Method for partially encrypting program data

• US 8,542,830 B2
• Filed: 06/25/2003
• Issued: 09/24/2013
• Est. Priority Date: 04/03/1995
• Status: Expired due to Fees

• Current Assignee: Tech 5 SAS
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wasilewski, Anthony J., Pinder, Howard G.
• Primary Examiner(s): Chai, Longbit
• Application Number:
  US10/602,988
• Publication Number:
  US 20040107350A1
• Time in Patent Office: 3,744 Days
• Field of Search: 713/189, 713193-194, 380200-202, 380210-213, 380239-241, 382/232
• 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 63/04 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 program in a conditional access system, the method comprising the steps of:

selecting a digital bit stream from a plurality of digital bit streams by using a packet identifier and encrypting a first portion of the selected digital bit stream according to a first encryption method to provide a first encrypted stream;

encrypting a second portion of the selected digital bit stream according to a second encryption method to provide a second encrypted stream wherein the second encryption method is different from the first encryption method;

multiplexing the first encrypted stream, the second encrypted stream, and the plurality of digital bit streams to provide a partially-encrypted stream; and

transmitting the partially-encrypted stream.

2. The method of claim 1, wherein a portion of the selected digital bit stream is encrypted, wherein the encrypted portion and an unencrypted portion of the selected digital bit stream are combined with the plurality of digital bit streams.

3. The method of claim 1, wherein the selected digital bit stream includes a plurality of packets, and wherein each packet includes a packet identifier identifying whether the packet is at least one of a video stream, an audio stream, and a data stream.

4. The method of claim 3, wherein the selecting step selects the digital bit stream by identifying a predetermined packet identifier.

5. The method of claim 3, wherein the selecting step selects the digital bit stream by identifying a plurality of predetermined packet identifiers.

6. The method of claim 5, wherein the plurality of predetermined packet identifiers is at least one of the video stream, the audio stream, and the data stream.

7. The method of claim 1, wherein the first encryption method comprises 3DES and the second encryption method comprises DES.

8. 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 transport stream by using a packet identifier and encrypting a first portion of the selected elementary bit streams according to a first encryption method to provide a first encrypted stream;

encrypting a second portion of the selected elementary bit streams according to a second encryption method to provide a second encrypted stream wherein the second encryption method is different from the first encryption method;

multiplexing the first and second encrypted stream and the remaining portion of the selected elementary bit stream with the transport stream; and

transmitting the multiplexed stream.

9. The method of claim 8, wherein each of the plurality of elementary bit streams includes a plurality of packets, wherein each packet includes a packet header that is indicative of at least one of a video stream, an audio stream, and a data stream.

10. The method of claim 9, wherein the selecting step selects the plurality of elementary bit streams by identifying at least one of the video stream, the audio stream, and the data stream.

11. The method of claim 8, wherein each of the plurality of elementary bit streams includes a plurality of packet identifiers, and wherein the selecting step selects the plurality of elementary bit streams by identifying a predetermined packet identifier.

12. The method of claim 8, wherein each of the plurality of elementary bit streams includes a plurality of packet identifiers, and wherein the selecting step selects the plurality of elementary bit streams by identifying a plurality of predetermined packet identifiers.

13. The method of claim 12, wherein the portion of the selected elementary bit stream includes at least one of a video stream, an audio stream, and a data stream.

14. The method of claim 8, wherein the first encryption method comprises 3DES and the second encryption method comprises DES.

15. A system comprising:

means for selecting a digital bit stream from a plurality of digital bit streams by using a packet identifier and means for encrypting a first portion of the selected digital bit stream according to a first encryption method to provide a first encrypted stream;

means for encrypting a second portion of the selected digital bit stream according to a second encryption method to provide a second encrypted stream wherein the second encryption method is different from the first encryption method;

means for multiplexing the first encrypted stream, the second encrypted stream, and the plurality of digital bit streams to provide a partially-encrypted stream; and

means for transmitting the partially-encrypted stream.

16. The system of claim 15, wherein a portion of the selected digital bit stream is encrypted, wherein the encrypted portion and an unencrypted portion of the selected digital bit stream are combined with the plurality of digital bit streams.

17. The system of claim 15, wherein the selected digital bit stream includes a plurality of packets, and wherein each packet includes a packet identifier identifying whether the packet is at least one of a video stream, an audio stream, and a data stream.

18. The system of claim 17, wherein the means for selecting selects the digital bit stream with a means for identifying a predetermined packet identifier.

19. The system of claim 17, wherein the means for selecting selects the digital bit stream with a means for identifying a plurality of predetermined packet identifiers.

20. The system of claim 19, wherein the plurality of predetermined packet identifiers is at least one of the video stream, the audio stream, and the data stream.