Analysis And Design Of Blockchain Consensus Mechanism

Blockchain technology has developed rapidly after the introduction of Bitcoin in 2018,and it has a wide range of application in the fields of finance,anti-counterfeiting,supply chain system,data traceability,etc.The key difficulty in its development is how to design a security and efficient consensus mechanism.Existing consensus mechanisms are more or less problematic in terms of security,scalability,performance efficiency and resource consumption.Therefore,it is especially necessary to analyze the advantages and disadvantages of each consensus mechanism and try to design a consensus mechanism with specific application scenarios.This paper studies the problem of the huge resource consumption in the PoW algorithm(mainly refers electric power resource),the performance bottleneck of the system(long consensus period),the concentration of the pool and the tragedy of the commons.The research focuses on the proof of work algorithm based on the credit model,consensus algorithm based on threshold cryptography scheme and the application of consensus algorithm in data sharing and tracing.The specific works are as follows:(1)A proof of work algorithm based on credit model.We design a node credit model based on BP neural network which is based on the idea of personal credit risk assessment.Secondly,a piecewise rotation model based on the credit level of the node is constructed,and the PoW algorithm is improved by using two models above.Finally,simulation experiments show that the CPoW algorithm reduces resource waste,suppress the generation of the large mine pool,and we analyze the security and performance of the protocol.(2)Consensus mechanism based on threshold cryptography scheme.We analyze the tragedy of the commons caused by only the transaction fee rewards in the later stage of the Bitcoin system from the perspective of game theory and propose a consensus mechanism based on threshold cryptography(TCCM)in this paper.Firstly,we introduce the idea of margin model,and propose a margin model based on threshold group signature theory.Secondly,a bidding model of the right of accounting is also constructed using the idea of threshold encryption to generate a node who can produce the block.At the same time,a new incentive mechanism is designed based on the original block rewards so that the more nodes can participate in the consensus process.Finally,the results of security and performance analysis show that the consensus algorithm uses limited resources and improves transaction processing efficiency.(3)Data sharing and tracing scheme based on blockchain.The existing data sharing models have some issues such as poor transparency of data transactions,data without security assurance and lacking of effective data tracking methods.We use TCCM algorithm to propose a scheme based on blockchain technology.Firstly,we introduce a blockchain double-chain structure about blockchain,one chain was used to store the original data and another was used to store transaction data.This structure separates the original data storage and data transactions.Secondly,we can achieve security and reliable data sharing by using proxy re-encryption technology.Finally,we implement a new design of the logical structure of data transaction records which can make data be traced.The results of correctness and security analysis show that this scheme can provide new technical ideas and methods for big data sharing and data tracing.