Conditional Access System And Its Implementation, On The Dvb-c Stb

With the developing of global digitization tide, the development of digital multimedia technology changes with each passing day.Television,one of the most popular amusement in our life, also go through the vicissitude from Analog Television to Digital Television.Not only improve the quality of program and increase the number of program, digital television also changing people's traditional manner of watching TV. Not only we can enjoy the program as Analog Television,but also we can enjoy a lot of individuation service such as Video on Demand (VOD),Internet etc.In order to enable consumer free choice the program content according to their own demand,and protect the program operation business's benefit, Conditional Access System has being used in the digital television broadcast, which is called CAS. CAS is a kind of digital charge system through scramble and encrypt the digital television program's content.Through some digital technology,the program co'uld be scrambled and encrypted, then the operation business can implement entitle control to the information which consumer receives, only the entitled consumer can watch the program which has been scrambled and encrypted, thus could safeguarded the operation business and the entitled consumer's benefit.The appearance of CAS also is the technique base and the powerful tool for broadcast television industry breaks the single business model that advertisement is the main income source, the business model of use condition access is the inevitable trend of television business can develop vigorously. Only through use condition access technology, implements perfect broadcast television charge system, the television business could progress to the higher level. In recent years, the research and development of CAS already became a hotspot of digital television system field.This article analysed the principle and the development situation of condition access system. Condition access system is a comprehensive system, involves many kinds of technologies, an integrated condition access system is composed by the sending end and the receiving end.There are two kinds of scramble in standard which is in DVB...