Toward Secure and Scalable IoT Authentication: A Survey of Protocols, Challenges, and Emerging Technologies

Abstract

The Internet of Things (IoT) comprises a wide range of heterogeneous devices, including sensors, radiofrequency identification (RFID) systems, and actuators, interconnected through large-scale networks to enable intelligentservices such as smart homes, smart cities, smart transportation, and industrial automation. While this connectivity offerssignificant benefits, it also introduces serious security and privacy challenges. Among the various security requirements ofIoT systems—such as access control, data confidentiality, network protection, and authorization—authentication remainsa fundamental component, as it governs the initial interaction between entities before any data exchange takes place.Conventional network security mechanisms cannot be directly applied to IoT environments due to the limited computationalpower, memory, and energy resources of IoT devices. As a result, the design of secure and lightweight authenticationmechanisms is essential to protect IoT infrastructures against diverse attacks. In this survey, we focus on IoT authenticationmechanisms by analyzing prevalent attack models and reviewing state-of-the-art authentication protocols. Furthermore,we examine existing security verification and evaluation techniques used to assess the robustness of these protocols. Acomparative analysis of current solutions is provided, highlighting their strengths, limitations, and unresolved challenges.Finally, this study aims to support future research by identifying open issues and outlining promising directions for thedevelopment of more secure and efficient IoT authentication schemes.