Privacy inference attacks based on sensor data is an emerging and severe threat on smart devices, in which malicious applications leverage data from innocuous sensors to infer sensitive information of user, e.g., utilizing accelerometers to infer user’s keystroke. In this paper, we present Sensor Guardian, a privacy protection system that mitigates this threat on Android by hooking and controlling applications’ access to sensors. Sensor Guardian inserts hooks into applications by statically instrumenting their APK (short for Android Package Kit) files and enforces control policies in these hooks at runtime. Our evaluation shows that Sensor Guardian can effectively and efficiently mitigate the privacy inference threat on Android sensors, with negligible overhead during both static instrumentation and runtime control.

中文翻译：

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传感器卫士：防止对Android传感器进行隐私推断

基于传感器数据的隐私推断攻击是对智能设备的一种新出现的严重威胁，其中恶意应用程序利用来自无害传感器的数据来推断用户的敏感信息，例如，利用加速度计来推断用户的击键。在本文中，我们介绍了Sensor Guardian，这是一个隐私保护系统，可通过挂钩和控制应用程序对传感器的访问来缓解Android上的威胁。Sensor Guardian通过静态检测它们的APK（Android Package Kit的缩写）文件将钩子插入应用程序，并在运行时在这些钩子中实施控制策略。我们的评估表明，Sensor Guardian可以有效地缓解Android传感器上的隐私推断威胁，而在静态检测和运行时控制期间的开销却可以忽略不计。