Enhancing location privacy for electric vehicles by obfuscating the linkages of charging events

Electric vehicles are in harmony with the environment, but in many cases the limited maximum driving distance prevents them from popularization. To overcome this disadvantage, many fast charging stations have been established, but privacy concern with respect to the locations of the vehicles arises. To preserve location privacy, sophisticated cryptographic approaches have been capitalized in designing authentication and communication protocols to achieve anonymity. However, from the system-level security standpoint, the arrival and departure events between electric vehicles and charging stations are often linkable. The linkages may still jeopardize the anonymization mechanism, resulting in decreased location privacy. In this paper, we propose a novel scheme to enhance location privacy for electric vehicles by introducing an infrastructure called the power routers to obfuscate the linkages between charging events. Our obfuscation will thwart location inference and improve the anonymization to enhance the location privacy. To evaluate the effectiveness of the power routers, we employ a metric called the linkability. Simulations reveal that the linkability will decrease to only about 10% after introducing the power routers. Meanwhile, the time to calculate all the linkages will increase as much as 10 times, which means it has become significantly more difficult for an adversary to cripple the location privacy for electric vehicles.