SemaDroid: A Privacy-Aware Sensor Management Framework for Smartphones

While mobile sensing applications are booming, the sensor management mechanisms in current smartphone operating systems are left behind -- they are incomprehensive and coarse-grained, exposing a huge attack surface for malicious or aggressive third party apps to steal user's private information through mobile sensors. In this paper, we propose a privacy-aware sensor management framework, called SemaDroid, which extends the existing sensor management framework on Android to provide comprehensive and fine-grained access control over onboard sensors. SemaDroid allows the user to monitor the sensor usage of installed apps, and to control the disclosure of sensing information while not affecting the app's usability. Furthermore, SemaDroid supports context-aware and quality-of-sensing based access control policies. The enforcement and update of the policies are in real-time. Detailed design and implementation of SemaDroid on Android are presented to show that SemaDroid works compatible with the existing Android security framework. Demonstrations are also given to show the capability of SemaDroid on sensor management and on defeating emerging sensor-based attacks. Finally, we show the high efficiency and security of SemaDroid.