An ultra-lightweight PUF and ASCON-based authentication and key agreement protocol for UAV-ground station and UAV-UAV communication

Unmanned aerial vehicles (UAVs) have been increasingly integrated into diverse domains such as environmental monitoring, intelligent transportation, border surveillance, and military reconnaissance, giving rise to the broader concept of the Internet of Drones (IoD). However, this rapid proliferation also underscores the urgent need for secure and efficient communication mechanisms, as UAVs typically operate over public channels that are highly vulnerable to various security and privacy threats. To address these issues, authentication and key agreement (AKA) protocols have been introduced to enhance secure communication. However, most of the existing AKA protocols either incur high computation cost due to complex cryptographic primitives, or fail to provide resilience against attacks such as replay, impersonation, and ephemeral secret leakage. In this paper, we propose an ultra-lightweight AKA protocol that integrates physical unclonable function (PUF) with the lightweight authenticated encryption with associated data (AEAD) primitive ASCON. The protocol supports UAV registration over open channels, achieves mutual authentication between UAV and ground station, and extends to secure UAV-UAV communication with the assistance of the ground station. A formal proof under the real-or-random (ROR) model demonstrates the semantic security of the proposed protocol, while informal analysis confirms robustness against diverse attacks. Comprehensive performance evaluation shows that the total computation cost of the proposed protocol is approximately 2.391 ms, which is the lowest among the compared schemes. Specifically, it reduces computation cost by up to 69.0% compared with representative IoD authentication protocols and remains approximately 10.9% lower than existing ultra-lightweight designs. These results demonstrate that the proposed protocol achieves a superior balance between security strength and resource efficiency, making it particularly suitable for resource-constrained IoD environments.