Research And Implementation Of Key Privacy Protection For Android

Android is a mature and stable open source mobile phone operating system based on Linux kernel.Mobile phones based on Android system currently occupy the vast majority of the global market.However,because it is open source,the system also has many security problems while users are highly free.At present,many applications are abusing and stealing user private information,and even crash without the user granting all permissions The user's media files,contact information,call records,etc.are all at risk of being stolen,and in more serious cases,hardware devices such as cameras and microphones will be used to covertly take photos and record audio in the background.Therefore,the research on privacy protection technology based on Android platform is of great significance to protect user privacy information.Mainly completed the following work:1.Completed the research on modular privacy protection technology based on authority control.It takes custom virtual permissions as the control core.A number of fake information permissions are built into the system,such as permission control module,fake location module,fake contact module,fake media module,fake camera module.By customizing the grant and forbidden of virtual permissions,it is decided whether to call the relevant privacy protection module,so as to help users protect privacy security.2.A new privacy trajectory obfuscation strategy is proposed.Aiming at the fact that the K-anonymity scheme,the mainstream solution for protecting location privacy information,is not suitable for this scenario,a privacy trajectory obfuscation strategy based on delay using,pause-considering and location mapping is proposed.The obfuscation strategy uses the historical node in the trajectory as the center to generate the current virtual location node,stops the generation of the virtual location node when the user's trajectory pauses,and supports the mapping from the customized part of the real positioning to the virtual positioning,so that it can protect the user's privacy.It can protect the use of LBS as much as possible on the basis of protecting user privacy.Through experimental,it is found that the privacy trajectory obfuscation strategy proposed in this thesis considering pausing and mapping is easier to use than the mainstream privacy protection strategy based on K-anonymity scheme,and combines the advantages of the rotation strategy and obfuscation strategy.The realism is higher than the obfuscation strategy,and the impact on LBS usage is lower than that of the rotation strategy.3.Developed a complete Android system based on AOSP,re-analyzed Android privacy protection on the basis of predecessors,abandoned the previous technical implementation form based on Xpost and other plugins,and adopted AOSP-based customized development of Android system.The system does not require users to install other software plugins,nor does it require users to obtain root privileges.Through the special test software written,the whole system and each privacy protection module completed in this thesis are tested,and the stability of the system and the effectiveness of the privacy protection system are verified and confirmed.Compared with previous solutions,it protects user system security and private information security in a finer-grained manner,provides higher autonomy,improves user experience and makes it easier for users to operate.