Persistent license for stored content

• US 20050187879A1
• Filed: 02/19/2004
• Published: 08/25/2005
• Est. Priority Date: 02/19/2004
• Status: Abandoned Application

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Barrett, Peter T., Zigmond, Daniel J., Green, Dustin L., Grossman, John H. IV
• Application Number:
  US10/782,678
• Publication Number:
  US 20050187879A1
• Time in Patent Office: Days
• US Class Current: 705/59
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0825 using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates
• CPC Class Codes: H04L 9/083 involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP]

Abstract

In an implementation, a method includes forming a request by a client for communication to a licensing server. The request is for storing encrypted content by the client. A persistent license is received at the client in response to the request. The persistent license includes a key that is encrypted. The key, when decrypted, provides access to the encrypted content. The key is configured to be decrypted by the licensing server. The client however, is not configured to decrypt the key from the persistent license. The persistent license and the encrypted content are stored by the client.

Claims

1. A method comprising:

forming a request by a client to access encrypted content, wherein;

the request includes a persistent license for communication to a licensing server; and

the persistent license includes a key that is encrypted such that the key is not accessible by the client; and

receiving a license in response to the request, wherein the received license includes the key that is;

accessible by the client; and

for accessing the encrypted content.

2. A method as described in claim 1, further comprising:

forming an initial request for;

communication to the licensing server; and

storing encrypted content by the client;

receiving the persistent license at the client in response to the initial request; and

storing the encrypted content and the persistent license by the client.

3. A method as described in claim 1, further comprising:

forming an initial request by another client for;

communication to the licensing server; and

storing encrypted content by the other client;

receiving the persistent license at the other client in response to the initial request;

storing the encrypted content and the persistent license by the other client; and

obtaining the persistent license by the client from the other client.

4. A method as described in claim 1, wherein the received license is a boundary license and the key is a boundary key, and further comprising:

decrypting a session license utilizing a client key to obtain a session key;

decrypting the boundary license utilizing the session key to obtain the boundary key;

decrypting a content license utilizing the boundary key to obtain a content key; and

decrypting the encrypted content utilizing the content key.

5. A method as described in claim 4, wherein:

the session license includes access rules for the client for a session initiated between the client and the licensing server;

the boundary license includes access rules for the client for the encrypted content that is within a rights boundary in the encrypted content; and

the content license includes access rules for the client for the encrypted content.

6. A method as described in claim 4, wherein:

the persistent license was encrypted using an asymmetric encryption algorithm; and

the encrypted content, the boundary license, and the content license were encrypted using respective symmetric encryption algorithms.

7. A method as described in claim 1, further comprising:

decrypting a session license utilizing a client key to obtain a session key, wherein the session license includes access rules for a session initiated between the client and the licensing server;

decrypting the received license utilizing the session key to obtain a decrypted boundary license, wherein;

the received license is an encrypted boundary license and the key within the boundary license is a boundary key; and

the boundary license includes access rules for content within a rights boundary in the encrypted content that is at least one of a television program and a television channel;

decrypting a content license utilizing the boundary key to obtain a content key, wherein the content license includes access rules for the encrypted content; and

decrypting the encrypted content utilizing the content key, wherein the encrypted content includes at least a portion of a television broadcast.

8. A method as described in claim 1, wherein the key is for decrypting the encrypted content.

9. A method as described in claim 1, wherein the encrypted content is streamed to the client.

10. One or more computer-readable media comprising computer-executable instructions that, when executed, perform the method as recited in claim 1.

11. A method comprising:

forming a request by a client for communication to a licensing server, wherein the request is for storing encrypted content by the client;

receiving a persistent license at the client in response to the request, wherein;

the persistent license includes a key that is encrypted;

the key, when decrypted, provides access to the encrypted content;

the key is configured to be decrypted by the licensing server; and

the client is not configured to decrypt the key from the persistent license;

and

storing the persistent license and the encrypted content by the client.

12. A method as described in claim 11, further comprising:

forming a subsequent request by the client to access the stored content, wherein the subsequent request;

is for communication to the licensing server; and

includes the persistent license; and

receiving a second license at the client in response to the subsequent request, wherein;

the second license includes the key; and

the second license is configured to be decrypted by the client such that the client obtains access to the key.

13. A method as described in claim 11, further comprising:

forming a subsequent request by another client to access the stored content, wherein the subsequent request;

is for communication to the licensing server; and

includes the persistent license; and

receiving a second license at the other client in response to the subsequent request, wherein;

the second license includes the key; and

the second license is configured to be decrypted by the other client such that the other client obtains access to the key.

14. A method as described in claim 11, wherein the encrypted content is streamed to the client.

15. A method as described in claim 11, wherein the license includes a certificate for verifying the licensing server by the client.

16. One or more computer-readable media comprising computer-executable instructions that, when executed, perform the method as recited in claim 11.

17. A method comprising:

forming a first request for communication to a licensing server, wherein the first request is for storing encrypted content;

receiving a persistent license in response to the request, wherein the persistent license includes a boundary key;

storing the persistent license and the content;

forming a second request to access the encrypted content, wherein the second request includes the persistent license;

sending the second request to the licensing server;

receiving a boundary license in response to the second request, wherein the boundary license includes the boundary key;

decrypting the boundary license using a session key to obtain the boundary key;

decrypting a content license using the boundary key to obtain a content key; and

decrypting the encrypted content using the content key.

