Method and system for protecting video data

• US 7,120,253 B2
• Filed: 05/02/2002
• Issued: 10/10/2006
• Est. Priority Date: 05/02/2002
• Status: Active Grant

• Current Assignee: Pixelworks Incorporated
• Original Assignee: VIXS Systems Incorporated (Pixelworks Incorporated)
• Inventors: Eng, Steven, Ducharme, Paul
• Primary Examiner(s): Louis-Jacques, Jacques
• Assistant Examiner(s): HENEGHAN, MATTHEW E
• Application Number:
  US10/137,151
• Publication Number:
  US 20030206636A1
• Time in Patent Office: 1,622 Days
• Field of Search: 380/211, 713/153, 725/31, 725/71
• US Class Current: 380/211
• CPC Class Codes: H04N 21/2221 being a cable television head-end CATV in broadcast systems H04H20/78
• CPC Class Codes: H04N 21/2343 involving reformatting operations of video signals for distribution or compliance with end-user requests or end-user device requirements video transcoding H04N19/40; media packet handling at the source H04L65/762
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/26606 for generating or managing entitlement messages, e.g. Entitlement Control Message [ECM] or Entitlement Management Message [EMM] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• 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 key protected data stream and an encryption key are received at a gateway device. The gateway devices unprotects the data stream based upon the encryption key. The unprotected received data is modified by the gateway to generate a modified data. The modified data is protected based upon the encryption key to generate a key protected modified data. The gateway then transmits the key protected modified data to one or more clients along with the encryption key.

Claims

1. A method comprising:

receiving a first video stream comprising a key protected first video data and an encryption key;

modifying the first video data to generate a second video data having a lower bit rate than the first video data;

providing a second video stream comprising a key protected second video data and the encryption key, wherein the second video data is different than the first video data; and

wherein the key protected first video data and the key protected second video data can be unprotected using the encryption key.

2. The method of claim 1 further comprising:

decoding the key protected first video data based upon the encryption key to obtain the first video data.

3. The method of claim 2 further comprising:

decrypting the encryption key to obtain a control word;

un-protecting the key protected first video data based on the control word to obtain the first video data; and

determining the key protected second video data based on the second video data and the control word.

4. The method of claim 1 further comprising:

providing the first video stream, wherein a client can use the encryption key to decode at least one of the first video stream and the second video stream.

5. The method of claim 1 further comprising:

providing the second video stream using a wireless protocol.

6. The method of claim 1, wherein providing further comprises providing the encryption key in a first packet of information prior to providing the key protected second video data.

7. A system comprising:

an information receiver portion having an input to receive key protected first video information and an encryption key from a content provider, and an output;

a storage portion having an input coupled to the output of the information receiver portion to receive the encryption key, and an output;

an information provider portion having a first input coupled to the output of the storage portion to access the encryption key, an output to provide a key protected second video information to a client, where the key protected second video information includes the encrypted key and wherein the key protected first video information and the key protected second video information can be unprotected using the encryption key;

a video reconstruction portion having a first input coupled to the output of the storage portion to receive a representation of the encryption key, and a second input coupled to the output of the information receiver to receive the key protected first video information, and an output to provide unprotected first video information;

a video stream modifier having a first input coupled to the output of the video reconstruction module to receive the unprotected first video information, and an output to provide a second video information that is different than the first video information; and

a video protection portion having a first input coupled to the output of the storage portion to receive the representation of the encryption key, and an output to provide the key protected second video information.

8. The system of claim 7, wherein the video reconstruction portion comprises a video descrambler.

9. The system of claim 8, wherein the video protection portion comprises a video scrambler.

10. The system of claim 7, wherein the video reconstruction portion comprises a key decryptor.

11. A method comprising:

receiving a first video stream comprising a key protected first video data and an encryption key;

modifying the first video data to generate a second video data having a lower resolution than the first video data;

providing a second video stream comprising a key protected second video data and the encryption key, wherein the second video data is different than the first video data; and

wherein the key protected first video data and the key protected second video data can be unprotected using the encryption key.