Survey on Security for Non-Terrestrial Networks

Non-terrestrial networks (NTN) are studied in a way that goes beyond the environmental limitations of existing terrestrial networks. In particular, it ensures connectivity in remote areas, rural areas, and areas where communication infrastructure is insufficient.NTN leverages state-of-the-art space and aviation platforms to provide highly versatile services in domains such as IoT and disaster management. These NTNs are the cornerstone of next-generation communication systems, and at the same time, they are likely to address gaps in the connectivity of communications. In this paper, we examine the latest trends related to the security of NTN, and analyze its network-specific characteristics, methodologies, and challenges. Integrating NTN with the ground infrastructure creates security challenges such as seamless handover management between satellites and ground systems, cyber threats from quantum computers, and development of encryption technologies for IoT environments with limited resources. To address these challenges, this study categorizes NTN security requirements into security requirements that apply to all network operations and security requirements for the inherent vulnerabilities of NTN. According to the analysis of NTN, it highlights the need for Post Quantum encryption algorithm, robust handover security protocol, and lightweight encryption method suitable for the dynamic and resource-limited nature of NTN. Advanced technologies such as AI-based threat detection, blockchain-based mechanisms for data integrity, and adaptive security frameworks are showing the possibility of secure and scalable NTN communication. This paper raises recommendations for the secure integration of NTN with ground network based on the results of a recent comprehensive study. This survey provides direction to aid in the development of standardized security protocol and at the same time provide NTN future oriented communication solution. Addressing these challenges will show the potential of NTN as a key component of the global communication infrastructure in the coming era.