条件接收系统是数字电视系统的重要组成部分之一,也是推广数字电视服务的必要条件。文中提出了一种数字电视条件接收系统授权解码部分的设计方案,介绍了解密、解扰以及节目流的解复用等系统中的关键技术,并采用VerilogHDL语言编程实现,在Quartus Ⅱ下编译仿真通过,设计出稳定可靠,占用资源少且能够完成要求的系统。 Conditional access system is an important part of digital television system, but also the necessary conditions to promote digital television service. This paper presents a digital TV conditional access system authorization decoding part of the design, introduced the decryption, descrambling and program flow demultiplexing system, such as the key technologies and the use of VerilogHDL language programming, compiled under the Quartus Ⅱ simulation Through the design of a stable and reliable, less resource-intensive and able to complete the requirements of the system.