# Lightweight and Security-Enhanced Key Agreement Protocol Using PUF for IoD Environments
## 2 Related Work  
Numerous studies have been conducted on the IoD environment and its security, focusing on the increasing use of UAVs and the formation of the IoD. [PERSON] et al. [17] presented the basic concept of the IoD environment and addressed the conceptual model of the IoD architecture and the implementation features for systems based on that architecture. Furthermore, they extracted critical concepts from three large-scale networks (air traffic control, cellular networks, and the Internet) and subsequently investigated the application of these concepts in their novel framework for drone traffic control. [PERSON] et al. [18] provided a holistic study on the evolution and prospects of UAVs in IoT environments. They also addressed the significant research challenges of this integration, including security and safe traffic management, and investigated the technical standardization landscape. [PERSON] [19] defined the core requirements and proposed a comprehensive taxonomy for the IoD environment. They analyzed recent advancements and solutions concerning security, privacy, and communication problems for the safe and efficient operation of the IoD. They contributed to the field by presenting crucial challenges and future research directions that the IoD research community must address. [PERSON] et al. [20] assessed the recent trends in security and privacy affecting the IoD network. They provided a taxonomy classifying these problems and discussed critical open challenges, highlighting vital areas for future IoD security and privacy research. Despite these significant potential and diverse applications of the IoD environment, its characteristics introduce critical security and privacy challenges. Thus, authentication and key agreement protocols have been introduced in numerous studies to mitigate these risks. [PERSON] et al. [21] focused on enabling secure and reliable user access in the IoD environment. They proposed a user access protocol that allows mobile users to interact with and employ drone-provided services efficiently. They addressed the challenges of ensuring the security and reliability of user connections in the dynamic and distributed IoD network. Addressing security weaknesses identified in existing authentication protocols for the IoD. [PERSON] et al. [22] proposed a revised lightweight authenticated key agreement scheme. They focused on providing a secure and efficient solution by employing only simple cryptographic primitives, such as hash functions and XOR operations. [PERSON] et al. [23] proposed an enhanced lightweight authentication scheme suitable for IoD environments. Their protocol employs dynamic identities for enhanced privacy and renews encryption keys to ensure message freshness during authentication and key agreement processes. This scheme provides efficiency and enhanced privacy for communication in the IoD environment. [PERSON] et al. [24] proposed a robust and lightweight authentication scheme for IoD by employing PUFs in drone hardware. This protocol applies only PUFs, XOR operations, and cryptographic hash functions for reliable and efficient IoD communications. They focused on providing a secure authentication solution for resource-constrained devices in the IoD environment. However, although these protocols [21; 22; 23; 24] are lightweight and efficient, the protocols proposed in [21; 23] are vulnerable to physical drone capture attacks. In addition, the protocols proposed in [22; 24] are vulnerable to stolen mobile device attacks and ephemeral secret leakage attacks. Therefore, to address the security problems of lightweight protocols, many researchers have proposed authentication schemes that apply ECC for the IoD environment. [PERSON] et al. [25] proposed an authentication scheme for securing message exchanges in UAVs. This scheme combines symmetric key cryptography with ECC to provide robust security features. They aimed to enhance communication security in IoD environments. [PERSON] et al.