Fig. 3From: An access control model for the Internet of Things based on zero-knowledge token and blockchainAccess control flow. The function of each module in the model and implementation process of access control is as follows:device registration, submit access information, application for access decision, security monitoring, call contract judgement, inter-contract invocation, generate the ruling result, return the verdict, the token is delivered to the access subject, the subject accesses the resource device through the token, access behavior exceptionBack to article page