Modelling and analysis of relay attack devices for passive-entry-passive-start wireless systems

Passive-entry-passive-start (PEPS) is a wireless communication system that enables a driver to enter and start their vehicle without the need of a physical key. In PEPS system, the vehicle sends low-power LF signal to communicate with the key-fob. If the key is in the vicinity of the automobile, it sends a RF signal which the vehicle senses and unlocks the door. In this work, we show how vulnerable these systems can be to external attacks using relay devices. In a relay attack, the objective is to amplify the vehicle signal to transmit to longer distances such that it can communicate with the key-fob and unlock the door, without the knowledge of the owner. This work includes a model of the relay devices developed using MATLAB, as well as a detailed explanation of an attack scenario. A distance-based test case has also been included to conclude the attack. In the introduction section, a few popular techniques which can be used to mitigate relay attacks have been reviewed.