Lightweight Tag-Based PHY-Layer Authentication for IoT Devices in Smart Cities

This article proposes a general and lightweight PHY-layer authentication framework for the Internet of Things (IoT) devices in smart cities, based on tag embedding and tag verification. More specifically, a tag signal carefully designed to be independent of the message signal of a transmitter [i.e., an IoT device (IoTD)] is encrypted and embedded into the signal of the device, and the tag signal is then retrieved at a receiver based on signal detection techniques to verify if it is from the legitimate IoTD or from an illegitimate adversary. With the help of matrix analysis and composite hypothesis testing theories, analytical models are further developed to depict the authentication performance of the proposed authentication framework under various tag signal models. We then provide numerical results to validate these analytical models and to illustrate how authentication performance against the typical impersonation attack varies with system parameters. Finally, we include discussions to demonstrate the effectiveness of the proposed authentication solution in resisting against other various attacks like replay, unauthorized detection, tampering, and man-in-the-middle.