Ad Hoc网络作为一种无线移动网络正成为网络研究 ,特别是军事研究的一个热点。由于 Ad Hoc网络的特点 ,其安全问题和安全策略正受到越来越广泛的重视。文中介绍了 Ad Hoc网络的特点 ,论述了 Ad Hoc网络的安全问题和路由协议的安全问题 ,最后介绍了 Ad Hoc网络的一些安全策略 ,并提出了一种在特定环境下的基于口令认证的密钥交换协议 As a wireless mobile network, Ad Hoc network is becoming a hot spot in network research, especially military research. Due to the characteristics of Ad Hoc network, its security issues and security policies are receiving more and more attention. In this paper, the characteristics of Ad Hoc networks are introduced, the security problems of Ad Hoc networks and the routing protocols are discussed. Finally, some security strategies of Ad Hoc networks are introduced, and a password-based authentication scheme Key exchange protocol