Abstract: The FastHotStuff algorithm achieves a twostage pipelined Byzantine fault tolerant consensus through aggregated signatures. When the leader node of FastHotStuff fails, the deadlock problem in the view change phase brings communication complexity of O(n2). However, current studies have only focused on the deadlock problem and have not considered the issue of continuous view timeouts caused by Byzantine nodes and volatile networks. To address this problem, we propose a FastHotStuff blockchain consensus algorithm with adaptive view dynamic timeouts, called AVDHotStuff. First, the view dynamic timeout strategy algorithm adaptively controls the duration of the next view timeout to avoid continuous view timeouts caused by volatile networks. Second, the leader waiting strategy algorithm reduces the communication complexity of view change from O(n2) to O(n), and ensures the efficiency of view change by adaptively controlling the leader waiting time. Finally, the reputationbased leader selection strategy algorithm introduces reliable nodes into the consensus process, avoiding continuous view timeouts by removing Byzantine nodes during the view change phase. We have conducted experiments to compare our algorithm with FastHotStuff. When Byzantine nodes are present, the average throughput of AVDHotStuff increases by approximately 51.4%, and its average latency decreases by about 59.9%.

Key words: FastHotStuff algorithm, leader waiting strategy, view dynamic timeout strategy, reputationbased leader selection optimization strategy, Byzantine fault tolerance

摘要： FastHotStuff算法通过聚合签名实现2阶段流水线拜占庭容错共识.然而，当FastHotStuff的领导者故障时，视图切换阶段的死锁问题导致通信复杂度为O(n2).现有研究主要关注死锁问题，并未考虑拜占庭节点和不稳定网络引起的连续视图超时问题.针对这个问题，提出了具有自适应视图动态超时的FastHotStuff区块链共识算法AVDHotStuff.首先，视图动态超时策略算法自适应控制下一次视图超时的持续时间，以避免不稳定网络引起的连续视图超时.其次，领导者等待策略算法将视图切换的通信复杂度从O(n2)降低到O(n)，并通过自适应控制领导者等待时间确保视图切换的效率.最后，基于信誉值的领导者选择策略算法选取可靠节点，防止在视图切换时选取拜占庭节点，避免连续视图超时.与FastHotStuff算法相比，当存在拜占庭节点时，AVDHotStuff算法吞吐量平均提高约51.4%，平均时延减少约59.9%.

关键词: FastHotStuff算法, 领导者等待策略, 视图动态超时策略, 基于信誉值的领导者选择策略, 拜占庭容错