System and method for conditional access key encryption

• US 20030035543A1
• Filed: 08/15/2001
• Published: 02/20/2003
• Est. Priority Date: 08/15/2001
• Status: Active Grant

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: Vulcan Ventures Inc. (Vulcan, Inc.)
• Inventors: Perlman, Stephen G., Gillon, William M.
• Granted Patent: US 7,463,737 B2
• Time in Patent Office: Days
• US Class Current: 380/270
• CPC Class Codes: H04L 2209/601 Broadcast encryption
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04N 21/23476 by partially encrypting, e.g. encrypting the ending portion of a movie
• CPC Class Codes: H04N 21/238 Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams hybrid fiber coaxial [HFC] networks for downstream channel allocation for video distribution H04L12/2801; flow control in packet networks H04L47/10; real-time communication protocols in data switching networks H04L65/00; scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/2389 Multiplex stream processing, e.g. multiplex stream encrypting
• CPC Class Codes: H04N 21/4331 Caching operations, e.g. of an advertisement for later insertion during playback
• CPC Class Codes: H04N 21/4334 Recording operations recording of a television signal H04N5/76; arrangements for recording or accumulating broadcast information or broadcast-related information H04H60/27
• CPC Class Codes: H04N 21/4347 Demultiplexing of several video streams
• CPC Class Codes: H04N 21/4384 involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency
• 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 21/4532 involving end-user characteristics, e.g. viewer profile, preferences monitoring of user activities for profile generation for accessing a video database G06F16/739; user profiles in network data switching protocols H04L67/306; processing of user preferences or user profiles in wireless networks H04W8/18
• CPC Class Codes: H04N 21/4623 Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/482 End-user interface for program selection broadcast systems using EPGs H04H60/72
• 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 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 system for processing multimedia channels is described comprising: transmitting decryption keys for decrypting the multimedia channels, the keys encrypted in both a first encryption format and a second encryption format; the keys encrypted in the first encryption format being decryptable by a first type of multimedia receiver; and the keys encrypted in the second encryption format being decryptable by a second type of multimedia receiver.

Claims

1. A computer-implemented method comprising:

encrypting a group of multimedia channel keys using a first type of encryption to produce a first group of encrypted multimedia channel keys;

encrypting said group of multimedia channel keys using a second type of encryption to produce a second group of encrypted multimedia channel keys;

concurrently transmitting said first group of encrypted multimedia channel keys with said second group of multimedia channel keys to a plurality of multimedia subscribers having multimedia receivers capable of decrypting either said first group of encrypted multimedia channel keys and/or said second group of multimedia channel keys.

2. The method as in claim 1 wherein said second type of encryption is digital video broadcasting (“

DVB”

) encryption.

3. The method as in claim 1 further comprising:

transmitting entitlement information with said group of multimedia channel keys encrypted using said second type of encryption, said entitlement information indicating which of said multimedia channels a user has the right to decrypt.

4. The method as in claim 3 further comprising:

decrypting said second group of encrypted multimedia channel keys at a multimedia receiver.

5. The method as in claim 4 further comprising:

searching said entitlement information to determine whether said user has the right to view a particular channel selected by said user; and

decrypting said channel using one of said decrypted keys if said user has said right.

6. A method comprising:

receiving a plurality of encrypted keys, each of said keys for decrypting a respective plurality of encrypted multimedia channels;

decrypting said encrypted multimedia keys;

using said decrypted multimedia keys to decrypt one or more of said multimedia channels;

re-encrypting said multimedia channels using an alternative encryption technique; and

storing said re-encrypted multimedia channels on a mass storage device.

7. The method as in claim 6 wherein said alternative encryption technique is DES encryption.

8. The method as in claim 6 further comprising:

decrypting one or more of said multimedia channels using said alternative decryption technique responsive to a user request to view said one or more multimedia channels.

9. The method as in claim 6 wherein decrypting comprises:

reading entitlement information identifying multimedia channels which a user has a right to view; and

decrypting only those decryption keys for multimedia channels identified by said entitlement information.

10. The method as in claim 6 wherein decrypting comprises:

reading entitlement information identifying multimedia channels which a user has a right to view;

decrypting all keys associated with said multimedia channels; and

using only those decryption keys for multimedia channels identified by said entitlement information.

11. A system for processing multimedia channels comprising:

transmitting decryption keys for decrypting said multimedia channels, said keys encrypted in both a first encryption format and a second encryption format;

said keys encrypted in said first encryption format being decryptable by a first type of multimedia receiver; and

said keys encrypted in said second encryption format being decryptable by a second type of multimedia receiver.

12. The system as in claim 11 wherein said second encryption format permits all of said keys to be decrypted in real-time as they are received by said multimedia receiver.

13. The system as in claim 12 wherein said second encryption format is digital video broadcast (“

DVB”

) encryption.

14. The system as in claim 11 further comprising:

transmitting entitlement information indicating which of said multimedia channels a user has a right to view.

15. The system as in claim 14 further comprising:

said second type of multimedia receiver decrypting only those keys identified by said entitlement information.

16. The system as in claim 14 further comprising:

said second type of multimedia receiver decrypting said decryption keys and using said decryption keys to decrypt multimedia channels identified by said entitlement information.

17. The system as in claim 11 further comprising:

said second type of multimedia receiver decrypting one or more of said keys and using said one or more keys to decrypt one or more multimedia channels; and

said second type of multimedia receiver re-encrypting said multimedia channels using an alternative encryption format.

18. The method as in claim 17 wherein said alternative encryption format is digital video broadcast (“

DVB”

) encryption.

19. The method as in claim 17 further comprising:

storing said multimedia channels in said alternative encryption format on a mass storage device.

20. The method as in claim 19 further comprising:

decrypting and playing back one or more of said multimedia channels from said mass storage device responsive to a user request to play back said one or more of said multimedia channels.