Emerging surveillance applications of UAV teams rely on secure communication to exchange information, coordinate their movements, and fulfill mission objectives. Protecting the network by identifying malicious nodes that are trying to disturb the system is an important task, particularly in the military domain. This paper presents the design and evaluation of UAVouch, an identity and location validation scheme that combines a public-key based authentication mechanism with a movement plausibility check for groups of UAVs. The key idea of UAVouch is to supplement the authentication mechanism by periodically checking the plausibility of the locations of neighboring UAVs, allowing the detection of intruders that are unable to follow expected trajectories. The proposed solution was evaluated in a simulated military surveillance scenario in which it detected malicious nodes’ position falsification attacks with an average accuracy of above 85%. © Copyright 2021 IEEE