Against Cooperative Detection and Eavesdropping Attacks for UAV Short-Packet Communications: Joint Power Control and Trajectory Optimization

Unmanned aerial vehicle (UAV)-aided short-packet communications have been anticipated to play critical roles in future Internet of Things (IoT) networks with low latency and high reliability requirements. However, the security of transmissions in open wireless environments is seriously threatened by cooperative detection and eavesdropping attacks. To this end, we develop a new framework for UAV-aided short-packet transmissions to counteract the cooperative warden and eavesdropper, which has not been investigated yet. Specifically, we derive the false probability of the cooperative detection by employing the likelihood ratio test and the bivariate Gaussian distribution property. Then, we formulate an optimization problem to maximize the covert secrecy rate (CSR) by joint UAV transmit power control and three-dimensional (3D) trajectory design. Finally, we introduce slack variables and employ the successive convex approximation (SCA) techniques to solve the formulated highly non-convex problem suboptimally. Numerical results are provided to verify the effectiveness and the superiority of our proposed solution in terms of improving the CSR.