TAIPEI (Taiwan News) — China may be testing fake Automatic Identification System signals as a cognitive warfare tactic against Taiwan, according to the Institute for the Study of War.

In a weekly update published on Friday, the institute said a few Chinese fishing boats in Taiwan’s Exclusive Economic Zone recently used fake AIS signals. It cited Starboard Maritime Intelligence data showing that the fishing boat Min Shi Yu 06718 traversed in the Taiwan Strait throughout August and September while transmitting its own AIS and the AIS of a ship called Hai Xun 15012. 

The China Maritime Safety Administration (MSA), which does not play a primary role in coercion against Taiwan, usually operates Hai Xun ships, the institute said. “The boat was likely a fishing boat transmitting a fake MSA identity, rather than the other way around.”

Min Shi Yu 07792 was another fishing boat at the same time and location, which used a fake signal to pose as “Russian Warship 532” on Sept. 17. Multiple other Min Shi Yu ships nearby also transmitted fake AIS signals at around the same time, “including one that broadcast as a tugboat and another that broadcast as a different fishing boat,” the institute said. 

These fishing boats likely belong to the Chinese Maritime Militia, which are often deployed to carry out gray-zone coercion, harassment, and surveillance in disputed waters, including the Taiwan Strait and the South China Sea.

China may be experimenting with fake AIS signals “to pollute Taiwan’s information environment and test Taiwan’s responses to different kinds of perceived incursions.” The institute suggested that multiple fishing boats with similar names simultaneously transmitting different fake signals at the same time and place could be a coordinated effort.