Patent ID: 7865723

Claim:
A method of providing program information to client devices for a multicast stream of digital content that is being multicast from a first multicast address, comprising: generating session description messages for the multicast stream of digital content, each of the session description messages having at least one content access parameter for the multicast stream of digital content, wherein the at least one content access parameter includes channel key identification data associated with a channel of the multicast stream of digital content, and wherein the channel key identification data identifies one or more channel key sets that are securely stored in a server device, and wherein the one or more channel key sets can be used to derive content decryption keys that can be used to decrypt digital content being multicast in the channel; signing each of the session description messages using a cryptographic key, comprising generating authentication data for each session description message using the cryptographic key, and appending the authentication data to each session description message; and multicasting the session description messages to the client devices using a second multicast address.