Research And Implementation Of A Security Stored File System

With the rapid development and application of digital, inforamtion and network, the computer security is becoming an important part to support the information system running and operation smooth. The security of electronic documents occure in two conditions: dynamic transmission and static storage. For the transmission security, firstly, we can encrypt data and transfer; then we use the digital signature technique to ensure the validity and integrality. For the storage security, we need encryption and authentication technique to realize the storage encryption and access control for electronic documents.Firstly,the theis analyse WDM Modal and reading and writting file procedure, Then introduce and compare four methods which encrypt and decrypt file, and we decide to adopt a new hardware and software encryption method to design and implement a file encrypt storaged system. In Kernel, we design and implement an engine to encrypt and decrypt file data.The engine adopts file filter driver technogy which is on the basis of windows driver modal. The filter driver creates volumn devices and then attaches those devices for the file system driver, so IRPs which send to file system driver can be captured by the engine, then we have chance to encrypt or decrypt data in which those IRPs contain. In application layer, we design and implement fingerprint monitor program which control the identity of the user access. In the end, we accomplish the testing work. From the result, we can draw a conclusion that the system makes the important files more confidentiality and integrated.The innovations of the thesis are as follow: the engine lies in kernel lever, so it is protected by the kernel; the system adopts many measures to protect encrypted file (user's fingerprint verify on user model; file filter driver cut off the path which unlayful user access encrypted file; encrypt file data by SMS4 cryptology); The key is stored on the memory of the fingerprint products which can be access only by trusted process.