基于改进实用拜占庭容错的可信分布式区块链信任机制研究

Research on Trust Mechanism of Trusted Distributed Blockchain Based on Improved Practical Byzantine Fault Tolerance

针对区块链中实用拜占庭容错共识算法(Practical Byzantine Fault Tolerance,PBFT)中存在节点通信次数高、主节点选取简单、缺少奖惩机制及节点缺乏积极性等问题,提出了一种基于改进PBFT的可信分布式信任机制设计方案,即TM-PBFT(Trust Mechanism-PBFT)。首先,引入信誉模型对节点进行信誉值排序,增强对节点Sybil女巫攻击的防御能力,提升节点的积极性;其次,对节点进行分层共识,减少节点间通信开销;结合应用超级账本(Hyperledger Fabric)与星际文件系统(InterPlanetary File System,IPFS)对链上数据进行处理,减轻了数据的链上存储负担,提高了共识效率。在40个节点参与共识的条件下,通信次数相较于传统PBFT下降了85.8%,相较于C-PBFT算法下降了27.7%。

Aiming at the problems of high node communication times,simple master node selection,lack of reward and punishment mechanisms and lack of motivation of nodes in Practical Byzantine Fault Tolerance(PBFT)consensus algorithm in blockchain,this paper paper proposes a trusted distributed trust mechanism design scheme based on the improvement of PBFT,i.e.,TM-PBFT(Trust Mechanism-PBFT).Firstly,a reputation model is introduced to rank the reputation value of nodes,enhance the defence ability against node Sybil witch attack,and improve the enthusiasm of nodes.Secondly,a hierarchical consensus is performed on nodes to reduce the communication overhead between nodes;and a combination of Hyperledger Fabric and InterPlanetary File System(IPFS)is applied to the on-chain trust mechanism.System(IPFS)to process the data on the chain,which reduces the burden of data storage on the chain and improves the consensus efficiency.With the participation of 40 nodes in consensus,the communication frequency decreases by 85.8%compared to traditional PBFT,and by 27.7%compared to the C-PBFT algorithm.