The Dangers of Relying too Heavily on Helm Electronics, by Capt. Bill Pike (continued)
A Cautionary Reminder
Experts like Humphreys and Goward say that the actual process of GPS spoofing is electronically complicated but, in theory at least, fairly simple. During a so-called “carry-off attack,” arguably one of the most common spoofing strategems these days, a spoofer targets a GPS unit and broadcasts signals towards it that synchronize with true, but comparatively weak satellite-generated GPS signals. Then, as time passes, the power of the counterfeit signals is gradually increased by the spoofer so that the true signals are eventually obscured or overcome, thereby hoodwinking the targeted GPS unit into specifying bogus positions of the spoofer’s choosing.
Such attacks need to be subtle in order to be effective, according to Humphreys, especially if they entail a cross-track shift in a vessel’s apparent location rather than a linear misplacement along the vessel’s projected course line. Still, a navigator who is unaware of a cross-track-type spoofing attack and unable to reliably check his position via sightlines and/or visual or electronic bearings, may well respond to subtle, seemingly necessary alterations in course as if adjusting to the vagaries of a powerful ocean current. And, in theory at least, the demand for alterations could be fed to him so infrequently and so modestly that he might never notice, especially if his confidence in his GPS is high.
What does the Navy have to say at this juncture, several months after the fracas? When contacted, a Navy spokesman at the Pentagon refused to comment on a probe that is still ongoing. “The investigation is complete but is still under review,” said Lieutenant Commander Tim Hawkins. “And will be for some time to come. So at this point we can’t comment.”
“Probably we’ll never know for sure what happened with these boats,” conceded GPS expert Goward, “Most everything you see in the press about the incident seems very unlikely. But, nevertheless, the episode should serve as a cautionary reminder—total reliance upon our present-day GPS technology, especially the technology that is of the unencrypted variety, is ultimately going to create very serious problems well beyond minor international embarrassments, not only for the United States, but for the rest of the world as well.”