Design And Implementation Of Blockchain System With Improved PBFT Consensus Algorithm

As the underlying technology of digital currency,blockchain technology integrates the research results of distributed system,cryptography,network protocol and other technical fields.It reduces the credit cost and accounting cost in the commercial field and has a broad market prospect in the fields of finance,credit investigation and e-commerce.By analyzing the implementation methods and technical characteristics of the practical Byzantine fault-tolerant algorithm widely used in the alliance chain,this paper concludes that the current PBFT consensus algorithm has the defects of low throughput,high delay and so on,and cannot effectively meet the performance requirements of the blockchain system.Therefore,the research focus is on the performance improvement of the consensus algorithm.An efficient CPBFT consensus algorithm based on credit mechanism is proposed,which mainly includes the following aspects:(1)Change the block chain network architecture from the traditional C/S architecture to the P2 P topology architecture to make it more suitable for the current blockchain technical features;(2)Change the five steps of traditional PBFT consensus algorithm into two steps to improve system performance;(3)Remove the client PBFT algorithm role,will be cut in all nodes to participate and vote the master node,in order to reduce the security hidden danger of the resulting credit rating and credit coefficient is put forward,according to the node performance history,the node is divided into multiple credit rating,and give different credit coefficient,the nodes of votes and credit coefficient calculated by the node the final vote,to sort of votes,thus high reliability of the master node;(4)In order to enhance the voting autonomy of nodes and improve the voting enthusiasm of low-credit-level nodes,a margin and voting rights mechanism is introduced.The number of votes each node has will be calculated based on its credit rating and the amount of margin.Nodes will have more voting rights;(5)Design data synchronization and verification mechanism,and complete the operation of data synchronization between master node and slave node.Finally,the performance test of the blockchain system improved by the above improvement scheme and implemented by Java is carried out.The test results show that the improved blockchain system has obvious performance improvement in throughput,delay and communication times.It meets the performance requirements of blockchain in most application scenarios.