instructions is provided to implement a descrambler that descrambles scrambled content to generate descrambled content. In another apparatus, a group of plain text and obfuscated cells of programming instructions is provided to implement an authenticator that provides appropriate authentication challenges to a scrambled content provider, and generates appropriate authentication responses to authentication challenges from the scrambled content provider. In yet another apparatus, a group of plain text and obfuscated cells of programming instructions is provided to implement an integrity verifier that performs integrity verification on a decoder. In yet another apparatus, a group of plain text and obfuscated cells of programming instructions is provided to implement a secrets holder that holds a number of secrets associated with playing scrambled contents.

Claims

1. An apparatus comprising:

a storage medium having stored therein a first group of plain text and obfuscated cells of programming instructions designed to implement a descrambler that descrambles scrambled content to generate descrambled content, wherein the obfuscated cells are mutated through an inter-cell dependent mutation process; and

an execution unit coupled to the storage medium for executing the programming instructions.

2. The apparatus as set forth in claim 1, wherein the first group of plain text and obfuscated cells of programming instructions include an obfuscated cell of programming instructions designed to implement a frequently invoked descrambling subfunction of the descrambler.

3. The apparatus as set forth in claim 1, wherein the first group of plain text and obfuscated cells of programming instructions is equipped to verify that an invocation of the descrambler is not originated from an intruder, and/or execution of the first group of plain text and obfuscated cells of programming instructions is not being observed.

4. The apparatus as set forth in claim 1, wherein the storage medium further having stored therein a second group of plain text and obfuscated cells of programming instructions designed to implement an authenticator that provides appropriate authentication challenges to a scrambled content provider device, and generates appropriate authentication responses to authentication challenges from the scrambled content provider device.

5. The apparatus as set forth in claim 4, wherein the second group of plain text and obfuscated cells of programming instructions is equipped to verify that execution of the second group of plain text and obfuscated cells of programming instructions is not being observed.

6. The apparatus as set forth in claim 1, wherein the storage medium further having stored therein a second group of plain text and obfuscated cells of programming instructions designed to implement a secrets holder that holds a plurality of secrets associated with playing the scrambled contents.

7. The apparatus as set forth in claim 6, wherein the second group of plain text and obfuscated cells of programming instructions is equipped to verify that execution of the second group of plain text and obfuscated cells of programming instructions is not being observed.

8. The apparatus as set forth in claim 1, wherein the storage medium further having stored therein a plurality of plain text programming instructions designed to decode the descrambled content, the plurality of plain text programming instructions having a structural relationship with the descrambler that facilitates exclusive communication of the descrambled content from the descrambler.

9. The apparatus as set forth in claim 8, wherein the storage medium further having stored therein a second group of plain text and obfuscated cells of programming instructions designed to implement an integrity verifier that performs integrity verification on the plurality of plain text programming instructions.

10. The apparatus as set forth in claim 9, wherein the integrity verifier is designed to perform the integrity verification on the plurality of plain text programming instructions at start-up time, and/or incrementally at run time.

11. The apparatus as set forth in claim 9, wherein the second group of plain text and obfuscated cells of programming instructions is equipped to verify that execution of the second group of plain text and obfuscated cells of programming instructions is not being observed.

12. An apparatus comprising:

a storage medium having stored therein a plurality of plain text programming instructions designed to decode descrambled content, and a first group of plain text and obfuscated cells of programming instructions designed to implement an integrity verifier that performs integrity verification on the plurality of plain text programming instructions, wherein the obfuscated cells are mutated through an inter-cell dependent mutation process; and

an execution unit coupled to the storage medium for executing the programming instructions.

13. The apparatus as set forth in claim 12, wherein the integrity verifier is designed to perform the integrity verification on the plain text programming instructions at start-up time, and/or incrementally at run time.

14. The apparatus as set forth in claim 12, wherein the storage medium further having stored therein a second group of plain text and obfuscated cells of programming instructions designed to implement an authenticator that provides appropriate authentication challenges to a scrambled content provider device, and generates appropriate authentication responses to authentication challenges from the scrambled content provider device.

