Method for partially encrypting program data

• US 20040003008A1
• Filed: 06/25/2003
• Published: 01/01/2004
• Est. Priority Date: 04/03/1995
• Status: Active Grant

• Current Assignee: Tech 5 SAS
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Pinder, Howard G., Wasilewski, Anthony J.
• Granted Patent: US 8,577,033 B2
• Time in Patent Office: Days
• US Class Current: 707/200
• CPC Class Codes: H04J 2203/008 Support of video
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management data processing systems or methods, specially adapted for commerce, e.g. marketing, shopping, billing, auctions or e-commerce G06Q30/00
• CPC Class Codes: H04L 63/04 for providing a confidential data exchange among entities communicating through data packet networks
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• CPC Class Codes: H04L 63/045 wherein the sending and receiving network entities apply hybrid encryption, i.e. combination of symmetric and asymmetric encryption cryptographic mechanisms or cryptographic arrangements using a plurality of keys or algorithms H04L9/14
• 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: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 63/126 the source of the received data
• 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 21/26606 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 21/4405 involving video stream decryption
• 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

A cable television system provides conditional access to services. The cable television system includes a headend from which service “instances,” or programs, are broadcast and a plurality of set top units for receiving the instances and selectively decrypting the instances for display to system subscribers. The service instances are partially-encrypted using public and/or private keys provided by service providers or central authorization agents. Keys used by the set tops for selective decryption may also be public or private in nature, and such keys may be reassigned at different times to provide a cable television system in which piracy concerns are minimized.

Claims

1. A method for providing a plurality of programs in a conditional access system, the method comprising the steps of:

selecting a plurality of digital bit streams from a transport stream;

encrypting a portion of each of the plurality of digital bit streams;

combining the encrypted portion and the unencrypted portion with the transport stream; and

transmitting the combined stream.

2. The method of claim 1, wherein each of the plurality of digital bit streams includes a packet identifier, and wherein the selecting step selects each of the plurality of digital bit streams by identifying a predetermined packet identifier.

3. The method of claim 1, wherein each of the plurality of digital bit streams includes a packet identifier, and wherein the selecting step selects the plurality of digital bit streams by identifying a plurality of predetermined packet identifiers.

4. The method of claim 3, wherein the selected plurality of digital bit streams are programs.

5. The method of claim 3, wherein the selected plurality of digital bit streams are elementary digital bit streams.

12. The method of claim 1, wherein the portion of the plurality of digital bit streams is encrypted according to a first level encryption method.

6. The method of clam 3, wherein a portion of the selected plurality of digital bit streams is encrypted according to the packet identifier associated with each of the plurality of digital bit streams.

7. The method of claim 6, wherein the packet identifier is indicative of each of the plurality of digital bit streams being one of a video stream, an audio stream, and a data stream.

8. The method of claim 7, wherein the encrypted portion includes at least one of the plurality of digital bit streams associated with the video stream.

9. The method of claim 7, wherein the encrypted portion includes at least one of the plurality of digital bit streams associated with the audio stream.

10. The method of claim 7, wherein the encrypted portion includes at least one of the plurality of digital bit streams associated with the data stream.

11. The method of claim 7, wherein the encrypted portion includes at least one of the plurality of digital bit streams associated with at least one of the video stream, the audio stream, and the data stream.

13. A method for providing a plurality of programs in a conditional access system, the method comprising the steps of:

selecting a plurality of elementary bit streams from a plurality of programs;

encrypting a portion of the selected streams;

combining the encrypted portion and the remaining portion of the selected streams with the plurality of programs to provide a partially-encrypted stream; and

transmitting the partially-encrypted stream.

14. The method of claim 13, wherein each of the plurality of elementary bit streams includes a plurality of packets, each packet having a packet header.

15. The method of claim 14, wherein the packet header includes a packet identifier identifying the packet, wherein the packet identifier is indicative of one of a video stream, an audio stream, and a data stream.

16. The method of claim 15, wherein the encrypted portion includes at least one of the plurality of packets associated with the video stream.

17. The method of claim 15, wherein the encrypted portion includes at least one of the plurality of packets associated with the audio stream.

18. The method of claim 15, wherein the encrypted portion includes at least one of the plurality of packets associated with the data stream.

19. The method of claim 15, wherein the encrypted portion includes at least one of the plurality of packets associated with at least one of the video stream, the audio stream, and the data stream.