Impacts of Mobility on Performance of Blockchain in VANET

This paper investigates how mobility affects the performance of a blockchain system operating in a vehicular ad hoc network (VANET). The mobility of nodes incurs a unique challenge to a blockchain system due to continuous change and dynamicity in the connectivity of the nodes. Specifically, the mobility makes a proof-of-work (PoW) process difficult since while moving the nodes can only have a limited length of time for a rendezvous to exchange a new block for verification. For this reason, accurate modeling for the block exchange behavior in a VANET is also challenging, which nevertheless has not been discussed in previous studies. Therefore, this paper provides an analysis framework that formulates the impact of mobility on a blockchain system's performance in a VANET based on three key metrics: (i) the probability of a successful addition of block to the chain; (ii) the stability of a rendezvous, and; (iii) the number of blocks exchanged during a rendezvous. The closed-form expressions and numerical results display the performance of a blockchain system in various scenarios in a VANET.