Research On Performance Improvement Of Blockchain Based On Dynamic Authorization Of Byzantine Fault Tolerance Consensus Algorithm

With the popularity of the bitcoin as the representative of the digital currency,the blockchain as its key underlying technology are also increasingly concerned by governments and corporate giants.The de-centralization,irreversibility,dynamic and flexible characteristics,make it have a very broad application prospect in banking,credit,finance and other fields.However,the current blockchain system can't meet the performance requirements of most of the application scenarios in terms of transaction throughput and latency.Mainly based on Proof-of-Work and Proof-of-Stake,the TPS of public blockchain in the TPS is only less than 7 and the average confirmed time of one transaction is up to 10 minutes,the time that the transaction can't tamper with is up to one hour;and POW,POS and other consensus algorithms are inefficient and serious energy consumption,which can't meet the performance requirements of the blockchain system.The traditional distributed consistency algorithm represented by Paxos and Raft does not consider the Byzantine fault-tolerant problem,nor does it apply to honest and malicious nodes.The practical Byzantine fault-tolerant algorithm is designed for distributed system messages,the order of the implementation of the system,using the C/S architecture,three-stage broadcast protocol.With serious waste of bandwidth and static network topology,PBFT can't meet the dynamic and P2P characteristics of blockchain system.After studying the principle of the above consensus algorithm,this paper applies the authorization mechanism of DPOS algorithm to PBFT,and improves the PBFT to form a dynamic authorization Byzantine fault-tolerant algorithm which is suitable for blockchain application.DDBFT compared to PBFT has the following three advantages:1)Authorized electoral mechanism,the specialization of consensus accounting node and supplemented by "downgrade" mechanism,dynamically updated consensus accounting representative2)Streamlined consensus states,and reduce the network overhead which is due to the PBFT three-stage consensus broadcast mechanism3)Discard C/S architecture,pure P2P network topology,and in full compliance with blockchain system characteristicsFinally,the blockchain system based on DDBFT is designed and tested by Java program.The experimental results show that the algorithm can maximize the bandwidth of the network at the optimal time of 20 seconds,and the TPS can reach 10000-12000 and the delay is between 100-200ms,which can meet the performance requirements of most application systems.