Design of anonymous authentication scheme for vehicle fog services using blockchain

With the advances in smart vehicles and fog computing, Fog computing is extended to traditional Vehicular Ad Hoc Networks (VANETs). As a geographically distributed paradigm, Vehicle Fog Service (VFS) overcomes the limitations of VANETs in real-time response and location awareness. It supports a wide range of traffic information services, such as road warnings, congestion control, and autonomous driving. Secure communication between VFS entities is a critical problem in an open network. Meanwhile, most fog nodes are deployed in the public domain and are vulnerable to physical attacks. This paper proposes a secure authentication scheme for VFS to address the above issues. The scheme combines blockchain and physical unclonable function (PUF) to achieve two-way authentication of on-board units (OBU) and road side units (RSU) with the untrusted fog nodes. Our scheme provides conditional anonymity and non-repudiation, offering recourse in case of malicious behavior. Unlike other schemes, the proposed scheme only needs to determine whether the pseudo-identity has a revocation tag instead of scanning the whole certificate revocation list (CLS), significantly reducing the computational overhead. In addition, we use the Real-Or-Random ROR model and formally prove that the proposed scheme is provably secure, and informal security analysis shows that the scheme is robust to various known attacks. Finally, compared with existing schemes, our scheme maintains lower communication and computation costs and provides more security features, which shows that our scheme is more suitable for secure VFS environments.