The British “Enigma:” Britain, signals security and Cipher Machines, 1906–19461

The British army, signals and security in the desert campaign, 1940–42

“…19 Such systems, however, were extremely slow (in 1937, for example, two hours were needed to encipher, transmit and decipher a message of 110 groups on the RAF's superenciphered codebooks) 20 and were cryptographically vulnerable when used to transmit large quantities of radio traffic. Nor, contrary to the implication in British Intelligence in the Second World War, did the use of Typex cipher machines overcome this problem.…”

J. F. W. Nuboer and the Reintroduction of Machine Cryptography by the Royal Netherlands Navy, 1915–1940

“…The decision to adopt cipher machines by the Great Powers during the years immediately preceding the war is usually taken for granted. John Ferris, who investigated the grounds for adopting the Typex by the British Defense bureaucracy [9], is an exception, as is David Kahn who established the reasons for introducing the Enigma by the German Navy in 1925 [13, pp. 38-41].…”

“…Koot acknowledged Käyser's device as theoretically superior, but he was afraid that the improvements would easily lead to mistakes in the encryption process. 9 Apparently, even Koot's original device did not function well, either. Gooszen proposed an unmixed plaintext alphabet and had index numbers in regular order.…”

The Intelligence Revolution: A Historical Perspective: Proceedings of the Military History Symposium (13th) Held in Colorado Springs, Colorado on 12-14 October 1988

“…"It was, for Japan, an 'abacus war'." Major Hori's praecis, with the preceding support data adduced, aptly sums up my contention that the Intelligence Revolution never pervaded Japan in the Pacific War, even at a time when its very fate was about to be decided on the landing beaches of Kyushu andHonshu in 1945 and1946. …”

“…Canadian Prime Minister William L. Mackenzie King's first reaction, on learning of Gouzenko's defection, was that "we should be extremely careful in becoming a party to any course of action which would link the Government of Canada up with this matter in a manner which might cause Russia to feel that we had performed an unfriendly act.. .For us to come into possession of a secret code book-of a Russian secret code book-would be a source of major complications." J. W. Pickersgill and D. F. Foster, The Mackenzie King Record: Volume 3, 1945-1946, (Toronto: University of Toronto Press, 1970 September 20, 1946, dispatch from the British Embassy in Washington to the Foreign Office on the subject of President Truman's firing of Henry Wallace. The dispatch, which among other things referred to "the President, the frail barque of whose judgment has been tossed hither and yon by the swirling eddies of circumstance," was sent by mistake en clair.…”