Research On Protection Mehtods Of Android Software

Recent years have witnessed a very fast increment of the applications on Android platform, which has been the most popular embedded operation system. However, because of its openness and the flaw of its security mechanisms, the security issues have always been upsetting the users and researchers of Android system. Meanwhile, sincethe protection for Android applications is not sufficient, they are facing very terrible threats of being pirated, reversed and tampered.Based on this background, by leveraging the existing protection methods of Win32PE file and the mechanisms of Android itself, this thesis presents an Android application protection model about encryption and tamper-proofing of the executable file in both research and experiment ways and implements a demo system for this model.The work of this thesis mainly includes the following parts:(1)The thesis analyzes the state of the art researches on Android application security and demonstrates the worrying terrible situation that Android applications are faced with. Firstly, the article explains the structure and framework of Android system and the compiling procedure of an application and then states the related security mechanism of Android including the permission model, the sand-box system and the signature mechanism. Based on which, this thesis then analyzes the origin of these security issues and demonstrates the threats of being pirated, being reversed or being tampered that are faced by Android applications.(2)This thesis presents an Android application protection model about encryption and tamper-proofing of the executable file based on the existing software protection methods for Win32PC and the mechanisms of Android system itself and tries to make a balance of the security level and the efficiency of the protected applications. By encrypting the executable files in an APK package and detecting the tampering to the packer file, the protection model can effectively thwart the threat of pirating, reversing, and tampering. (3) This thesis designs and develops a demo system of the protection model and conducts some experiments to test and verify the effectiveness and efficiency of this demo system as well as the protection model. The experimental results show that the applications protected by this demo system can resist the attacks of pirating, reversing and tampering with negligible runtime overhead. So the Android application protection model can effectively protect Android applications.