Conditional access system for controlling the access to a data content

Abstract

A conditional access system for controlling the access of receivers of end-users to data content transmitted from a data content source in an uplink system. The uplink system scrambles the content supplied from the content source, generates entitlement control messages containing a control word and an entitlement identification, and transmits the scrambled content and the entitlement control messages. A descrambler, an entitlement control message decoder and storage for recording entitlement identifications are associated to the receiver. The entitlement control message decoder supplies a control word to the descrambler for descrambling a part of the received scrambled content for which the receiver is entitled, if a match between the entitlement identification in the entitlement control message and the recorded entitlement identification exists. The content is subdivided into scenes having their own scene identification. The uplink system incorporates the scene identifications in the entitlement control messages.

Dependencies are inferred from the claim text.