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A DRM scheme that may be optionally invoked by the owner. With the DRM protection turned on, the media is encrypted before it is distributed in a P2P network, and is decrypted prior to its use (play back). The peers may still efficiently distribute and serve without authorization from the owner. Nevertheless, when the media is used (played back), the client node must seek proper authorization from the owner. The invention further provides a hierarchical DRM scheme wherein each packet of the media is associated with a different protection level. In the hierarchical DRM scheme of the invention there is usually an order of the protection level. As a result, in one embodiment of the invention, the decryption key of a lower protection layer is the hash of the decryption key at the higher protection level. That way, a user granted access to the high protection layer may simply hold a single license of that layer, and obtain decryption keys of that layer and below. The invention further...

Inventors: Jin Li, Yi Cui
Original Assignee: Microsoft Corporation
Current U.S. Classification: 726/28

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Claims

1. A process for managing digital rights to media, comprising the process actions of:

in a media file comprised of media packets, for each packet designating one of a set of predetermined hierarchical access levels ordered from lowest to highest;

assigning to a user an access level from said set of hierarchical access levels; and

granting access to a user to media packets that are designated with his hierarchical access level and below.

2. The process of claim 1 wherein the predetermined access levels relate to movie ratings.

3. The process of claim 1 wherein the predetermined access levels relate to media quality.

4. The process of claim 1 wherein each media packet is encrypted/decrypted with a separate key based on its hierarchical access level.

5. The process of claim 4 wherein the decryption key of each lower access level is the hash of the decryption key of the higher access level.

6. The process of claim 5 wherein when a user is granted access to the decryption key of a higher access level may automatically generate the decryption keys of that level and below.

7. The process of claim 1 wherein the predetermined access levels relates to the ability to access only a portion of the media packets in the media file.

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