An exhibition showcasing the Tunny machine, which was used to break German codes in World War II, opened at the National Museum of Computing at Bletchley Park on Thursday. Researchers have announced it tool three years for the completion of a replica code-breaking machine.
The Tunny machine represents an important milestone in Britain’s military efforts in World War II. Bletchley Park cryptographers at the time had no access to the Lorenz cipher machines used by the Germans to encrypt their messages. Their big breakthrough came on August 30th, 1941, when a German operator mistakenly sent the same message (bar a few alterations) twice using the same key settings. By the end of the war, 15 Tunny machines were in operation, cracking in the region of 300 messages per week.
At the end of the war, Tunny machines were broken up and the components recycled, while the original circuit diagrams were destroyed or hidden. The team had to piece together plans for the machine from odd pieces of circuit diagram that had been squirreled away by engineers, as well as from the recollections of some of the original builders, according to John Whetter, one of the team leaders for the Tunny rebuild project.
“We are leaving [the Tunny machine] as a legacy and a tribute to those legends at Dollis Hill [Post Office Research Station] and Bletchley Park who never got the recognition they deserved,” Whetter told ZDNet UK on Wednesday.