The Study And Implement Of WFSFD-based File Encryption/Decryption Technology

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 Filter Driver to implement a kernel file encryption system is a effective way to improve the security of computer host. File system is closely related with operation system. If you want to grasp the technology , you must have deep understanding of the operation system . The paper analyzes the Windows system components especially the Windows Executive components, such as the I/O Manager , the Object Manager . 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. The paper refers Microsoft Corporation Installable File System Development Kit to analyze some important data structures in developing a filter driver, such as the File Object, IRP ,VPB, explaines every important filed in such data structure.On this study,the paper designs and implements a File Encryption System using File System Filter Driver technology, releases some code details and principle flow chart. By analyzing the kernel technology of the File Encryption System, especially comparing to the Windows EFS, we can get the pluses and minuses of the File Encryption System. My system implements some functions that EFS dosen't implement,: my system can encrypt some kind of file automatically while EFS only...