The Study Of Dyanmic Graph-Based Software Watermarking

With the development of network,users can obtain the digital products anytime and anywhere.The piracy problem of digital products becomes more and more serious. Software watermarking technology has been paid more attention,which is used to protect the Copyright of software.Software watermark information included ownership information of the software,user identity and Copyright proof,and the proceed of software watermarking is embed it in the program use a coding algorithm.The software watermarking is divided into static and dynamic watermark,and the dynamic gragh watermark belongs to dynamic watermark is very effective.the main idea of the dynamic graph watermarking is use the watermark embedded in the topology.The dynamic watermarking algorithm is use the pointer methord,which makes the structural of embedded watermark program become more difficult to analysis.so robustness has been greatly improved.The current dynamic graph watermarking algorithm is PPCT and Radix-K coding scheme.The Radix-K coding scheme has a simple structure and easy to implement.Just becuase that it will easy to attack.Otherwise,Radix-k coding has a high embedding data rate.The PPCT structure of the PPCT coding scheme has been improved based onbinary tree.It has good stability and concealment.But the drawback is the embedding data rate is not high.This new coding scheme is based on a complex nonlinear data structure which is different with binary tree and linked list data structure.we use the vertex-nodes and edge-nodes to encode the information.The vertex-nodes creat a circular linked list.Each vertex-nodes represents a weight value according to its location.According to the performance analysis,in the best case,the datarate of our coding scheme exceeds the datarate of all the current watermarking data coding structure.The mixed coding scheme based on tamper-resistant is combined the advantage of the Radex-K coding scheme and PPCT coding scheme,and add a technology of tamper-resistance.This scheme improves the pointing of the right pointer of the right leaf nodes which is in the PPCT topology structure.The encoding methord is similar to Radex-K coding scheme.Then,code the watermarking digital according to the circular.so,the program will not be able to play,when the watermark topology structure is destroyed.This paper introduce the implementationes scheme of the mixed coding scheme based on the tamper-resistant in the article,and do a simulatione experiment on the SandMark platform.And then statistical experimental results are compared with the Radix-K coding scheme and the PPCT coding scheme.we can come to the conclusion that coding structure of the mixed coding based on the tamper-resistant dynamic graph has a good concealment and tamper-resistance.However the embedding data rate is still below with the Radex-K coding scheme,it has been improved significantly with PPCT encoding scheme.so,this is a good dynamic graph encoding scheme.