PostQat addresses critical vulnerabilities in air traffic management communication and surveillance systems that rely on unauthenticated or insecure technologies, including automatic dependent surveillance–broadcast (ADS-B), controller–pilot data link communications (CPDLC), aircraft communications addressing and reporting system (ACARS), and traffic alert and collision avoidance systems (TCAS). The advent of quantum computing threatens to render existing cryptographic methods ineffective, creating an urgent need for quantum-resistant security solutions.

The project assesses cybersecurity needs across ground–ground, air–ground and air–air communications, identifies high-impact operational use cases, and defines requirements for post-quantum cryptography in aviation. It develops a blueprint for a quantum-resistant public key infrastructure and crypto-agility framework, aligned with certification requirements. By building on existing research and providing open guidance and a deployment roadmap, PostQat strengthens the cybersecurity foundations of the Digital European Sky and supports secure data exchange for aviation operations.