Research And Application Of Three Common Types Of File Security Mechanism

With the development of computer and internet technology, electronic files are widelyapplied to office work、 data storage、digital information dissemination and other occasions.At the same time, the electronic files have become the important information and data carriers.For encrypted electronic files, password loss may bring important data loss and cannot berecovered. So, how to restore the password of electronic file has practical application valueand significance. This paper focuses on the study of three kinds of common electronic filespassword authentication mechanism, including Office (including Office2007, Office2010)、PDF、RAR, password authentication mechanism including file format、keyword extraction、password authentication algorithm. At the same time, because the password space increasesexponentially varying with the length of the password, when the password has a certain length,password space becomes very huge. On the process of the three kinds of common filepassword authentication every time, it needs many hash algorithm or encryption algorithmiterations, so the time cost is large, serial password authentication has been unable to meet theactual needs. With the development of GPU parallel computing, especially when the NVIDIAcompany introduced Compute Unified Device Architecture CUDA, GPU parallel computingis applied to scientific calculation, engineering, biotechnology and other fields. Comparedwith CPU, GPU has more calculation units (more than100stream processors, far more than2to16cores of the multi CPU), more memory bandwidth, can provide much greater ability ofparallel computing than CPU. Because the password authentication process of each passwordis independent, so it is suitable for parallel computing. After the study of of the file structure,key field extraction and password authentication algorithm procedure, based on GPUarchitecture and the characteristics of password authentication algorithm, this paper focuseson the password parallel verification and optimization in GPU.