Research On Lightweight And Scalable Blockchain Technology For Internet Of Things

Blockchain can effectively deal with the security and trust issues in the Internet of Things(Io T)environment depending on its decentralization,immutability,traceability,openness and transparency.However,the traditional blockchain has problems such as high resource consumption and poor scalability,which leads to its integration with the Internet of Things is facing huge challenges.On the one hand,there are a large number of resource-constrained devices in the Internet of Things scenario,which makes it difficult to undertake the maintenance work of the blockchain.On the other hand,the Internet of Things requires efficient business processing,and the traditional blockchain cannot meet the business needs of the actual application of the Internet of Things in terms of scalability.Therefore,this thesis explores the blockchain technology from the aspects of consensus computing and ledger storage.Aiming at the problems of high resource consumption and low scalability of traditional blockchain,a set of lightweight and scalable blockchain system for the Io T is proposed to realize lightweight consensus computing,ledger storage and efficient transaction processing.In this thesis,the main works are shown as follows:(1)A lightweight blockchain framework based on edge computing is proposed to solve the contradiction between the high resource consumption of traditional blockchains and the limited resources of Io T devices,so that more resource-constrained devices can participate in the consensus.First,optimize the consensus mechanism and design a lightweight Proof of Random consensus mechanism.Nodes compete for bookkeeping rights through two-stage random testing,and the consensus process consumes only a small amount of computing resources.Second,the block structure is optimized based on the account model,and a storage optimization strategy is designed to divide the blockchain ledger into a full ledger and a state ledger.Nodes with limited resources only need to store a smaller state ledger to participate in the consensus.Finally,the security analysis and experimental evaluation prove that the scheme can effectively improve the performance of ledger storage cost,block consensus calculation cost,throughput and transaction confirmation delay under the premise of ensuring security.(2)A scalable consensus protocol is proposed by developing a double-chain model to further improve the scalability of blockchain,specifically in terms of the transaction throughput and transaction confirmation latency.First,this consensus protocol divides the mining process into two parallel processes,i.e.,bookkeeping right competition and transaction packaging.Accordingly,there is an accounting chain and a transaction chain.They replace the traditional single-chain architecture.Second,a smaller candidate accounting group was selected to validate and sign transactions.And an efficient transaction packaging and confirmation process is designed to improve consensus efficiency and reduce transaction confirmation latency.Finally,the security analysis and performance evaluation show that,the proposed scheme has a further improvement in throughput and transaction confirmation latency,when ensuring the original security.(3)Design and implement a lightweight and scalable food chain system.Combined with the actual requirements of the Io T,this thesis takes the food supply chain scenario as an example,and designed an overall architecture and various functional modules of the system.The system builds a blockchain platform based on the lightweight and scalable blockchain technology proposed in this thesis.The system adopts a front-end separation design.The backend uses Java language and Spring Boot framework.The front page shows the main system functions.