Decoding system and data format for processing and storing encrypted broadcast, cable or satellite video data

• US 6,016,348 A
• Filed: 11/27/1996
• Issued: 01/18/2000
• Est. Priority Date: 11/27/1996
• Status: Expired due to Term

• Current Assignee: Thomson Consumer Electronics Incorporated (Vantiva SA)
• Original Assignee: Thomson Consumer Electronics Incorporated (Vantiva SA)
• Inventors: Horlander, Thomas Edward, Deiss, Michael Scott, Bridgewater, Kevin Elliott, Blatter, Harold
• Primary Examiner(s): Barron, Jr., Gilberto
• Application Number:
  US08/762,488
• Time in Patent Office: 1,147 Days
• Field of Search: 380/5, 380/16, 380/20
• US Class Current: 380/228
• CPC Class Codes: H04N 21/4147 PVR [Personal Video Recorder] H04N5/76 takes precedence ; arrangements for broadcast with accumulation-type receivers H04H20/40
• CPC Class Codes: H04N 21/4181 for conditional access
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/42646 for reading from or writing on a non-volatile solid state storage medium, e.g. DVD, CD-ROM
• CPC Class Codes: H04N 21/4345 Extraction or processing of SI, e.g. extracting service information from an MPEG stream
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4623 Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] 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 decoder conditional access system incorporates different encryption systems for providing access to programs derived from different sources. A conditional access processor for processing encrypted program data and an associated encryption code includes a first algorithm means for decrypting the encryption code to provide an encryption key. The conditional access processor also includes a second algorithm means for encrypting the encryption key and the second encryption algorithm is different to the first encryption algorithm. A datastream representing the program is generated from encrypted program data and an associated encryption code. The encryption code is decrypted to provide an encryption key using a first algorithm. The encryption key is encrypted using a second algorithm different to the first encryption algorithm and the program datastream is formed from the encrypted program data and the encrypted encryption key. The program datastream is decrypted by selecting between a first and a second decryption algorithm and by decrypting the encryption code to provide an encryption key. The encryption key is used to decrypt the encrypted program. A storage medium data format for recording encrypted program data is also disclosed.

Claims

1. A conditional access processor for processing a digital datastream containing encrypted program data and an encryption code, comprising:

first algorithm means for decrypting said encryption code to provide an encryption key; and

second algorithm means for encrypting said encryption key, wherein

said second encryption algorithm is different from said first encryption algorithm wherein

said conditional access system resides within a host device;

said first and second algorithms are contained in an electronic device employed within said conditional access system; and

said electronic device is insertable into said host device.

2. A method of decrypting a program representative datastream containing encrypted program data and an associated encryption code, using an encryption key recovery algorithm stored in an electronic device insertable into a host device, comprising the playback mode steps of:

selecting between a first and a second algorithm to obtain said encryption key recovery algorithm;

employing said encryption key recovery algorithm to decrypt said encryption code to recover a broadcast encryption key; and

using said encryption key to decrypt said encrypted program data to recover said program.

3. In a video decoder for receiving and processing digital video data for storage in encrypted form, a system for processing digital video data containing broadcast encrypted program data and an encryption code, comprising:

a conditional access processor including,

first algorithm means for decrypting said encryption code to provide an encryption key for use in decrypting said broadcast encrypted program data; and

second algorithm means for encrypting said encryption key to provide an encrypted playback key for use in decrypting encrypted program data recovered from a storage medium; and

third algorithm means for decrypting encrypted program data using one of,

a) said encryption key, and

b) said playback key; and

means for formatting encrypted program data together with an associated encrypted playback key to be suitable for storage on a storage medium, wherein

said first algorithm is different from said second algorithm and may be updated at a different rate and independently of said second algorithm.

4. A system according to claim 3, wherein

said second algorithm means includes means for decrypting an encrypted playback key recovered from a storage medium to provide said playback key.

5. A system according to claim 3, wherein

said first algorithm is updated more frequently than said second algorithm.

6. A system according to claim 3, wherein

said conditional access processor selects one of, a) said encryption key, and b) said playback key for use by said third algorithm.

