Research On Smartphone Permission Security Of Android System

Android has the highest market share of smartphone operating system.The open access mechanism on Android brings more users, developers aswell as many security problems, especially the privilege escalationloophole which makes the security of Android facing enormous challenges.In view of the Android system privilege escalation，the architecture ofAndroid system is briefly introduced firstly. And then，the paper analysesthe module of Android frame，Android inter-process communication andAndroid permission mechanism. At the last of second part，the paperintroduces the Android privilege escalation attack and analyses the harmand influence brought by the attack.Then the paper introduces the existing methods to enhance defensefor Android privilege escalation attack：static method and dynamic method.Through the analysis of these methods’ advantages and disadvantages，wecan find that：（1）the static method can find can only find the privilegeescalation attack but can’t accurately identify the source of theattack;(2)dynamic method can instantly and effectively find the privilege,but occupy too much resources and decision process is too complex todefense in time.Based on the two methods， the paper presents a new defensemechanism, this mechanism is mainly divided into two parts:(1) theapplications of Android system are evaluated based on the evaluationcriteria to get detecting applications and sensitive permissions set;（2）thedefense system detects the inter-process communication of the detectingapplications. According to the comparison between request permission and sensitive permission set，the defense system determines whether there areprivilege escalation attacks. Then the defense system determines the sourceof the privilege escalation attacks according to the direction of applicationscommunication. Finally, the system makes alarm to remind the user thatrunning application is the source of privilege escalation attack.Finally, the defense system is realized and evaluated throughcomprehensive experiments. The results of the study show that the defensesystem can effectively defend privilege escalation attacks, but there arestill some deficiencies.