This is a simulation of the famous Enigma cipher machine used in the twentieth century and especially in the Second World War.
The Enigma Machine was a typewriter-like machine with 26 keys and corresponding lamps. It used a set of mechanical Rotors to achieve polyalphabetic substitution.
The Enigma Machine was broken during the second world war by Marian Rejewski, Jerzy Różycki and Henryk Zygalski, who created a Machine called "Bomba" which could break the enigma code.
After Germany invaded Poland, the british mathematician Alan Turing (known for his work on theoretical computer science) succeeded in completely breaking the Enigma.