Secure delivery of encrypted digital content

• US 20030123665A1
• Filed: 12/28/2001
• Published: 07/03/2003
• Est. Priority Date: 12/28/2001
• Status: Active Grant

• Current Assignee: Tahoe Research Limited (f/k/a Learndale Limited) (Vector Capital Corporation)
• Original Assignee: Intel Corporation
• Inventors: Dunstan, Robert A., Saint-Hilaire, Ylian
• Granted Patent: US 7,400,729 B2
• Time in Patent Office: Days
• US Class Current: 380/255
• 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: H04N 21/42684 Client identification by a unique number or address, e.g. serial number, MAC address, socket ID network arrangements, protocols or services for addressing or naming H04L61/00
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/8193 dedicated tools, e.g. video decoder software or IPMP tool
• 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 content decoder is split into a decoder core and remaining portions. The decoder core implements decryption of encrypted content according to a selected encryption scheme, and the remaining portions provide an interface between the decoder core and content presentation systems/devices. Isolating the selected encryption scheme within the decoder core allows the content decoder to be produced and delivered to end users before the encryption scheme has been selected or developed. A logical separation of the content decoder from the decryption core allows the decryption core software to be updated and/or changed as needed.

Claims

1. A method comprising:

transmitting a decoder core to be used with a predefined content decoder, the decoder core comprising instructions for causing the predefined content decoder to decrypt an encrypted version of digital content.

2. The method of claim 1, further comprising receiving a request to access digital content, wherein the transmitting comprises transmitting in response to the request.

3. The method of claim 2, further comprising generating the decoder core in response to the request.

4. The method of claim 3, wherein the decoder core further comprises information corresponding to the request.

5. The method of claim 4, wherein the information comprises a serial number for a session.

6. The method of claim 4, wherein the information comprises timing information.

7. The method of claim 1, wherein the decoder core further comprises a decryption key.

8. The method of claim 1, wherein the decoder core further comprises obfuscated software.

9. The method of claim 8, wherein the obfuscated software comprises content-specific obfuscated software.

10. The method of claim 9, wherein the content-specific obfuscated software corresponds to a content-specific encryption algorithm, the method further comprising:

encrypting the requested digital content using the content-specific encryption algorithm; and

delivering the encrypted digital content.

11. The method of claim 9, wherein the content-specific obfuscated software includes hashed portions of the digital content.

12. The method of claim 1, wherein the predefined content decoder comprises a previously delivered media player.

13. The method of claim 12, wherein the previously delivered media player comprises a satellite transmission receiving device, and wherein the transmitting a decoder core comprises transmitting the decoder core along with the encrypted version of the digital content from a satellite.

14. A method comprising:

receiving a decoder core comprising instructions for decrypting encrypted digital content; and

using the decoder core with a previously acquired content decoder to access the encrypted digital content.

15. The method of claim 14, wherein receiving a decoder core comprises receiving the encrypted digital content and the decoder core together.

16. The method of claim 15, wherein receiving the encrypted digital content and the decoder core together comprises receiving the encrypted digital content and the decoder core over a unidirectional network.

17. The method of claim 14, further comprising receiving the encrypted digital content separate from the decoder core.

18. The method of claim 17, wherein receiving the encrypted digital content comprises receiving the encrypted digital content on an optical disc, and the previously acquired content decoder comprises an optical disc playing device.

19. The method of claim 14, further comprising re-encrypting the digital content using an intra-home content protection scheme.

20. The method of claim 14, wherein receiving a decoder core comprises receiving the decoder core over a network in response to a request for access to the digital content, and wherein the decoder core further comprises information corresponding to the request.

21. The method of claim 20, wherein the information comprises a serial number and timing information, the method further comprising:

requesting a signed time check from a server;

comparing the signed time check with the timing information; and

preventing access to the encrypted digital content if the signed time check does not match the timing information within a predetermined time difference.

22. The method of claim 14, wherein the decoder core further comprises obfuscated software.

23. The method of claim 22, wherein the obfuscated software comprises software that has been obfuscated with respect to the digital content.

24. A machine-readable medium embodying information indicative of instructions for causing one or more machines to perform operations comprising:

defining an interface between a presentation portion and a decryption portion of a digital content player;

identifying a decoder core that uses the interface to effect the decryption portion of the digital content player; and

using the decoder core with the digital content player to access encrypted digital content.

25. The machine-readable medium of claim 24, wherein defining an interface comprises establishing a public interface for a procedure in a class.

26. The machine-readable medium of claim 24, wherein the interface comprise a dynamic interface in which a portion of the interface is definable by the identified decoder core.

27. A content decoder comprising:

a module defining an interface between the content decoder and a mutable decoder core comprising instructions for causing the content decoder to decrypt encrypted media.

28. The content decoder of claim 27, wherein the interface comprises input and output format information for a decryption procedure to be defined by the mutable decoder core.

29. A system for facilitating secure delivery of digital content, the system comprising:

means for transmitting in response to a request, software plug-in means for decrypting digital content; and

means for receiving the software plug-in means and for presenting the digital content using the software plug-in means.

30. The system of claim 29, further comprising means for generating the software plug-in means in response to the request.