Dual-use technologies, defense and safety
From 1940 to 1945, Alan Turing and the 10,000 cryptanalysts at Bletchley Park deciphered German Enigma communications — 158 × 10¹⁸ daily combinations, cracked through mathematical logic. Estimate by the official historian Harry Hinsley: the war shortened by at least two years.
Discovered in June 2010 by the Belarusian firm VirusBlokAda, Stuxnet is a 500 KB worm exploiting 4 Windows zero-day vulnerabilities to alter the rotational frequency of the Iranian IR-1 centrifuges at Natanz (Iran), driven by Siemens S7 controllers — from 1,064 Hz to 1,410 Hz then down to 2 Hz — while displaying normal data to operators. Result: ~1,000 centrifuges destroyed out of the ~9,000 installed.