Security Concept for Unoccupied Aerial Systems

The number of unoccupied aerial systems (UAS) is projected to exponentially increase in the next few decades for a variety of civil and military uses. However, this poses significant challenges with respect to airspace integration. This paper reviews identified security vulnerabilities of the two main options for UAS communication and airspace management, aircraft communications addressing and reporting system (ACARS) and automatic dependent surveillance-broadcast (ADS-B). Based on a comprehensive threat model, open questions and challenges to secure communication of UAS are discussed. As the state of the art is unable to apply security functionalities, this paper presents the safety and security for UAS (S2UAS) system architecture. This novel approach incorporates relevant safety and security aspects for UAS operation, while taking the aforementioned challenges into account. S2UAS covers four essential aspects: (1) detect incoming aerospace vehicles, (2) authenticate those vehicles and establish a secure communication channel, (3) safely react to failed authentication and (4) enable collaboration such as formation flight, even if vehicles are only partially trustworthy.