一种可应用于联盟链的拜占庭容错混合共识机制

A Byzantine Fault Tolerant Hybrid Consensus Mechanism Applicable to Consortium Blockchain

拜占庭容错(BFT)在提供分布式系统的可靠性方面将变得越来越重要,其中实用性拜占庭容错(PBFT)是目前用的最佳算法之一,但是面对具有众多节点的分布式系统,PBFT并不令人满意。由于PBFT共识失败率接近1/3,共识失败率较高会造成主节点切换频繁,拖慢共识效率,概率分组算法降低了共识失败率,从而提高了共识效率。为了防止拜占庭节点串通攻击分组,基于可验证随机函数VRF抽签方式让拜占庭节点无法预判分组,进一步提高共识安全性。混合共识机制组内采用拜占庭容错chain-raft加快共识效率,组间采用PBFT保证对现有PBFT共识的兼容性。本文提出的共识机制在16个节点分为四组的情况下消息复杂度比PBFT降低了92%,吞吐量是PBFT的3.6倍。

Byzantine Fault Tolerance(BFT)will become more and more important in providing the reliability of distributed systems.Among them,practical Byzantine Fault Tolerance(PBFT)is one of the best algorithms currently used,but it faces distributed systems with many nodes,and PBFT is not satisfactory.Since the PBFT consensus failure rate is close to 1/3,the high consensus failure rate will cause frequent master node switching,slowing down the consensus efficiency,and the probability grouping algorithm reduces the consensus failure rate,thereby improving the consensus efficiency.In order to prevent Byzantine nodes from colluding and attacking groups,the VRF lottery method based on the verifiable random function makes the Byzantine nodes unable to predict the grouping and further improves the security of consensus.Byzantine fault-tolerant chain-raft is used in the hybrid consensus mechanism group to accelerate consensus efficiency,and PBFT is used between groups to ensure compatibility with existing PBFT consensus.In the consensus mechanism of this paper,when 16 nodes are divided into four groups,the message complexity is 92(lower than PBFT,and the throughput is 3.6 times that of PBFT).