Hollywood movie The Imitation Game brought the work of mathematicians in Bletchley Park, England, in decrypting morse code messages from German spies during the Second World War to the big screen.
A lone Irish codebreaker genius, Dr Richard Hayes, was back in Dublin during the Nazi conflict helping to crack impossible ciphers from Berlin agents.
The Documentary On One: Richard Hayes, Nazi Codebreaker reveals how his ingenious plan to take an imprisoned German spy’s trousers without his knowledge helped him solve the key to coded messages being transmitted back to Berlin.
The mild-mannered librarian from Limerick shared his successes with British mathematicians in Bletchley Park and in the aftermath of the war quietly accepted a medal for his efforts from Winston Churchill.
Mark Hull, a serving member of the US army and military historian, told the documentary that the prolific codebreaker is widely recognised for his brilliance in the international intelligence circles.
“The tragedy here is he was lost in terms of the Irish public. People in the intelligence services, Irish American, British, and certainly Allied intelligence services, understood and recognised his contribution for being as significant as it was.
“I think in large measure, he kept Ireland safe.”
During wartime Europe, Dr Hayes and the head of Ireland’s G2 intelligence service, Colonel Dan Bryan, led the secret Irish counter- intelligence war to decode wireless messages being covertly transmitted through morse code from a house in north Dublin owned by the German embassy.
Dr Hayes worked for months to solve the infamous Görtz Cipher, a fiendish Nazi code that had stumped some of the greatest code breaking minds at Bletchley Park.
It was a code used by a flamboyant German spy, Dr Herman Görtz, who had been captured by gardaí and held in Arbour Hill prison after parachuting into Meath a year earlier.
Hayes, director of the National Library from 1940-67, tricked Görtz into getting an X-ray during one of his weekly visits to see him in jail so he could find the cipher in his trouser pockets without his knowledge and spent months cracking it.
In the aftermath, he and his superior, Col Bryan, intercepted messages from the spy and sent their own messages back to him to dupe him into revealing more information which was passed on to Bletchley Park.
“He masterminded the counter-intelligence program. He ensured Germany felt they could not certainly directly invade Ireland,” said Mr Hull.
Hayes has been referred to by MI5 as Ireland’s “greatest unsung hero” and the American Office of Strategic Services as “a colossus of a man”.
“The heroic thing about this, with both Dan Bryan and Dr Hayes, is they are doing this in some measure without their own government’s approval or knowledge,” said Mr Hull.
“It’s almost impossible to overestimate their contribution to the country and their part in winning the larger war. Without Hayes I think we could have well had a different outcome to WWII.”
Documentary on One: Richard Hayes, Nazi Codebreaker is aired on RTÉ Radio 1 at 2pm today