“Ultra was the designation adopted by British military intelligence in June 1941 for wartime signals intelligence obtained by breaking high-level encrypted enemy radio and teleprinter communications at the Government Code and Cypher School at Bletchley Park.”
The deciphering of messages generated by the enemy’s Enigma machines for land and naval forces was, by all accounts, a decisive factor of the Allied victory in Western Europe. By the end of the war “Ultra” designated the entire body of intelligence gathered from Axis forces’ radio and teleprinter emissions.
The successful development of the method and procedures leading to the breaking of ciphered communications was largely due to the mathematical analytical work of a small group of Polish, British and American scientists and engineers led by the mathematician Alan Turing. Turing is widely considered as the father of computer science and Artificial Intelligence.
The story of WWII code breaking inspired Neal Stephenson’s novel “Cryptonomicon”.
- Alan Turing Cryptanalysis Papers (schneier.com)
- Two of Alan Turing’s wartime cryptography papers released (theverge.com)