Research On Blockchain Consensus And Privacy-preserving Mechanism Based On Internet Of Things Environment

Blockchain technology has been popular in recent years,and the application scope of blockchain is gradually expanding.Many enterprises have deployed blockchain applications.The Internet of Things(Io T),as a key development direction in the future,is one of the hottest research directions at present.However,the current Io T architecture and technical solutions have serious problems in terms of security,privacy,and trusted collaboration.Blockchain technology can provide a solution to these shortcomings in the Io T.But the current blockchain technologies also show shortcomings such as low throughput,high resource consumption,large network traffic and transaction disclosure,which made it cannot be directly used in the Io T scenario.Improving the performance and privacy of blockchain to meet the requirements in the Io T scene have become one of the new research directions.The main work and contributions of this paper are as follows:(1)This paper designs and implements a dynamic Byzantine fault-tolerant protocol based on broadcast multi-signature for the consortium blockchain system in the Io T environment.The protocol uses an improved single-round broadcast multi-signature mechanism to aggregate messages exchanged by nodes in the protocol,which reduces the amount of network messages.A consensus group mechanism is designed for the scenario of consortium blockchain.The consensus group composed of a few blockchain nodes is responsible for the execution of consensus agreement and the block packaging,which improves the throughput of alliance chain.In order to ensure the security of the consortium blockchain,a consensus group election and node evaluation mechanism are proposed.The credibility evaluation of the block chain node is conducted based on the historical block information,and the Byzantine node can be removed from blockchain network by the alliance chain certificate node.Afterwards,the security and availability of the protocol were proved by security analysis.Finally,the experimental results show that the proposed protocol has higher throughput and lower traffic than the existing Byzantine consensus protocols.Finally,the experiment results show that the algorithm has a fast execution time and only produces a small amount of additional data.(2)This paper proposes corresponding privacy-preserving mechanisms for the micro-payment and data interaction scenarios under the Io T.In the micro-payment scenario,the concept of private accounts is introduced which use Pederson commitment and Range Proof to hide the payment amount in the commitment.When users use private accounts for transactions,others cannot know the transaction content,which protects the data privacy of the micro-payment scenario.In this scheme,the one-time address and commitment merge are used to hide the identity information of the trading party,and the identity information cannot be obtained by analyzing the Pederson commitment,thus ensuring the privacy of the user's identity.In the data interaction scenario,the short data and data index are encrypted and stored in the blockchain,and transaction credential and arbitration mechanism are introduced to ensure the security and privacy of data interaction.The security analysis proves that the scheme can guarantee the privacy of data while satisfying the security.Finally,the experiment shows that the scheme has a faster algorithm execution time and only a small amount of data is generated.(3)This paper designs and implements a consortium blockchain prototype system and the corresponding command line program.The system is written in Golang language and runs on Linux systems and Docker containers.The system uses the consensus protocol and privacy-preserving mechanism designed in this paper to implement basic blockchain functions such as user registration,micro-payment,and data interaction in the Io T scenario.Experimental results verify the effectiveness and availability of the above protocols.At the end of the paper,the research contents of the full text are summarized,and the future development direction of the blockchain for Io T scenarios is prospected.