Secure presentation of media streams in response to encrypted digital content

• US 7,702,101 B2
• Filed: 07/09/2003
• Issued: 04/20/2010
• Est. Priority Date: 07/09/2002
• Status: Expired due to Fees

• Current Assignee: Kaleidescape Incorporated
• Original Assignee: Kaleidescape Incorporated
• Inventors: Watson, Stephen, Rechsteiner, Paul, Hui, Kevin, Collens, Daniel A., Malcolm, Michael A.
• Primary Examiner(s): Moazzami; Nasser G
• Assistant Examiner(s): Reza; Mohammad W
• Application Number:
  US10/616,899
• Publication Number:
  US 20040088557A1
• Time in Patent Office: 2,477 Days
• Field of Search: 380/725, 380212-220, 380/37, 380/27, 380/202, 380/239, 713/193, 705/50
• US Class Current: 380/37
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 21/23476 by partially encrypting, e.g. encrypting the ending portion of a movie
• CPC Class Codes: H04N 21/4181 for conditional access
• CPC Class Codes: H04N 21/4182 for identification purposes, e.g. storing user identification data, preferences, personal settings or data restricting access to computer systems by authenticating users using a predetermined code in combination with an additional device, e.g. dongle or smart card G06F21/123
• CPC Class Codes: H04N 21/4367 Establishing a secure communication between the client and a peripheral device or smart card
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4627 Rights management associated to the content 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 21/8355 involving usage data, e.g. number of copies or viewings allowed
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• 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

Abstract

Secure presentation of media streams includes encoding the media streams into digital content, encrypting a portion of that digital content, the portion being required for presentation, in which the encrypted version is substantially unchanged in formatting parameters from the clear version of the digital content. Selecting those portions for encryption so there is no change in distribution of the media stream: packetization of the digital data, or synchronization of audio with video portions of the media stream. When encoding the media stream into MPEG-2, refraining from encrypting information by which the video block data is described, packet formatting information, and encrypting the video block data using a block-substitution cipher. A block-substitution cipher can be used to encrypt each sequence of 16 bytes of video data in each packet, possibly leaving as many as 15 bytes of video data in each packet in the clear.

Claims

1. A method, comprising:

importing, by a processor, a media stream having an encrypted portion;

decrypting said encrypted portion;

encoding said media stream into digital content, wherein said encoding comprises;

encrypting a portion of that digital content, less than the entire digital content, the portion of the digital content that is encrypted being required for presentation of the media stream, said encrypting comprising;

encrypting at least some audio or video data using a block-substitution cipher;

not encrypting at least some audio or video data using that block-substitution cipher;

identifying a first set of data and a second set of data in the digital content; and

encrypting the first set of data and the second set of data, such that the first set of data can be made available to a first set of users and the second set of data can be made available to a second set of users, the first set of users being distinguishable from the second set of users; and

not encrypting a portion of that digital content, less than the entire digital content, the portion of the digital content that is not encrypted being necessary for conducting navigation operations on, without decrypting, the media stream represented by the digital content.

2. A method as in claim 1, wherein

said steps of encoding provide an MPEG encoding of at least some video data.

3. A method as in claim 1, wherein said encrypting said portion further comprises:

refraining from encrypting formatting information.

4. A method as in claim 1, wherein said digital content includes at least some audio or video data and at least some formatting information.

5. A method as in claim 1, wherein

the digital content includes a set of layers, each relatively higher-level layer representing an abstraction for which each relatively lower-level layer represents an implementation thereof

a first set of relatively higher-level layers represent audio or video information for the media stream, while a second set of relatively lower-level layers represent techniques by which that information is formatted or supplemented;

and

the step of encrypting is applied only to that portion of the digital content representing audio and video information.

6. A method as in claim 1, wherein

the digital content includes a set of layers, each relatively higher-level layer representing an abstraction for which each relatively lower-level layer represents an implementation thereof;

a first set of relatively higher-level layers represent audio or video information for the media stream, while a second set of relatively lower-level layers represent techniques by which that information is broken into packets, indexed, multiplexed, or supplemented with metadata; and

the step of encrypting is applied only to that portion of the digital content representing audio and video information.

7. A method as in claim 1, wherein

the digital content includes a set of layers, each relatively higher-level layer representing an abstraction for which each relatively lower-level layer represents an implementation thereof;

a first set of relatively higher-level layers represent audio and video information for the media stream, while a second set of relatively lower-level layers represent techniques by which that information is broken into packets, indexed, multiplexed, or supplemented with metadata; and

the step of encrypting is not applied to that portion of the digital content representing other than audio and video information.

8. A method as in claim 1, wherein the media stream includes at least one of:

still media, an illustration.

9. A method as in claim 1, including steps of selecting that portion of the digital content for encryption so there is no substantial change in distribution of that digital content.

10. A method as in claim 9, wherein said steps of selecting include ensuring there is no substantial change in packetization of a set of digital data in that digital content.

11. A method as in claim 9, wherein said steps of selecting include ensuring there is no substantial change in synchronization of audio with video portions of the media stream.

12. A method as in claim 9, wherein said steps of selecting include ensuring there is no substantial change in length of at least some identifiable audio or video data in that digital content.

14. A method as in claim 1, wherein those navigation operations include at least one of:

a rewind operation, a fast forward operation, a movement operation to a selected location within the digital content, a pause operation, a halt operation.

