Optimization And Application Of PBFT Consensus Algorithm Based On Dynamic Credit Authorization And Multi-signature

With the rise of digital currency represented by Bitcoin,blockchain has received extensive attention due to its advantages of decentralization,detrust,non-tampering,and non-forgery.Blockchain applications and research have shown explosive growth,and their applications have been From digital currency expansion to finance,trade,Internet of Things and supply chain industries.On the one hand,blockchain technology brings opportunities for the development of traditional industries.The blockchain can safely and transparently track the data stored in the block,and can effectively ensure the accuracy and consistency of the data stored by each participating node The combination of blockchain and traditional industries can easily solve the problems caused by the centralization of traditional industries.But at the same time,there are many problems in the development process of blockchain applications,such as low system consensus efficiency,small block capacity,low throughput,large energy consumption and poor data availability,which make it difficult to meet actual business needs.Starting from the above two aspects,this article first analyzes the problems of the traditional Byzantine consensus algorithm PBFT:high message complexity,poor dynamicity,no processing of malicious nodes,and C/S request response mode is not suitable for blockchain systems.In response to the problems of PBFT,a dynamic authorization PBFT algorithm based on credit value is proposed to improve the dynamics and deal with malicious nodes,and take advantage of the multi-signature algorithm to optimize the complexity of the PBFT message and improve the PBFT consensus process so that it can be applied to Blockchain system.Secondly,in order to solve the problems of data being easily tampered and poor integrity of traceability results caused by the centralization of the traditional traceability system,an optimized PBFT algorithm was used as a consensus mechanism to design and implement a blockchain traceability system.Based on the above research content,the main work content and results are as follows:Firstly,it analyzes the principles of blockchain and its underlying technologies,and then details the principles and processes of the Po W,Po S,DPo S,and PBFT consensus algorithms,and summarizes the performance indicators and performance characteristics of the four consensus algorithms.The underlying principles of these consensus algorithms provide theoretical basis and technical support for the research and improvement of blockchain consensus algorithms.Secondly,there are also problems in the application of the PBFT algorithm to the blockchain system.The message complexity is high,the dynamic is poor,the malicious node is not processed,and the C/S request response mode is not applicable to the blockchain system.PBFT consensus algorithm.Specifically:In the alliance chain network,this paper proposes a PBFT optimization algorithm based on dynamic authorization of credit value and multi-signature,abbreviated as CPBFT(credit practical byzantine fault tolerance).The system establishes a set of credit mechanisms for all consensus nodes.The consensus value is used to select a consensus node for each round of consensus.The system also adjusts the credit value of the consensus performance of each round of consensus nodes.The credit value of reliable nodes will become higher and higher.The probability of being selected as a consensus node in the next round is increasing,and the credit value of Byzantine nodes will be lower and lower and will be excluded from the consensus node.In the end,the entire system will become more and more reliable.In view of the high message complexity of the PBFT consensus algorithm,in order for large-scale nodes to participate in the consensus,the multi-signature algorithm DG-Co Si is used to optimize the preparation and confirmation stages of the PBFT,reducing the communication complexity of the PBFT algorithm fromO(N~2)to O(log N),the verification complexity Reduce from O(N)to O(1).It can be seen from the experimental results that the system throughput and block generation delay have been greatly improved.Thirdly,a decentralized traceability system is designed based on the blockchain.In order to solve the problems that the traditional centralized source tracing system can easily tamper with the data and the integrity of the source tracing result is poor.Combining the advantages of blockchain decentralization,this paper designs and implements a blockchain traceability system.The consensus algorithm uses the optimized PBFT algorithm.The system can record all the information about the production and trading of commodities,and consumers can query the complete production and sales process of products in the system.This article describes in detail the purpose of the blockchain traceability system,the basic structure of the system,and the basic flow of the system.The detailed function design and implementation of the system are given at the end.