Abstract:Android system has been one of main targets of hacking. Since its realease, it has been facing security risks such as root, image tampering, and malicious programs. System security usually overlooks framework layer which may cause high security risks. This study analyzes the component in Android framework and how it works. We present an Integrity Measurement Method for Android Framework (FIMM) to ensure Android framework's code integrity and runtime integrity. We focus on the issue of lack of protection for Android framework. The method is able to measure the integrity of component of Android framework and verity it. We consider that Android system service has a long running period, then we analysis the calling process for Android system services and present a dynamic integrity measurement for process providing fine-grained measurement. It measures and verities system service process every time system service is called. Finally, the FIMM impelemention based on Android emulator is discussed and presented. We believe that FIMM achieves the security goals, nevertheless, it causes a little performance loss as well.