CTA 679-C (R2013)

CEA-679-C Part A describes the physical and electrical parameters of the interface for conditional access (CA) devices for consumer electronics (CE). The purpose of this standard is to specify the interface to a CA device that performs the signal access and, optionally, descrambling and key generation. It is possible to imagine that several CA devices could be interfaced to the same CE device, simultaneously (see Annex A (informative)). This interface definition allows the entire CA system to be removable and hence replaceable. Very few constraints, if any, are placed on the CA system architecture. A set of standards has been designed to be used in digital video broadcasting. These standards include source coding, channel coding, service information and decoder interfaces. In addition, a conditional access system is used when there is a need to control access to a broadcast service. It has been decided that the conditional access system need not be standardized, although a common scrambling algorithm is provided. It remains for broadcasters to access decoders with different conditional access systems and to ensure that they have choice of supply of such systems. A solution is to use the common scrambling algorithm and to execute solutions for access based on commercial agreements between operators. This solution can operate with single CA systems embedded in decoders. A second solution is based on a standardized interface between a module and a host where CA and more generally defined proprietary functions may be implemented in the module. This solution also allows broadcasters to use modules containing solutions from different suppliers in the same broadcast system, thus increasing their choice and anti-piracy options. The scope of this document is to describe this common interface.

The decoder, referred to in this specification as the host, includes those functions that are necessary to receive MPEG-2 video, audio and data in the clear. This specification defines the interface between the host and the scrambling and CA applications, which will operate on an external module.