Access Control for Smart Home System using Smart Contracts at Edge Computing devices to enhance Security and Performance

The rise of Internet of things technology has been exponential in the last few years. With its wide range of applications like smart home, healthcare and industries it is associated with huge amounts of data generation. The involvement of data that may be private or sensitive has introduced challenges like privacy and security as the most researched challenges. The traditional centralized access control policies are not best suited in IoT inviting decentralized mechanisms. The Blockchain technology intrinsic features help to solve this problem. Also as Blockchain technology involves computing which is also an IoT concern due to latency issues Edge computing fills this gap of bringing computing closer to IoT nodes. As discussed earlier in our research the integration of Blockchain does not quantitatively affect the performance of IoT. As the traditional access control policies like attribute-based access control(ABAC), role-based access control(RBAC) and capability-based access control(CBAC) use centralized mechanisms, custom access control policy for distributed environments is required for IoT. In this research, we propose a hybrid of ABAC and RBAC that is embedded in Blockchain nodes over edge devices to achieve a better access control mechanism than using a traditional single access control model. Features of both role-based and attribute-based access control mechanisms are combined to grant access to IoT devices. Through our experimentation we intend to show that through negligible performance changes that are less than 300 milliseconds delay, we can improve the security in IoT. We say that security is improved as all the transactions of users accessing IoT devices either to retrieve the data or modify the state of the device are passed through smart contracts and logged in Blockchain. Any illegal access to the IoT device is denied and users are penalized.