SmartChain RBAC: A Lightweight Role based Access Control Protocol using Private Blockchain for Smart Cities

Smart cities depend on connected devices and data-enabled services, so secure and efficient access control mechanisms are crucial for protecting sensitive resources. These limitations lead to issues such as centralized access control, a poor audit trail of activities, and challenges with scalability. In this paper, we propose a lightweight and decentralized role-based access control protocol, called SmartChain RBAC, which operates on a private blockchain infrastructure that serves to address these issues. This model uses the role-based access control (RBAC) principle to determine detailed permissions according to types of roles for a user, and employs smart contracts to enforce policies in a distributed manner without a central party. SmartChain RBAC guarantees secure, tamper-proof access control decisions, all role hierarchies, revocation and delegation are made via transactions logged on the blockchain. This allows the system to stay true to the high throughput and low latency required for real-time smart city functions through a private blockchain. Best of all, the protocol is designed to be lightweight to allow deployment in resource-constrained environments such as IoT-enabled public services. The paper further details the architecture, the implementation approach with performance analysis between SmartChain RBAC and the conventional centralized RBAC. Results show better security, transparency, and decentralization with low performance overhead. This work proposes a flexible and privacy-preserving access control mechanism for the dynamic nature of smart city environments.