Abstract: To solve the problems of fixed primary node selection method and high communication cost of the practical Byzantine fault tolerance consensus algorithm widely used in alliance chain,this paper proposes a selective Byzantine fault tolerance consensus algorithm named SBFT based on verifiable random function.The first proposal is to dynamically calculate node contribution value by evaluating the node behavior after each round of consensus,and select the nodes participating in consensus based on the node contribution value.Next,a combination of node contribution value and verifiable random function is used for random selection of primary nodes by cryptographic sortation,which makes the selected primary node unpredictable while reducing the probability of non-honest nodes becoming primary node.Finally,the consistency protocol of PBFT is improved by changing the mesh communication network topology of PBFT into a star communication network topology and incorporating the view replacement process into the normal consensus process.Simulation experimental results show that the proposed SBFT algorithm has higher throughput,lower consensus latency and higher algorithmic efficiency compared with the PBFT algorithm.

Key words: Blockchain, Consensus algorithm, PBFT, Verifiable random function, Contribution value of nodes