A Nintendo DS homebrew that allows users to encrypt keys.
From the developer: "Theoretically, the application allows you to encrypt text with a key (rotors, the rotor position and configuration of steckers) and if then the text shown above, the ciphertext is re-encrypted with the same key, you get original text. That is, if you figure "HELLO", and the machine will figure as "OIIQ" then if we put the rotors in the position they were when we encrypt "HELLO" if encrypt "OIIQ" should appear on the screen decrypted text: "Hello."