摘要： 针对实用拜占庭容错算法PBFT共识时延高、视图切换效率低、动态性不足等问题，提出一种基于备选投票机制的低时延共识算法IPBFT。通过增设候补集合，使系统的共识节点能够支持动态增加和减少，同时优化视图切换协议，使算法能够在只有两个阶段的情况下完成共识过程，降低系统的通信开销。在此基础上，将算法的主节点选取方式改进为投票选举机制，在节点进行共识的过程中实现主节点的选举，从而减少视图切换所需的通信次数和时延。实验结果表明，IPBFT算法较原始PBET算法具有更低的共识时延和更高的吞吐量，并且能够较好地支持节点动态的加入或退出。

关键词: 区块链, 共识算法, PBFT算法, 备选投票机制, 低时延

Abstract: The Practical Byzantine Fault-Tolerance(PBFT) algorithm is limited by the high latency of consensus, inefficient view switching and lack of dynamicity.To address the problems,an improved algorithm called IPBFT with lower delay based on alternative voting mechanism is proposed.By adding an alternate set,the algorithm enables the number of consensus nodes in the system to be dynamically adjusted.At the same time,the view switching protocol is improved to allow the algorithm to complete the consensus process in only two phases,reducing the communication overhead of the system.On this basis,the way of selecting the primary node is changed to a voting election mechanism, which realizes primary node election in the process of node consensus to reduce the number of communication times and latency required for view switching.The experimental results show that the IPBFT algorithm has lower consensus delay and higher throughput than the original PBET algorithm.Meanwhile,it can support the nodes to dynamically join or exit.

Key words: blockchain, consensus algorithm, PBFT algorithm, alternative voting mechanism, low delay

中图分类号: 

• TP311