Abstract: With the widespread application of 5G technology and the rapid development of IoT technology, it is foreseeable that the number of IoT devices and the scale of connections will further expand. The Internet of Things can effectively use the existing network infrastructure to connect the physical world and the Internet world to achieve data sharing between devices. However, the large-scale and complexity of its network structure brings potential security risks to the Internet of Things system. Access control technology can be used to protect the security of the device and the data on the device. The traditional access control model and implementation are more complex and centralized. Therefore, this article expects to build a new type of blockchain-based Internet of Things access control system： Based on the RBAC model and the ABAC model, the DARBAC model is proposed, and the access control system is built in conjunction with the blockchain technology to overcome the single-point failure problem of centralized entities. It has the characteristics of scalability, lightweight, and fine-grained. Experimental test results show that the system has good concurrency performance, can be effectively deployed and implemented in Internet of Things system and can achieve the expected results.

Key words: blockchain, Internet of Things, access control, RBAC model, ABAC model, DARBAC model, concurrent performance