Cybersecurity Threat Analysis of a Free-Space Optical Communication System Through Model-Based Systems Engineering

Emerging systems within the aerospace domain are opting to utilize free-space optical communication (FSOC) as opposed to radio frequency (RF) communications. FSOC is gaining popularity for its advantages which include high data rates, ease of use, excellent bandwidth-to-cost ratio, and inherent security. Although FSOC communication is described as highly secure from threats and jamming resistant, recent literature has identified potential threat interference that can occur both within and outside the FSOC detector field of view (FoV). Cybersecurity concerns often arise after system deployment due to the lack of a comprehensive security threat analysis during system development. It is necessary to perform vulnerability analysis prior to system deployment, ideally, during the system design and development stages. This paper presents a PASTA threat analysis of a free-space optical communication system through system modelling diagrams. Using both MITRE AT\&CK and a complete FSOC model, specific tactics, techniques, and procedures that advance persistent threats to execute their objectives can be identified early in the system’s design phase. Attack flows are developed to identify potential future threats to FSOC communication systems to include eavesdropping from signal scattering of fog particles in the atmosphere and compromises to a singlepath transmission. The artifacts presented in this paper help understand future threats to FSOC communication systems.