Maritime cyber security is the protection of a ship's computers and control systems against cyber attacks. A ship is hard to protect for a simple reason: it is out at sea, with a slow and costly link to the shore, and a small crew who are not security specialists.
The ship's computers run navigation, the engine and the cargo equipment. They are a kind of operational technology, and they are often connected through a satellite link, such as maritime satellite internet. That link also carries the crew's messages and the ship's reports to the shore office, through maritime communications.
Maritime cyber security software uses an idea that is easy to state. A ship has physical signals that cannot be faked easily: its speed, its engine revolutions and its position. If the computer data say one thing and the physical signals say another, something is wrong. The software compares signs of an attack with these physical signals.
GPS spoofing means sending a false satellite signal, so that a ship's receiver believes it is somewhere else. It is a main risk at sea, because the officers on the bridge depend on position data for navigation. Other risks are a virus brought on board by a USB stick that a crew member or a repair engineer plugs in, and an unprotected link between the engine control system and the ship's office network.
Take, for example, a cargo ship sailing at 14 knots. A knot is a speed of one nautical mile an hour, which is about 1.85 km an hour. Its position, as reported by GPS, suddenly jumps 40 km in one minute. At 14 knots, a ship covers only about 0.4 km in a minute. So the jump is impossible, and the GPS signal may have been faked. The software sends an alert to the shore team's SIEM, which collects security alerts, and the crew navigate with other instruments.
The shore office also holds the ship's maintenance and crew records in ship management software. Ships that sail with no crew, called unmanned systems, depend on this kind of protection even more.
The buyers are shipping companies and the ship management companies that run ships for their owners. They are pushed to buy by the International Maritime Organization (IMO), which requires ship operators to include cyber risk in their safety management systems. It differs from OT and IoT security on land mainly in the link: a ship has a slow satellite connection and cannot call a security expert on site.