A technological mystery hangs over the port of Shanghai. For nearly a year, the GPS of ships that dock there is taken of madness, reveals the MIT Technology Review, magazine of the famous American technological university which publishes, Friday, November 15, a long investigation on the setbacks of the system of geolocalisation global in the most important commercial port of the world.

In July 2018, a US ship transmits anomalies in the operation of its GPS to the US maritime authorities when it arrives in the port of Shanghai. The signal from another boat, though docked, appeared and disappeared from his control panel at locations where he was not located and the captain of the US carrier could not obtain its own geolocation.

A weapon that has become democratized

He first thought of a jamming of the GPS signal, a technique that involves parasitizing the information transmitted by the satellites to the receiver. But it is a much more worrying reality that American authorities have discovered: for several months, someone was cheating on the GPS system, and thousands of ships on the outskirts of Shanghai were appearing at places in the port where they were not. The day the American ship had reported their problem, about 300 other boats were in the same situation, says the MIT Technology Review which was able to view all geolocation data.

It is clear that the port of Shanghai is the scene of a vast operation to deceive the GPS system. So far, "nobody has been able to establish who is behind it and why ships arriving in Shanghai are paying the price," notes the MIT Technology Review. But the consequences could be deadly because every second accident at sea is due to navigation errors related to erroneous or missing data, according to the European Maritime Safety Agency.

"GPS decoy is much more subtle than the scrambling that comes back, to take a picture, to 'scream' louder than the satellites that are at more than 20 000 km altitude to prevent signals from reaching the receiver" says Jean-Michel Friedt, professor-researcher at the Femto-st Institute of the University of Franche-Comté, who worked on GPS decoy techniques. Deceiving the GPS is the equivalent of an identity theft of the geolocation system: "we must succeed in manufacturing a signal that mimics all the data received by the satellites". The most obvious goal is to be able to send a boat, an airplane or a drone to a place different from its original destination.

Historically, it is a weapon used primarily by states. Russia, for example, is famous for having used it in the 2010s, in Crimea, in Syria or around the Murmansk (Barents Sea) port. "One of the uses was to make drones think they were flying over an airport, because these machines are programmed to land in these cases," says the researcher.

For a long time, the technology needed to carry out such attacks was beyond the reach of private actors. But from the beginning of the years 2010, its use became democratized. "Today with 100 euros of equipment, it is possible to lure receivers on a radius of one kilometer," says Jean-Michel Friedt.

Laboratory rats or sand merchants?

The resources deployed in Shanghai, whose port covers 3,619 km², requires a much larger budget, even if the interference appears to be localized in a smaller area, towards the Huangpu River, which leads to the port. The scale of the operation suggests that it would be the work of the Chinese authorities.

The suspicions are all the more on Beijing as the techniques used "look like nothing of what exists, and we could be dealing with a new weapon," extrapolates the MIT Technology Review. GPS decoying is sending a false signal to all receivers - boats, cars, smartphones - concerned who direct them to the same place. But in Shanghai, the ships all seem to be located in different places, leaving the experts puzzled. When Todd Humphreys, an eminent US GPS safety expert, presented the data collected by MIT at a satellite navigation convention in September 2019, "people have been speechless," he says. it to the magazine.

In this hypothesis, the ships in the port of Shanghai, would be so many laboratory rats. But it may seem risky to use the world's largest trading port for such experiments, knowing that any accident can have significant economic repercussions.

These GPS manipulations could also be the work of ... sand merchants, notes the MIT Technology Review. The port of Shanghai sees, indeed, the Chinese police deliver a real hunt for contraband ships of the very precious sand of Yang-Tsé-Kiang. Known for its perfect qualities for cement, it has been overexploited. In the face of ecological and security risks, the authorities finally banned their exploitation in 2000, giving birth to a lucrative trafficking sector.

This operation in Chinese waters, whoever the author is, prefigures the impact that decoy GPS could have in the future. And the possibilities are not limited to deceiving boats on their location, says Jean-Michel Friedt. GPS is also used as a reference in real time, for example, to date the trades carried out by the algorithm, that is to say the famous "high frequency trading". Satellites embark, indeed, atomic clocks that allow to know very precisely when a signal is emitted. Luring the authorities by manipulating the GPS signal to backdate a stock market operation could be very big.