For nostalgia's sake, I just went and found Gardner's RSA article. It was from 1977 - I was 10 (by which stage I was almost certainly grabbing the magazine from Dad as soon as he'd finished reading it).
Notable quote: "For example, to test a 130 digit odd number for primality requires at the most (that is when the number is actually prime) about 7 minutes on a PDP-10 computer."
Notable quote: "For example, to test a 130 digit odd number for primality requires at the most (that is when the number is actually prime) about 7 minutes on a PDP-10 computer."
http://simson.net/ref/1977/Gardner_RSA.pdf
(Tonight I might see if I can still remember how to make a hexaflexagon...)