ProxiCar: Proximity-Based Secure Digital Key Solution for Cars

Remote key-less entry systems (KES) are one of the most important and desirable features of modern vehicles. However, due to platform dependencies and/or design flaws, majority of the KES used even in recent high end cars are vulnerable to signal relay attacks. In this work, we propose ProxiCar - an architecture for secure Digital Key Solution that enables user to use an authorised digital key stored in his/her personal device for remote vehicle access. We study the feasibility of employing physical layer features i.e., Received Signal Strength Indicator (RSSI) of Low Power Bluetooth (BLE) technology for (i) proximity estimation, (ii) user activity detection, and (iii) second factor authentication between the vehicle and user's device. We highlight the major challenges involved in using BLE channel features for security, and present a method to overcome those issues. We implement our proposed method on off-the-shelf android-based devices and experimentally evaluate the performance. Our promising results show that BLE physical layer features can be effectively employed to design secure KES.