A conditional access system for direct broadcasting by satellite

This paper outlines the main features of a proposed Conditional Access television system, especially for DBS and suitable for large numbers of subscribers. The system includes a computer with a data-base in which all subscriber-related data are stored and processed and which outputs Validation Codes, scrambling-control and key signals for transmission control. A detachable induction-coupled sub-system carrying a unique Address and Distribution Key is provided for each receiver. Payments for a service result in the over-air delivery of new Validation Codes, which, in combination with the Distribution Code, determine the Authorization Key needed for decrypting the signals which control descrambling of the picture and sound signals.