Research And Realization On Android Software Protection Technology

Because of its open source nature, Android system become one of the most widely used mobile operating system. However, because of the rapid development of Android applications market, Android applications has become an improtant target for crackers. Because Android system’s release time is short, and the software protection technology on mobile platform is still in its infancy, Android applications face piracy, tampering and other serious problems. Mobile software developers’intellectual property rights have been arbitrarily violated.This article mainly focuse on software protection technology research on the Android platform. On this basis, combining with the mature Windows platform protection scheme to implement a more effective software protection to prevent reverse engineering, enhance the security of Android applications, protect software developers’intellectual property rights, prevent disclosure of users’personal information, and so on.Mainly work done by this thesis as follows:1. In-depth study haved been done for the Android platform system structure and operation mechanism. Analysis of the Android platform of the four layer architecture and security mechanism, the compilation process of the Android software for analysis and reverse, forward security threats faced by Android software.2. As the Android software is easy to be reverse distortion, this paper presents confusion scheme and algorithm of Android oriented software code, combined with the algorithm and improved insertion branch path and flattening the excess flow of control of these two kinds of control flow obfuscation method, insert the branch path is redundant to confuse the program execution path, flattening control stream processing is the destruction of the original program nesting of loops and conditional statement on the further destruction of the original program control flow graph, strengthen the procedure analysis difficulty. At the same time, through the establishment of access control policy to strengthen the opaque predicates, further strengthen the confusion strength. The program is actually running is reduced when the next variable in the switch structure update times control confused time overhead of redundant paths do not carry compressed delete operation of obfuscated file size increase in spending also control.3. After in-depth study on Windows platform of self modifying code technology, the possibility of self modifying code technology in the Android platform has carried on the detailed analysis and explanation, related to its implementation of the Java native interface technology and NDK local development technology is studied and implemented, and through the examples to prove that self modifying code-technology in the implementation of the Android platform the.4. On the platform of Android code based on the self modification technology to realize the foundation, proposed the self modifying protection scheme of double code based on Android platform, and the program and software signature verification, integrity protection combination, coupled with the key code protection and code obfuscation module, the design and implementation of a software based security protection the Android system platform, software of Android authentication, integrity, confidentiality and tamper proof of a full range of protection.5. According to the proposed Android software protection system, conduct experiments from the feasibility, security, efficiency and integrity to verity the effectiveness of the system.