Patent ID: 8452008
Filing Date: 2013-05-28
Classification: H04N

Abstract:
1. A computer-implemented method of distributing content to a plurality of clients, the method comprising: accessing a set of encoded content to be distributed to a plurality of clients, wherein the set of encoded content comprises a plurality of independently decodable frames and a plurality of frames that require other frames in order to be decoded; identifying a first portion of the set of encoded content to be distributed as a set of crucial content, wherein the set of crucial content is the plurality of independently decodable frames and is required to properly render, after a decryption process, the set of encoded content; identifying a second portion of the set of encoded content to be distributed as a set of non-crucial content, wherein the set of non-crucial content is all remaining content in the set of encoded content to be distributed including the plurality of frames that require other frames in order to be decoded; encrypting, for each of the plurality of clients, the set of crucial content with a first encryption key that is unique to each of the plurality of clients; determining a second encryption key that is common between each client in the plurality of clients; encrypting the set of non-crucial content with the second encrypting key that is common between each client in the plurality of clients; establishing a multicast channel with the plurality of clients; establishing a unicast channel with at least one of the plurality of clients; transmitting the encrypted set of crucial content to at least one of the plurality of clients on the unicast channel; and transmitting the encrypted set of non-crucial content to each of the plurality of clients on the multicast channel.