Secure pairing of Internet-of-Things (IoT) devices is a challenging problem because many of them lack the typical user interfaces to provide credentials in the authentication process different from conventional computing platforms. The identical problem is observed in a modern automotive environment. Users bring various smart devices besides smartphones to the cabin and want to connect to their vehicles. Moreover, as car/ride-sharing economy is expected to be continuously grown, such an in-vehicle device authentication will soon become a roadblock, without a proper mechanism, before enabling emerging services. In this study, we develop a novel authentication mechanism, which uses the shared context of two pairing ends. In a moving vehicle, for example, a vehicle and an IoT device located in cabin share the motion. The proposed mechanism compares the motion data from accelerometer sensors in both paring ends to determine their spatial co-existence. We implement a proof-of-concept Android app to prove its feasibility and evaluate in practical user scenarios. By minimizing the user interaction in device authentication, the proposed mechanism will improve safety and usability as well as security.
