Harold Bernard Willson (25 February 1919 – 1994) was a British linguist and noted academic, who during the Second World War was the first person to decrypt the Italian Navy Hagelin C-38 code machine.
[4] Willson was recruited in 1941 by J. R. M. Butler to join a team with two others in Hut 4 at Bletchley Park, the Italian subsection of the GC&CS.
With shipping losses increasing, from reading the resultant Ultra traffic the team learn that between May and September 1941 the stock of fuel for the Luftwaffe in North Africa fell by 90 per cent.
After the war, Hagelin founded Crypto AG, which made new versions of his coding machine based on the same logic of encryption.
The KGB (the Soviet Intelligence Service) probably already knew of the backdoor, via their US-based spies, Aldrich Ames and Robert Hanssen.