Research Of A Encryption/Decryption File System Based On Minifilter Model

The file is the logic components of information storage, and which security hasbecome one of the most important subjects in current information science. The fieldencryption and decryption technology as the research hot of information security,nowadays the method to solve this problem is file encryption which is based on themodem cryptology. In this paper, the advantages and disadvantages of different types ofencryption file technology are compared, and in accordance with the secure file storagerequirements, we come to a conclusion that the kernel layer transparent encryptiontechnology based on Minifilter combined with USBKEY is the most economical andefficiently method to achieve protection the file system. Some basic theories which arenecessary in research of a encryption/decryption file system based on Minifilter modelare introduced in this thesis, including windows structure, kernel mechanism, filebuffering, virtual memory management and so on.The working principle of Minifilterdriver is discussed also, the principles and relationship of these theoretical knowledgeare discussed further, reinforced the theoretical basis for the encryption file system.In conclusion, this paper introduces the design of a encryption/decryption filesystem based on Minifilter model. The overall framework of the system are given, andthen closely analyzes the control flow for file accessing under the file system kernel. Inthe framework of Minifilter driver, the thesis details the ideas of filter driver designedand the key technologies for using. At last, through analysis of key technologies,summed up the advantages and disadvantages of the system, and ways to improvefuture prospects.The contribution of this paper is that, based on NT architecture, combined withUSBKEY, a IAES algorithm that deal with the data for the state array by line isimplemented, and a encryption/decryption file system based on Minifilter model isdesigned. During implementing several key problems such as encrypted fileidentification, deal with the file buffering, process filtration and IAES algorithm etc. aresolved.Success in this research will bring economic and social benefits for informationindustry, and it is significant for the rapid development of information industry.