Unified Broadcast Encryption System
AssigneeInternational Business Machines Corporation
InventorsHongxia Jin, Jeffrey Bruce Lotspiech
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Abstract
A system and method is disclosed for performing unified broadcast encryption and traitor tracing for digital content. In one embodiment a media key tree is divided into S subtrees, the media key tree including media keys and initial values, which may be random values. The digital content is divided into a plurality of segments and at least some of the segments are converted into a plurality of variations. The random values are transformed into media key variations and a separate media key variant is assigned to each of the subdivided subtrees. A unified media key block including the media key tree is stored on the media.
Claims20
A processor-implemented method of performing a unified broadcast encryption and a traitor tracing for digital content, comprising:
- dividing a media key tree into subtrees, said media key tree including media keys and initial values;
- dividing said digital content into a plurality of segments and converting at least some of said segments into a plurality of variations;
- transforming said initial values into media key variations;
- assigning a separate media key variant to each of said subtrees;
- storing a unified media key block including said media key tree on said media;
- decrypting said digital content by reading and processing said media key block on said media to obtain said media key variations required for each of said variations of said digital content;
- and
- transforming said initial values using a program on said media into media key variations.
A processor-implemented system for performing a unified broadcast encryption and a traitor tracing for a digital content stored on digital media comprising:
- a unified media key block module including a media key tree having media keys and initial values said initial values being transformable into media key variations;
- said unified media key block module dividing said digital content into a plurality of segments and converting at least some of said segments into a plurality of variations;
- a transformation unit for transforming said initial values into media key variations, wherein said unified media key block module generates a unified media key block encrypting said digital content.
A method for encrypting digital content, comprising:
- receiving digital content;
- introducing a plurality of content variations into said media;
- generating a media key tree including media keys and initial values;
- transforming said initial values into media key variations;
- assigning a separate media key variant to subtrees within said media key tree;
- storing a unified media key block including said media key tree on said digital media;
- calculating at least one title key and identify at least zero content variations;
- and
- said unified media key block module decrypting the particular variation of said segment, for each segment in said content, using said calculated title key.
A computer program product comprising a computer usable medium having a computer readable program, wherein said computer readable program when executed on a computer causes said computer to:
- generate a media key tree including media keys and initial values;
- divide said digital content into a plurality of segments and convert at least some of said segments into a plurality of variations;
- transform said initial values into media key variations;
- assign a separate media key variant to each of said subdivided subtrees;
- and
- store a unified media key block including said media key tree on said media.
Dependencies are inferred from the claim text.