Files Within The Network Security System Transparent Encryption / Decryption Design And Implementation

The increasing popularization of computer and computer network obviously improved people's work efficiency, and realized the large capacity of information accumulation and processing. When people were enjoying the conveniences which were brought by computer and computer network, the information safety problem already appeared and highly concerned by people.Why digital information safety is more concerned by people than traditional digital information? One reason is digital information is easy to copy,steal and transmit. The other is the teleinformation access facility belonging to computer network is more easy to be destroyed and changed. Obviously, farthest ensure the interior digital information safety for government department and secret organization is an urgent problem waiting for every safety department to solve.The paper begins from analyzing the current situations of file encryption technologies, analyzes the pluses and minuses of different encryption ways, draws the conclusion that utilizing Windows File System Filer Driver to implement a kernel file encryption system is a effective way to improve the security of computer host.The paper analyzes the Windows system components especially the Windows Executive components. The paper analyzes the File System Driver and the Filter Driver, discusses the working principle of filter driver and the evolution of development of filter driver. The paper also tells us every step of developing a filter driver in detail and discusses some important problems in developing steps.Based on this theoretical system, we and our institutions cooperating spent two years designing an inner-network defiance and security system, which can filtrate drives by file system. Meanwhile, we studied out a frame diagram which covered whole function system, including Encryption & Decryption implementation module diagrammatic sketch for client-side file system. Besides this, this system can limit bring the important date out, and control the use right of shared data for different user. After analyzing key techniques in system, we hope summarize the advantage and disadvantage of system, at the same time, point out the deficiency and bring up the improvement method.