In this dissertation, concepts and technologies of symmetric and asymmetric cryptography are discussed; the direction of cryptography is analyzed based on their status and use in modern information security fields . there are varies information security services, of which authentication is the concern of the thesis . the objectives, means and protocols of authentication are studied in detail 本文系统地介绍了传统密码技术和现代公钥密码技术,并在讨论两种密码技术在现代信息安全中的地位和作用的基础上分析了密码学的方向;在讨论现代信息安全服务的基础上重点研究了验证服务的目的、手段和协议,并研究了应用广泛的ban验证逻辑;讨论了密钥分配技术。