Enigma

In August of 1939, British Codebreakers Receive A Stolen German Cipher Machine Called "Enigma". The Machine Was Used To Send Coded Information Between German U-boats And Land Based Command. - We've pretty much deciphered how this thing works. One thing - we're still having trouble setting the bloody clock. Can't seem to stop it from showing '12:00' all the time.

As seen in World War II for Dummies