Privacy-Preserving User-Centric Authentication Protocol for IoT-Enabled Vehicular Charging System Using Decentralized Identity

There has been a shift towards the use of Electric Vehicles (EV) in recent years. Though EVs offer many advantages, there are concerns on the cyber security of its components and the privacy of its users. When users charge their EVs at a charging station, they need to reveal their personal details. An attacker can compromise the users' privacy by identifying and tracking where users charge their EVs. Hence, there is a need to protect EVs from cyber-attacks and preserve its users' privacy. In this paper, we address the problem of privacy preservation of users while charging their EVs in a 5G-enabled vehicular charging system. We propose a user-centric authentication protocol for EV charging based on Decentralized Identifier (DID) and blockchain. We use Verifiable Credential (VC) together with DID which provides Zero-Knowledge Proof (ZKP) about the user. Users have complete control over their identities resulting in user-centric authentication. At the same time, a third party can verify the user's legitimacy before providing services. Hence, our protocol makes the charging service available in a secure way, preserving the privacy of the user.