Research On Delegated Proof Of Stake Blockchain Consensus Algorithm Based On PBFT

With the rapid rise of digital currencies such as Bitcoin,more and more researchers and fintech companies begin to devote themselves to the research of its underlying technology – Blockchain Technology.Consensus mechanism is one of the core technologies of blockchain system,which directly determines the performance indicators of the system and the scenarios for application.By improving the DPOS algorithm,this paper proposes a consensus algorithm of block chain based on PBFT,and the main ideas of the algorithm are as follows:First of all,to solve the problem that the DPOS node is not active in voting and the malicious node may be elected as the agent node,it defines the concepts of credit rating and credit coefficient,and introduces the agent node election model based on credit reward and punishment.In this election model,network nodes greatly reduce the proportion of exception nodes becoming agents by voting against them.Meanwhile,due to the credit stability and time reset mechanism,normal nodes need to participate in the election voting as much as possible,which effectively improves the enthusiasm of the election.Secondly,in view of the problem that DPOS consensus algorithm cannot deal with malicious nodes in a timely manner within one election cycle,it elects agents and alternative agent node sets,among which the alternative agent node set is used to timely replace the nodes in the agent node set due to multiple block-producing failures,thus effectively processing the malicious nodes.On the other hand,in view of the problem that the verification delay of DPOS algorithm is much larger than the block production delay,thus affecting the efficiency of block production,this paper selects the verification node set,and then introduces the PBFT algorithm to quickly verify the block.Finally,it uses the method of simulation experiment to design a simple version of the blockchain system with Node.js language,and evaluates the PDPoS algorithm from the aspects of block throughput,verification delay,fault tolerance and so on.The experimental results show that the PDPoS algorithm not only has the characteristics of high block throughput and low resource consumption of the DPoS algorithm,but also has lower verification delay and better security,which makes it better applied in the pursuit of free,open and fair public blockchain scenarios.