I’ve just finished reading Code Breaker, an account of the work of Richard Hayes on behalf of G2, Irish military intelligence, during WW2. Just published, written by Marc Mc Menamin, it’s a fascinating record of the relatively unknown work by this man. Hayes was responsible for the breaking of several german code systems and this information was shared with the British Inteligence services. Unfortunately the book contains several significant errors and makes several irritating exaggerated claims about the significance of Hayes’ work which is particularly unfortunate given that Hayes was a very low key modest man. However, credit to Mc Menamin for highlighting the work done by Hayes.
In 1939 Richard J Hayes was head of the National Library. In 1940, Colonel Dan Bryan, head of G2, approached Hayes, asking for his assistance in unlocking the cipher used by the recently captured Wilhelm Preetz, the first german agent to land in Ireland. In early 1941 a more formal arrangement was made and Hayes was given an office an 3 assistants.
His two most notable achievements were the breaking of a particularly sophisticated cipher used by agent Hermann Görtz and discovering the use of microdots by the Germans.
Hermann Görtz was the most successful of the various german agents sent to Ireland. Unlike all of the others he was not captured immediately after his landing and he remained at large for 18 months, establishing links and giving funds to sympathetic republican persons. When he was captured towards the end of 1941 he was carrying a code that was later described by MI5 as "one of the best three or four in the war". A similar cipher had already baffled cryptologists at Bletchley Park. Hayes identified that it worked on a system of decoding based on a sequence of rotating keywords. The first of the Goertz messages to be successfully decoded was unlocked with the keyword 'Cathleen Ni Houlihan'. Eventually informed of the breakthrough Cecil Liddell, Director of Counter Espionage MI5, visited Dublin in 1943.....(Hayes wanted to immediately inform the British but this was blocked by his immediate superior and the news was only when the director of G2, Col Bryan, belatedly found out about it). The Irish secret service continued to share intelligence information with the British until the end of the war. Afterwards, Cecil Liddell said that there was a "whole series of ciphers that couldn't have been solved without Hayes' input".
Another agent, Günther Schultz, was captured shortly after his arrival in March 1941(he subsequently escaped and remained at large for a time). During his captivity he was interrogated by Hayes(going by the suitably bookish name of Captain Grey). Schultz explained that he had microscope because of his stamp collecting hobby. Hayes, using the microscope, discovered that a large amount of information was hidden within the physical text of a number of newspaper cuttings that Schultz also had on him. Thirty pages of instructions as well as extensive lists of names and addresses of Nazi sympathisers in Ireland were hidden in random characters in these cuttings. He identified messages, reduced in size 400 times, and secreted within three letter 'o's in the text. On an article about Oxford Pamphlets, he spotted a further four microdots, with three more in an ad for the Green Park Hotel. Within 10 days of Schultz's arrest, Hayes had found and translated the entire contents of his highly sensitive microdots. It would take the FBI a further four months to even identify that such a system of transmitting messages existed. Schultz commented after the war that....
Another notable point about Hayes was the manner in which he conducted these interrogations. He put the subject at ease with his amiable manner and set about establishing a friendly relationship with them. The agents seem to have been treated well and lived in relatively comfortable rooms. In the case of agent Görtz this seemed to be particularly effective given that he was a rather vain and arrogant person and prone to say more than he should. During the course of his captivity, Görtz believed that he had succeeded in restablishing contact with Berlin via smuggled coded notes........however the notes had been intercepted by his captors and in reality he was, unbeknownst, corresponding with Hayes rather than german intelligence. In one correspondence Hayes “promoted” Görtz to Major in recognition of his services to the Fatherland.The germans were so cocksure that the microdots couldn't be discovered that they didn't even encode them. They were to be a vital weapon in espionage. Finding them as the Irish intelligence officers did was an act of brilliance
After the war Hayes continued on as Director of the National Library. His recommendations that a specific cryptology section be maintained after the war was ignored. He later became Director of the Chester Beatty Library and also continued on his extensive academic works.