Encrypted content streaming

• US 9,071,421 B2
• Filed: 12/15/2010
• Issued: 06/30/2015
• Est. Priority Date: 12/15/2010
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Oney, Adrian J., Burns, Quintin S., Born, Bryan
• Primary Examiner(s): HOLDER, BRADLEY W
• Application Number:
  US12/969,414
• Publication Number:
  US 20120155639A1
• Time in Patent Office: 1,658 Days
• Field of Search: 726/30, 726/26, 726/27, 726/28, 726/29
• US Class Current: 1/1
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0836 using tree structure or hierarchical structure
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• 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 21/47202 for requesting content on demand, e.g. video on demand
• 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 21/8355 involving usage data, e.g. number of copies or viewings allowed

Abstract

Encrypted content streaming is provided by a method comprising holding an encrypted content stream that is cryptographically encrypted from a content stream with a content key, and holding an encrypted content key that is cryptographically encrypted from the content key with one or more intermediate encryption keys. The method further comprises serving the encrypted content stream to a plurality of content consumption devices, wherein the encrypted content stream is embedded with a leaf license comprising the encrypted content key, and wherein the encrypted content stream is cryptographically decryptable by a content consumption device having a scalable root license providing one or more intermediate root keys from which the content consumption device derives the one or more intermediate decryption keys paired to the one or more intermediate encryption keys.

Claims

1. A method of streaming encrypted content from a content server computing system, the method comprising:

at the content server computing system, holding an encrypted content stream that is cryptographically encrypted from a content stream with a content key;

at the content server computing system, holding an encrypted content key that is cryptographically encrypted from the content key with one or more intermediate encryption keys; and

from the content server computing system, serving the encrypted content stream to a plurality of content consumption devices via a computer network, at least one of the plurality of content consumption devices having a different scalable root license than another of the plurality of content consumption devices, the encrypted content stream embedded with a plurality of copies of a leaf license comprising the encrypted content key, the encrypted content stream cryptographically decryptable by a content consumption device having a scalable root license providing one or more intermediate root keys from which the content consumption device derives one or more intermediate decryption keys paired to the one or more intermediate encryption keys, the encrypted content stream not cryptographically decryptable by another content consumption device that does not have the scalable root license, and the plurality of copies of the leaf license temporally spaced-apart within the encrypted content stream to accommodate one or more of the plurality of content consumption devices just joining the encrypted content stream.

2. The method of claim 1, wherein the encrypted content stream is one of a plurality of encrypted content streams collectively constituting a channel, each encrypted content stream embedded with a leaf license comprising an encrypted content key corresponding to that encrypted content stream.

3. The method of claim 2, wherein each of the plurality of encrypted content streams of the channel is cryptographically encrypted with a same content key.

4. The method of claim 2, wherein each of the plurality of encrypted content streams of the channel is cryptographically encrypted with different content keys.

5. The method of claim 2, wherein the plurality of encrypted content streams includes at least one video stream and at least one corresponding audio stream.

6. The method of claim 5, wherein the plurality of encrypted content streams further includes a second audio stream.

7. The method of claim 5, wherein the plurality of encrypted content streams further includes a second video stream.

8. The method of claim 1, further comprising changing the one or more intermediate encryption keys cryptographically encrypting the content key to form an updated encrypted content key and serving the encrypted content stream embedded with an updated leaf license comprising the updated encrypted content key.

9. The method of claim 8, wherein the encrypted content stream is embedded with the updated leaf license in addition to the leaf license.

10. A method of streaming encrypted content from a content server computing system, the method comprising:

at the content server computing system, holding an encrypted content stream that is cryptographically encrypted from a content stream with a content key;

at the content server computing system, holding an encrypted content key that is cryptographically encrypted from the content key with one or more intermediate encryption keys; and

from the content server computing system, serving the encrypted content stream to a plurality of content consumption devices via a computer network, at least one of the plurality of content consumption devices having a different scalable root license than another of the plurality of content consumption devices, the encrypted content stream embedded with a plurality of copies of a leaf license comprising the encrypted content key, the encrypted content stream cryptographically decryptable by a content consumption device having a scalable root license providing one or more intermediate root keys from which the content consumption device derives one or more intermediate decryption keys paired to the one or more intermediate encryption keys, the one or more intermediate decryption keys being related to the one or more intermediate root keys via a hierarchical key tree having a binary tree structure, the encrypted content stream not cryptographically decryptable by another content consumption device that does not have the scalable root license, and the plurality of copies of the leaf license temporally spaced-apart within the encrypted content stream to accommodate one or more of the plurality of content consumption devices just joining the encrypted content stream.

11. The method of claim 10, wherein the encrypted content stream is one of a plurality of encrypted content streams collectively constituting a channel, each encrypted content stream embedded with a leaf license comprising an encrypted content key corresponding to that encrypted content stream.

12. The method of claim 11, wherein each of the plurality of encrypted content streams of the channel is cryptographically encrypted with a same content key.

13. The method of claim 11, wherein each of the plurality of encrypted content streams of the channel is cryptographically encrypted with different content keys.

14. The method of claim 11, wherein the plurality of encrypted content streams includes at least one video stream and at least one corresponding audio stream.

15. The method of claim 14, wherein the plurality of encrypted content streams further includes a second audio stream.

16. The method of claim 14, wherein the plurality of encrypted content streams further includes a second video stream.

17. The method of claim 10, further comprising changing the one or more intermediate encryption keys cryptographically encrypting the content key to form an updated encrypted content key and serving the encrypted content stream embedded with an updated leaf license comprising the updated encrypted content key.

18. The method of claim 17, wherein the encrypted content stream is embedded with the updated leaf license in addition to the leaf license.

19. A method of streaming encrypted content from a content server computing system, the method comprising:

holding a plurality of encrypted content streams each cryptographically encrypted from a corresponding content stream with a corresponding content key, the plurality of encrypted content streams collectively constituting a channel;

for each encrypted content stream, holding an encrypted content key that is cryptographically encrypted from the corresponding content key with one or more intermediate encryption keys; and

from the content server computing system, serving one or more of the plurality of encrypted content streams to a plurality of content consumption devices via a computer network, at least one of the plurality of content consumption devices having a different scalable root license than another of the plurality of content consumption devices, each of the one or more encrypted content streams embedded with a leaf license comprising an encrypted content key corresponding to that encrypted content stream, each such encrypted content stream cryptographically decryptable by a content consumption device having a scalable root license providing one or more intermediate root keys from which the content consumption device derives one or more intermediate decryption keys paired to the one or more intermediate encryption keys, each such encrypted content stream not cryptographically decryptable by another content consumption device that does not have the scalable root license.