IoTSafe: Enforcing Safety and Security Policy with Real IoT Physical Interaction Discovery

The Internet of Things (IoT) platforms bring significant convenience for increased home automation. Especially, these platforms provide many new features for managing multiple IoT devices to control their physical surroundings. However, these features also bring new safety and security challenges. For example, an attacker can manipulate IoT devices to launch attacks through unexpected physical interactions. Unfortunately, very few existing research investigates the physical interactions among IoT devices and their impacts on IoT safety and security. In this paper, we propose a novel dynamic safety and security policy enforcement system called IoTSafe, which can capture and manage real physical interactions considering contextual features on smart home platforms. To identify real physical interactions of IoT devices, we present a runtime physical interaction discovery approach, which employs both static analysis and dynamic testing techniques to identify runtime physical interactions among IoT devices. In addition, IoTSafe generates physical and non-physical interaction paths and their context in a multi-app environment. Based on paths and context data, IoTSafe constructs physical models for temporal physical interactions, which can predict incoming risky situations and block unsafe device states accordingly. We implement a prototype of IoTSafe on the SmartThings platform. Our extensive evaluations demonstrate that IoTSafe effectively identifies 39 real physical interactions among 130 potential interactions in our experimental environment. IoTSafe also successfully predicts risky situations related to temporal physical interactions with nearly 96% accuracy and prevents highly risky conditions.