7. In a video decoder for receiving and processing digital video data for storage in encrypted form, a method for processing digital video data containing broadcast encrypted program data and an encryption code, comprising the steps of:

decrypting said encryption code using a first algorithm to provide an encryption key for use in decrypting said broadcast encrypted program data;

encrypting said encryption key using a second algorithm to provide an encrypted playback key for use in decrypting encrypted program data recovered from a storage medium;

decrypting encrypted program data with a third algorithm using one of,

a) said encryption key, and

b) said playback key; and

formatting encrypted program data together with an associated encrypted playback key to be suitable for storage on a storage medium, wherein

said first algorithm is different from said second algorithm and may be updated at a different rate and independently of said second algorithm.

8. A method according to claim 7, wherein said formatting step provides a datastream that is MPEG compatible.

9. A method according to claim 7, including the step of

updating said first algorithm more frequently than said second algorithm.

10. A method according to claim 8, wherein in said formatting step

said encrypted playback key is included in Program Specific Information (PSI).

11. A method according to claim 10, wherein

said encrypted playback key is included in a program map table (PMT) in said PSI.

12. A method according to claim 10, wherein

said encrypted playback key is included in a conditional access table (CAT) in said PSI.

13. A method, according to claim 7, further including the step of

storing a datastream produced in said formatting step on a storage medium.

14. A method according to claim 7, further including the step of

initiating billing in response to application of said second algorithm.

15. In a video decoder, a method for adaptively decoding broadcast encrypted digital video data and encrypted digital video data retrieved from a storage medium, comprising the steps of:

receiving broadcast encrypted program data and an associated broadcast encryption code;

receiving encrypted program data and an associated encrypted playback key retrieved from storage;

decrypting said broadcast encryption code using a first algorithm to provide an encryption key for use in decrypting said broadcast encrypted program data;

decrypting said encrypted playback key retrieved from storage using a second algorithm to provide a playback key for use in decrypting said encrypted program data retrieved from storage; and

using a third algorithm in decrypting one of,

a) broadcast encrypted program data with said encryption key, and

b) encrypted program data retrieved from storage with said playback key;

wherein

said first algorithm is different from said second algorithm and may be updated at a different rate and independently of said second algorithm.

16. A method according to claim 15, wherein

said first and second algorithms are applied within a smart card.

17. A method according to claim 15, including the step of

updating said first algorithm more frequently than said second algorithm.

18. A method according to claim 15, including the step of

deriving said encryption code from received Program Specific Information (PSI).

19. A method according to claim 18, wherein

including the step of

deriving said encryption code from a program map table (PMT) in said received PSI.

20. A method according to claim 18, wherein

including the step of

deriving said encryption code is from a conditional access table (CAT) in said received PSI.

21. A method according to claim 15, further including the step of

initiating billing for playback of said datastream in response to application of said second algorithm.

22. A storage medium having recorded thereon encrypted program data in a data format including:

program data encrypted using a first encryption algorithm; and

an encrypted playback key obtained by encrypting an encryption key associated with said encrypted program data using a second encryption algorithm, said playback key being suitable for use in decrypting said encrypted program data upon recovering said program data from said storage medium, wherein

said first encryption algorithm and said second encryption algorithm are different and said first encryption algorithm may be updated at a different rate and independently of said second algorithm.

23. A storage medium according to claim 22, wherein

said encrypted playback key is included in Program Specific Information (PSI) in said program data.

24. An insertable electronic smart card for use in a video decoder conditional access system for processing broadcast encrypted video data received from a broadcast source and encrypted video data received from local storage, comprising:

first algorithm means for decrypting an encryption code received from a broadcast source to provide an encryption key for use in decrypting said broadcast encrypted video data; and

playback algorithm means for,

a) encrypting an encryption key to provide an encrypted playback key for storage with encrypted video data, and

b) decrypting said encrypted playback key to provide a playback key for use in decrypting said encrypted video data received from local storage wherein

said first algorithm is different from said playback algorithm and may be updated at a different rate and independently of said playback algorithm.

25. A smart card according to claim 24, further including,

second algorithm means for decrypting an encryption code received from a broadcast source to provide an encryption key for use in decrypting said broadcast encrypted video data, wherein

said smart card allows selection between said first and said second algorithms.