随着当今信息水平的不断提高,人们通过计算机网络便可非常方便地存储、交换以及搜索信息,在工作、生活以及娱乐中享受到了极大的便利。然而,在人们享受信息化社会所带来的巨大利益的同时,也受到计算机网络暴露出的各种安全问题的困扰。本文着重介绍网络安全的定义,网络安全的评估准则,现访问控制和保护模型本身存在的问题,入侵容忍技术定义以及实现方式。 With the continuous improvement of information level, people can conveniently store, exchange and search information through the computer network, enjoying great convenience in work, life and entertainment. However, while people enjoy the enormous benefits brought by the information society, they are also plagued by various security problems exposed by the computer network. This article focuses on the definition of network security, evaluation criteria of network security, existing problems of access control and protection model itself, the definition of technology of intrusion tolerance and its implementation.