System for Securing Access to Data Streams

• US 20070297603A1
• Filed: 11/16/2003
• Published: 12/27/2007
• Est. Priority Date: 04/13/2003
• Status: Active Grant

• Current Assignee: Synamedia Limited
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wald, Stephanie, Belenky, Yaacov, Stroh, Uri, Kamins, Josh, Wachtfogel, Abraham, Ickowicz, Gabi, Bogot, Carmi
• Granted Patent: US 8,755,523 B2
• Time in Patent Office: Days
• US Class Current: 380/201
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/2541 Rights Management protecting software against unauthorised usage in a vending or licensing environment G06F21/10; security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• 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 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• 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 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 21/835 Generation of protective data, e.g. certificates protecting software against unauthorised usage in a vending or licensing environment G06F21/10

Abstract

A method for protecting digital content is described. The method includes receiving compressed encrypted digital content (810), determining an output format based, at least in part, on all of the following: a user-requested output format; received control information; and a rule determining whether a clear compressed output format is allowed (820); and producing output from the compressed digital content (830) based on a result of the determining (820), wherein, if the rule does not allow clear compressed output format, the compressed encrypted digital content is provided in a form which prevents production of clear compressed output in the producing step. Related apparatus and methods are also described.

Claims

1. A method for protecting digital content comprising:

receiving compressed encrypted digital content;

determining an output format based, at least in part, on all of the following;

a user-requested output format;

received control information; and

a rule determining whether a clear compressed output format is allowed; and

producing output from the compressed digital content based on a result of the determining,

wherein, if the rule does not allow clear compressed output format, the compressed encrypted digital content is provided in a form which prevents production of clear compressed output in the producing step.

2. The method according to claim 1 and wherein the form which prevents production of clear compressed output comprises compressed encrypted digital content, additionally encrypted in accordance with a second encryption method, and

the producing comprises:

decrypting in accordance with the second encryption method; and

decompressing, and the producing comprises an atomic operation.

3. The method according to claim 1 and also comprising:

providing an output-producing hardware device,

wherein at least the producing is performed in the hardware device.

4. The method according to claim 3 and wherein the hardware device is characterized by a device profile, and

the determining is also based, at least in part, on the device profile.

5. The method according to claim 3 and wherein the determining is also performed in the hardware device.

6. The method according to claim 3 and wherein the hardware device is comprised in a single integrated circuit.

7. The method according to claim 6 and wherein the integrated circuit is comprised in a smart card.

8. The method according to claim 1 and also comprising:

rendering the output sensible to at least one human sense.

9. The method according to claim 8 and wherein the rendering comprises at least one of the following:

audio rendering;

visual rendering; and

audio/visual rendering.

10. The method according to claim 1 and wherein the compression comprises null compression.

11. The method according to claim 1 and wherein local scrambling is applied to the content.

12. The method according to claim 1 and wherein no output is produced.

13. Apparatus for protecting digital content comprising:

a digital content receiver receiving compressed encrypted digital content;

an output format determination unit determining an output format based, at least in part, on all of the following;

a user-requested output format;

received control information; and

a rule determining whether a clear compressed output format is allowed; and

a content output unit producing output from the compressed digital content based on a result produced by the output format determination unit,

wherein, if the rule does not allow clear compressed output format, the compressed encrypted digital content is provided to the digital content receiver in a form which prevents production of clear compressed output by the content output unit.

14. Apparatus according to claim 13 and wherein the form which prevents production of clear compressed output comprises compressed encrypted digital content, additionally encrypted in accordance with a second encryption method, and

the content output unit comprises:

a decrypting unit decrypting in accordance with the second encryption method; and

decompressing apparatus, and

the content output unit produces output in an atomic operation.

15. Apparatus according to claim 13 of claim 14.and also comprising:

an output-producing hardware device,

wherein at least the content output unit is comprised in the hardware device.

16. Apparatus according to claim 15 and wherein the hardware device is characterized by a device profile, and

the output format determination unit determines the output format based, at least in part, on the device profile.

17. Apparatus according to claim 15 and wherein the output format determination unit is also comprised in the hardware device.

18. Apparatus according to claim 15 and wherein the hardware device is comprised in a single integrated circuit.

19. Apparatus according to claim 18 and wherein the integrated circuit is comprised in a smart card.

20. Apparatus according to claim 13 and also comprising:

a rendering device which renders the output sensible to at least one human sense.

