Robustness of remote keyless entry systems to intentional electromagnetic interference

Cars equipped with remote keyless entry systems are very vulnerable to electromagnetic interference because of the wireless link. Carrying the encrypted signal between the key fob and the car, it can deliberately be jammed by a malicious person. Jamming on the physical layer leaves the encryption and code algorithms on the higher communication layers useless. Jamming for criminal purposes is considered to be intentional electromagnetic interference. In this paper, the robustness of the remote keyless entry system to intentional electromagnetic interference is investigated. Two commercially available remote keyless entry systems are analyzed. Measurements are performed in an anechoic chamber to estimate the robustness of the RF receivers. Both systems are equipped with super regenerative receivers. Results show that the selectivity of both systems are poor and they are easily jammed. Field strenghts as low as 0.1 V/m can already jam the wireless link over a wide frequency bandwidth of 4 MHz. A super heterodyne receiver would be robuster to electromagnetic interference than a super regenerative receiver, but this type of receiver has a relative high cost.