PMAKE: Physical Unclonable Function-based Mutual Authentication Key Exchange Scheme for Digital Aeronautical Communications

Growth of civil air traffic and new entrants into the air transportation sector such as Unmanned Aeronautical Vehicles (UAV) pose a great challenge for air traffic management and its supporting Communication, Navigation and Surveillance (CNS) infrastructure. Analogue systems have to be replaced by digital systems to optimize spectrum efficiency, and automation needs to be introduced to support human decision making at scale. As safety and security are strongly intertwined in aviation, cybersecurity is one key enabler for digitalization in civil aviation. However, few deployed digital aeronautical communications systems incorporate dedicated cybersecurity measures. Link requirements of low latency, low bandwidth, and long range make aeronautical datalinks especially challenging in terms of security design. Further, challenging are the nature of wireless communication itself and the political boundaries in international air transportation concerning unique communication participant identification. Thus, this paper proposes a concept for a challenge-response (CR) based Physical Unclonable Function (PUF) Mutual Authentication Key Exchange scheme, short PMAKE, binding communication identity and radio device together. Initial evaluations show its suitability for the digital aeronautical communications system LDACS.