Research On The Key Technology Of Blockchain Security

Blockchain is the cross application of cryptography,distributed final consensus mechanism,point-to-point transmission and other different technologies.With its decentralized characteristics,blockchain creates a chain like trusted environment that can not be tampered with and traced.It has been widely concerned by the current finance,law,Internet of things and other industries.Blockchain technology has become a hot topic of current research,and how to improve the security and efficiency of blockchain in the practical application of the project is an urgent problem to be solved.In view of the above problems,this paper takes different levels of the underlying architecture of the blockchain as the research object,comprehensively analyzes the key points in the consensus mechanism and smart contract,and deeply studies the pbft protocol combined with the redundancy mechanism and dynamic integration,proposes an improved PBFT consensus algorithm,and verifies the algorithm through simulation experiments.The main contents of this paper are as follows:(1)This paper studies and analyzes the underlying architecture of blockchain,compares the existing blockchain architecture platforms in terms of access rights,block award,contract script,and summarizes the key technologies involved.This paper makes an in-depth study on the current application principle of smart contract in blockchain,and summarizes the security loopholes and defects of smart contract.(2)Compare and analyze the principles and characteristics of various consensus mechanisms of blockchain.This paper analyzes the advantages and disadvantages of typical blockchain consensus mechanisms such as Po W,POS,DPo S and their derivative algorithms,so as to provide a theoretical basis for improving the consensus mechanism of alliance chain.(3)Aiming at the problems of low efficiency,insufficient expansibility and large communication volume in the direct combination of PBFT consensus and alliance chain in blockchain,this paper makes an in-depth study.The PBFT consensus protocol is combined with the characteristics of blockchain alliance chain nodes that need to meet the requirements of access qualification examination,and improved by setting verification certificate and password redundancy mechanism.According to the performance of the nodes when they reach a consensus in the cycle,a node score evaluation standard is created.According to the redundant value of the certificate or password of the node in the initial state,the existence cycle and whether the consensus is reached in the current round,the dynamic evaluation of the score is carried out,and the nodes in the alliance chain are classified according to the score.The nodes with good performance are classified into consensus nodes in the current round to reduce the probability of malicious nodes and the frequency of consensus view and node replacement,so as to make the system more stable.According to the different number and performance of nodes,the parameters of dynamic integration are adjusted,and the consensus nodes are classified according to the integration.Comparing the performance differences among the improved PBFT algorithm,reputation PBFT algorithm and traditional PBFT algorithm,with the increase of the number of nodes,the improved PBFT algorithm has a certain improvement in performance and efficiency.