Fork Probability Analysis of PoUW Consensus Mechanism

Abstract

In Blockchain, fork is a fundamental impediment to consensus mechanisms such as Proof-of-Work (PoW). In this paper, we study the fork probability of the famous Proof-of-Useful-Work (PoUW) consensus mechanism, which has recently been proposed to solve the huge waste of computing resources in PoW. With PoUW, each miner first does useful work (e.g., data classification), and then competes for the leader according to the number of the executed CPU instructions. Compared with conventional factors such as network delay, the time of doing useful work is a new and salient factor leading to a fork for a PoUW-based blockchain. Taking into account some important factors (e.g., the time of doing useful work, computational power, network delay), we propose a theoretical model to characterize the impact of these factors on the PoUW fork probability. Extensive simulations verify that our model is very accurate. This study is helpful for providing guidance of configuring PoUW parameters.