The Enigma Machine was an impressive piece of encryption technology. Marian Rejewski, Jerzy Różycki and Henryk Zygalski were the Polish mathematician who first cracked early versions of it. Combining three rotors from a set of five, each of the 3 rotor settings with 26 positions, and the plugboard with ten pairs of letters connected, the military Enigma has 158,962,555,217,826,360,000 different settings (nearly 159 quintillion or about 67 bits). | City Tours - The London Spy