Method and Apparatus for Secure Content Recording

• US 20080267399A1
• Filed: 09/06/2007
• Published: 10/30/2008
• Est. Priority Date: 04/27/2007
• Status: Abandoned Application

• Current Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Original Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Inventors: Medvinsky, Alexander, Peterka, Petr
• Application Number:
  US11/851,066
• Publication Number:
  US 20080267399A1
• Time in Patent Office: Days
• US Class Current: 380/201
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 9/0841 involving Diffie-Hellman or related key agreement protocols
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04N 21/43622 Interfacing an external recording device
• CPC Class Codes: H04N 21/4367 Establishing a secure communication between the client and a peripheral device or smart card
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• 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 is provided that establishes a secure tunnel with a content acquisition processor that acquires encrypted content from a content source and decrypts the encrypted content to obtain content. The content acquisition processor is not trusted for providing digital rights management. Further, the method transmits a request through the secure tunnel to the content acquisition processor to re-encrypt the content with a content encryption key so that re-encrypted content is generated and stores the re-encrypted content on a storage medium. The request includes the content encryption key.

Claims

1. A method comprising:

establishing a secure tunnel with a content acquisition processor that acquires encrypted content from a content source and decrypts the encrypted content to obtain content, the content acquisition processor not being trusted for providing digital rights management; and

transmitting a request through the secure tunnel to the content acquisition processor to re-encrypt the content with a content encryption key so that re-encrypted content is generated and store the re-encrypted content on a storage medium, the request including the content encryption key.

2. The method of claim 1, wherein the content source includes a content protection module.

3. The method of claim 1, further comprising generating the content encryption key through a digital rights management system.

4. The method of claim 1, further comprising loading encrypted code having a global key and accessing long-term keys stored in the device by decrypting the long-term keys with the global key in the code.

5. The method of claim 4, wherein the long-term keys stored in the device have to first be decrypted using a device-unique key before decrypting the long-term keys the second time with the global key in the code.

6. The method of claim 3, wherein the establishing of the secure tunnel includes determining a shared secret key through a key agreement algorithm, the shared secret key being utilized to encrypt or decrypt one or more messages communicated with the content acquisition processor.

7. The method of claim 6, wherein the establishing of the secure tunnel further comprises authenticating the shared secret with a pre-shared key.

8. The method of claim 7, wherein the pre-shared key is one of the long-term keys stored in the device and is encrypted with the global key in the code and then encrypted with the device-unique key.

9. The method of claim 7, further comprising authenticating the shared secret by determining if the content acquisition processor is running an outdated version of software.

10. The method of claim 8, further comprising preventing communication with the content acquisition processor if the outdated version of software is running on the content acquisition processor.

11. The method of claim 1, further comprising receiving a copy control information update from the content acquisition processor.

12. The method of claim 11, further comprising generating, in response to the copy control information update, a new content encryption key and sending the new content encryption key to the content acquisition processor to re-encrypt the content.

13. The method of claim 12, further comprising receiving copy control information, sending a new content encryption key to the content acquisition processor, and invaliding a content license associated with the content if an acknowledgement of delivery for the new content encryption key is not received within a predetermined time.

14. A method comprising:

establishing a secure tunnel with a digital rights management processor that is trusted for maintaining a digital rights management system;

receiving encrypted content from a content source;

decrypting the encrypted content to obtain content; and

receiving, from the digital rights management processor through the secure tunnel, a request to re-encrypt the content with a content encryption key and store the re-encrypted content on a storage medium, the request including the content encryption key.

15. The method of claim 14, wherein the content source includes a content protection module.

16. The method of claim 14, wherein the establishing of the secure tunnel includes determining a shared secret key through a key agreement algorithm, the shared secret key being utilized to encrypt or decrypt one or more messages communicated with the digital rights management processor.

17. The method of claim 16, wherein the establishing of the secure tunnel further comprises authenticating the shared secret with a pre-shared key.

18. The method of claim 14, further comprising receiving a copy control information update, sending the copy control information update to the digital rights management processor, and halting recording if a new content encryption key is not received within a predetermined time.

19. A method comprising:

establishing a secure tunnel between a digital rights management processor that is trusted for maintaining a digital rights management system and a content acquisition processor that is not trusted for maintaining the digital rights management system;

receiving, at the content acquisition processor, encrypted content from a content source;

decrypting, at the content acquisition processor, the encrypted content to obtain content; and

transmitting a request from the digital rights management processor through the secure tunnel to the content acquisition processor, the request being to re-encrypt the content with a content encryption key and store the re-encrypted content on a storage medium, the request including the content encryption key.

20. The method of claim 19, wherein the content encryption key is generated through a digital rights management system.