Network Isolation System

With the development of Internet, network turns to be an important role in almost any fields of our society. Therefore, the information security is becoming more and more important. And the information security issues in Intranet have become a significant research field. GAP technique has its own characteristic design method. It can provide a high-level protection on Intranet against possible attacks. The research of the thesis is funded by national 863 project named "The network isolation and secure high-speed transfer technique based on ASIC chip". The main contributions of the thesis are as follows.1) Several advanced GAP techniques are investigated firstly. Then we develop a dual-buffer-based switch system which has an architecture that can effectively isolate Intranet and Internet and at the same time transfer information with high speed between the two networks.2) The cryptological problems involved in the development of the GAP system are studied from the aspects of hash function, message authentication and key generation. The MD5 hash function and HMAC (Hash Message Authentication Codes), are deeply studied, and the test result of HMAC is presented.3) The requirement and the design of the software for GAP system are given based on the system architecture and partition of system function. Main function modules of the data flow, the mailboxes between the modules and the message format through the mailboxes have been studied. Additionally, the hardware driver program based on WINDOWS NT has been studied.4) According to the requirement of the hardware of GAP system, framework of the hardware system has been designed, and the main components are studied.