Research On Internet Of Things Access Control And Data Sharing Based On Blockchain And Fog Node Credit

With the rapid development of Internet of Things(IoT)technology,the number of IoT devices is growing exponentially.Because IoT devices are mostly resource-constrained devices and difficult to run large security software,IoT devices are vulnerable to hacker attacks and data leakage.Therefore,secure access and data sharing among IoT devices is an important research topic.Traditional access control schemes and data sharing schemes are mostly based on centralized cloud server management.In these schemes,the central cloud server is vulnerable to a single point of failure.Moreover,with the massive growth of the number of IoT devices,it becomes more and more difficult for the central cloud server to manage the massive growth of IoT devices and the data generated.Therefore,these schemes also have scalability problems.This paper focuses on the security access control and data sharing of the IoT based on blockchain and fog computing.The main work is as follows:1)Aiming at the single point failure and scalability of the existing access control system of the IoT,a secure access control scheme of the IoT is constructed based on the blockchain and the credit of fog nodes.The scheme is based on the Ethereum public chain and uses the Ethereum smart contract to design a decentralized access control policy.The access control policy is divided into four modules:Registration and Authentication Module,Access Control Module,Credit Management Module and Behavior Management Module.In the decentralized access control system,in order to avoid the system being attacked by Sybil Attack,the scheme uses the method of mutual authentication of devices to ensure that the identity of most nodes in the system is legitimate.In order to ensure that IoT devices are not accessed by malicious nodes,the method of behavior detection is used to ensure the legality of the request behavior.In order to maintain the fairness among nodes,the scheme uses the credit of fog nodes to constrain the behavior of fog nodes.Compared with the original scheme using blockchain to dircctly manage IoT devices,the method of using blockchain to manage fog nodes and using fog nodes to manage Internet of Things devices in this scheme has more advantages,which increases the scalability of the system.2)Aiming at the single point of failure,data leakage and scalability problems existing in scheme based on blockchain and fog node credit.The scheme is based on the Ethereum private chain and uses the Ethereum smart contract to design a decentralized IoT data sharing policy.In this scheme,IoT devices can share valuable data in the form of transactions and get paid.In order to ensure the confidentiality and integrity of data transmission,the scheme uses AES encryption algorithm and Elliptic Curve Cryptography(ECC)algorithm to encrypt the transmitted data.In order to ensure the authenticity of data shared by devices in the IoT,a data evaluation mechanism based on the credit of fog nodes is designed.In order to prevent malicious evaluation of IoT devices,the scheme designs an evaluation and supervision mechanism.