A PARTIAL DUAL ENCRYPTED STREAM UTILIZING PROGRAM MAP TABLES

• US 20060233369A1
• Filed: 12/06/2005
• Published: 10/19/2006
• Est. Priority Date: 04/03/1995
• Status: Active Grant

• Current Assignee: Tech 5 SAS
• Original Assignee: Anthony Wasilewski, Howard Pinder, Jonathan Evans, William Woodward
• Inventors: Pinder, Howard G., Evans, Jonathan Bradford, WASILEWSKI, ANTHONY J., WOODWARD, WILLIAM D. Jr.
• Granted Patent: US 7,496,198 B2
• Time in Patent Office: Days
• US Class Current: 380/216
• CPC Class Codes: H04J 2203/008 Support of video
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/062 for key distribution, e.g. centrally by trusted party cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819
• CPC Class Codes: H04N 21/2265 Server identification by a unique number or address, e.g. serial number network arrangements, protocols or services for addressing or naming H04L61/00
• CPC Class Codes: H04N 21/23476 by partially encrypting, e.g. encrypting the ending portion of a movie
• CPC Class Codes: H04N 21/235 Processing of additional data, e.g. scrambling of additional data or processing content descriptors
• CPC Class Codes: H04N 21/2362 Generation or processing of Service Information [SI]
• CPC Class Codes: H04N 21/23897 by partially encrypting, e.g. encrypting only the ending portion of a movie
• 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 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/435 Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream
• CPC Class Codes: H04N 21/43607 Interfacing a plurality of external cards, e.g. through a DVB Common Interface [DVB-CI]
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/44055 by partially decrypting, e.g. decrypting a video stream that has been partially encrypted
• CPC Class Codes: H04N 21/4524 involving the geographical location of the client retrieval from the Internet by querying based on geographical locations G06F16/9537; systems specially adapted for using geographical information in broadcast systems H04H60/70; protocols in which the network application is adapted for the location of the user terminal in communication control or processing H04L67/52; services making use of the location of users or terminals in wireless networks H04W4/02; locating users or terminals in wireless networks H04W64/00
• 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 7/162 Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing
• CPC Class Codes: H04N 7/163 by receiver means only
• 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
• CPC Class Codes: H04N 7/17354 : in an intermediate station common to a plurality of user terminals

Abstract

The present invention is suitable for use in a partial dual encrypted system. The present invention allows for two different decryption devices (e.g., an incumbent, or first, set-top and an overlay, or second, set-top) to be located in a single system having an incumbent encryption scheme and a second encryption scheme. Each set-top is designed to decrypt the first or second proprietary encryption schemes, respectively. In accordance with the present invention, the second set-top utilizes a novel program map table to ensure that the second set-top chooses correct elementary streams in the partial dual-encrypted stream (i.e., a combined stream including a first encrypted stream, a second encrypted stream, and a clear stream) for a desired program.

Claims

1. A method for encoding and encyrpting a program in at least two distinct partial-encrypted streams, a plurality of set-tops for decrypting one of the at least two distinct partial-encrypted streams, the method comprising the steps of:

encoding a program association table to include at least two program numbers in accordance with at least one program, and for associating a program map table with an identifier for each of the at least two program numbers;

encoding a first program map table corresponding to a program, the first program map table including first audio and video identifiers in accordance with a first encryption scheme; and

encoding a second program map table corresponding to the program, the second program map table including the first audio and video identifiers in accordance with the first encryption scheme and second audio and video identifiers in accordance with a second encryption scheme.

2. The method of claim 1, the method further comprising the step of encoding the second program map table to include second encryption scheme conditional access descriptors.

3. The method of claim 1, the method further comprising the step of encoding the first program map table to include first encryption scheme conditional access descriptors.

4. The method of claim 1, the method further comprising the step of encoding the first and second program map tables with clear audio and video identifiers identifying a clear portion of the program.

5. The method of claim 4, wherein existing headend equipment encodes and encrypts the first program map table having the first encryption scheme as designed, and wherein a single device encodes and encrypts the second program map table having the second encryption scheme.

