Research On Performance Improvement Of Consortium Blockchain Based On Leaders Election Mechanism Consensus Algorithm

In recent years,as digital currency like bitcoin has become popular around the world,the blockchain,which is its core supporting technology.Because of its own characteristics of decentralization,data unchangeable,and data transparency,have broad application prospects in banks,credit reporting and other fields,and also have the possibility of combining cutting-edge technologies such as the Internet of Things and artificial intelligence.According to the different identity of the participating nodes,the blockchain can be divided into public chain,consortium chain and private chain.The data in the consortium chain usually is not transparent to everyone.According to the application,fine-grained read permission control is adopted.Compared with the uncontrolled public chain,the consortium chain can achieve message sharing within a limited range,which is more in line with The needs of most potential users.This thesis attempts to propose a consensus algorithm through related research,which brings performance improvement to the consortium chain.The consensus mechanism adopted by the existing consortium chain depends on the trustworthiness of the participating network nodes.In the case of complete credibility,the distributed consistency resolution algorithm can be used as a consensus mechanism,With multiple access permissions,can use the Byzantine fault-tolerant algorithm.And in the most complex non-access environment,use the Proof of Work(PoW),Proof of Stack(PoS)and other consensus algorithms.Public blockchains with PoW have serious performance deficiencies,the speed of transaction processing is less than 7 times per second,the time of transaction confirmation is more than 10 minutes,and the time of transactions ensuring security is up to 60 minutes.At the same time,the PoW still has some other serious problems such as energy consumption,cannot meet the performance requirements of most commercial blockchain systems.As an improved algorithm of the PoW,the PoS attempt to use the number of resources held by the participants to determine who generates the new block.It will rely on the existence of the token and cannot apply to all scenarios.In the traditional consensus algorithm,such as two-phase submission,three-phase submission and Raft algorithm,only node crushdown can be tolerated,and can not avoid the malicious behavior.The PBFT uses client/server architecture,is designed to synchronize through three-stage broadcast communication.This communication process wastes bandwidth,and the algorithm is suitable for the network which with a small number of nodes.This thesis studies the existing consensus algorithms,summarizes the core mechanism of the consensus algorithm through classification and horizontal comparison,and completes the design,implementation and testing of the consensus algorithm.Finally,choose a blockchain platform to localize the new consensus algorithm and provide consensus service.The consensus algorithm in this thesis has better performance,the transaction processing speed can reach one thousand times per second,and can tolerate the existence of a certain number of malicious nodes,will be used in the network with more node.My work including:1)Research on blockchain technology and master the structure and key technologies.2)Research on existing consensus algorithms,identify multiple key operational mechanisms,and summarize the advantages and disadvantages of different types.3)Finish the design of Fiji,and the Golang implemention,also testing.4)Apply Fiji to the existing blockchain platform.