Software Watermark Algorithm Based On Double Chaotic Sequence

With the widespread use of the Internet and mobile Internet, software protectionhas become an important part of software development and promotion. Thesisstudies the theory of software protection and dynamic graph watermarking algorithm,by analyzing data embedding rate and embedding methods about the CT algorithm(Chritian Collberg and Clark Thomborson propose), then propose watermarkingalgorithm optimization about CT based on dual chaotic sequence, therebyovercoming the low data rate and the problem about embedding. The major work ofthesis as follow: analyzing of embedding of CT algorithm, the watermarkinformation. On the basis, the thesis gives an improved watermark algorithm basedon double chaotic sequence.CT algorithm embeds sub-watermarks by avoiding Hotspot, but don’t considerthe distribution. Because of the sub-watermarks according to splitting algorithm, therelationship of sub-watermarks leads to problem of sub-watermark, and introducedesign on double chaotic sequence.The design about watermark information in the thesis can change track ofsub-watermark sequence to enhance the security of watermark. The embeddingfirstly evaluates the class to choose the best class, and then according to the functionon chaos embeds sub-watermarks. To achieve high rate, the coding has more pointerson nodes.The thesis is about watermark embedding, data rate and pretreatment in CTalgorithm. In experimental section, results show keeping good performance of thealgorithm in concealment, data rate and resistance to attacks according to a largenumber of software applications.