  During the second half of 1941, messages encoded by means of a totally different method began to be intercepted. This new cipher machine, code-named ‘Tunny’ by Bletchley Park, was broken in April 1942 and current traffic was read for the first time in July of that year. Based on binary teleprinter code, Tunny was used in preference to Morse-based Enigma for the encryption of high-level signals, for example messages from Hitler and members of the German High Command.