Software Watermarking is widely used for software ownership authentication, but it is susceptible to various de-watermarking attacks such as obfuscation. Dynamic Graph Watermarking is a relatively new technology for software watermarking, and is believed the most likely to withstand attacks, which are trying to distort watermark structure.
In this thesis, we present a new technology for protecting Dynamic Graph Watermarks. This technology encodes some of the constants, which are found in a software program, into a tree structure that is similar to the watermark, and generates decoding functions to retrieve the value of the constants at program execution time. If the constant tree is modified, the value of some constants will be affected, destroying program correctness. An attacker cannot reliably distinguish the watermark tree from the constant tree, so they must preserve the watermark tree or risk introducing bugs into the program.
Constant Encoding technology can be included in Dynamic Graph Watermarking systems as a plug-in module to improve the Dynamic Graph Watermark protection. In this thesis, we present a prototyping program for Constant Encoding technology, which we call the JSafeMark encoder. Besides addressing the issues about Constant Encoding technology, we also discuss the design and implementation of our JSafeMark encoder, and give a practical example to show how this technology can protect Dynamic Graph Watermarking.