15. A method as in claim 1, wherein the encrypted version of that digital content is substantially unchanged in formatting parameters from an unencrypted version of that digital content.

16. A method as in claim 1, farther comprising:

encrypting substantially all of that digital content using an encryption approach relatively less secure than said encrypting said portion of that digital content.

17. A method as in claim 1, wherein said encrypting said portion further comprises:

encrypting only packet payloads when said digital content is one of the group;

an MPEG encoding, a variant of an MPEG encoding.

18. A method as in claim 1, wherein said decrypting comprises decrypting only formatting information within that digital content.

19. A method as in claim 1, wherein said decrypting comprises not decrypting metadata.

20. A method as in claim 1, wherein said decrypting comprises not decrypting data necessary for browsing or searching within a library of files.

13. A method, comprising:

importing, by a processor, a media stream having an encrypted portion;

decrypting said encrypted portion;

encoding said media stream into digital content, that digital content having a set of information nodes, those information nodes being disposed in at least a partial ordering, said encoding comprising;

encrypting a portion of that digital content, less than the entire digital content, the portion of the digital content that is encrypted being required for presentation of the media stream, said encrypting comprising;

encrypting at least some audio or video data using a block-substitution cipher;

not encrypting at least some audio or video data using that block-substitution cipher;

identifying a first set of data and a second set of data in the digital content; and

encrypting the first set of data and the second set of data, such that the first set of data can be made available to a first set of users and the second set of data can be made available to a second set of users, the first set of users being distinguishable from the second set of users; and

wherein an unencrypted portion of that digital content is substantially closed in a direction under that partial ordering, whereby it is possible to navigate the encrypted portion of that digital content without having to decrypt it.

21. A method as in claim 13, further comprising:

encrypting substantially all of that digital content using an encryption approach relatively less secure than said encrypting said portion of that digital content.

22. A method as in claim 13, wherein the encrypted version of that digital content is substantially unchanged in formatting parameters from an unencrypted version of that digital content.

23. A method as in claim 13, wherein those navigation operations include at least one of:

a rewind operation, a fast forward operation, a movement operation to a selected location within the digital content, a pause operation, a halt operation.

24. A method as in claim 13, wherein said encrypting said portion further comprises:

encrypting only packet payloads when the digital content is one of the group;

an MPEG encoding, a variant of an MPEG encoding.

25. A computer-readable storage medium having computer-executable instructions for performing steps comprising:

importing, by a processor, a media stream having an encrypted portion;

decrypting said encrypted portion;

encoding said media stream into a digital content format representing that media stream, said encoding comprising;

encrypting a portion of that digital content, less than the entire digital content, the portion of the digital content that is encrypted being required for presentation of the media stream, said encrypting comprising;

encrypting at least some audio or video data using a block-substitution cipher;

not encrypting at least some audio or video data using that block-substitution cipher;

identifying a first set of data and a second set of data in the digital content; and

encrypting the first set of data and the second set of data, such that the first set of data can be made available to a first set of users and the second set of data can be made available to a second set of users, the first set of users being distinguishable from the second set of users; and

wherein a portion of that digital content, less than the entire digital content, is not encrypted, the portion of the digital content that is not encrypted being necessary for conducting navigation operations on, without decrypting, the media stream represented by the digital content.

26. A computer-readable storage medium as in claim 25, wherein said encrypting comprises refraining from encrypting formatting information.

27. A computer-readable storage medium as in claim 25, wherein the media stream includes at least one of:

still media, an illustration.

28. A computer-readable storage medium as in claim 25, further comprising:

selecting that portion of the digital content for encryption so there is no substantial change in distribution of that digital content.

29. A computer-readable storage medium as in claim 28, further comprising:

ensuring there is no substantial change in packetization of a set of digital data in that digital content.

30. A computer-readable storage medium as in claim 28, farther comprising:

ensuring there is no substantial change in synchronization of audio with video portions of the media stream.

31. A computer-readable storage medium as in claim 28, farther comprising:

ensuring there is no substantial change in length of at least some identifiable audio or video data in that digital content.

32. A computer-readable storage medium having computer-executable instructions for performing steps comprising:

importing, by a processor, a media stream having an encrypted portion;

decrypting said encrypted portion;

encoding said media stream into digital content, that digital content having a set of information nodes, those information nodes being disposed in at least a partial ordering;

encrypting a portion of that digital content, the portion being encrypted less than the entire digital content format representing that media stream, the portion of the digital content that is encrypted being required for presentation of the media stream, said encrypting comprising;

encrypting at least some audio or video data using a block-substitution cipher;

not encrypting at least some audio or video data using that block-substitution cipher;

identifying a first set of data and a second set of data in the digital content; and

encrypting the first set of data and the second set of data, such that the first set of data can be made available to a first set of users and the second set of data can be made available to a second set of users, the first set of users being distinguishable from the second set of users; and

wherein an unencrypted portion of that digital content is substantially closed in a direction under that partial ordering, whereby it is possible to navigate the encrypted portion of that digital content without having to decrypt it.

33. A computer-readable storage medium as in claim 32, further comprising:

encrypting substantially all of that digital content using an encryption approach relatively less secure than said encrypting said portion of that digital content.

34. A computer-readable storage medium as in claim 32, further comprising:

encrypting only packet payloads when the digital content is one of the group;

an MPEG encoding, a variant of an MPEG encoding.