Autonomous transportation will profoundly change maritime traffic. Human-crewed and autonomous vessels or ships will have to share the oceans, seas, rivers and canals. As autonomous vessels can operate at various levels of autonomy or control, cybersecurity on board will vary. Autonomous maritime vehicles, surface or submarine, commercial or military, provide advantages for specific missions. Being still under development, the effects of cyberattacks on autonomous vessels are not yet apparent. It is more efficient to consider security issues in the development phase since the security-by-design principle embraces the consideration of potential threats and countermeasures at an earlier stage. The insecurity of autonomous ships could lead to environmental disasters caused by collisions with other ships and port facilities, vessel hijacking, theft or blackmail. However, relatively little attention has been paid so far to the security of autonomous vessels compared to other similar applications such as autonomous cars, drones and aircraft.
This paper provides an overview of a general framework and components of autonomous vessels and related work on their security. Then, it provides nine distinctive threat categories with explanations of scenarios and applicable countermeasures at a high level: attacks to disrupt radio frequency (RF) signals; attacks to deceive or degrade sensors; Attacks to intercept/modify communications; Attacks on Operational Technology systems; Attacks on Information Technology systems; Attacks on Artificial Intelligence used for autonomous operations; Attacks through supply chains; Attacks through physical access; and Attacks on the Shore Control Centre. As the concept and technology related to autonomous vessels are still evolving, identification and determination of detailed specific countermeasures at this stage are not feasible. Moreover, detailed countermeasures will be different by application and the targeted level of autonomy. Nevertheless, potential threat scenarios and high-level considerations of countermeasures would help ship engineers, owners and operators identify and implement security functionalities essential for autonomous vessels.