Sharding and Its Impact on Fork Probability

Abstract

Blockchain is an emerging technology that has encountered a number of challenges, including forks and low transaction processing rates compared to other payment systems. While sharding was designed to resolve the problem of low processing rates, it also increases the scalability of the network. However, its effect on the probability of forking is still unclear. Our primary goal in this study is to determine the impact of adding new shards to a blockchain on the probability of forks occurring. In order to achieve this goal, we first developed a novel simulator which enables us to simulate sharded networks. Then, we examined the effect of sharding on fork occurrence. Two EIP-1559 enabled networks containing 60 and 120 nodes have been studied in several experiments. As a result of our study, we have found that adding one shard on average results in a 60% reduction in the number of orphan blocks. In addition, we have proposed a fork probability model which results in 23% and 15% reductions for networks with 60 and 120 nodes, respectively.