Application Research On Digital Watermarking In Software Protection

Software watermarking is a new software protecting technique. Software watermarking can be divided into static watermarking and dynamic watermarking. The dynamic watermarking keeps in the performance appearance of procedure, so this kind of watermarking may even is used for physically applied. Dynamic graph software watermarking is the dynamic watermarking which is one of the most typical.The dynamic graph software watermarking includes watermarking encoding, embedding, watermarking retrieval and watermarking protection. Combining the PPCT (Planted Plane Cubic Tree) watermarking structure, an improved PPCT watermarking structure is presented. Theoretical research and experimental analysis are made in details about their usability, stealth and anti-attack capacity.An improved dynamic software watermarking algorithm is presented by using Chinese remainder theorem to split the watermarking into smaller, more manageable pieces, and inserting error check strings that correspond to the split watermarking graph to improve tamper-proofing and error-correcting performance. The new algorithm is highly capable of error-correcting and preventing from attack, as well as protecting software from sabotage.Finally, the improved path based dynamic software watermarking algorithm is validated. Verification consists of watermarking embedding and watermarking retrieval. The two sub-systems validate their validity, robustness and performance overload caused by watermarking embedding separately. Moreover, some extensible interfaces to be perfected are leaved.