18. A method as described in claim 17, wherein the forming of:

the first request is performed by a first client; and

the second request is performed by a second client.

19. A method as described in claim 17, wherein the first and second requests are formed by a client.

20. A method as described in claim 17, further comprising at least one of decoding the decrypted content and outputting the decoded content.

21. A method as described in claim 17, wherein:

the persistent license was encrypted using an asymmetric encryption algorithm; and

the content, the boundary license, and the content license were encrypted using respective symmetric encryption algorithms.

22. One or more computer-readable media comprising computer-executable instructions that, when executed, perform the method as recited in claim 17.

23. A client comprising:

a processor; and

memory configured to maintain;

a persistent license including a key that is encrypted; and

a playback application that is executable on the processor to;

form a request to access encrypted content, wherein the request;

is for communication to a licensing server; and

includes the persistent license;

receive a response to the request that includes the key; and

access the encrypted content utilizing the key.

24. A client as described in claim 23, wherein the key is for decrypting the encrypted content.

25. A client as described in claim 23, wherein:

the memory is further configured to maintain a content license;

the key included in the persistent license is for decrypting the content license;

the content license includes a content key; and

the content key is for decrypting the encrypted content.

26. A client as described in claim 23, wherein:

the memory is further configured to maintain a content license;

the key included in the persistent license is for decrypting the content license;

the content license includes a content key;

the content key is for decrypting the encrypted content; and

the playback application is executable to;

decrypt the content license using the key to obtain the content key; and

decrypt the content using the content key.

27. A client as described in claim 23, wherein:

the memory is further configured to maintain a session license, a content license, and a client key;

the client key is for decrypting the session license;

the session license includes a session key for decrypting the response;

the response is a boundary license;

the key included in the response is a boundary key for decrypting the content license;

the content license includes a content key; and

the content key is for decrypting the encrypted content.

28. A client as described in claim 23, wherein:

the memory is further configured to maintain a session license, a content license, and a client key;

the client key is for decrypting the session license;

the session license includes a session key for decrypting the response;

the response is a boundary license;

the key included in the response is a boundary key for decrypting the content license;

the content license includes a content key;

the content key is for decrypting the encrypted content; and

the playback application is executable to;

decrypt the session license using the client key to obtain the session key;

decrypt the boundary license using the session key to obtain the boundary key;

decrypt the content license using the boundary key to obtain the content key; and

decrypt the content using the content key.

29. A client as described in claim 23, wherein the playback application is further executable to:

form an initial request for;

communication to the licensing server; and

storing encrypted content by the playback application;

receive the persistent license in response to the initial request; and

store the encrypted content and the persistent license.

30. A client as described in claim 23, wherein the playback application is further executable to form a request to obtain the encrypted content from another client.

31. A client as described in claim 23, further comprising a tuner configured to receive the encrypted content when streamed over a network.

32. A client as described in claim 23, wherein the license includes a certificate for verifying the licensing server.

33. A system comprising:

a network;

a client including;

a persistent license having a key that is encrypted; and

a playback application that is executable to;

form a request to access encrypted content, wherein the request includes the persistent license;

receive a response to the request that includes the key; and

access the encrypted content utilizing the key; and

a licensing server including a licensing module that is executable to;

receive the request including the persistent license;

decrypt the persistent license to obtain the key; and

form the response that includes the key for communication to the client over the network.

34. A system as described in claim 33, wherein:

the client includes a content license;

the key included in the persistent license is for decrypting the content license;

the content license includes a content key; and

the content key is for decrypting the encrypted content.

35. A system as described in claim 33, wherein:

the client includes a content license;

the key included in the persistent license is for decrypting the content license;

the content license includes a content key;

the content key is for decrypting the encrypted content; and

the playback application is executable to;

decrypt the content license utilizing the key to obtain the content key; and

decrypt the content utilizing the content key.

36. A system as described in claim 33, wherein:

the client includes a session license, a content license, and a client key;

the client key is for decrypting the session license;

the session license includes a session key for decrypting the response;

the response is a boundary license;

the key included in the response is a boundary key for decrypting the content license;

the content license includes a content key; and

the content key is for decrypting the encrypted content.

37. A system as described in claim 33, wherein:

the client includes a session license, a content license, and a client key;

the client key is for decrypting the session license;

the session license includes a session key for decrypting the response;

the response is a boundary license;

the key included in the response is a boundary key for decrypting the content license;

the content license includes a content key;

the content key is for decrypting the encrypted content; and

the playback application is executable to;

decrypt the session license utilizing the client key to obtain the boundary key;

decrypt the boundary license utilizing the session key to obtain the boundary key;

decrypt the content license utilizing the boundary key to obtain the content key;

decrypt the content utilizing the content key; and

play the decrypted content.

38. A system as described in claim 33, wherein the key is for decrypting the encrypted content.

39. A system as described in claim 33, wherein the persistent license is encrypted with an asymmetric encryption algorithm and the server includes a server private key for decrypting the persistent license.

40. A system as described in claim 33, wherein the playback application is further executable to:

form an initial request for;

communication to the licensing server; and

storing encrypted content by the playback application;

receive the persistent license in response to the initial request; and

store the encrypted content and the persistent license.

41. A system as described in claim 33, wherein the playback application is further executable to form a request to obtain the encrypted content from another client.

42. A system as described in claim 33, wherein the encrypted content is streamed to the client over the network.