Method and Apparatus for Composing a Digital Rights Management License Format
A process composes a content license for a set of content. The content license has a static portion and a dynamic portion. Further, the process inserts a master key into the static portion. In addition, the process inserts a plurality of content rule sets of values into the dynamic portion and composes a unique content encryption key for each segment of content associated with one of the content rule sets of values as each of the content rule sets of values is sequentially received during recording of the content. The unique content encryption key is based on the master key and at least a subset of the content rule set of values for a corresponding segment of the content. The unique content encryption key is utilized for encryption of each segment of the content to generate a plurality of encrypted content segments for storage on the storage medium.
1 . A method comprising:
composing a content license for a set of content, the content license having a static portion and a dynamic portion;
inserting a master key into the static portion; and
inserting a plurality of content rule sets of values into the dynamic portion and composing a unique content encryption key for each segment of content associated with one of the content rule sets of values as each of the content rule sets of values is sequentially received during recording of the content, the unique content encryption key being based on the master key and at least a subset of the content rule set of values for a corresponding segment of the content, the unique content encryption key being utilized for encryption of each segment of the content to generate a plurality of encrypted content segments for storage on the storage medium.
2 . The method of claim 1 , wherein the storage medium is associated with a digital video recorder.
3 . The method of claim 1 , wherein the subset of the content rule set includes one or more copy protection bits.
4 . The method of claim 1 , wherein the static portion also includes a start time at which recording of the content begins.
5 . The method of claim 1 , wherein the static portion also includes a content name.
6 . The method of claim 1 , wherein the static portion also includes a content source identifier to identify from which source the content was received.
7 . The method of claim 1 , wherein the dynamic portion also includes a list of the plurality of content rule sets and an index associated with each content rule set in the list.
8 . The method of claim 7 , wherein the list is stored in a dynamic array.
9 . The method of claim 1 , wherein the dynamic portion also includes a start of recording timestamp for each corresponding segment of the content.
10 . The method of claim 1 , wherein the dynamic portion also includes, for each segment, an expiration time for the corresponding segment.
11 . The method of claim 1 , wherein the dynamic portion also includes, for each segment, content resolution information for the corresponding segment.
12 . A method comprising:
receiving a segment of content and a content rule set of values corresponding to the segment of content;
providing the content rule set of values to a digital rights management component so that a content license is composed, the content license having a static portion and a dynamic portion, the static portion including a master key, the dynamic portion including the content rule set of values;
encrypting the segment of the content with a unique content encryption key to generate an encrypted segment of content, the unique content encryption key for the segment of content being generated by the digital rights management component based on the master key and the content rule set of values; and
recording the encrypted segment of content on to a storage medium.
13 . The method of claim 12 , further comprising decrypting the encrypted segment of content during playback with the unique content encryption key.
14 . The method of claim 12 , wherein the storage medium is associated with a digital video recorder.
15 . The method of claim 12 , wherein the content rule set of values includes one or more copy protection bits.
16 . A method comprising:
receiving a segment of content and a content rule set of values corresponding to the segment of content;
providing the content rule set of values to a digital rights management component so that a content license is composed, the content license having a static portion and a dynamic portion, the static portion including a master key, the dynamic portion including the content rule set of values;
encrypting the segment of the content with a unique content encryption key to generate an encrypted segment of content, the unique content encryption key for the segment of content being generated by the digital rights management component based on the master key and the content rule set of values;
inserting a marker token corresponding to the unique content encryption key into an index file, the marker token including an index and the content rule set of values associated with the unique content encryption key so that the content rule set of values associated with the unique content encryption key is retrieved during trick mode playback; and
recording the encrypted segment of content on to a storage medium.
17 . The method of claim 16 , further comprising decrypting the encrypted content segment associated with a trick play during trick mode playback with the unique content encryption key.
18 . The method of claim 17 , wherein the content segment associated with a trick play is a content segment to which a user provides a rewind instruction.
19 . The method of claim 17 , wherein the content segment associated with a trick play is a content segment to which a user provides a fast forward instruction.
20 . The method of claim 17 , wherein the content segment associated with a trick play is a content segment to which a user provides a jump instruction.