一、引言在设计保密通信系统时,除了要考虑加密算法的保密度以及密码机的使用特性外,另一个重要的问题是保密通信系统的密钥管理问题。在古典密码的应用中,由于密码操作等都是手工作业而且多数是点对点的通信,因而所有的密钥管理工作都基于手工作业。 I. INTRODUCTION In designing secure communications systems, in addition to considering the security of cryptographic algorithms and the characteristics of cryptographic machines, another important issue is the key management of secure communications systems. In the application of the classical password, since the password operation is manual operation and most of the point-to-point communication, all the key management work is based on manual operation.