Based On The Technology On The Shell Of Software Protection

With the rapid development of the Internet era and the advent of the information age, now the dependence on computer systems and software is becoming higher and higher. Because computer applications can significantly improve the overall efficiency and performance, global infrastructure are dependent on using computer systems by a large proportion, such as the national defense, education, government and healthcare. Therefore, the security of application software is even more important, in order to prevent the software has been cracked or protect the business value of software or ensure its own technology or the fruits of labor, software should be taken to encrypt protection measures such as hardware encryption software encryption when the software finally released.Shell encryption is the most common and safest software encryption technology, which compresses and encryptions the original file (sometimes without encryption, just simple compression),then add a block of executable code in original file and modify the file information the original file (generally refers to running parameters). So that when a packed executable file is executed, the order of execution has been changes:firstly the shell is executed, and then run the code of the original file. The execution order and characteristics of the original file will not only be changed, and the static characteristics of its file have been changed when the executable file is packed. Only when the executable file is loaded and executed, the shell restores and decryption the packed parts in memory. It not only can prevent the illegal crack of the executable file, but also can prevent executable files to be static recompilation.The thesis takes shell technology as a starting point, and analyzes the executable file format. Then detailed introduce the current software protection technology, and analyze packing shell and unpacking shell in the software protection technology. Finally we propose new software protection model based on Shell technology which is based on the integration of software shell protection model, the so-called "integration "is making the shell program and the original program combined together. When the shell is taken off by cracker, then the part of the original program was also given away, thus reach the purpose of protection software.This thesis also puts forward the solution implementing the model which is based on the code-of-unordered mechanism which means that the original program with shell code are out of order for reaching the goal of integration, at the same time For defensing static recompilation we will add junk code and use SHE technology for anti-dynamic tracking. Ultimately we will implement packing based on the integration of software shell protection model by this solution.