makes receivers behave any way you like.
“So far as I know, no commercial
GPS receivers offer any strong defense against spoofing or even any reliable spoofing detection capability,”
Stealing an $80-Million Superyacht
In 2013, Humphreys, then a researcher
in the Department of Aerospace Engineering and Engineering Mechanics at
the Cockrell School of Engineering, was
invited, along with a team of students,
aboard an $80-million yacht in the Ionian Sea to test their GPS spoofing technology. Using his hardware and software rig, Humphreys managed to falsify
GPS data used by the ship, effectively
giving him control over the vessel.
Humphreys explained GPS receivers
calculate their distance from several
satellites at the same time. Each satel-
lite has a code—called a pseudoran-
dom noise (PRN) code—that identifies
which satellite in the GPS network is
broadcasting. Humphreys’ spoofing
equipment slowly replaced the real
drifting slightly off course, likely as a
result of strong currents buffeting their
ship. The crew made adjustments and
went back to work—without realizing
they were now taking directions from a
In the bowels of the ship, Todd
Humphreys, an associate professor in
the Department of Aerospace Engineering and Engineering Mechanics at
the University of Texas at Austin,
worked with his team to feed the superyacht’s crew false navigation data using a few thousand dollars worth of
hardware and software.
The crew was completely unaware
they were now piloting in a direction of
Thankfully, it was all an experiment
that took place with the yacht owner’s
blessing. If it had been real, Humphreys could have sent the superyacht
1,000 miles off-course into the hands
of a rogue government, terrorist group,
or professional criminal organization—and the crew would not have realized it until it was far too late.
Welcome to the very real dangers
posed by Global Positioning System
(GPS) spoofing, or the dark art of convincing computers you are somewhere
that you’re not. It is surprisingly easy—
and shockingly dangerous, because
we’re not prepared for it at all.
GPS Is Easy to Spoof
The U.S. Global Positioning System
consists of 24 satellites that orbit Earth.
GPS devices receive signals from the
nearest satellites that allow them to de-
termine their precise location, whether
you’re looking for creatures in the wild-
ly popular Pokémon Go app, or going to
war in a billion-dollar battleship. A
range of GPS devices and networks are
used for everything from military appli-
cations to commercial needs—and all
the use cases in between.
Yet all of these systems rely on the
data from the network of GPS satellites. If you can corrupt the data coming from those satellites, you can create a world of headaches for systems
that rely on this data.
GPS spoofing can be performed with
relatively low-cost tech, which is an expensive problem for the people, companies, and governments that trust the
system implicitly. In the case of Humphreys’ superyacht hacking, he and his
team used about $2,000 worth of tech.
Even in more advanced spoofing scenarios, the technology is still straightforward, says Dinesh Manandhar, an
associate professor and GPS expert at
the University of Tokyo.
“A device that can generate GPS signals is necessary. Such devices are available from GPS signal simulator device
manufacturers,” Manandhar explains.
These devices are used to test GPS receivers in factories. As such, they can be
programmed to transmit a signal that
Why GPS Spoofing Is a Threat
to Companies, Countries
Technology that falsifies navigation data presents
significant dangers to public and private organizations.
Society | DOI: 10.1145/3121436 Logan Kugler
Part of an animation showing how a radio navigation research team from The University of
Texas at Austin was able to successfully spoof the GPS system of an $80-million private yacht.