This is new to me -- Thanks to David Mee for the pointer.
'During WWII, one of Nazi Germany’s most notorious communication codes was broken by a mild mannered librarian and family man from West Limerick, Richard Hayes. His day-job was as Director of the National Library of Ireland - but during wartime, he secretly led a team of cryptanalysts as they worked feverishly on the infamous "Görtz Cipher" - a fiendish Nazi code that had stumped some of the greatest code breaking minds at Bletchley Park, the centre of British wartime cryptography.
But who was Richard Hayes? He was a man of many lives. An academic, an aesthete, a loving father and one of World War Two’s most prolific Nazi Codebreakers.
At the outbreak of WWII, Hayes, being highly regarded for his mathematical and linguistic expertise, was approached by the head of Irish Military Intelligence (G2), Colonel Dan Bryan, with a Top Secret mission. At the behest of Taoiseach Éamon de Valera, Hayes was given an office and three lieutenants to decode wireless messages being covertly transmitted via Morse code from a house in north Dublin owned by the German Embassy. The coded messages posed a huge threat to Irish national security and the wider war effort. As Hayes team worked to break the code, it was all academic until he met his greatest challenge yet. The man who was to be his nemesis, Dr. Herman Görtz, a German agent who parachuted into Ireland in 1940 in full Luftwaffe uniform in an attempt to spy and transmit his own coded messages back to Berlin. [...] The events that transpired were a battle of wits between the mild mannered genius librarian and his nemesis, the flamboyant Nazi spy.
Hayes has been referred to by MI5 as Irelands "greatest unsung hero" and the American Office of Strategic Services as "a colossus of a man" yet due to the secret nature of his work he is virtually unheard of in his own country.'
Hayes was our lead code-breaker, director of the National Library of Ireland, and then director of the Chester Beatty Museum; he was the first to discover the German use of microdots to hide secret messages; and MI5 credited him with a "whole series of ciphers that couldn't have been solved without [his] input". Quite the polymath!
The book is apparently well worth a read: Code Breaker, by Marc McMenamin, and I can strongly recommend this RTE radio documentary. It's full of amazing details, such as the process of feeding Hermann Görtz false information while he was in prison, in order to mislead the Nazis.
After the war, he fruitlessly warned the Irish government not to use a "Swedish cipher machine", presumably one made by Boris Hagelin, who went on to found Crypto AG, which later proved to be providing backdoors in its machines to the CIA and BND.
Quite a towering figure in the history of Irish cryptography and cryptanalysis!
