Research Of File Confidential Technology Based On Transparent Encryption

With the popularity of computer and the arrival of the age of the Internet, The use of electronic document is more and more widely, a large number of electronic document storage and spread on the Internet.At the same time, The security problem of the electronic document is more outstanding, especially related to sensitive information and confidential information in the electronic document. For example, the problem of the company internal confidential documents copy happened to be in the spread out, personal Internet writings were malicious download illegally sharing and so on. Thus, the safety of various electronic documents on technology and products is constantly to come out. For example, digital watermarking technology, file encryption software,hard disk software, and so on. But most of the encryption techniques are active operations required users, and when need to use,it is still have to decryption by himself(herself), In the process if there is improper operation or lost password, it will lead to the disastrous consequences. In view of these situations, this article is from another angle, not to interfere with the normal operation of the user to premise, combined with the operating system itself of some functions, when the user is editing the document,the software is dynamicly and "invisibly" encrypting the conment on the back. And this is the hot technology in the fild of the electronic document encryption at present.First this paper is connection with the Windows kernel driver development introduced the theory of transparent encrypt/decrypt technology. The Windows file system principle and the kernel driver development related knowledge, discussed the development of documents transparent encrypt/decrypt system comprehensively. Because transparent encryption/decryption is based on the kernel drivers, involves large knowledge. So in this paper writer does a lot of research on the Windows operating system kernel related knowledge, and mainly study the technology of file system filter driver, explain the principle of useing the filter driver to achieve transparent encrypt/decrypt. Analysis the import kernel data structure based on the WDK, analysis the new generation of micro filtering model developed by Microsoft.On the basis of this study, this paper designs a transparent encryption and decryption system used the file system filter driver based on Microsoft’s next-generation framework-minifilter. gives the system structure, the kernel driver encryption and decryption module structure, and defines a number of important functions and data. Through the logical reasoning and procedural debugging,in this paper,it resolves the cache processing, the process controling and other vital issues. Finally test by the OFFICE,WPS,TXT and so on. Realize the" transparent"effect. And, only the coperation system be instanlled the filter driver is authorized to process the decoments freely. Once out of the environment, such as through the USB interface to copy files or use E-mail through the network to spread out, the documents will be automatically becomed the ciphertext,and prevent information disclosure effectively.