21. Apparatus according to claim 20 and wherein the rendering device comprises at least one of the following:

an audio rendering device;

a visual rendering device; and

an audio/visual rendering device.

22. Apparatus according to claim 13 and wherein the compression comprises null compression.

23. Apparatus according to claim 13 and wherein local compression is applied to the content.

24. Apparatus according to claim 13 and wherein no output is produced.

25. A digital content receiver (DCR) comprising:

a local scrambling descrambler;

a broadcast descrambler receiving an output produced by the local scrambling descrambler;

a local scrambler;

a combined extra encryption algorithm decryptor and decoder/decompressor (XDDC); and

a switch operative to provide an output of the broadcast descrambler to exactly one of the local scrambler and the XDDC,

wherein the DCR is operative to receive control information and compressed encrypted digital content, and

at least the setting of the switch is determined, at least in part, by the control information, and

the DCR is operative to produce an output based on all of the following;

the compressed digital content;

a user-requested output format;

the received control information; and

a rule determining whether a clear compressed output format is allowed, and

if the rule does not allow clear compressed output format, the compressed encrypted digital content is provided to the DCR in a form which prevents production of clear compressed output as the output of the DCR.

26. The DCR according to claim 25 and wherein the local scrambling descrambler is operative to perform exactly one of the following operations based, at least in part, on the received control information:

receive an input and produce an output substantially identical to the received input; and

receive an input, and perform descrambling on the received input, thereby producing an output.

27. The DCR according to either claim 25 or claim 26 and wherein the local scrambler is operative to perform exactly one of the following operations based, at least in part, on the received control information:

receive an input and produce an output substantially identical to the received input; and

receive an input and perform local scrambling on the received input, thereby producing an output.

28. The DCR according to claim 25 and also comprising:

an output-producing hardware device,

wherein at least the content output unit is comprised in the hardware device.

29. The DCR according to claim 25 and wherein the hardware device is comprised in a single integrated circuit.

30. The DCR according to claim 29 and wherein the integrated circuit is comprised in a smart card.

31. The DCR according to any of claim 25 and also comprising:

a rendering device which renders the output sensible to at least one human sense.

32. The DCR according to claim 31 and wherein the rendering device comprises at least one of the following:

an audio rendering device;

a visual rendering device; and

an audio/visual rendering device.

33. The DCR according to claim 25 and wherein the XDDC is operative, based, at least in part, on the received control information, to receive an input, and descramble and decode the received input in an atomic operation, thereby producing an output.

34. A content-protected personal video recorder (PVR) comprising:

the DCR of claim 25;

and

a PVR unit comprising PVR storage media, the PVR unit receiving the output produced by the DCR.

35. The content-protected PVR according to claim 34 and wherein the PVR unit is operative to store the received output on the PVR storage media.

36. The content-protected PVR according to claim 34 and wherein the output produced by the DCR comprises locally scrambled output.

37. The content-protected PVR according to claim 34 and wherein the PVR unit is operative to retrieve the stored output from the PVR storage media.

38. The content-protected PVR according to claim 37 and wherein the output retrieved by the PVR comprises locally scrambled output.

39. The content-protected PVR according to claim 37 and wherein the DCR performs at least one of the following on the locally scrambled output retrieved by the PVR:

decryption; and

decompression.

40. The content-protected PVR according to claim 34 and wherein the PVR unit is operative to store received XEA encrypted output on the PVR storage media.

41. The content-protected PVR according to claim 34 and wherein the output produced by the DCR comprises XEA encrypted output.

42. The content-protected PVR according to claim 34 and wherein the PVR unit is operative to retrieve the stored XEA encrypted output from the PVR storage media.

43. The content-protected PVR according to claim 42 and wherein the output retrieved by the PVR comprises XEA encrypted output.

44. The content-protected PVR according to claim 42 and wherein the DCR performs, as an atomic operation, decryption and decompression on the XEA encrypted output retrieved by the PVR.

45. A content-protected television system comprising:

the DCR of claim 25;

and

a television unit, the television unit receiving the output produced by the DCR.

46. The content-protected television system according to claim 45 and wherein the television unit comprises an analog television unit.

47. The content-protected television system according to claim 45 and wherein the television unit comprises a digital television unit.