6. The method of claim 5, further comprising the steps of:

multiplexing the first program map table, the second program map table, and the clear portion of the portion into a single stream; and

transmitting the single stream to the plurality of set-tops.

7. A communications facility for encoding and transmitting a partial dual-encrypted program stream, the communications facility comprising:

existing headend equipment for providing a clear program stream and a first encrypted program stream in accordance with a first encryption scheme, wherein the clear program stream and the first encrypted program stream have associated program map tables including a plurality of program numbers each corresponding to a program, wherein a program number is found in both the clear program stream and the first encrypted program stream; and

an additional device for receiving the clear stream and the encrypted program stream, the additional device comprising;

a first demultiplexer for demultiplexing the plurality of programs in the clear stream and providing each demultiplexed program to an output of the first demultiplexer;

a second demultiplexer for demultiplexing the plurality of programs in the first encrypted program stream and providing each demultiplexed program to an output of the second demultiplexer; and

for each of the plurality of demultiplexed programs, an identifier for receiving the demultiplexed program of the clear stream and the corresponding demultiplexed program of the first encrypted stream and for identifying critical packets of the clear program,

wherein, when a critical packet is identified in the clear program, the identified critical packet is encrypted by a second encryption scheme.

8. The communications system of claim 7, further comprising a multiplexer for multiplexing the second encrypted critical packet and a corresponding critical packet of the first encryption scheme.

9. The communications system of claim 8, wherein the multiplexer further multiplexes non-critical packets of the clear program, the second encrypted critical packets, and the corresponding critical packets of the first encryption scheme to provide a single partial dual-encrypted program stream.

10. The communications system of claim 7, wherein the program map tables for the clear program stream and the first encrypted program stream include audio and video packet identifiers for each corresponding program number.

11. The communications system of claim 10, each identifier further comprising:

a first buffer for buffering the demultiplexed first encrypted program;

a second buffer for buffering the demultiplexed clear program; and

a packet comparator for ensuring the audio and video packet identifiers for each program number of the demultiplexed first encrypted program and clear program are in alignment.

12. The communications system of claim 7, each identifier further comprising a critical packet selector for identifying and selecting the critical packets of the clear stream, and for allowing the critical packet of the clear stream to pass and dropping the corresponding critical packet of the first encrypted program to drop.

13. The communications system of claim 7, each identifier further comprising a critical packet selector for identifying and selecting the critical packets of the clear stream, and for dropping non-critical packets of the clear stream and passing the corresponding non-critical packets of the first encrypted program.

14. The communications system of claim 7, each identifier further comprising a remapper for encoding a second encrypted program map table including audio and video packet identifiers for each program number of the second encrypted program, the program map table of the first encrypted program stream, and the program map table of the clear program stream.

15. A communications facility for encoding and transmitting a partial dual-encrypted program stream, the communications facility for receiving a clear program stream, the clear program stream including a plurality of programs, the communications facility comprising:

a first encryptor for receiving the clear program stream and encrypting the plurality of programs according to a first encryption scheme;

a second encryptor for receiving the clear program stream and encrypting the plurality of programs according to a second encryption scheme;

a first demultiplexer for demultiplexing the first encrypted plurality of program streams and for providing a plurality of first encrypted programs;

a second demultiplexer for demultiplexing the second encrypted plurality of program stream and for providing a plurality of second encrypted programs;

a third demultiplexer for demultiplexing the clear program stream and for providing a plurality of clear programs; and

for each common program number of the first encrypted programs, the second encrypted programs, and the clear programs, an identifier for identifying critical packets in the clear program, and, when a critical packet is identified, for dropping the critical packet of the clear program and passing corresponding critical packets of the first and second encrypted programs.

16. The communications facility of claim 15, wherein for non-critical packets in the clear program, the identifier for passing the non-critical packets in the clear program and dropping the corresponding non-critical packets of the first and second encrypted programs.

17. The communications facility of claim 15, the identifier further comprising a multiplexer for multiplexing the passed clear program packets, the first encrypted program packets, and the second encrypted program packets.

18. The communications facility of claim 15, each identifier further comprising a remapper for encoding a second encrypted program map table including audio and video packet identifiers for each program of the second encrypted program, a program map table of the first encrypted program, and a program map table of the clear program.