Design And Implementation Of The Software Dynamic Protection System Based On Virtual Machine

With the rapid development of computer and Internet technology, software security problem has become increasingly serious and the phenomenon of software piracy has harmed the interests of software developers seriously, therefore how to protect software copyright and core technology effectively has become an urgent problem in industry and academia. In theory, there is no absolute safety of software protection system, but if the attacker's cost will be more than their obtained information, the method of protection is effective. Based on the above reasons, the core of current software protection is to increase the difficulty and cost of software cracking for the attacker.At present, the software protection technology based on virtual machine has attracted extensive attention and become an important research direction in the field of software security. Its main principle is to convert the assembly instruction to bytecode, and then the software is protected by designing a unique virtual machine which is used to execute the bytecode. This kind of software protection technology, which can increase the usability while reducing the cost, has strengthened the ability of software to prevent the reverse analysis and the software piracy. So the authors will launch the study of the software protection technology based on virtual machine on the basis of the existing software protection technology and virtualization technology, then the authors will study the software model of interests, software attack methods and the protection measures from the angle of the attacker. Finally, the authors have proposed a software dynamic protection system based on virtual machine. Main work in this thesis includes:First of all, the authors have summarized the theory and technology of the existing software protection while having a detailed analysis of the current development of software protection at home and abroad. Secondly, the authors have researched the software attack methods starting from the aspect of the software security threat model, and studied the software protection system on the basis of the analysis of the existing software protection technology and the software reverse engineering. Thirdly, the authors have a detail discussion of the related technologies based on virtual machine software protection, including the bytecode file format after compiling, instruction addressing mode of simulation, the architecture of virtual machine, and the working process of interpreter and so on. Finally, the authors have designed a software protection system based on virtual machine while discussing the design of the system, overall structure and the working process, and then the authors have described the design and implementation of each main module in detail. Experiments show that the software protection technology based on virtual machine on windows and android can effectively achieve the goal of software protection with high intensity and strong extensibility.The authors have explored the application of the software protection technology. The system, which is based on the virtual machine platform and integrated into the software dynamic invocation mechanism, can effectively prevent the attacker's reverse analysis and the software piracy. It has a broad application prospect.