Trust for Thrust

Trust is a fundamental concept across various domains, yet it has often been defined as an absolute value in binary terms: either an entity is trusted, or it is not. We provide a new quantitative definition of amount of trust and apply this to different PKI employing certificates and trust models. These considerations are then applied to establishing secure connections in the context of aircraft-to-aircraft communication in civil aviation, showcasing its practical relevance in real-world scenarios.