VFAS: Reliable and Privacy-Preserving V2F Authentication Scheme for Road Condition Monitoring System in IoV

Fog-based road condition monitoring systems (RCMS) have been widely deployed to reduce traffic congestion and improve road safety. Considering the semi-credibility of fog nodes (FNs), it is vital to perform mutual authentication between vehicles and FNs (V2F). However, existing schemes require the remote trusted authority (TA) participating in V2F authentication online, which results in huge network delays. Besides, these schemes pre-store numerous pseudonyms and private keys into vehicles for identity privacy protection, resulting in an excessive memory burden. Moreover, most schemes fail to consider the reliability and confidentiality of road information provided by vehicles. Inspired by this, we design an reliable and privacy-preserving V2F authentication scheme (VFAS) without real-time participation of TA. Notably, pseudonyms and full private keys are produced by the vehicle itself rather than being pre-stored in the vehicle, which greatly reduces the vehicle's memory burden. Moreover, to ensure the reliability and confidentiality, FN receives road information encrypted with session keys from more than threshold $\omega$ different vehicles. Simulation result from real-world datasets is used to fix the threshold $\omega$. Formal security proofs and analysis show the VFAS's security properties. According to experimental results, the VFAS performs better than related works in regard to computation, communication and memory burden.