The Research On APP Reinforcement Technology Based On Android Platform

With the development of mobile Internet technology,the demand for mobile security is becoming increasingly urgent.Android occupy the largest market share of mobile operating system.As an important part of the Android architecture,APP's security issues directly threaten the interests of Android users and APP developers.APP reinforcement is an important measure to ensure the safety of APPs.However,with the development of technique of reverse engineering,the original reinforcement method can be attacked and bypassed.Therefore,researching on the technology of APP reinforcement and enhancing the capability of APP security protection have important theoretical significance and practical value.In the current methods for DEX protection,based on function extractions,will restore the extracted method to Java form in memory,which makes it possible to recover the DEX file through the function information in memory dynamically and to achieve the unpacking.In our work,we propose a DEX protection method based on dynamic loading and MethodNativization.The method turns the protected Java methods into Native methods by modifying the DEX file,and encrypts the whole DEX file.When the APP starts,DEX is decrypted and loaded dynamically.At the same time,the native methods is redirected.When the protected method is called,it implements the original Java method through the Java reflection.The experimental results showed that the method could prevent the DEX from being analyzed statically and realize the Method-Nativeization,which can effectively resist the attacks through DEX dynamic recovery and dynamic unpacking.The existing anti-debugging methods,which use a single feature or multi-feature series,can be bypassed by anti-anti-debugging methods one by one.In our work,we propose an anti-debugging method combining multiple features.First,the method proactively tracks the parent process with child process.Then the parent process reads the status files of the parent and child processes and detects the Tracerpid.Finally,the parent process monitors the system files.When the debugging is detected,the application exit by creating the system Crash.Experiments showed that the method could effectively resist the debugging attacks and the anti-anti-debugging attacks.A reinforcement system of mobile terminal is researched and developed.The system can automatically identify the third-party APP reinforcement information and extract the APP parameters.It also can reinforce the APP,and make the APP having some selfprotection abilities such as anti-reverse and anti-debugging.At the same time,the system can also provide users with customized functions which will be protected by extracting and encryption.