一、引言作为一种战略资源,信息在社会生产、生活的各个领域中的作用日益显著,计算机网络的飞速发展,加强了信息的共享程度,随之而来的网络安全问题日益突出。网络如同一座不设防的城市,其应用程序、操作系统、通信协议的安全隐患比比皆是,网络安全可谓危机四伏。据权威机构统计,平均每20秒就发生一起Inter- I. INTRODUCTION As a kind of strategic resource, information plays an increasingly significant role in all fields of social production and life. The rapid development of computer networks has strengthened the sharing of information. As a result, cyber security problems have become increasingly prominent. Network as a non-fortified city, its application, operating system, communication protocols, security risks abound, the network security can be described as crisis. According to authoritative statistics, an average of 20 seconds occurred Inter-