Asian Journal of Research in Computer Science

The use of Internet of Things (IoT) applications has increased. However, IoT devices have limited computing, memory, bandwidth, and battery power. Therefore, authentication methods that provide security while using fewer resources are required. Traditional security mechanisms, such as Public Key Infrastructure (PKI) and Identity-Based Encryption (IBE), have high computational and communication overheads, making them infeasible for low-end IoT devices. This review examines lightweight authentication methods for resource-limited IoT devices. It compares symmetric-key-based, hash-based, lightweight cryptography-based, Physical Unclonable Function (PUF)-based, multifactor, and hybrid methods. The analysis considered computational and communication costs, memory requirements, hardware demands, energy use, and security strength. The findings show that hash- and PUF-based methods offer a balance between security and resource use. Hybrid methods combining PUFs with lightweight techniques, such as hash functions, XOR operations, nonces, and ASCON, operate with low computational, communication, and power demands while providing mutual authentication, protection against replay attacks, confidentiality, information integrity, and secure session-key generation. The work also describes challenges, including key distribution, scalability, protection against physical attacks, balancing security and power consumption, and the lack of standardised frameworks. Overall, PUF-based lightweight hybrid approaches have the potential to support secure, low-power authentication systems in future IoT and 6G environments.