Research Of Blockchain Consensus Algorithm Based On Byzantine Fault Tolerance

With the popularity of digital currencies such as Bitcoin,blockchain as its underlying technology is increasingly concerned by governments and business giants.Because blockchain technology has the characteristics of decentralization,traceability,and anti-tampering,it has begun to be applied to various fields such as copyright protection,logistics management,supply chain finance,supply chain management,cross-border payment and so on.As the engine and core of the blockchain,the consensus algorithm not only guarantees the distributed consistency of the blockchain,but also affects the system throughput,transaction confirmation delay,and application scenarios of the blockchain application.In blockchain applications,facing the problems of low throughput,extended transaction time,and limited application scenarios in current consensus algorithms,this paper proposes three consensus optimization algorithms to improve them.The main findings and contents of this paper are as follows:(1)Aiming at the problems of limited application scenarios and the waste of communication bandwidth in the blockchain,this paper proposes a Byzantine Fault Tolerant consensus algorithm based on Dynamic Weight Adjustment(DWA-BFT).The algorithm keeps the richer details of consensus voting by continualizing the consensus voting process.The algorithm evaluates user behavior during the consensus process and dynamically adjusts the weight of voting,which enriches the application scenarios of the consensus algorithm.The algorithm will also optimize the communication in the PBFT three-phase protocol,reduce the number of invalid communications,and improve the consensus performance to a certain extent.In the same environment,the DWA-PBFT algorithm and PBFT algorithm are simulated.It is concluded that DWA-PBFT has lower transaction confirmation delay and less waste of communication bandwidth.(2)Aiming at the problems of long transaction confirmation time and privacy leakage in blockchain applications,this paper proposes a Byzantine Fault Tolerant consensus algorithm based on linkable ring signatures(ringPBFT).The algorithm uses the linkable ring signature to provide privacy protection during the consensus process and increase system security.In addition,the algorithm optimizes the three-phase protocol and view switching protocol of PBFT,reduces the complexity of the consensusalgorithm,and improves the performance of the consensus process and view switching.The ringPBFT is simulated and compared with the PBFT algorithm.The simulation results show that when the consensus node is equal to 100,the transaction confirmation delay of the ringPBFT algorithm with the main domain node of 10 is about 11 times lower than that of PBFT,and the view switching efficiency is improved about 20 times.(3)Aiming at the problem of low system throughput of the consensus algorithm in the blockchain,this paper proposes a Byzantine Fault Tolerant consensus algorithm based on the Domain and Margin mechanism(DM-BFT).By applying the idea of the Lightning Network to the consortium blockchain,the system throughput(TPS)of the blockchain application is greatly improved,the transaction confirmation delay is reduced,and the problem that the size of the consensus nodes in the PBFT consensus algorithm affects the efficiency of the consensus is solved.The DM-BFT is simulated and compared with the TPS of Bitcoin and Ethereum.With the same block size,the TPS of a subdomain of DM-BFT is about 8-9 times larger than Ethereum,and is about 40 times larger than Bitcoin.In addition,as the number of subdomains increases,the TPS of DM-BFT will increase exponentially.Comparing the DM-BFT algorithm with the mainstream algorithm in the consortium blockchain,the throughput performance of the DM-BFT algorithm is obviously optimized.