System for denying access to content generated by a compromised off line encryption device and for conveying cryptographic keys from multiple conditional access systems
US7076661B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 2005 |
| Grant date | Jul 11, 2006 |
| Priority date | — |
| Expiry date | Mar 9, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/8549
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.