Security of the Internet of Things represents a field that strongly attracts academia and industry since it represents one of the main obstacles in its adoption. In this area, authentication and authorization methods holds a golden place in priority rank. Indeed, current approaches suffers from numerous limits. Moreover, generally, deployment systems use separately two methods one dedicated to the authentication and the other to the authorization, while the number of methods that combine both requirements is limited. In this work we propose an adaptive blockchain based authentication and authorization approach for IoT use cases. We provided a real implementation of our approach using Java language. The extensive evaluation provided, shows clearly the ability of our scheme in meeting the different requirements, as well as its ability in ensuring a very lightweight cost.