Implementation of a Cost Efficient Passive Keyless Entry Device for the Communication Protocol

Abstract

The susceptibility to relay attacks is a major safety risk in modern vehicles, due to the system for responding to challenges, such as those used in the Passive Keyless Entry (PKE) of most commercial cars. This form of attacks requires a long-range contact between a vehicle and its key, which circumvents encryption and unlocks the vehicle without direct access to the key. While a number of defences have in recent years been proposed, many are not robust or realistic. Any feasible system is likely to rely on a non-easily manipulated environmental parameter. The device must also be: cost efficient; simple to implement; and take comfort into account, for example the life of the main battery. This work implements and assesses a Relay Attack-resistant PKE device, analyses several of the suggested feasibility strategies in literature, as well as proposes a new method: Curve matching approach. The most promising methods have been concluded: immobility identification, distance limitation protocols and curve-matching approaches - the first of which is to be implemented in the PKE-system prototype. Instead of traditional RFID, the project introduces a PKE device and uses Bluetooth to implement the communication protocol. Disturbance detection is then applied using an accelerometer. The final device is subsequently checked and measured. It is found to be easily implementable, cost-efficient and can improve the protection of PKE systems, although immobilisation detection is not entirely effective. Finally, the recommendation is that manufacturers should employ immobility detection promptly while exploring techniques that are potentially more successful, though uncertain.