Patent ID: 7343013

Claim:
A Video On Demand (VOD) method that provides session based selective encryption, comprising: processing content by selecting first portions of the content for encryption under a selective encryption system and selecting second portions of the content to remain unencrypted; storing the first portions; storing second portions; receiving a request for delivery of the content from a subscriber terminal to initiate a VOD session; determining if the subscriber terminal has decryption capabilities associated with a first decryption method or a second decryption method; if the request is from a subscriber terminal having decryption capabilities associated with the first decryption method, then for each such request from a subscriber terminal having decryption capabilities associated with the first decryption method to initiate a VOD session: routing the first portions to a first encryption device that encrypts content for decryption under the first encryption method, to provide encryption of the first portions for the VOD session; routing the second portions around the first encryption device; encrypting neither the first nor the second portions using a second encryption device that encrypts content for decryption under the second decryption method for the VOD session; encrypting the first portions using a first encryption process at the first encryption device to produce encrypted first portions; and if the request is not from a subscribing terminal having decryption capabilities associated with the first decryption method: routing the first portions to a second encryption device that encrypts content for decryption under the second encryption method, to provide encryption of the first portions for the VOD session: routing the second portions around the second encryption device; encrypting neither the first nor the second portions using the first encryption device that encrypts content for decryption under the first decryption method for the VOD session; encrypting the first portions using the second encryption process at the second encryption device to produce encrypted first portions; and assembling a stream of selectively encrypted content from the encrypted first portions and the second portions to produce a selectively encrypted stream of content that is individually encrypted for delivery during the VOD session.