15. The apparatus as set forth in claim 14, wherein the second group of plain text and obfuscated cells of programming instructions is equipped to verify that execution of the second group of plain text and obfuscated cells of programming instructions is not being observed.

16. The apparatus as set forth in claim 12, wherein the storage medium further having stored therein a second group of plain text and obfuscated cells of programming instructions designed to implement a secrets holder that holds a plurality of secrets associated with playing the scrambled contents.

17. The apparatus as set forth in claim 16, wherein the second group of plain text and obfuscated cells of programming instructions is equipped to verify that execution of the second group of plain text and obfuscated cells of programming instructions is not being observed.

18. An apparatus comprising:

a storage medium having stored therein a first group of plain text and obfuscated cells of programming instructions designed to implement a secrets holder that holds a plurality of secrets associated with playing scrambled contents, wherein the obfuscated cells are mutated through an inter-cell dependent mutation process; and

an execution unit coupled to the storage medium for executing the programming instructions.

19. The apparatus as set forth in claim 18, wherein the first group of plain text and obfuscated cells of programming instructions is equipped to verify that execution of the first group of plain text and obfuscated cells of programming instructions is not being observed.

20. The apparatus as set forth in claim 19, wherein the storage medium further having stored therein a second group of plain text and obfuscated cells of programming instructions that implement an authenticator that provides appropriate authentication challenges to a scrambled content provider device, and generates appropriate authentication responses to authentication challenges from the scrambled content provider device.

21. The apparatus as set forth in claim 20, wherein the second group of plain text and obfuscated cells of programming instructions is equipped to verify that execution of the second group of plain text and obfuscated cells of programming instructions is not being observed.

22. An apparatus comprising:

a storage medium having stored therein a first group of plain text and obfuscated cells of programming instructions designed to implement an authenticator that provides appropriate authentication challenges to a scrambled content provider device, and generates appropriate authentication responses to authentication challenges from the scrambled content provider device, wherein the obfuscated cells are mutated through an inter-cell dependent mutation process; and

an execution unit coupled to the storage medium for executing the programming instructions.

23. The apparatus as set forth in claim 22, wherein the second group of plain text and obfuscated cells of programming instructions is equipped to verify that execution of the second group of plain text and obfuscated cells of programming instructions is not being observed.

24. A method comprising:

a) executing a first group of plain text and obfuscated cells of programming instructions to perform integrity verification on a plurality of plain text programming instructions designed to decode descrambled content; and

b) executing a second group of plain text and obfuscated cells of programming instructions to store a plurality of secrets associated with descrambling scrambled content if integrity of the plurality of plain text programming instructions is verified in (a).

25. The method of claim 24, wherein each of (a) and (b) includes determining if execution of the first/second group of plain text and obfuscated cells of programming instructions is being observed.

26. The method of claim 24, wherein the method further comprises (c) executing a third group of plain text and obfuscated cells of programming instructions to provide appropriate authentication challenges to a scrambled content provider device, and to provide appropriate responses to authentication challenges of the scrambled content provider device.

27. The method of claim 26, wherein each of (a), (b) and (c) includes determining if execution of the first/second/third group of plain text and obfuscated cells of programming instructions is being observed.

28. The method of claim 24, wherein the method further comprises (d) executing a fourth group of plain text and obfuscated cells of programming instructions to descramble scrambled content to generate the descrambled content if authentication with the scrambled content provider device is successful in (c).

29. The method of claim 28, wherein each of (a), (b), (c) and (d) includes determining if execution of the first/second/third/fourth group of plain text and obfuscated cells of programming instructions is being observed.

30. The method of claim 28, wherein (d) includes determining if an invocation of the fourth group of programming instructions is originated from an intruder.

31. The method of claim 28, wherein the method further includes (e) executing the plurality of plain text programming instructions to decode the descrambled content.