Internet是一种开放和面向所有用户的技术,其资源通过网络共享。资源共享和网络安全是一对矛盾,随着Internet的飞速发展,资源共享程度不断加强,导致网络安全问题日益突出。文中分析了不断增长的网络安全威胁,介绍了网络安全需求及网络安全关键技术,重点讨论了入侵检测系统。 The Internet is an open and all-user technology whose resources are shared over the network. Resource sharing and network security are a pair of contradictions. With the rapid development of the Internet, the degree of resource sharing has been continuously strengthened, which has led to the increasingly prominent problems of network security. This article analyzes the growing threat of network security, introduces the network security needs and network security key technologies, with emphasis on the intrusion detection system.