Research On Access Control Of Internet Of Things Devices Based On Blockchain And Smart Contract

Access control of Internet of things equipment is the core technology to ensure the security of Internet of things system.In the Internet of things system,access control of its devices is the key to effectively prevent users from illegally accessing the system and using resources.However,the massive,dynamic,distributed and lightweight characteristics of the current IoT devices lead to the problems of insufficient stability,low authority decision performance and low security of the IoT device access control mechanism.As well as the limited storage capacity of Internet of things devices,large-scale access control data is stored in the traditional large-scale storage system,which has the problems of low access efficiency,insufficient security and so on,indirectly making the access control of Internet of things devices have security risks.Blockchain technology is a new information technology which combines P2 P network,encryption algorithm,smart contract,consensus algorithm and other technologies perfectly.It fundamentally solves the traditional security problem.Secondly,more and more researchers have integrated blockchain technology into the access control mechanism of Internet of things devices,which has improved the problems existing in the access control mechanism of Internet of things devices.Therefore,based on the Ethereum blockchain technology,this paper makes a more in-depth study on the access control mechanism and access control data access method of Internet of things devices.(1)Based on RBAC model and improved model,this paper proposes a device access control mechanism of Internet of things based on blockchain smart contract.Firstly,the model of RBAC is improved,and the core object of the improved model is defined by formal method.Then,it designs the access control architecture of IoT devices based on the Ethereum blockchain technology,and introduces the basic framework and process of access control;at the same time,it describes the process framework and detailed work process of SCRBAC-IoT,the IoT device access control mechanism based on the blockchain smart contract;then,it describes the policy decision contract,user assignment contract and permission assignment contract in SCRBAC-IoT,and designs specific algorithms.Finally,through experimental tests,it is verified that the proposed access control mechanism of IoT devices based on the blockchain smart contract effectively improves the stability,decision performance and security of permissions.(2)This paper proposes the access control data access method of Internet of things devices based on Ethereum blockchain technology.Firstly,a decentralized access control data access method for IoT devices based on the combination of Ethereum blockchain technology and distributed IPFS cluster is designed,and the storage and query of IoT device access control data are realized through the combination of smart contract technology;secondly,an access control data access system for IoT devices based on Ethereum smart contract is designed and implemented,and the consensus layer uses the improved POS(Casper)consensus mechanism.Finally,based on the built Ethereum private chain and IPFS nodes,the access method of this paper is tested.The results show that the access method has high overall performance,which improves the access efficiency and security of the access system.