The Design And Implementation Of Data Forensics System Using GPU

With the development of internt and the computer technology, an amount of data is generated, stored, and processed with the internet, which brings the difficulty of monitoring the big data. Especially, some crime is executed with the help of computer net, it is vital to obtain the evidence of the accusation of crime. All these technologies that to recover the sensitive data encrypted with the private password are defined the electronic forensics technology, in which the crack to the RAR, and Word is the main target. In a result, it is important to research the method to crack the RAR and Word.RAR is a file compression format, Word is Microsoft released a Word processing software, with its reliability and practicability that has been widely userd around the world. RAR for compressed file is encrypted, together with the compound Word document encryption mechanism has been widely used, and the corresponding file password cracking has certain market demand.This thesis based on GPU high performance parallel computing ability and CUDA development platform, through the analysis of the principle of RAR and Word encryption mechanism, using the GPU multi-thread parallel computing ability, put forward the exhaustive method and the rainbow method based on GPU fast decoding algorithm, achieve the effect of rapid crack RAR file and the Word encryption system. After the NVIDIA Tesla C1060 GPU platform test, show that the method operation stability, cracking rate is high, fast break, but in the judicial forensics and plays an important role to combat the illegal behaviour of the network.The main research contents have five parts: RAR file encryption analysis module, the analysis of the KEY and the Hash Value how to encrypt data compression; The decryption module of RAR file, unzip the decrypted data block, then solution into a source file, and then by comparing the CRC check code to obtain the correct password; Calculate the MD5 Hash value module, namely the MD5 value of an enum password, and passwords and user input the MD5 value comparison, if match the output code; Define a Word document of one-way function, put the rainbow table tradeoff between time and space technology in the GPU; GPU parallel computing module, it is using multithreading acceleration parallel cracking.