Packet TV program component detector

摘要

Apparatus for selecting predetermined ones of packets of signal components, from a signal stream of packets includes a control device, responsive to user selection and a transmitted program guide, for determining packet identifier codes, SCID's, for respective program signal components. SCID's, from respective packets in the signal stream, are successively compared with selected, stored SCID's. Transmitted signal components associated with appropriately detected SCID's are coupled to decryption apparatus. The decryption apparatus selects from a plurality of decryption keys in accordance with decryption flags include in transmitted signal packets. Decryption keys per se are provided by a smart card.