Research Of Dynamic Graph Software Watermarking And Related Technology

The rapid development of computer network technology posed a serious challenge for copyright protection of software products. Traditional software protection technology mainly uses cryptography theory and implemented by software encryption technology. But as people deeper understanding of encryption technology, the drawbacks of using software encryption technology to protect software copyrights are gradually exposed. Even aware of piracy occurs, the copyright of the software protected by encryption technology is difficult to be proved, let alone track down the source of software piracy. Software watermarking is one of the software anti-piracy technologies. By hiding information in software as a watermark, when copyright disputes occur, using the watermark information to prove copyright or trace the piracy sources. Software Watermark is usually divided into static watermarks and dynamic watermarks. The Dynamic Graph Watermarking(DGW) which this paper will explore is one of dynamic watermarking technology.It uses the graph topology structure as the carrier of the watermark information. DGW is a high robust software protection techniques.This paper describes the Dynamic Graph Watermarking technology in detail, and for the shortcomings of the current dynamic graph watermarks, conducts in-depth researches, the main work is as follows:1. For the dynamic graph watermarks, an attacker can employ structural analysis and debugging techniques to comprehend the procedure, locate the position of the watermark embedded, and the modify or erase the watermark. To solve this problem, this paper proposed a dynamic graph software watermarking scheme based on dynamic obfuscation. This scheme combines dynamic graph watermark with dynamic obfuscation technologies. Through using Reducible Permutation Graph(RPG) as the watermark carrier, obfuscating the embedded watermark program, the software watermarking scheme can withstand decompiling the program, improve software watermark scheme against aggression. Comparing the scheme with traditional software watermark scheme, the results show that it has high robustness and data rate and has obvious advantages in resist code analysis.2. For the program of the dynamic graph watermark vulnerable to attack and difficult to recover after the attack, we propose a watermark recoverable software watermarking scheme. First, propose the TDPPCT structure. Compared to PPCT structure, TDPPCT structure improves the software watermark data rate and dynamic bit rate, and TDPPCT structure contains a Hash map to detect whether the extracted watermark graph is correct or not. Threading watermark has high elusive, this scheme will combine the dynamic graph software watermarking with threading watermark technology, TDPPCT structure is used to represent the watermark information, application thread relation matrix is used in hiding the error correcting code of the structure. In the process of extracting software watermark, once detected the watermark graph has been tampered, then extract the error correcting code on the execution of the program and recover the tampered watermark. Theory analysis and experiment indicate that compared with other dynamic graph watermarks, software watermarking scheme presented in this paper has a better performance of date rate and security. This scheme can also recover the tampered watermark.