会议电视加扰系统中的三级加密体制

A Three Level Scrambling Scheme for a Conference TV Scrambling System

提出了电视会议加扰系统中用加扰密钥Ｋｓ，工作密钥Ｋｗ，分配密钥Ｋｍ实现的三级加密体制，给出了寻址与密钥管理构造原理图，着重分析了数据加密算法ＦＥＡＬ－８的特点以及系统的抗攻击性能。

A three level scrambling scheme realized with scrambling key K s, working key K w and allocating key K m for a conference TV scrambling system is presented. The schematic diagram of structure of the addressing and key management is given, which consists of a customer management PC in the conference centre and the control modules of the scrambler and descrambler. The specific features of the data encryption algorithm FEAL 8 are analyzed at length. It is a program oriented algorithm suitable for single chip microcomputer and microprocessor at terminal. It is compatible with DES algorithm. Since a smaller number of iterations or less iterative time is required, the scrambling and descrambling process is shortened. The attack resisting performance of the conference TV system is analyzed. As the line segmentation and rotation technique with 8 segmentation points and large scale EPLD as well as a three level scrambling scheme with algorithm FEAL 8 are adopted, it can be concluded that the system is secure and reliable.