Partial dual-encrypted stream utilizing program map tables

• US 20040136532A1
• Filed: 11/21/2003
• Published: 07/15/2004
• Est. Priority Date: 04/03/1995
• Status: Abandoned Application

• Current Assignee: Tech 5 SAS
• Original Assignee: Tech 5 SAS
• Inventors: Pinder, Howard G., Evans, Jonathan Bradford, Woodward, William D. Jr., Wasilewski, Anthony J.
• Application Number:
  US10/719,161
• Publication Number:
  US 20040136532A1
• Time in Patent Office: Days
• US Class Current: 380/239
• 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 receiving a program in a dual-encrypted stream by a plurality of set-tops, the plurality of set-tops for decrypting one of a first encryption stream and a second encryption stream, the method comprising the step of:

transmitting a program association table including a plurality of programs, wherein each program has two program numbers, wherein a first program number is associated with a first program map table for the first encryption stream and a second program number is associated with a second program map table for the second encryption stream,

wherein the plurality of set-tops retrieve packets associated with a desired program via one of the first program map table and the second program map table.

2. The method of claim 1, wherein the first program map table includes a plurality of program identifiers for the first encryption stream, and wherein the second program map table includes the plurality of program identifiers for the first encryption stream and a plurality of program identifiers for the second encryption stream.

3. The method of claim 1, wherein the first program map tables includes a plurality of packet identifiers for one of the first encryption stream and a clear stream, and wherein the second program map tables includes the plurality of packet identifiers for one of the first encryption stream and the clear stream and a plurality of packet identifiers for the second encryption stream.

4. The method of claim 3, wherein a set-top for decrypting the second encryption stream retrieves the packets associated with the desired program via the second program map table, wherein a packet identifier is associated with one of the second encryption stream and the clear stream.

5. A method for receiving a clear transport stream and for providing an encrypted transport stream, the clear stream including a plurality of programs, each program comprising a plurality of packets each having a packet identifier (PID), the method comprising the steps of:

scrambling the clear transport stream according to a first encryption method to provide a first encryption program;

scrambling the clear transport stream according to a second encryption method to provide a second encryption program;

passing packets of the clear transport stream to a multiplexer, wherein when at least one critical packet is identified in the packets of the clear transport stream, the critical packet of the clear stream drops and the scrambled critical packets included in the first and second encryption programs pass to the multiplexer; and

multiplexing the passed packets of the clear transport stream and the critical packets of the first and second encryption programs to provide a partial dual-encrypted stream,

wherein a program association table is provided along with the partial dual-encrypted stream indicating a plurality of first program numbers associated with the critical packets of the first encryption stream and a plurality of second program numbers for the passed packets of the clear stream and the critical packets of the second encryption stream.

6. The method of claim 5, wherein each of the plurality of second program numbers indicates a program map table, wherein the program map table includes packet identifiers identifying the critical packets of the first and second encryption programs and the passed packets of the clear transport stream.

7. The method of claim 6, the steps further comprising remapping at least one PID value associated with the second encryption program, whereby the scrambled packets of the first and second encryption programs each have a differing PID value, wherein the different PID values are reflected in the program map table associated with each of the plurality of second program numbers.

8. The method of claim 5, wherein each of the plurality of first program numbers indicates a first program map table, wherein the first program map table includes a plurality of packet identifiers for one of the first encryption program, and wherein each of the plurality of second program numbers indicates a second program map table, wherein the second program map table includes a plurality of packet identifiers for one of the first and second encryption programs and the clear transport stream.

9. A method for receiving a clear transport stream and for transmitting an encrypted transport stream, the clear transport stream including a plurality of programs, each program comprising at least one elementary stream, the at least one elementary stream comprising a plurality of packets each having a packet identifier (PID), the method comprising the steps of:

scrambling with a first scrambler a first clear transport stream according to a first encryption method to provide a first encrypted program;

identifying a critical packet associated with a second clear transport stream, wherein prior to identification, the second clear transport stream is allowed to pass and the first encrypted program drops, and wherein subsequent to identification, the identified critical packet associated with the first encrypted program passes to a multiplexer, and the identified critical packet associated with the second clear transport stream is provided to a second scrambler;

scrambling the critical packet associated with the second clear transport stream according to a second encryption method to provide a second encrypted program, wherein the second encrypted program is provided to the multiplexer; and

multiplexing non-critical packets associated with the second clear transport stream and the encrypted critical packets associated with the first and second encrypted programs to provide a partial dual-encrypted stream,

wherein a program association table is provided along with the partial dual-encrypted stream indicating a plurality of first program numbers associated with the critical packets associated with the first encrypted program and a plurality of second program numbers associated with the non-critical packets associated with the second clear transport stream and the critical packets associated with the second encrypted program.

10. The method of claim 9, wherein each of the plurality of second program numbers indicates a program map table, wherein the program map table includes packet identifiers identifying the critical packets associated with the second encrypted program.

11. The method of claim 10, the steps further comprising remapping at least one PID value associated with the second encrypted program, whereby the scrambled packets of the first and second encrypted programs each have a differing PID value, wherein the different PID values are reflected in the program map table associated with each of the plurality of second program numbers.

12. The method of claim 10, wherein a set-top for decrypting the second encrypted program retrieves packets determined by the program map table associated with one of the plurality of second program numbers, wherein a packet identifier is associated with one of the critical packets of the second encrypted program and the non-critical packets of the clear transport stream.