The Research On The Method Defending CSCD Data Security

Computer Supported Collaboration Design (CSCD) is one of the product development technologies, which is based on computer network and is attended by different experts, and which focuses on product performances. With the supports of computer network and information technology, CSCD can overcome the obstacles of time and distance and enables attending experts share all the product design informatioa CSCD has been one of the most popular fields in product design engineering.The exchange and share of product design information are fundamental to CSCD. Because computer network is the carrier of product design information, the security and performance of computer network are also important to CSCD. The method of defending data security has been one of the key technologies in CSCD, but the corresponding researches on it and its influence when realizing CSCD platform are not paid much attention to.The thesis mainly focuses on the security environment of computer network in CSCD, and discusses the useful methods and technologies in realizing CSCD platforms. The principle contents studied in this thesis are as follows:(1) Bringing forth and discussing the data security problem of CSCD, and further making it clear that the research work on computer network is necessary to CSCD.(2 ) Researching on the method of defending data security and the architectures of computer network firewall, and constructing the prototype of CF FIREWALL.(3) Researching on the packet filter technology in computer network firewall, designing and realizing CF_FIREWALL Packet Filter Router.(4) Researching on the proxy technology in computer network firewall, discussing the applications of proxy technology in computer network, designing and realizing CF_FIREWALL HTTP Proxy Server and CF_FIREWALL FTP Proxy Server.(5) Researching on the reverse proxy technology and VPN (Virtual Private network) technology, which can be utilized to realize all the types of computer network services in CSCD system.CF_FIREWALL Packet Filter Router is developed using GCC compiler and Linux LKM (Loadable Kernel Models) technology. The performance of this router is quite good.CF-FIREWALL HTTP Proxy Server and CF-FIREWALL FTP Proxy Server are developed using Microsoft Visual C++. They run on Windows NT/2000,and they work as expected.