Design and Implementation of Network Secure Infrastructure in National Audit System

With the stratification, grouping and broad band development of National Auditing System, more and more statistic and decision-making job, daily supervise and check-up job, administration job such as OA, and integrative job facing multimedia will convert digital and network affairs, all that accord with trend of development together of information and network. But this bring forward high request to application security. Otherwise, National Auditing System come down to much important information about economy security, therefore how to ensure all sided security of e-government network will be a problem that builder and governor will face.The security aim of National Auditing System is to prevent all kinds of intrusion and attack, access without authorization, imitation, juggle, and disavowal from exterior or inside. So we must fit user’s all kinds of request,synthesize all kinds of security technology, and integrate all kinds of security administration measure, take integrated stratagem such as "united planning, stepped deployment" to realize integrated security defense of National Auditing System.This thesis firstly touches upon the development situations of e-government, and the challenges it is facing, followed by an analysis of several types of popular network security technologies, such as firewall, IDS, VPN,VLAN, encryption techniques, etc. Then the thesis analyzes the security defense system of National Auditing System in terms of security mechanism, framework, design criteria, and architecture hierarchy. And with applying a kind of network system security frame based on group ware, the thesis give a design and implement of encryption and authentication framework based on PKI/CA in "National Auditing System". Again, by a case-study of network system security project in Shenyang Auditing bureau in Liaoning province, This thesis particularly analyses the network structure of its "National Auditing System", potential problems of network security, then offers the requirement analysis and the design scheme of network security for the actual complexion. The solution proposed in the thesis has utilized the main stream network security technologies. The core firewall and the IDS protection configuration strategies are discussed in detail. A summary and a prospect of the network security system for the "National Auditing System" are given.