A control system provides secure transmission of programs, including at least one of video, audio, and data, between a service provider and a customer's set top unit over a digital network. Program bearing data packets are received in a first network protocol over a first data link and removed from the...http://www.google.fr/patents/US6424714?utm_source=gb-gplus-shareBrevet US6424714 - Method and apparatus for providing conditional access in connection-oriented interactive networks with a multiplicity of service providers
Method and apparatus for providing conditional access in connection-oriented ...
