Research And Implementation Of Information Hiding System Based On Digital Watermarking Technology

With the development of computer network technology, the spread of softwareproducts has become very easy and convenient; however, it also raises serious softwarepiracy. At the earliest, people use encryption methods to protect softwareproducts.However, with the computer’s computing capacity increasing, cipher text canbe easily cracked. For solve the issue, a novel method, named software watermarking,has been put forward..In software watermarking technology, certain secret information (watermark)embedded in the software program; secret information can be extracted when you wantto prove the software copyright. Software watermark includes static software watermarkand dynamic software watermark. Dynamic Graphic Watermark is a sort of dynamicsoftware watermark, which is widely studied is a widely studied technique. Thistechnique dynamically generates a graphic structure when the program is running, anduses this graphic topology to represent a digital watermark. Therefore, a good graphictopology to represent the watermark digital watermark can be found or not is animportant factor which influences improving the Dynamic Graphic Watermarktechnology level.In this thesis, based on the theory of Dynamic Graphic Watermark, apply adynamic graphic software watermark algorithm based on CJ threshold scheme (for short:CJ algorithm). The algorithm introduce Chinese remainder theorem into softwarewatermark. The watermark w is divided into n part, and each part does not includeanother part. By any t (t≤n) part can recover w, but any t-1part can not be. DesignedCJWatermark_tester system based on CJ algorithm; this system is a software watermarksystem based on Java byte-code files. Finally, do experiments in theCJWatermark_tester system, carrying out evaluation and experimental analysis for theCJ algorithm’s data embedding rate, robustness, embed overload performance andconcealment performance. Experimental data indicate that CJ algorithm can extract thewatermark based on parts of the contents, with a strong robustness.