Optimization Of Consensus Mechanism Based On Node Roles And Transaction Priorities In Consortium Blockchain

Different from the traditional database technology,blockchain technology has a broad application prospect in the fields of finance,public welfare and Internet of things due to its characteristics of decentralization,openness,autonomy,information tampering and anonymity.At present,blockchain technology is developing from the direction of applying to the public chain to the direction of the consortium blockchain.Because consensus mechanisms of consortium blockchains are limited to problems of throughput,storage bandwidth,delay,and insufficient supervision,they aren't completely implemented in existing reality scenarios.The most prominent problem is that it is difficult to reach a credible consensus quickly.Therefore,it is necessary to design an optimized consensus mechanism to improve system performance of consortium blockchains.In this paper,an optimized consensus mechanism for consortium blockchains is designed based on node role classification and and transaction priority.The main research work is as follows:(1)An consensus mechanism is proposed for consortium blockchains based on node role classification.Node trust value properties are added to consortium blockchains and trust values are calculated based on them.Nodes are ordered by their trust values,a certain proportion of them are partitioned.They are divided into account,verification,propagation nodes.Nodes with high trust values act as account and validation ones during a consensus process in a consortium blockchain.It can reduce the number of nodes to reach a consensus and increase the efficiency of the credible consensus,so as to reduce transaction delay and system energy consumption.In addition,trust values of nodes change dynamically with their behavior.Node role may be upgraded and demoted accordingly,so as to improve node credibility.(2)Proposed a method for optimization of consensus mechanism based on the transactions priority.According to the amount of trading information size and the degree of emergency,transactions are prioritized in the consortium blockchain.Nodes improvethe processing speed of high priority transaction,according to the priority on the transaction propagated,validation,and packaging,thus improving the throughput of the consortium blockchain system.In addition,in order to set a reasonable transaction amount threshold and emergency degree,"prisoner dilemma" in game theory and ideas of repeated game are applied to design consortium blockchain nodes in cost and revenue calculation method;the strategy of adjusting the degree of urgency with transaction nodes and adjusting the amount threshold with accounting nodes is taken,making the transaction node cost and the revenue of the accounting node reach a stable state,meanwhile making the transaction node and the accounting node have reasonable cost and revenue respectively.