Electronic File Operations Safety Monitoring Technology Research

With the rapid development of modern computer, network communication and multimedia technology, electronic files have been constantly replacing the traditional files, becoming a new kind of information storage and dissemination carrier. Especially in recent years, the degree of informationization is improved greatly whether in military, commercial or civilian fields. Electronic files bring conveniences to us, with the accessary security risks at the same time. Today more and more sensitive information, concerning state secrets, business secrets and personal privacy is spreaded without authorization, or is directly exposed upon Internet, which has brought great threats to the government, enterprises, society and every people.In this dissertation, the technology on access controlling and operation monitoring of removable starage media is studied. After a thorough investigation of the system architecture, kernel drivers and file systems of the Windows OS, the client software of controlling and monitoring system for electronic files is designed and implemented. The main work can be concluded as follows:(1) Based on the technology of the Windows driver development, the transparent encryption and decryption system is designed, supporting a variety of current encryption and decryption algorithms. The encryption and decryption is designed on the level of disk sector and the encrypted disk is mapped to a virtual disk on the local computer, which makes it easy to be used directly.(2) The scheme of the loading of the access control information based on the token file is designed. Through the interaction with the remote server, the system completes the legitimate user's authentication and obtains the authorization information.(3) Based on the technology of the Windows file system filter driver, access controlling for the storage medium is completed. User's operation records will be uploaded to the security audit server in the real time.(4) Software testing is carried on the client system. The client software is verified to be able to run stably, reliably and efficiently, which statisfies the requirements of secure storing, access controlling and operation monitoring.Finally, a summary is given for the full thesis, and the deficiencies and the corresponding improvements are pointed out as well. The remaining problems of the paper are discussed, and the future works are listed.