Alan Turing’s Enigma-Breaking Notes Found in Roof Insulation

Papers written by Alan Turing during his famous work breaking the Germans' "Enigma" code have been found being used as crude insulation in a hut where the pioneering computer scientist and cryptographer worked. The documents are the only known examples of what are called Banbury sheets, which were used to help calculate the correct settings for the Enigma-decoding machine. They were top-secret documents during WWII and were supposed to have been destroyed, but poor working conditions ended up working in posterity's favor: Workers in Hut 6 at Britain's Bletchley Park, where the code-breaking took place, wadded up Banbury sheets and other documents to stuff into drafty cracks and insulate the roof.

The Times reports that the notes were found in 2013 during a restoration effort and immediately frozen until they could be restored — as they now have, for an exhibition at Bletchley Park later this month. The story of Turing and the effort to break the Enigma code was told recently in the film "The Imitation Game." Also, a notebook belonging to Turing will be sold at auction in April, where it is expected to fetch upwards of a million dollars.



—Devin Coldewey