The pinnacle of code-breaking at Bletchley Park can now be told in its entirety from encrypt to decrypt using the full set of 1940’s cutting edge technology following the presentation of an extremely rare Lorenz SZ42, Hitler’s “unbreakable” cipher machine, for display at The National Museum of Computing.
The breaking of the top-secret Lorenz messages of German High Command is credited with shortening the war and saving countless lives. Much more complex than Enigma, the Lorenz cipher could be broken only thanks to Bill Tutte’s deduction of the architecture of a Lorenz machine without ever having seen it.
As a result, the Allies were routinely able to read German High Command’s top secret messages. From 1944, with the creation of the Colossus computer by Tommy Flowers, the Allies were able to reduce the decrypt time from weeks to hours, a speed that effectively undermined the German military machine.
At a ceremony in central London, Lieutenant Colonel Stein Wilhelm Aasland of the Norwegian Armed Forces Museum presented a Lorenz SZ42 as a long-term loan to Andy Clark, Chairman of TNMOC. The audience included two Wrens who had worked on Colossus along with relatives of those involved in the breaking of Lorenz.
It is estimated that about 200 Lorenz machines were in existence during World War II, but only four are known to have survived. The particular Lorenz SZ42 machine to be displayed at TNMOC has the serial number 1137 and was used at the German HQ in Norway at Lillehammer, north of Oslo.
The technologies at the core of the Lorenz story – encryption, communications and computing – are at the very heart of our modern world, so the narrative is as relevant today as it was then and an inspiration to the next generation of computer scientists and engineers
The loan of a Lorenz SZ42 machine to TNMOC completes the set of artefacts that tell the remarkable Lorenz story in its entirety from encrypt to decrypt. Nowhere else in the world is it possible to see the full range of innovative technologies used by both the British and the Germans to send and receive the most complex and important encrypted messages of World War II.
ABOVE: Sue and Ken Flowers (son of Tommy Flowers) with Bill Tutte (nephew of Bill Tutte) and Patricia Tutte
Irene Dixon, one of the first operators of Colossus in 1944, said: “I am thrilled that TNMOC is able to tell the Lorenz story even better than before by displaying the amazingly complex Lorenz machine. For years, I had to keep silent about the incredible work of Tommy Flowers and his team, but the growing publicity today about their achievements is very exciting. I would love every schoolchild to know the names of Tommy Flowers and Bill Tutte.”
Receiving the Lorenz machine, Andy Clark, chairman of TNMOC, said: “We are enormously grateful to the Norwegian Armed Forces Museum for its generous loan. It completes a truly unique set at TNMOC and helps bring further life to the story that we have always wanted to tell as clearly and dynamically as possible. The technologies at the core of the Lorenz story – encryption, communications and computing – are at the very heart of our modern world, so the narrative is as relevant today as it was then and an inspiration to the next generation of computer scientists and engineers.
“In leading the team to rebuild Colossus and co-founding TNMOC, the late Tony Sale had the dual aims of honouring all those who worked in wartime Bletchley Park and ensuring that the once-secret story of the breaking of Lorenz could inspire future generations. I’m sure that he would be thrilled that his vision is being advanced by the arrival of the Lorenz. It brings into even sharper focus the astonishing achievements of those wartime code-breakers.”
A re-union of Colossus veterans and relatives of those connected with the breaking of Lorenz is to be held at The National Museum of Computing later this spring.