网络安全综述

随着计算机网络的不断发展，全球信息化已成为人类发展的大趋势，但由于计算机网络具有联结形式多样性、终端分布不均匀性和网络的开放性、互连性等特征，致使网络易受攻击，所以网上信息的安全和保密是一个至关重要的问题。无论是在局域网还是在广域网中，都存在着自然和人为等诸多因素的脆弱性和潜在威胁。网络的安全措施应是能全方位地针对各种不同的威胁和脆弱性，这样才能确保网络信息的保密性、完整性和可用性。

Internet network security

With the development of computer network, gobal informatization is the future of the world. But network is vulnerable today because it is joined by a lot of ways, and the end terminals spread over the whole world. It is also because of its characters of open and interlinking. So how to protect the information in network is becoming more and more important. Whether in LAN or WAN, there are a lot of factors made by human or nature lead to frangibility and threaten. The measures for security are to cope with all kinds of frangibility and threaten. With these meathures, the information in network can be kept confidential, integrality, and useful.