Scrambling and controlling access to an all-digital broadcast programme

The paper introduces the general architecture of a conditional access system and points out most of the specific requirements of conditional access that each designer should be aware of when specifying a new broadcast service. It deals with: the scrambling methods and their adaptation according to the bit rate, the number of components in the signal, data encoding and multiplexing; the signalling that forestalls any changes in the scrambling parameters; the synchronization that indicates when these changes happen; the impact of conditional access on the structure of the multiplex; and the resources required by the access control services. To illustrate these concepts, newly designed conditional access systems are demonstrated, and compared to the existing D2MAC-Eurocrypt system