Efficient and privacy-aware authentication scheme for EVs pre-paid wireless charging services

One of the most promising technologies that will be used for charging Electric Vehicles (EVs) is wireless charging. By employing this technology, an EV is able to charge its battery without the need to stop. The charging stations should authenticate the EVs before allowing them to charge their batteries. Traditional digital signature reveals the real identity of the driver and degrades the location privacy. In this paper, we propose an efficient privacy-preserving authentication scheme for EVs wireless charging scenario. Our objective is not only to enable the EVs and the charging station to perform mutual authentication but to protect the privacy of the drivers without the need of a Third Trusted Party (TTP). The EVs use blind signature for authentication with the charging station to protect their privacy. Then, they use hash chains to authenticate themselves to the charging pads which are limited constraint devices. The verification of a hash chain requires performing simple hash operations which is computationally cheap and light-weight. The communication between the EVs and the charging station is secured by establishing an encrypted session. Our extensive evaluations demonstrate that our scheme preserves the drivers' privacy while mutually authenticate the EVs and the charging pads with low communication and computation overhead.