Vulnerability Analysis and Performance Enhancement of Authentication Protocol in Dynamic Wireless Power Transfer Systems

Recent advancements in wireless charging technology, as well as the possibility of utilizing it in the Electric Vehicle (EV) domain for dynamic charging solutions, have fueled the demand for a secure and usable protocol in the Dynamic Wireless Power Transfer (DWPT) technology. The DWPT must operate in the presence of malicious adversaries that can undermine the charging process and harm the customer service quality, while preserving the privacy of the users. Recently, it was shown that the DWPT system is susceptible to adversarial attacks, including replay, denial-of-service and free-riding attacks, which can lead to the adversary blocking the authorized user from charging, enabling free charging for free riders and exploiting the location privacy of the customers. In this paper, we study the current State-Of-The-Art (SOTA) authentication protocols and make the following two contributions: a) we show that the SOTA is vulnerable to the tracking of the user activity and b) we propose an enhanced authentication protocol that eliminates the vulnerability while providing improved efficiency compared to the SOTA authentication protocols. By adopting authentication messages based only on exclusive OR operations, hashing, and hash chains, we optimize the protocol to achieve a complexity that varies linearly with the number of charging pads, providing improved scalability. Compared to SOTA, the proposed scheme has a performance gain in the computational cost of around 90% on average for each pad.