Federated digital rights management scheme including trusted systems
View Patent ↗Federated systems for issuing playback certifications granting access to technically protected content are described. One embodiment of the system includes a registration server connected to a network, a content server connected to the network and to a trusted system, a first device including a non-volatile memory that is connected to the network and a second device including a non-volatile memory that is connected to the network. In addition, the registration server is configured to provide the first device with a first set of activation information in a first format, the first device is configured to store the first set of activation information in non-volatile memory, the registration server is configured to provide the second device with a second set of activation information in a second format, and the second device is configured to store the second set of activation information in non-volatile memory.
1. A method of decoding encrypted content using a playback device on which an active user encryption key is stored, where the content includes frames of video and at least a portion of a plurality of frames of video are encrypted using at least one frame encryption key, and the at least one frame encryption key is encrypted using a content encryption key, and copies of the content encryption key are separately encrypted using a plurality of different user encryption keys including the active user encryption key, the method comprising:
obtaining encrypted content using a playback device, where the content includes frames of video and at least a portion of a plurality of frames of video are encrypted using at least one frame encryption key;
obtaining using the playback device a copy of the at least one frame encryption key that is encrypted using a content encryption key and copies of the content encryption key that are separately encrypted using a plurality of different user encryption keys including an active user encryption key stored on the playback device;
determining using the playback device which of the encrypted copies of the content encryption key was encrypted using the active user encryption key stored on the playback device;
decrypting the identified copy of the content encryption key using the playback device and the active user encryption key;
decrypting the at least one frame encryption key using the playback device and the decrypted content encryption key;
playing back frames of the encrypted content using the playback device, where playing back frames of the encrypted content further comprises:
identifying any portions of a frame that are encrypted;
identifying the frame encryption key used to encrypt the identified portions of the frame;
decrypting the encrypted portions of the frame using the identified frame encryption key; and
decoding the unencrypted frame of video.
2. The method of claim 1 , wherein the encrypted copies of the content encryption key are entries in a table.
3. The method of claim 1 , wherein the encrypted content is sent in response to a request from the playback device.
4. The method of claim 1 , wherein the active user encryption key is encrypted by a base encryption key, where the base encryption key is inherent to the class of devices to which the playback device belongs.
5. The method of claim 1 , wherein digital rights specified with respect to the content by a content provider are encrypted using at least one base encryption key, where the base encryption key is inherent to the class of devices to which the playback device belongs.
6. The method of claim 1 , further comprising:
identifying, using the playback device, an active base encryption key for the particular class of device that is attempting to access the content; and
accessing, using the playback device, information concerning the type of playback parameters supported by a playback certification included with the content.
7. The method of claim 6 , where the playback certification includes multiple base encryption keys.
8. The method of claim 7 , where each of the base keys is identifiable using a unique identifier.
9. The method of claim 7 , where each of the base encryption keys is used to encrypt the same information.
10. A playback device configured to playback encrypted content, where the content includes frames of video and at least a portion of a plurality of frames of video are encrypted using at least one frame encryption key, and the at least one frame encryption key is encrypted using a content encryption key, and copies of the content encryption key are separately encrypted using a plurality of different user encryption keys including the active user encryption key, the playback device comprising:
memory comprising a playback application;
a processor;
wherein the processor is configured by the playback application to:
obtain encrypted content, where the content includes frames of video and at least a portion of a plurality of frames of video are encrypted using at least one frame encryption key;
obtain a copy of the at least one frame encryption key that is encrypted using a content encryption key and copies of the content encryption key that are separately encrypted using a plurality of different user encryption keys including an active user encryption key stored on the playback device;
determine which of the encrypted copies of the content encryption key was encrypted using the active user encryption key stored on the playback device;
decrypt the identified copy of the content encryption key using the active user encryption key;
decrypt the at least one frame encryption key using the decrypted content encryption key;
play back frames of the encrypted content, where playing back frames of the encrypted content further comprises:
identifying any portions of a frame that are encrypted;
identifying the frame encryption key used to encrypt the identified portions of the frame;
decrypting the encrypted portions of the frame using the identified frame encryption key; and
decoding the unencrypted frame of video.
11. The playback device of claim 10 , wherein the encrypted copies of the content encryption key are entries in a table.
12. The playback device of claim 10 , wherein the encrypted content is sent in response to a request from the playback device.
13. The playback device of claim 10 , wherein the active user encryption key is encrypted by a base encryption key, where the base encryption key is inherent to the class of devices to which the playback device belongs.
14. The playback device of claim 10 , wherein digital rights specified with respect to the content by a content provider are encrypted using at least one base encryption key, where the base encryption key is inherent to the class of devices to which the playback device belongs.
15. The playback device of claim 10 , wherein the processor is further configured by the playback application to:
identify an active base encryption key for the particular class of device that is attempting to access the content; and
access information concerning the type of playback parameters supported by a playback certification included with the content.
16. The playback device of claim 15 , where the playback certification includes multiple base encryption keys.
17. The playback device of claim 16 , where each of the base keys is identifiable using a unique identifier.
18. The playback device of claim 16 , where each of the base encryption keys is used to encrypt the same information.