System for denying access to content generated by a compromised off line encryption device and for conveying cryptographic keys from multiple conditional access systems

Abstract

A method for forwarding messages containing cryptographic keys from a conditional access system that controls a population of set-top boxes to an encryption renewal system. The method includes storing a fictitious address of a virtual set-top box; generating a message based on the fictitious address, the message containing a cryptographic key; and forwarding the message to the fictitious address of the virtual set-top box. The encryption renewal system has information regarding the virtual set-top box, and is the recipient of the message. In addition, the encryption renewal system is for controlling access to pre-encrypted content generated by an encryption device. The system includes software instructions for receiving a request to retrofit an entitlement control message that allows a home device to access pre-encrypted content; and software instructions for retrofitting the entitlement control message only after verifying that the pre-encrypted content was generated prior to or contemporaneous with an authorized timestamp.

Dependencies are inferred from the claim text.