Digital Tv Conditional Access System

Digital video broadcasting system(DVB), which can provide not only many digital programs, but also variety of services, brings valuable opportunities to the traditional broadcast industry. Conditional access system (CAS) is the key to realize the increment of the DVB system and provides effective system management and subscriber control. It covers many advanced techniques such as system-scheduling management, network, digital coding and decoding, scrambling and descrambling, encrypting and decrypting, multiplexing, modulating and demodulating, set-top box, smart card and some practical database techniques, for example program management, subscriber management and charging management.CAS appeared firstly in western countries, and at present, there are many mature CAS providers who provide complete solutions with various services throughout the world. Facing the impending of the digitalized era, some CAS providers have appeared in China and put some of their products into practical implementation, all of which are immature and should be checked by time.This paper is based on the concise and deep-going survey of CAS and finished the following three parts.In the first part, this dissertation introduces some digital TV CAS key technologies, such as criteria on MPEG-2 and DVB, encryption and de-encryption, simulcrypt and multicrypt etc.In the second part, this dissertation carries on the design of CA system architecture and realize. This dissertation is adopted with the DVB simulcrypt technology and three layers of key systems . The basic function of CAS is realized based on Microsoft .NET Framework. Particularly, this dissertation has designed several following parts: the structure of ECM and EMM,the architecture of key systems,the concrete structrure of CAS and the interface each other,etc. According to the design, the software with basic function of CAS is realized with C# language .In the third part, this dissertation carries on the test of CAS. A basic system will...