Research On PBFT Consensus Algorithm Based On Consortium Chain

The consortium chain is a blockchain network formed for cooperation between enterprises.Compared with the public chain represented by digital currency,the consortium chain has a lower degree of decentralization and clear node identities,but it has great impact on transaction throughput and transaction confirmation.Time has higher demands.The consensus algorithm is a key technology of the alliance chain,an important basis for ensuring the decentralized structure of the alliance chain,and also the bottleneck that restricts the throughput of the alliance chain.Therefore,improving the efficiency of the alliance chain consensus algorithm is a current research hotspot.Due to the structural characteristics and efficiency requirements of the consortium chain,voting-based consensus algorithms such as Practical Byzantium Fault Tolerance(PBFT)consensus algorithms are more efficient than Proof of Word(Po W)consensus algorithms.It is more suitable for alliance chain scenarios.However,the communication volume in the PBFT consensus process is relatively large,and with the increase of the number of nodes,the communication volume will increase more,which will easily cause communication congestion,thereby reducing the consensus efficiency and limiting the network scale of the consortium chain.In addition,the master node rotation mechanism of PBFT is that all nodes take turns to act as the master node.This mechanism can easily cause Byzantine nodes to repeatedly serve as the master node,thereby performing the master node switching process multiple times,reducing consensus efficiency and throughput.In view of the above problems,this thesis proposes two improvement schemes:Combined with the BLS aggregate signature technology,an improved practical Byzantine fault-tolerant algorithm(BLS aggregate signature Byzantine fault tolerant algorithm,BPBFT)is proposed,which modifies the two full-node broadcast behaviors in the PBFT consensus process.The master node broadcast replaces the full node broadcast,and the collective data in the broadcast message is changed to an aggregate signature,which greatly reduces the message length and communication complexity without affecting the consensus effect.The experimental data shows that BPBFT reduces the communication traffic in the consensus process,reduces the consensus delay,and improves the system throughput.For the master node switching process,a practical Byzantine fault tolerant algorithm(Random timer and Voting sore Byzantine fault tolerant algorithm,RVPBFT)based on random timing and voting points is proposed.Master node;through the voting scheme,the probability of a stable and good node being the master node is higher,and malicious nodes are prevented from being the master node.In addition,the timer scheme can detect and switch the master node in time when the master node fails to send heartbeat information after the master node crashes,avoiding the situation that some requests are sent to the crashed node.Experimental data show that RVPBFT has improved both in throughput and node switching time.