An improved PBFT consensus mechanism based on quality of service
Wen-Liang Cai, Xiaowei He, Yong Nie · 2022
As a new distributed database technology, consensus algorithm is the main difference between blockchain and traditional database technology. Consensus algorithm decides the safety and performance of blockchain technology. PBFT(Practical Byzantine Fault Tolerance) has the problem that the main node is relatively fixed, and when network scale is large, communication cost is unacceptable. To solve this problem, this paper proposes an improved PBFT consensus based on quality of service. By dynamically evaluating the service quality of nodes to divide the participation status of nodes in the blockchain network. Nodes with high service quality will have a greater chance to participate in the consensus, reducing the probability of low service quality and malicious nodes becoming block producers, thereby improving the security of the system; The FTS tree is used in the eligible nodes to randomly determine the block- producing node to ensure that the block-producing node will not be fixed for a long time; A node state transfer mechanism is proposed to dynamically divide the role of nodes. Simulation experiments show that, compared with the original PBFT consensus mechanism, the system proposed in this paper can significantly reduce the communication overhead in the consensus mechanism and increase the fault tolerance rate and security of the system.