PBFT共识算法性能分析  

Performance Analysis and Optimization of PBFT Consensus Algorithm

作　　者：林楷松 钱恭斌[1] 张沛昌 LIN Kaisong;QIAN Gongbin;ZHANG Peichang(School of Electronical and Information Engineering,Shenzhen University,Shenzhen Guangdong 518060)

机构地区：[1]深圳大学电子与信息工程学院,广东深圳518060

出　　处：《软件》2023年第6期21-29,共9页Software

基　　金：广东省“服务乡村振兴计划”重点领域基金(2019KZDZX2014);深圳市基金项目(20200823154213001);深圳市基金项目(JCYJ20170302142545828);部分由广东省“服务乡村振兴规划”重点领域基金会资助项目(2020ZDZX1037);部分由深圳市基金会资助项目(20220810142731001);广东省基础和应用基础研究根据拨款2021A1515011855设立的基金会。

摘　　要：众所周知,共识机制是区块链的核心,是区块链实现分布式存储的关键。随着各种区块链共识机制地出现,基于共识机制的优化方法也相继被提出,主要从优化共识过程以及控制共识节点的数量入手,解决共识机制吞吐量低、高时延、高资源等问题。然而,许多基于共识机制的优化缺乏理论的分析,也没有提及关键参数会影响共识机制的性能。为此,文中将以实用拜占庭算法(Practical Byzantine Fault Tolerance Algorithm,PBFT)、基于分组的实用拜占庭算法(Practical Byzantine Fault Tolerant Algorithm Based on Group,G-PBFT)以及基于分组和信誉的实用拜占庭算法(Practical Byzantine Fault Tolerant Algorithm Based on Clustering and Reputation,GR-PBFT)为例,构建三者的数学模型,进行性能分析。根据交易吞吐量、交易失败概率、区块认证失败概率和通信复杂度等性能指标进行对比。仿真结果表明:在同等节点数量下,G-PBFTD、GR-PBFT算法的吞吐量为PBFT的1.57倍、2.38倍;G-PBFTD、GR-PBFT算法的交易认证失败概率比PBFT下降了16%、39%;G-PBFTD、GR-PBFT算法的通信复杂度比PBFT下降了3.1倍、4.0倍,优化效果显著。As we all know,consensus mechanism is the core of blockchain,which is the key to achieve distributed storage in blockchain.With the emergence of various blockchain consensus mechanisms,optimization methods based on consensus mechanisms have been proposed one after another,mainly from optimizing the consensus process and controlling the number of consensus nodes to solve the problems of low throughput,high latency and high resources of consensus mechanisms.However,much of the consensus-based optimization lacks theoretical analysis and does not mention the key parameters that can affect the performance of the consensus mechanism.For this reason,the paper will construct mathematical models of the practical Byzantine algorithm,the grouping-based practical Byzantine algorithm,and the grouping-and reputation-based practical Byzantine algorithm as examples for performance analysis of all three.The performance metrics are compared based on transaction throughput,transaction failure probability,block authentication failure probability and communication complexity.The simulation results show that the throughput of G-PBFTD and GR-PBFT algorithms is 1.57 times and 2.38 times of PBFT with the same number of nodes;the transaction authentication failure probability of G-PBFTD and GR-PBFT algorithms decreases 16%and 39%compared with PBFT;The communication complexity of G-PBFTD and GR-PBFT algorithms decreases 3.1 times and 4.0 times,with significant optimization effects.

关 键 词：PBFT 共识算法 分组 信誉 区块链 

分 类 号：TP302[自动化与计算机技术—计算机系统结构]