Relay attack prevention for passive entry passive start (PEPS) vehicle security systems

Abstract

A passive entry passive start (PEPS) vehicle security system configured to thwart a relay attack on the system. The system includes one or more ultra wideband transceivers (UWBX) installed on a vehicle and configured to transmit a request pulse at a request time. A mobile UWBX, possibly installed in a nomadic device such as a smart phone, is configured to transmit a reply pulse in response to the request pulse. A controller is configured to determine a distance between each UWBX and the mobile UWBX based on a time interval between the request time and a time that corresponds to when the reply pulse is received by the each UWBX. The controller may also be configured to unlock doors of the vehicle only if the distance is less than an unlock threshold.

Dependencies are inferred from the claim text.