What Would Happen If G.P.S. Failed?
In front of an audience of military and government officials, Humphreys fed faulty G.P.S. coördinates to a test drone aircraft from a third of a mile away, causing it to plummet. (He would later hear that officials were “shocked” upon reviewing video of the demonstration.)
.. The good news, he said, was that there were, at most, a hundred people in the world who could build a spoofer as mighty as his. For the moment, it was probably beyond the reach of organized crime or terrorist groups but “well within the capabilities of near-peer nation-states.” He spent the next few years documenting how his spoofer could induce the kinds of clock errors that might undermine power companies, telecoms, and financial firms. The last of these, Humphreys thinks, are particularly vulnerable to attack.