A Fully Anonymous Authentication Scheme with Cryptographic Reverse Firewalls in Vehicle-to-Grid Networks

The automotive industry is rapidly moving toward new energy, intelligence, and connectivity, driven by policies, technological advances, and growing environmental awareness, which are pushing more people to adopt electric vehicles (EVs). Moreover, EVs are driven as distributed energy storage units by Vehicle-to-Grid (V2G), which facilitates a two-way exchange of energy. The grid and vehicles can change the power. By managing when and how EVs charge, V2G helps organize the charging process, making EVs more flexible and valuable energy resources. However, a major challenge in V2G is the authentication between EVs and charging stations (CSs), as attackers may impersonate legitimate EVs to gain unauthorized access, wasting resources and harming real users. Current authentication methods also suffer from weaknesses in key security and user privacy. In this paper, a novel method based on Cryptographic Reverse Firewalls (CRFs) is proposed, which uses random numbers to ensure the security of the private key and prevent leakage and malicious tampering. This makes it difficult for attackers to steal original keys. Moreover, the proposed scheme can conceal the relationship between signatures and vehicle owners, thereby ensuring user anonymity. Security analysis shows that the proposed scheme can resist spoofing attacks, prevent signature forgery, and ensure secure key management. Besides, experimental results confirm that the scheme is efficient, making it suitable for practical V2G applications.