The Research And Improvements Of The Software Protection Model Based On Serial Number Technique

Now the computer industry has entered the era of the Internet and information technology. The application of computer software products is extremely wide, from the industry point of view, software products is now widely used in almost all industries, especially in financial, education, manufacturing, scientific research and so on. Because of the great responsibility of computer software, there will be immeasurable loss if any problems happens. At the same time the computer software product itself is also facing a serious threat. Relying only on the legal aspects to protect the computer software product is not enough, the technical means are also needed to improve the protection on the software product.The current mainstream commercial software protection technology is based on the serial number technology, the paper has done a detailed study on the traditional software protection model based on the serial number technology, and summed up two problems:one is the user information and the corresponding serial number are easily spread, and the other is the module used to check the serial number is easily to be track and tampered. After putting forward these two questions, the paper is going to improve the traditional model:First, the machine fingerprint technology will be introduced, and in which the random string is added to increase the difficulty of the attacker, the second is to combine the code obfuscation technique with the serial number check module but not to obfuscate the serial number check module itself, while to make the serial number check module to be a parameter used to obfuscate other module, and to increasing the randomness by introducing the switch variables into the serial number check module, thereby improving the performance of the program resisting dynamic analysis. In order to verify the feasibility of the improved scheme, the paper implements an software protection system(about 3000 lines of C++ code amount) using improved model of the software protection based on the serial number techniques, tested and successfully run, and analyzed the cost and impact of the new method to bring the cost of time and space, and have concluded that the improved method gives more effective protection to the software, and the additional space and time cost are acceptable. The result of this paper provides the reference meaning to prevent the software from being illegally attacked and cracked.