METHOD AND APPARATUS FOR PRE-ENCRYPTING VOD MATERIAL WITH A CHANGING CRYPTOGRAPHIC KEY

摘要

Streaming content is encrypted by segmenting the content into a plurality of crypto periods, and by encrypting the content for each of a plurality of crypto periods with a different cryptographic key. The crypto periods are based on either (i) fixe d time intervals, (ii) a fixed number of packets, (iii) a fixed marker count, or (i v) a pseudo random number of packets. Methods are provided for determining how to record the key changing criteria, and how to convey this information to VOD servers.