The Mansion 7/10/2004

4-rotor Enigma machine @ Bletchley Park

Bombes were used against the Enigma cipher. Prior to the start of WW2 Polish cryptographer Marian Rejewski had designed 'Bomba' machines to help work out the settings of the German encoding/decoding machines. Alan Turing and Gordon Welchman later designed improved 'Bombes' built for Bletchley Park. These were electro-mechanical machines.

Front panel, 3-rotor Bombe mockup

Bombe under reconstruction

Bombe under reconstruction

The Colossus computers were used against the Lorenz cipher; Mathematician Max Newman and engineer Tommy Flowers led their design and construction [Rob18]. Mathematician Bill Tutte had worked out how the German encoding/decoding machine worked without ever seeing one, and this enabled an equivalent British "Tunny" machine to be built. Colossus helped in working out the settings of the coding machines to aid the human code-breakers. The reconstructed Colossus Mk2 below has 2,500 valves.

Reconstructed Colossus Mk 2 working(!) + Tony Sale (1931-2011)

Reconstructed Colossus Mk 2 working(!) 7/10/2004
(tape wheel frozen by the flash)

References

[Rob18] Jerry Roberts. 'Lorenz: Breaking Hitler's Top Secret Code at Bletchley Park', History Press, 2018.

JR was the last surviving code-breaker who had worked at Bletchley Park during WW2.

Also seach for [Bletchley Park] in the Bibliography.