On Forks and Fork Characteristics in a Bitcoin-Like Distribution Network

Abstract

Chain growth in a permissionless blockchain-based ledger is mostly defined by the characteristics of the distribution network and the chosen consensus protocol. In this paper, we investigate the performance of block propagation in a Bitcoin-like peer-to-peer distribution network, and highlight the impact of the Nakamoto consensus protocol on the dynamics of blockchain growth. We use a simulated network with nodes located in different geographic regions, each with its own propagation characteristics; the values of network parameters are chosen to match available data for the Bitcoin peer-to-peer network. We show that the latency of block propagation is mainly affected by the mean round-trip time; that forks occur more often when mean round-trip time is longer, and that the ratio of the number of nodes opting for one or the other of competing blocks as the main chain tip can occur in almost any ratio; finally, that the mean time to resolve a fork is approximately equal to block inter-arrival time.