Quantum in Aviation Security: ADS-B Protection with QKD

Automatic Dependent Surveillance Broadcast (ADS-B) is the standard for aircraft surveillance and has been required on almost all aircraft within the National Airspace System since 2020. Data transmissions from ADS-B transponders are non-encrypted and, as a result, pose a variety of safety and security risks. Prior research has been conducted that provides solutions for retrofitting ADS-B systems with FPE (format-preserving encryption) algorithms. These require safe key distribution protocols to create the keys between parties. Classical key distribution protocols have been proposed and recently tested with some promise. However, with the rise of quantum computing, there is also a need for protection from future quantum threats. This paper explores the implementation of a quantum key distribution (QKD) protocol for the key generation of ADS-B transmissions using an FPE encryption algorithm with both free-space and optical links for air and ground distribution. This creates a level of security bounded by the laws of physics, as opposed to proposed key distribution methods, which are vulnerable to being hacked by both quantum and classical algorithms. Coupled with creating the protocol, a simulation is created to visualize the approach. This research stands to benefit all aircraft, national and international, that implement the ADS-B system, creating an increased sense of security, safety, and order in the air.