Research On Consensus Performance Of Blockchain Based On PBFT

The Practical Byzantine fault tolerance(PBFT)algorithm is able to achieve strong consistency in the network environment with malicious nodes.So it is the mainstream consensus algorithm of Consortium Blockchain.However,the primary node selection method of PBFT algorithm has security risks,and all-node communications in algorithm flow brings problems such as poor scalability,high communication cost and low consensus efficiency.Therefore,this dissertation focuses on the main topic of “Consensus mechanism optimization”,and researches the problems in PBFT algorithm.This dissertation mainly completes the following tasks:1)This dissertation analyses the algorithm flow and the safety mechanism of PBFT and researches the problems and influences of the methods of master node selection,request service and all-node communication applied to the Hyperledger Fabric.2)This dissertation combines the mechanisms of Proof of Hashrate and Voting to propose a primary node selection algorithm.Simulation results show that this algorithm can select the primary node with strong comprehensive ability and this algorithm has unpredictability and flexible decentralization ability.This algorithm can solve the problems of PBFT algorithm in the primary node selection method,improve the stability and security of blockchain network,and meet the needs of higher requirements of applications.3)This dissertation analyses the improved PBFT algorithm based on the divide-and-conquer algorithm and verifies the effectiveness in improving performance and reveals the security problems.To solve this problem,this dissertation proposes a Core Consensus algorithm based on Trust Accumulation.Simulation results show that this algorithm is superior to the PBFT algorithm in performance and scalability,and has similar security to the PBFT algorithm.