Top secret papers written by cryptographic genius Alan Turing were found scrunched up in the roof of Hut 6 at Bletchley Park as the now-famous site was being renovated, it has emerged.
The documents should have been destroyed at the end of WW2 under the Official Secrets Act, but seem to have escaped the same fate as most of Turing’s work as they were shoved into the roof of the hut where he worked as insulation.
Key among them are so-called ‘banburies’ or ‘Banbury sheets’, according to MKWeb.
Turing would apparently punch two cipher texts onto different sheets and then slide one over the other, counting the overlapping holes to see where there was a match, as described here.
The Turing-devised process was key in helping the code-breakers accelerate their efforts at cracking encrypted German naval communications.
“Discovering these pieces of code-breaking ephemera is incredibly exciting and provides yet more insight into how the codebreakers worked,” Bletchley Park Trust CEO Iain Stander is quoted as saying.
“The fact that these papers were used to block draughty holes in the primitive hut walls reminds us of the rudimentary conditions under which these extraordinary people were working.”
The papers were found during a multi-million pound renovation of the site, including the famous Hut 6, according to the report. They were first frozen to preserve them and then cleaned and restored.
A cryptographic genius, Turing is widely acknowledged to be the father of modern computing thanks to his invention of the so-called ‘Turing machine’ – a universal machine which could effectively be controlled by means of a program of instructions stored in its memory.
“These are the actual documents used by codebreakers, and in terms of the codebreaking process they are pivotal,” said Bletchley Park curator, Gillian Mason. “I can just see these people beavering away. There is a lot of pencil and crayon activity.”