As the number of Internet of Things (IoT) devices increases, services expand and illegal hacking and infringement methods become more sophisticated, an effective solution for blockchain technology is required as a fundamental solution to security threats. In this paper, we develop the security module of an IoT device based on blockchain technology that blocks hacking and information infringement and forms a multi-security blockchain system between the IoT device and the user device and we develop a user application. We contribute to addressing the security threats faced by IoT application services by developing a new method. In particular, we present some schemes for the development of a multi-security certification system based on blockchain for IoT security.