Rising US–Iran tensions in the Persian Gulf raise concerns about GPS spoofing and jamming

The U.S. administration has issued a maritime advisory for vessels transiting the Persian Gulf and surrounding waters. Among the risks identified are GPS interference (jamming or spoofing), as well as intrusion, jamming, and impersonation in VHF communications with ships. In some cases, vessels have reportedly impersonated U.S. or coalition ships over the radio.

Since May 2019, the U.S. authorities have recorded numerous unlawful activities in the region. In two of those cases, GPS interference occurred at the same time as other suspicious events.

On July 19, 2019, the British tanker Stena Impero was seized by Iranian forces in waters whose exact status remains debated (international, Omani, or Iranian). According to the Daily Mirror, the British intelligence agencies GCHQ and MI6 reportedly investigated whether the vessel may have been subjected to GPS spoofing—possibly conducted by Iran or Russia—in order to alter the ship’s perceived position and cause it to enter Iranian territorial waters. Reports differ regarding the exact location of the vessel at the time of the seizure.

The hypothesis of GPS spoofing has also been mentioned by Lloyd’s List Intelligence, which identified suspicious AIS data at the time of the incident, suggesting that the vessel may indeed have been the victim of a spoofing operation.

Another report, published in April 2019, documented more than 10,000 cases of GPS spoofing over a one-year period.