This Is How They Tell Me the World Ends: The Cyberweapons Arms Race

by Nicole Perlroth

For thirteen days, it did nothing but measure the speed of the centrifuge rotors. It was checking to make sure the rotors ran at speeds between 800 and 1100 hertz, the exact frequency range used by Natanz’s centrifuges. (Frequency converters that operate past 1000 hertz are actually bound by U.S. export controls because they are primarily used for uranium enrichment.) Once that thirteen-day waiting period was over, the payload got to work. The code was designed to speed up the rate at which the rotors spun to 1400 hertz for exactly fifteen minutes, before returning to normal for twenty-seven days. After those twenty-seven days were over, it would slow the speed of the rotors to just 2 hertz for fifty minutes, before returning to normal for another twenty-seven days, and repeating the whole process all over again.