Research On Blockchian Based IoT Data Sharing Systems

Blockchain,as an emerging distributed storage technology,has been widely used in IoT systems.Using the blockchain as the underlying protocol for the IoT data sharing system provides valuable data consistency,reliability,and traceability.However,the combination of IoT systems and blockchain technology also brings new problems to be studied and solved.(1)Each message in the blockchain system is digitally signed to ensure the reliability of the message content,but when facing a large number of sensor message sharing scenarios,it will bring a high burden of key storage and communication.(2)The information release of the traditional IoT data sharing system only requires a single round of broadcast process.However,when a blockchain system is used for IoT data sharing,multiple rounds of consensus processes are required to ensure the consistency of the shared data.The consensus process will bring additional time consumption,reduce the speed of data sharing,and limit the overall throughput of the system.(3)The blockchain system uses multi-node synchronous storage to save block data.However,in applications involving a large amount of sensor data,simultaneous storage of multiple nodes will occupy a large amount of storage space,resulting in some nodes not being able to guarantee such a huge storage capacity,which affects the effective application of IoT data sharing systems.To address the above problems,this research deeply investigates and analyzes the scenario of the IoT data sharing system and the technical characteristics of the blockchain,and designs a blockchain-based IoT data sharing scheme and a block storage scheme.The two solutions can make the blockchain technology better adapt to the IoT data sharing system scenario on the premise of ensuring the consistency,reliability,and integrity of the IoT data,reducing the above problems for blockchain-based IoT data sharing Impact of the system.The specific work done in this thesis includes:(1)This thesis assumes an IoT data sharing system model and designs a blockchain-based IoT data sharing scheme.In this solution,IoT data messages containing signatures from sensor nodes are packaged into blocks and published to the blockchain network.This research designed a message signature method and block structure based on the aggregate signature algorithm.While protecting the reliability of block data and preventing malicious aggregation nodes from tampering with the data,the compression characteristics of the aggregate signature are used to reduce the communication and storage costs of a large number of sensor signatures and increase the effective IoT data's share in the block.(2)In this thesis,a multi-state chain blockchain architecture is designed,each state chain has a unique fixed proposal node,and the SCBFT consensus algorithm is designed based on the multi-state quantity architecture.The consensus algorithm can resist limited Byzantine attacks,reduce consensus processes,and increase consensus speed.According to experimental testing and analysis,the SCBFT consensus algorithm has a faster consensus speed than the PBFT algorithm,can support higher system throughput,and has better robustness in the system model considered in this study.(3)This thesis designed a block storage scheme for the data sharing scenario of the Internet of Things.This solution allows ordinary nodes to require storage nodes to save specific complete block data by paying storage nodes.Ordinary nodes only need to save the block header data to continue participating in the consensus process.This study designed a smart contract-based payment and a challenge-response-based data integrity verification mechanism to effectively guarantee the interests of both ordinary nodes and storage nodes.In addition,a data integrity verification algorithm based on zero-knowledge proof is designed,and the zero-knowledge feature is used to reduce the additional storage burden of verification tags on the blockchain.According to testing and analysis,the verification speed of the data integrity verification algorithm is superior to the existing BPDP data integrity verification algorithms,reducing the computational complexity of the verification process on the blockchain.