Kjell-Ove Widman
Professor Emeritus, Sweden
Download article![](/images/PDF_24.png)
Published in: Proceedings of the 1st International Conference on Historical Cryptology HistoCrypt 2018
Linköping Electronic Conference Proceedings 149:5, p. xix
NEALT Proceedings Series 34:5, p. xix
Published: 2018-06-13
ISBN: 978-91-7685-252-1
ISSN: 1650-3686 (print), 1650-3740 (online)
Arne Beurling was a 34-year old professor of mathematics at Uppsala University when the Second World War broke out in 1939. He reported immediately to the Swedish SIGINT service and was first entrusted with Soviet military codes which he helped solve, partly in cooperation with Finnish colleagues. After the occupation of Norway in 1940, a hitherto unknown type of encrypted traffic was picked up from telegraph cables running from Norway to Germany through Sweden. Given the task of analysing the traffic, Beurling took the collected material from two days in May and retreated to his office. Two weeks later he reappeared, having diagnosed the type of the transmission, deduced the ciphering algorithm, and found a way to attack it. Special machines were built, and over a three-year period, more than 250 000 messages sent between Berlin and the occupying forces in Norway were deciphered and forwarded to the relevant Swedish authorities. Beurling’s achievement is surely one of the more remarkable ones in the history of cryptography, in particular since he worked with ciphered messages only and had no á priori knowledge of the system. This talk will try to give a hint of his cryptanalytic work and the Swedish code breaking effort during the war, as well as touch on his personality and his career as a mathematician.