A Lightweight Privacy Preserving Authentication Framework for Secure UAV Communication in IoD Networks

In modern Internet-of-Drone (IoD) environments, secure communication between unmanned aerial vehicles (UAVs) and user equipment is essential to protect data privacy and prevent unauthorized access. This paper presents a lightweight three-factor authentication scheme for UAVs using ElGamal-based elliptical curve cryptography (ECC-ElGamal) encryption and physical layer security (PLS). The scheme integrates the device's media access control (MAC) address, user ID, and password for enhanced authentication. Using the MAC address as a security parameter strengthens device-specific authentication and reduces the risk of impersonation and unauthorized access. To prevent replay attacks and ensure message freshness, timestamps are included in the authentication process. ECC-ElGamal encryption enables secure communication through session key generation and hash functions, optimizing security and efficiency. Additionally, the scheme employs PLS to protect against eavesdropping and provide location-based authentication. A novel secret key ($K_{\mathrm{PLS}}$) is generated using channel state information (CSI) and is used to encrypt the device's MAC address, ensuring privacy-preserving authentication. The proposed scheme is designed to minimize computational and communication costs, making it suitable for resource-constrained UAVs in real-time IoD environments. Security evaluations and comparative analysis show that the scheme effectively resists known attacks while maintaining robust protection and system efficiency.