In-Progress: Exploring Tire Pressure Monitoring Systems (TPMS) for Secure Key Generation for Intra-Vehicular Device Authentication

Modern vehicular systems increasingly rely on secure wireless communications for both inter-vehicle and intra-vehicle device interactions. While traditional wireless authentication methods require manual user intervention and complex authentication procedures, zero-interaction authentication has emerged as a promising alternative, leveraging environmental randomness to generate identical keys that are naturally shared between co-located devices. In this work, we explore the potential of using Tire Pressure Monitoring System (TPMS) transmissions as a novel source of environmental randomness for automotive authentication. Through extensive experimentation, we demonstrate that underlying RF signal characteristics of TPMS provide reliable entropy that can be consistently measured by devices within the vehicle while being difficult to be captured from outside. Our evaluation shows 95% bit agreement rate between legitimate in-vehicle devices while external adversarial devices only achieve 50% agreement rate. Such results suggest that TPMS-based authentication could offer a practical, secure, and user-friendly solution for modern vehicular security challenges.