Conditional access filter as for a packet video signal inverse transport system

摘要

Apparatus in a receiver, for processing transmitted entitlement control information, includes a packet transport processor for selecting signal packets having payloads containing a conditional access payload header and a remaining payload of entitlement data. Respective payload headers include groups of bytes which are coded in a manner to allow or disallow the respective receiver from processing the entitlement data. A conditional access filter preprogrammed with a subscriber specific conditional access codeword examines respective byte groupings of the conditional access header for a match with the subscriber specific conditional access codeword. Only if a match occurs is the processor permitted to process the entitlement data. The entitlement data is thereafter utilized to generate decryption keys for descrambling portions of the transmitted signal.