Beyond Enigma: The German Lorenz cipher that stumped Allied codebreakers at Bletchley Park

While Enigma is famous, Hitler's High Command relied on a faster, more complex system called Lorenz. Allied forces initially encountered this mysterious cipher without knowing its origins, leading them to nickname it Tunny. This video explores its role in the history of early computer science.

The Lorenz cipher was the primary communication method for the German High Command, operating at speeds that surpassed the better-known Enigma machine. When Allied intelligence first intercepted these transmissions, the nature of the system was entirely unknown to them.

The code-name 'Tunny' was assigned to the system by the British, who had to develop entirely new methods to decrypt it. Professor Brailsford details how the challenge of breaking Tunny became a pivotal moment in the development of early computing, marking a significant, often overlooked chapter in the work performed at Bletchley Park.

Source: Fishy Codes: Bletchley's Other Secret - Computerphile