Research And Implement Of Monitoring Technology Of Client In Secure Document Manager System

With the coming of information age, government, corporation and college store important information even confidential information by computer. At the same time, danger from both inside and outside threatened the information security. Firewall could protect information from destroying, filching and juggling by the outside threat efficiently. According to the report, the bigger threat came from inner user. Because the problem is more and more attached importance, a lot of companies who devote themselves to inner security and documents security protection products come out.The documents security protecting system had to ensure the security and integrity of document. Recently, most of document security protecting systems protected the document by the way of encrypting them. And the method could make document secure in some ways. Although the document was encrypted, they would be decrypted when the users would like to read them. Some user with illegal purpose could leak the important information by some ways. In the point of view of inner security, we can sum up the idear that monitoring and controling the inner user are undoubtedly important.The paper analyses the main framework of the secure document manger system and the function of its several child module and the interrelation of them. Then it researches several kinds of key technology in user mode and kernel mode.1,Several kinds of process protecting method are enumerated and merit and demerit of them are analyzed. It comes out combining two of them could work more stably.2,The paper also researches the inner principle of clipboard and dragdrop, which helps realizing the method to control them.3,The paper also researches the principle of NT file filter driver and implements encryption and decryption when the file is I/O.4,And it implements the control of USB device by the method of exchanging of the kernel routine.