Advancements in physical layer key generation: a review on channel reciprocity and IoT security techniques

Syed Shafaq Ali Shah (Southeast University)
Ajab Noor (University of Science and Technology Bannu)
Ruiyue Liang (Changchun University of Science and Technology)
Rahmat Ullah Zadran (FAST National University of Computer and Emerging Science)

TELKOMNIKA (Telecommunication Computing Electronics and Control)
Vol 24, No 1: February 2026

With the burgeoning internet of things (IoT), securing communication becomes paramount. Traditional cryptography does not meet computational needs and brute-force attacks. This review explores the state-of-the-art physical layer secret key generation (PLKG) that takes advantage of the inherent reciprocity and randomness of wireless channels. We investigate cutting-edge techniques such as feature extraction networks, domain adversarial training, and deep learning-based approaches, evaluating their effects on the security and efficiency of key generation. In addition to these methods, the review addresses real-world challenges such as multi-user scenarios, reconciliation overhead, and inconsistent channel measurement. We believe that improved key generation rates and security can be achieved through the use of millimeter wave technology and full-duplex communication. To strengthen the robustness of key generation, the paper concludes by suggesting future directions, such as incorporating more random sources, such as physiological signals and sensor data. This comprehensive overview offers deep insights into the state-of-the-art and paves the way for reliable communication in ever more complicated IoT settings.