Design And Implement Of Transparent File Encryption Protect System

With the rapid development of information construction, information security hasbecome the new concern in this field. Electronic documents are insecure because theycan be easily transmitted and spread. To ensure the security of enterprise datainformation, it is necessary to encrypt the data of electronic documents data. At present,there have been some kinds of technologies and products for file encryption protect.However, they all have their own defects. Thus, file encryption protect system needsfurther research and development.Through the deep analysis and research on file encryption protection technology,according to the actual customer application requirements, the transparent fileencryption protection system based on file filter driver is designed and implemented.The design objective of the system is to achieve the goal of encrypted storage anddecryption display of the file in user’s computer system, in order to ensure the securityof user’s files. The design principle of this system is transparency, which means that theusers don’t need to change their original habits of file operation.The transparent file encryption protection system which is based on the file filterdriver framework sfilter and the DES encryption algorithm of USBKey is designed inthis paper, in order to implement the filter and file encryption and decryption processing.Meanwhile, the application management program in the user layer provides thefunctions as login, logout, selection of the encryption file type, path selection etc. And italso realizes the interaction between with USBKey and the interaction between with thefilter drivers.File system filter driver is the core of this design. When users open the file, the filefilter driver intercepts the user’s operation request, and obtains the relevant data file.Then it calls the DES algorithm in USBKey to complete data decryption aftercommunicate with the application management program, and finally shows the cleartextto the users. Encryption process is the opposite. In addition, the system adds a fileheader as the encryption identification, for ensuring the system can rightly distinguishthe encrypted files. Moreover, the hidden protecting and access shielding in thenon-logged state are implemented in the system, and a three-level protection strategy isobtained by cooperating with the filter driver. It significantly improves the security ofthis system.The test result indicates that each function designed in this systerm has a very highstability, achieving the expected goal of security. Compared with the system that completes only based on the filter driver, the proposed system has an obvious advantagein efficiency.