The no-brainer code was in use between 1962 until 1977 when John F Kennedy required the use of Permissive Action Link (PAL) security encoding on nuclear weapons.
According to news.com.au, the Strategic Air Command chose the numbers to make the weapons quick and easy to launch over concern that command centres or communication lines could be destroyed in war and preventing soldiers from launching the missiles.
A paper written by Dr. Bruce Blair, who worked as a Minuteman launch officer in the 1970s, detailed how Strategic Air Command remained far less concerned about unauthorised launches than about the potential of these safeguards to interfere with the implementation of wartime launch orders.
Blair mentioned that the eight zeroes code, written in checklist for officials, instructed them to double-check the locking panel in underground launch bunker to ensure that no digits other than zero had been inadvertently dialed into the panel, the report added.
--ANI (Posted on 02-12-2013)