A Secure Structure for UAV-Aided IoT Networks: Space-Time Key

The Internet of Things (IoT) has been extensively investigated as an enabling technology for situation awareness and data collection. Since power-limited or battery-free IoT devices may have limited transmission coverage, unmanned aerial vehicles (UAVs) can be employed as mobile edge computing (MEC) servers to collect and process data packets from multiple IoT devices due to their high mobility and low operating cost. However, data transmission becomes vulnerable when eavesdroppers exist, as those IoT devices may have limited computing power for encryption. Moreover, it is noteworthy that the identity and location information of IoT devices themselves are also crucial to particular implementations (e.g., regional situation awareness), especially when massive IoT devices are involved using random access schemes. In this article, a secure structure is proposed as a promising strategy to support UAV-aided IoT networks, where the identity and location information of multiple IoT devices are utilized as the key to encrypt data packets collected from IoT networks. In the new structure, the trajectory planning of UAVs is developed to minimize the energy consumption among multiple clusters of a UAV, while the deployment optimization is used to maximize the secrecy capacity in each cluster, and the beam hopping is carried out to encrypt multi-access IoT devices within a coverage of a UAV. After introducing the structure, some key technologies are presented, and then future works for the secure UAV-aided IoT network are discussed.