Then paper analyses the working theory of normal conditional access system , and gives the realization frame for conditional access system 随后文章分析了一般条件接收系统工作原理,给出了条件接收系统的实现框架。
Conditional access is the process of determining which individual digital receivers shall be able to deliver particular broadcast programs to end users 加扰系统对其业务数据进行加扰处理，是条件接收系统的核心技术。
The development of conditional access system with our own ip is the key aspect for rapid acceptance of digital tv in our country 开发具有我国自主知识产权的有条件接收系统( conditionalaccess )是推动,保证这种良好发展的关键
Chapter 3 describes detailedly an advanced solution of conditional access system , including the details of scramble / descramble and encrypt / decrypt 第三章介绍了一种多层加密条件接收系统的详细设计方案，包括加解扰系统、加解密系统。
Chapter 2 describes all aspects of conditional access systen in dvb architecture including struct , principium , encrypt arithmetic , dvb simulcrypt and common interface 第二章在dvb规范下论述了数字电视条件接收系统的结构和原理、加密算法、 dvb同密规范和通用接口规范。
Determine scrambler and unify data interface through the adapter layer , to enable different type of conditional access system to set the descrambler by retrieving the descrambler code 通过适配层对加扰层进行判断并统一数据接口,使不同的条件接收系统都能成功提取解扰字对解扰器进行设置。
Composite technology supplies the possibility for the realization of conditional access , and the relative definitions for conditional access in standard supplies the feasibility of conditional access 复用技术为条件接收技术实现提供了可能性,而标准中对条件接收的相关定义为其实现提供了可行性。
But this will not become reality without the surport of another technology - conditional access system . conditional access system guarantee that only those entitled costomer can access services 然而如果没有另外一项重要的技术?有条件接收系统技术的保障，新的业务不会变成现实，因为电视运营商不愿意做没有回报的投资。
In general , the implementation of the scheme proposed in this paper will ultimately contribute to the realization of multimedia services such as vod , high speed dvb data broadcasting and conditional access system 本课题的实现与完善，将为视频点播， dvb高速数据广播，条件接收等多媒体业务的实现提供必要的技术基础。
And in - depth research is made in this thesis . after analyzing some practical issues , i design and implement a scrambling and conditional access system with full functions , appropriate size and certain application field 在此基础上，设计了相应的系统硬件和软件，完成了一个基于pc的、规模适中但功能完备的同密条件接收系统。
