Decentralized Role-Based Access Control in IoT Using Blockchain A Trustless Approach to Device Authorization

The rapid expansion of the Internet of Things (IoT) has intensified the need for robust and scalable access control mechanisms to manage device interactions and protect sensitive data. Traditional Role-Based Access Control (RBAC) systems, while effective in centralized environments, face significant challenges in distributed IoT ecosystems due to their reliance on trusted third parties and centralized policy enforcement. This paper presents a decentralized RBAC model powered by blockchain technology, offering a trustless, transparent, and tamper-resistant solution for device authorization in IoT networks. By leveraging smart contracts, access policies are enforced autonomously and immutably, reducing administrative overhead and enhancing security. We outline the architecture of the proposed system, evaluate its performance, and discuss its advantages in terms of scalability, interoperability, and resistance to single points of failure. The results demonstrate that blockchain-based RBAC can significantly enhance the resilience and integrity of access control in heterogeneous and large-scale IoT environments.