Channel correlation-based relay attack avoidance in vehicle keyless-entry systems

In passive keyless entry and start (PKES) systems, the car unlocks or starts the car when the key is in the proximity of the car. In conventional PKES systems, the car determines the physical proximity of the key on the basis of the received signal strength or the round-trip time (RTT). However, the conventional schemes are vulnerable to relay attacks because the relay amplifies the signal and minimises the processing time. A solution to avoid the relay attacks in PKES systems is proposed, where the car verifies the proximity of the key on the basis of the correlation of the channel state information as well as the RTT.