What is the history of authenticating nuclear launch codes? Were hashes used for verification? How would a nuclear launch base be able to verify that the code is correct, and how were new codes transmitted (networks? radios?) to the bases? Has anyone ever 'hacked' the nuclear code authentication mechanism? Did nuclear devices stop working if the incorrect code was entered? Other than personnell related security measures, what sort of technical measures existed? How secure were the actual codes?

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    By any chance you seen the movie "war games"? – Vipul Nair Jul 2 at 15:31
  • This is an interesting question, but I'm not sure you'll get an answer. The US government probably severely restricts access to this information -- if it wasn't TS/SCI I'd be shocked. Security through obscurity is bad for most people, but when you're a nation-state protecting literal nuclear weapons, even its low ROI is preferable to not having it. – Fund Monica's Lawsuit Jul 2 at 15:52
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    Try asking this on history.stackexchange.com. – ztk Jul 2 at 17:03
  • Many different methods were used depending on the time, hardware, ICBM, platform (silo vs bomber vs sub), etc... Here's a video of the Titan missile procedure being launched from a silo (Titan Missile Museum, near Tucson, AZ): youtube.com/watch?v=KfPA7NIhvps that answers many of your questions for that specific platform. – Ghedipunk Jul 2 at 17:06
  • @ztk I think you're right, but I'm not sure and don't want to incorrectly flag it. Maybe a high-rep user could chime in as to whether this would be a good candidate for migration? Either way, very interesting question! – Cowthulhu Jul 2 at 17:59

The details have of course changed with time and technology. For many years the final launch code deep inside the ICBM missle sites was "00000000" 20 years Launch Code. The logic was that it was a very difficult assignment for constantly rotating crew in the bunkers and they needed something they could remember.

It has been standard policy in the U.S. to always maintain a human in the loop, multiple humans actually, to preclude any possibility of an automated launch.

There are a number of relatively current descriptions of the details:


Old Nike Launch

Wikipedia Gold Codes

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