Pe File Software Watermark And Its Application Research In Copyright Protection

As an important branch of the digital watermark, software watermarking technology is proposed to solve the problem of software piracy. The traditional software watermarking technologies always embed the watermark in general source-level, so they have low efficiency in embedding and extraction. In order to solve this problem, this thesis made a research on software watermarking based on PE files. Existing researches in this field face the following issues. Firstly, they only use one single watermark to protect the software, thus the strength of protection is low. Secondly, the watermark itself has less concealment and security. Thirdly, the watermarking protection technology is not combined with other effective protection methods so that the watermark has weak anti-attack capability and low robustness. To solve the above problems, on the basis of in-depth study of software watermarking technology for copyright protection, this paper proposes a scheme-software watermarking copyright protection in PE file based on chaos theory. The details of the activities are as follows:At first, through analyzing existing software watermarking technology in PE file and its application in copyright protection, we propose a scheme--software watermarking copyright protection in PE file based on chaos theory. This scheme is proposed to solve the existing software piracy. It combines with chaos theory and uses double watermark to protect the software copyright.Secondly, in order to enhance the strength of the software copyright protection, in this scheme, we realize two improved software watermark protection algorithms in PE files. One is called software watermarking in PE files based on chaos theory and redundant space (CRW) and the other one is called software watermarking in PE files based on chaos theory and code moving (CMW). The algorithms both combine with the chaotic hash and encryption technology to improve the watermark concealment and security. They both use the Generalized Chinese Remainder Theorem (GCRT) to split the watermark digital so as to enhance the concealment of the watermark. The watermark is embedded in the PE file directly in the algorithms, so the efficiency of the software watermark embedding and extracting is improved. In addition, CRW algorithm has a higher embedding and extraction efficiency, so it can be detected and extracted rapidly. And CMW algorithm combined with program code has a higher robustness to prove the copyright by extracting private watermarking when the suspected piracy occurs.At last, we design and realize a prototype system called CRMW-PE. And we do an experiment by using it. According to the experimental data, we analyze the performance of CRW algorithm and CMW algorithm and then prove the effectiveness and feasibility of the scheme.