The Design And Implementation Of PDF Document For Password Recovery Based On PRCA Architecture

With the rapid development of science and technology, high performance computing has become one of the tools to support the development of science and technology in the most strategic significance. The development and manufacturing capacity of high performance computer is an important part of the national innovation system and an important indicator to measure the comprehensive national strength. With the rapid improvement of computer system performance, the energy consumption of the system is more and more big. For improving the calculation efficiency of the many approaches of computer system, the system structure on the energy efficiency of the system influence greatly. Therefore, through the innovation of system structure to improve efficiency has already become the focus of increasing concern to the study of computer, and the new computer system research with great practical significance and long-term strategic significance.The numerous users of the Internet produced a large number of encrypted document, but computational structure and computing power is difficult to meet the encrypted document password recovery.Because traditional CPU architecture password recovery is limited to the calculation speed of encryption algorithms,can only solve simple passwords, and can little validate the password to the relatively every second.The calculation efficiency is far from being able to meet the requirements of the development of science and technology. The existing structure is difficult to deal with a large amount of calculation, variable calculation cycle.It need to seek a more efficient computational structure.The heterogeneous computing system, according to the different application of computing resources, can effectively improve the computing efficiency. Dictionary attack is efficient way to crack the document, but it has a higher demand on the storage space and speed requirements in the case of high speed crack. Therefore, choosing effective password structure is an effective method to improve the hit rate of password dictionary attack.In this paper the PDF encrypted documents algorithm is as the research content which is the core module of password recovery of the typical document standard encryption mode for PDF document. We analysis the computing needs and characteristics of typical document password recovery, combine with the advantages of reconfigurable computing.This paper uses a password cracking method to divide structures again based on the probabilities of divisions, on the other hand, this paper do the experiments based on multi-FPGA dictionary attack scheme in the national "863" project of the PRCA system to realize parallel transmission, and solves the problem of the hit radio and the password transmission bottleneck in dictionary attack. In this paper, the comparison of design performance and power consumption between FPGA and universal server is made. The experimental results show that the proposed scheme is effective and feasible, which significantly improves the performance and reduces the power consumption.