A Single Sign-On Architecture for Integrated Smart City Information Systems

Abstract

The increasing adoption of smart city initiatives has accelerated the development of diverse digital services across government sectors, including public administration, healthcare, transportation, education, and utility management. However, these services are frequently developed as independent systems with separate authentication mechanisms, resulting in fragmented user identities, redundant login processes, increased administrative complexity, and greater exposure to security risks. This study proposes a Single Sign-On (SSO) architecture for integrated smart city information systems to provide unified authentication, centralized identity management, and secure interoperability across heterogeneous applications. The proposed architecture adopts a federated identity management approach based on OAuth 2.0 and OpenID Connect (OIDC), with Keycloak serving as the Identity Provider to facilitate standards-compliant authentication and authorization. The architecture was implemented and evaluated using multiple representative smart city applications to assess functional integration, authentication performance, interoperability, and security. The evaluation results demonstrate that the proposed architecture enables seamless access to multiple services through a single authentication process while reducing authentication redundancy, simplifying user and administrator management, and improving system interoperability. Furthermore, token-based authentication enhances access security by minimizing credential exposure and supporting standardized authorization across interconnected services. The proposed architecture also exhibits low authentication latency, stable performance under concurrent access, and compatibility with heterogeneous technology platforms. This study contributes a scalable, interoperable, and standards-based authentication framework that strengthens identity and access management, improves user experience, and provides a practical foundation for secure and sustainable smart city digital ecosystems.