Research And Implementation Of P2P Network And Consensus Mechanism Of Consortium Blockchain

Driven by Bitcoin and Ethereum,the global blockchain boom has begun,and blockchain technology has attracted more and more attention.However,most of the current blockchain projects,especially public blockchain projects,still focus on the digital currency,which greatly limits the development of blockchain technology.The public blockchain system widely uses a fully distributed structure,although it bears the advantage as complete decentralization,a large number of broadcast messages will not only cause waste of resources,but even block the network,which makes it not so suitable when applied in business scenarios such as supply chain finance,property insurance,and product traceability.Proof of Work consensus mechanism of public blockchain has a long transaction confirmation time.A block is generated every ten minutes and it can only be confirmed after six blocks.The efficiency cannot meet the demand for scenarios with high transaction efficiency requirements.At the same time,there will be a waste of computing power and power resources.The consortium blockchain has excellent features such as low-cost operation and maintenance,supervision,and fast transaction speed.It is very suitable for application scenarios such as settlement between companies and banks,real-time finance,transnational transactions,and copyright management.Compared with the public blockchain,the consortium blockchain has greater development potential.This thesis aims to research on P2P(Peer-to-Peer)networks and consensus mechanism based on consortium blockchain.In this thesis,we conducts deep research on existing blockchain technology,especially the blockchain network architecture and consensus mechanisms,compares and analyzes the existing blockchain network architecture and consensus mechanisms such as Paxos,PoW(Proof of Work),PoS(Proof of Stake),and DPoS(Delegated Proof of Stake).For consortium blockchain,we improves the existing P2P network topology.The improved network architecture has better performance and load capacity.For the PBFT(Practical Byzantine Fault Tolerance)algorithm is better adapted to the consortium blockchain,an improved PBFT algorithm is proposed by using fuzzy mathematical theory(FPBFT)based on the network architecture of the consortium blockchain.This algorithm abandons the C/S(Client/Server)request response mode of PBFT algorithm,making it more suitable for the application scenarios of the blockchain;and by introducing a fuzzy comprehensive evaluation algorithm,it builds a trust evaluation system for super nodes and screens out super nodes with high credibility as a candidate for the primary,which avoids frequent view changes during the consensus process and improves system performance.Finally,in the consortium blockchain scenario,the network architecture and consensus mechanism improved were tested.The test results show that compared with blockchain systems such as Bitcoin and Ethereum,the system has faster block generation speed and higher transaction throughput.It can confirm more than 2000 transactions per second on average,which is well adapted to the consortium blockchain and can meet the needs of most commercial application scenarios.