Research On Security Control Of File System

Information security has two meanings: one is safety of processing data, which meanssome sensitive or confidential data may be read or modified by one who is not qualified and itwill cause data divulgence. We mainly used the modern cryptographic algorithm and accesscontrol to protect data actively. And the other is safety of the data itself, that is to show howto effectively prevent data destruction or loss during the processing due to hardware failureand human operation.This article puts forward pertinent protective measure for the problem of file storage andfile transfer in data safety process. First, during the process of file storage, we use DESalgorithm to encrypte files, and the key of DES algorithm would be encrypted by RSAalgorithm which accelerated by CRT.Then，during the transmission of the files，we set upuser’s authority strictly by USB security management module in Windows system. Systemusers are divided into the ordinary user and administrator. If ordinary user who is subordinatetakes operations on files or uses mobile equipment interface, the process will be saved by theserver. When ordinary user needs USB interface, he should apply to the administrator. AndUSB interface can be turned off actively when administrator found the operation throws anexception. At last, by calling file monitoring module in Windows system, we can monitorclient file operations and keep related documents in archives by server.The construction of whole system is based on small and medium-sized enterprise.Through TCP/IP socket, the communication of server and the client can be achieved. Whensystem starts, the initial state can be achieved by reading and writing the registry. Windowscall is the key technologies to realize monitoring for reading and writing of USB interfaceand file operations.