16PROGRAMMING THE SIMPLE SUBSTITUTION CIPHER
“The internet is the most liberating tool for humanity ever invented, and also the best for surveillance. It’s not one or the other. It’s both.”—John Perry Barlow, co-founder of the Electronic Frontier Foundation
In Chapter 15, you learned that the affine cipher has about a thousand possible keys but that computers can still brute-force through all of them easily. We need a cipher that has so many possible keys that no computer can brute-force through them all.
The simple substitution cipher is one such cipher that is effectively invulnerable to a brute-force attack because it has an enormous number ...