Research On Access Control Model Of Edge Nodes In Internet Of Things Based On Blockchain

The Internet of Things(Io T)is a complex information supervision system with perception as the core.As an extension of the Internet,through various network protocols,the interconnection and intelligent linkage of massive devices are realized.With the rapid development of Io T technology,it is promoting the arrival of the intelligent era.However,the Io T architecture based on centralized cloud servers cannot meet the practical application scenarios of distributed Io T nodes,fragmented data,massive traffic,and high transmission frequency while achieving intelligence.On the one hand,there must be a single point of failure and a crisis of trust in a centralized architecture.On the other hand,the storage and bandwidth pressure of cloud servers is brought by the transmission of high-frequency and massive data.A growing number of studies show that new solutions for current Io T architectures can be provided by edge computing and blockchain.Bandwidth,transmission delay and storage pressure are reduced by edge computing to process Io T data,and blockchain can realize fine-grained management and trustless mechanism of Io T nodes,but the combination of the two in Io T is still difficult.At the same time,the sensitive private data collected by Io T devices on the user side urgently needs security protection,and Io T devices also need protection.As an important measure for security protection,access control technology realizes the legal operation of the subject to the object in the specified scenario through the preset access control policy.However,implementing secure,efficient and fine-grained access control on the Io T architecture with integrated edge computing has become another challenging problem.Therefore,this paper studies the above problems and proposes a blockchain-based Io T edge node access control model.The main research work and results are as follows:(1)A four-layer access control architecture for Edge-Iot based on blockchain is designed.This paper analyzes the necessity of the current integration of edge computing and the Io T.Based on the concept of Edge Computing in Io T(Edge-Iot),aiming at the deficiencies of the centralized cloud server in the traditional Io T architecture,combined with blockchain technology,a four-layer access control architecture for Edge-Iot based on blockchain is proposed.(2)Design and propose a lightweight blockchain for edge nodes of the Io T.In view of the high resource consumption and difficult expansion of the current blockchain platform,a lightweight blockchain(LBC)was developed based on Node.JS.In view of the problem of long time-consuming block generation in Proof of Work(POW),we optimize the POW consensus mechanism based on a random sequence.The throughput of LBC is 300 times higher than that of other blockchains with the same configuration over time,while the CPU consumption is stable at about 7%.It is proved that the access control-oriented LBC in this paper can meet the requirements of low latency,high security,and trustlessness of Edge-Iot.(3)Design and propose an attribute access control model based on smart contracts.Aiming at the problems that the traditional access control models centralized entity authority granting method is not suitable for the network decentralized architecture,and the attribute-based access control model(ABAC)realizes fine-grained access control based on attributes without realizing the punishment mechanism under illegal access,we propose a smart contract for ABAC model(SC-ABAC).The access control policy that apply(t,n)threshold tree and linear secret sharing scheme(LSSS)are used to protect the integrity and privacy of the policy.Through experimental verification and performance analysis of related functions,the time consumption of other contracts in SC-ABAC is stable at the millisecond level,and the time consumption of only accessing contracts increases linearly with the number of accesses.It is proved that the model is feasible and can effectively realize the fine-grained access control and policy protection of Edge-Iot data.(4)Propose a lightweight access control scheme for Edge-Iot.Aiming at data integrity and privacy issues,using attributes as the entry point,an attribute-based encryption and access control scheme(ABE-ACS)has been proposed in this paper.In view of the high computing power consumption of attribute-based encryption,the edge outsourcing scheme is optimized to ensure the security of the privacy of restricted devices.For users who need to verify the final results bringing computing power consumption,we optimize the consensus algorithm to ensure the consistency of the decryption results.From the aspects of outsourcing and consensus,the performance is verified.The limited equipment in the outsourcing process does not need to be decrypted.Compared with other solutions,the edge node consumes only half of the computing power in the key generation and encryption process.The encryption and decryption process only varies linearly with the property size,taking no time and data size.At the same time,the security of the scheme is analyzed from multiple perspectives,which proves that the scheme is safe and efficient,and can achieve secure access and privacy protection of data and devices.(5)Build a real Edge-Iot blockchain scene.In response to the above research content,a heterogeneous network composed of three resource-constrained devices and three high-computing nodes was constructed,and LBC was deployed.Edge nodes preprocess time series data collected by restricted devices.Outsourced encryption based on predicted data and real data,devices and users complete access to the device and access and decryption of the ciphertext they own.The data encryption and decryption time stored by Io T devices every day is stable at the millisecond level without significant fluctuations.Based on the optimized consensus,the block generation time after multi-node decryption and result verification is basically stable.Its performance evaluation shows that the research in this paper is in line with the real Internet of Things scenario,with good performance and certain practical value.In short,this paper innovatively designs a lightweight blockchain LBC for the Edge-Iot access control architecture,and proposes the SC-ABAC model to realize the security protection of restricted devices: based on smart contracts to realize the punishment of illegal access and the protection of legal access with quickly response;combined with edge computing to propose ABE-ACS scheme to achieve privacy protection for restricted devices and data: based on edge outsourcing scheme to achieve high control and high privacy protection of data;and finally the complete process of Io T data from generation to processing to encryption to access to verification to acquisition to decryption.We combine the blockchain to realize the security and controllability of trustless,decentralized and verified data and equipment under the Edge-Iot architecture,therefore,it provides a new research scheme for the combination of blockchain and edge computing in the Io T to realizes fine-grained access control,data security and privacy protection,which has high research significance and value.