Dynamic Software Watermark Based On Function Invocations

Software watermarking is technology which intends to combat software piracy, offers copyright protection and secure software distribution management solutions. The strategy is to embed secret information into the program and extract it to demonstrate the ownership whenever needed. Most of the existing software watermarking algorithms have many disadvantages, such as low data rate, weak robustness, and so on. Even for the existing typical watermarking algorithm, since this kind of algorithm has used for a long time, the attacker usually has researched it for long enough to have the targeted way of cracking. To sum up, the study of new watermarking algorithm has a great significance for the field of software security.Based on the study of a variety of existing static and dynamic software watermarking algorithm this paper proposed a new software watermarking algorithm which is based on dynamic invocations of the watermark-function. The algorithm not only has great flexibility on the watermark expression, it also has a great robustness and concealment against a variety of attacks.The main work of this paper includes:Learn conventional thinking, basic model and concepts of software watermark and study the classical framework and basic knowledge of software watermarking and software security, to lay a good theoretical foundation for the research of watermarking algorithm.Study the existing watermarking algorithm to learn both advantages and disadvantages of the existing watermarking algorithm, understand the basic idea and strategies of the typical software watermarking algorithm, analysis of the focus and difficulty of watermarking algorithm design. In doing so to seek a deep understanding of software watermark.Designing the new software watermarking algorithm which is based on dynamic invocations of the watermark-function, including the overall architecture of the whole algorithm, embedding and extraction scheme.Researching several technical difficulties of the algorithm, including the identification scheme of the watermark-function, watermarking information’s expression scheme and so on.Using the java byte code as carrier, implements the new watermarking algorithm.Based on this implementation, provides experimental evaluation of the new watermarking algorithm on data rate, robustness, etc.The study on the base of learning the existing watermarking algorithm, proposes a new software watermarking algorithm, and also implements the algorithm using the Java byte code as carrier. According to the result of experiments, this watermarking algorithm has great performance on robustness, efficiency and concealed.