A system for a vehicle comprising: a communication gateway for the vehicle configured to establish a secure Bluetooth low energy communication connection with a portable device; a plurality of sensors for the vehicle, each including a BLE chipset and an antenna, said BLE chipset is connected to the antenna, the sensors being in communication with the communication gateway, said sensor is configured to measure signal information about at least one communication signal sent from the portable device to the communication gateway; a localization module for the vehicle configured to receive the signal information from each of the plurality of sensors and to determine a location of the portable device based on the signal information from the plurality of sensors; and a passive entry / passive start (PEPS) system for the vehicle configured to receive the location of the portable device from the localization module and to perform a vehicle function including at least one of unlocking a door of the vehicle, unlocking a trunk of the vehicle, and allowing the vehicle to be started based on the location of the portable device, characterized in that the plurality of sensors in communication with the communication gateway is each configured to receive, from the communication gateway, connection information about the secure BLE communication connection to eavesdrop on the secure BLE communication connection based on the connection information; and a security filtering module for the vehicle is provided configured to receive information indicating an arrival time at which a communication packet was received at each of the plurality of sensors, to compare the arrival time with an expected arrival time, and to determine whether the communication packet was received from an unauthorized device based on the comparison. a communication gateway for the vehicle configured to establish a secure Bluetooth low energy communication connection with a portable device; a plurality of sensors for the vehicle, each including a BLE chipset and an antenna, said BLE chipset is connected to the antenna, the sensors being in communication with the communication gateway, said sensor is configured to measure signal information about at least one communication signal sent from the portable device to the communication gateway; a localization module for the vehicle configured to receive the signal information from each of the plurality of sensors and to determine a location of the portable device based on the signal information from the plurality of sensors; and a passive entry / passive start (PEPS) system for the vehicle configured to receive the location of the portable device from the localization module and to perform a vehicle function including at least one of unlocking a door of the vehicle, unlocking a trunk of the vehicle, and allowing the vehicle to be started based on the location of the portable device, characterized in that the plurality of sensors in communication with the communication gateway is each configured to receive, from the communication gateway, connection information about the secure BLE communication connection to eavesdrop on the secure BLE communication connection based on the connection information; and a security filtering module for the vehicle is provided configured to receive information indicating an arrival time at which a communication packet was received at each of the plurality of sensors, to compare the arrival time with an expected arrival time, and to determine whether the communication packet was received from an unauthorized device based on the comparison.