本书详细介绍了UNIX系统安全的问题、解决方法和策略。其内容包括：帐号安全及相关工具Crack；日志系统的机制和安全性，日志安全工具Swatch；如何测试系统的弱点，系统弱点的测试工具COPS和Tiger；网络安全的概念；提高网络安全性的防火墙等。本书语言简洁，层次清晰，是UNIX系统管理员的必备参考书。

-the book details the UNIX system security problems, solutions and strategies. Its contents include the following : Account safety and related tools Crack; Log system mechanisms and safety, Swatch log security tools; how to test weaknesses in the system. weaknesses in the system of testing tools COPS and Tiger; The concept of network security; improve network security, such as the firewall. The book succinct language, the level of clear and UNIX system administrator is an essential reference books.