Multicast-Based PBFT Consensus Algorithm And Its Application In Blockchain

In public blockchain,the consensus algorithm is used to determine the signing rights of each block in the blockchain network to reach consensus recognition and consensus algorithm based on the incentive mechanism,however,the consensus algorithm is not suitable for application in non-public blockchain based on the incentive mechanism,because the application group of private blockchain and consortium blockchain,no one willing to pay the reward,to explore without reward mechanism and applied to the private blockchain or the consortium blockchain consensus algorithm is of great significance.Practical Byzantine fault tolerant(PBFT)algorithm is a consensus protocol for information interaction between nodes,some non-public blockchains have evolved on the basis of the algorithm to consensus algorithm,practical Byzantium fault tolerance consensus algorithm in three phase interaction information,on the Internet network,the small area can support broadcast,but the big scope does not exist a message distributed to all the receiver on the physical meaning,but it is not like physical meaning of broadcasting,to a wide range of moment with a message distributed to all the receiver,the message can only be a transfer to a receiver,points many times to achieve full distribution.The messages can only be delivered to one receiver at a time,and can only be delivered multiple times to achieve full distribution.The communication complexity of the consensus algorithm is O(n~2),so the three phase interaction information efficiency is low,especially when large number of nodes,node information interaction between time consensus process much time efficiency will be lower.(1)This specialization proposes an improved method based on multicast protocol to realize the multicast transmission of information in the three phase information interaction of PBFT consensus algorithm.The communication complexity of the improved consensus algorithm is O(n),which reflects the advantage that group communication can greatly improve the efficiency of information interaction.(2)Modify the network protocol for the network simulator NS2,then NS2 was used to conduct a simulation experiment on the multicast combined PBFT consensus algorithm to test its three phase information interaction efficiency.The simulation experiment data showed that the improved consensus algorithm efficiency was greatly improved.(3)Relevant literatures have shown that the improved consensus algorithm,Byzantine node breaches consensus security increased from 33% to 51%.