The Research And Practice On Software Watermark Technology Based On Executable File

The development of computer software, hardware and network technologies has brought a great convenience for the spread of digital products. But the side effects followed is the digital products transmissed through the network can easily be illegally used. The software, as a digital product, its copyright protection has become a very important problem and also has been paid much more attention.By embedding the secret watermark information into software carrier; the software watermarking technology is useful for software copyright protection. Recently, even though there is quite a number of academics did a lot of research on software watermarking, there are still many aspects to be improved on software watermark embedding, extracting and ant-attack capacity.Based on the analysis of existing software watermarking technology, this paper mainly study the feasibility of portable executable(PE) file when it used as a carrier to embed information and bring forward a new software watermarking algorithm model on the basis of portable executable file. The model is divided into five modules called armored module,feature extraction module,Integrity check module,watermark embedding and extracting modules. These modules accomplish certain function respectively. According to the characteristics of PE header, section table and sections, based on the redundant space and integrated with the features of PE file loading process, the armored module constructs vacant space which used for storing watermark embedding, extracting procedures and other control code by adding a new section to the original PE file. This model proposes a new watermark generating scheme that the watermark is formed of characteristics information extracted from PE file. Through message digest of characteristics information, the integrity check module can easily find out whether the software is intact. The watermark embedding module takes full advantage of the redundant space of PE file, combined with the characteristics in the load procedure of PE file. And then make a compound chaotic encryption and division of watermark information; at last, embed the software copyright information into redundant space of PE file in accordance with designed assembled table. and the watermark extracting module complete the integrity check of the software, according to the different check results, make a further watermark extraction and testing,it also makes different statements of software copyright. In the last part of the paper, on the basis of the framework, some practice about software watermark based on PE file was carried out.By means of research and analysis, experimental simulation, in accordance with its own characteristics of PE file, combined with encryption algorithm in Cryptography and makes a reference of assembled table design in virology; the software watermark algorithm model in this paper can make a better protection of software products. By aid of the summary information extraction, the algorithm can make a clear distinction about the software integrity verification; because of information pre-processing such as encryption of watermark and assembled table, it guarantee the information security; Be formed of the information by mean of feature extraction in software its own information, the watermark is unique and able to make better software copyright cognizance.