Abstract: A transaction protocol for communicating between an encryption renewal system communicably coupled to one or more video on demand systems via a communication network. The encryption renewal system permits pre-encrypted content to be accessed by clients of the video on demand systems. The protocol comprises, receiving, by the encryption renewal system, a request transaction document having a first format from the video on demand system; parsing the request transaction document to retrieve data from the request transaction document; generating a request object code in a second format for processing by encryption renewal system, the request object code based on the data in the request transaction document; responsive to processing of the request object code, generating a response object code having the second format; converting the response object code to a response transaction document having the first format; and forwarding the response transaction document to the video on demand system.

Abstract: 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) fixed time intervals, (ii) a fixed number of packets, (iii) a fixed marker count, or (iv) 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.

Abstract: A transaction protocol for communicating between an encryption renewal system communicably coupled to one or more video on demand systems via a communication network. The encryption renewal system permits pre-encrypted content to be accessed by clients of the video on demand systems. The protocol comprises, receiving, by the encryption renewal system, a request transaction document having a first format from the video on demand system; parsing the request transaction document to retrieve data from the request transaction document; generating a request object code in a second format for processing by encryption renewal system, the request object code based on the data in the request transaction document; responsive to processing of the request object code, generating a response object code having the second format; converting the response object code to a response transaction document having the first format; and forwarding the response transaction document to the video on demand system.

Abstract: A method of delivering content from a head end to subscriber terminals within one or more cable systems. Such content may be video, audio or the like. The method includes the step of encrypting the content offline to form pre-encrypted content, generating an encryption record containing parameters employed for encrypting the content. Based on the encryption record, a control message for permitting access to the pre-encrypted content is generated using a periodical key provided by the first cable system. The pre-encrypted content and associated control message is thereafter forwarded to the first subscriber terminal for decryption of the content. For a second subscriber terminal within a second cable system, the pre-encrypted content is retrofitted with a second control message permitting the pre-encrypted content to be decrypted by the second subscriber terminal.