1引言网际间的数据交换是指内容、设备相对独立的部门内部网站之间,相互用于信息往来的电子数据传递事件。随着计算机网络的迅猛发展,网络安全问题日益突出。航天科技公司系统的计算机应用和信息化建设已具规模,内部网站和网络办公系统已相继投入使用。在总部、子公司、基层网站三级网络的支撑下,以公司网站和网络办公等电子政务应用 1 Introduction Inter-network data exchange refers to the content and equipment are relatively independent of the internal departments of the Web site, mutual information for the electronic data transfer events. With the rapid development of computer networks, network security problems have become increasingly prominent. Aerospace science and technology company system of computer applications and information technology has been established, the internal website and network office systems have been put into use. In the headquarters, subsidiaries, grassroots website three networks under the support of the company’s Web site and office e-government applications