Simon Singh demonstrates the German enigma machine from the Second World War. 

As technology increases, so do the methods of encryption and decryption we have at our disposal. World War II saw wide use of various codes from substitution ciphers to employing Navajo code talkers in the Pacific theater. Here, science journalist and author Simon Singh demonstrates the German enigma machine, a typewriter-like device used to encrypt communications. He demonstrates not only its operation, but both the strength and fatal flaws in its method. via World Science Festival