Intra-Shard and Inter-Shard Collaborative Incentive Scheme for Shard-Based Permissionless Blockchain

Abstract

Shard-Based blockchain technology is currently one of the effective ways to improve the throughput of permissionless blockchain. By distributing transactions into multiple shards, the validators in each shard verify transactions and reach in consensus in parallel, thereby increasing system throughput and scalability. However, most of the existing Shard-Based Blockchain schemes lack an incentive scheme that can promote mutual cooperation among the nodes in the shard and participate in consensus as much as possible, which leads some selfish nodes to adopt strategies that are not conducive to the maintenance of the blockchain system in order to obtain higher profits, thereby endangering the stability and security of the entire blockchain system. In this paper, we introduce the concept of node reputation to evaluate node behavior, and establish the correlation between reputation and profit. In that case, nodes with higher reputation can get more rewards, thereby achieving the fairness of reward distribution. In addition, we use the N-player static game model in game theory to analyze the changes in utility corresponding to different strategies for node, and design a dynamic transaction distribution scheme through genetic algorithm(GA) to ensure that the majority of nodes participate in consensus and shard liveness. Our research results show that our solution can better improve incentive fairness and liveness compared to the general transaction uniform distribution scheme.