Fig. 3
From: An access control model for the Internet of Things based on zero-knowledge token and blockchain
Access 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 exception