Re: A lack of US cryptanalytic security before Midway?
The conventional wisdom is that the successful US cryptanalytic efforts against Japanese naval codes was a closely-held secret. Has the conventional wisdom forgotten that it was reported in the Chicago Tribune in 1942? See, for example, http://www.newseum.org/warstories/essay/secrecy.htm Fortunately, the Navy Department had enough sense not to make a public stink, and the Japanese evidently didn't read the Chicago paper. R's, John - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: A lack of US cryptanalytic security before Midway?
On 7 Sep 2006 15:33:15 -, John Levine [EMAIL PROTECTED] wrote: The conventional wisdom is that the successful US cryptanalytic efforts against Japanese naval codes was a closely-held secret. Has the conventional wisdom forgotten that it was reported in the Chicago Tribune in 1942? See, for example, http://www.newseum.org/warstories/essay/secrecy.htm Fortunately, the Navy Department had enough sense not to make a public stink, and the Japanese evidently didn't read the Chicago paper. The URL you cite does not support your claim. It speaks of the successful cryptanalysis of JN-25 as one of the closest kept secrets of World War II. It also notes that the reporter learned of some data just from seeing a piece of paper in a senior officer's quarters, rather than knowning about the real source of the data, and that the Trib's headline -- NAVY HAD WORD OF JAP PLAN TO STRIKE AT SEA -- was not in fact justified by what the reporter had seen and written. In other words, there was not a factual leak of the real secret, though admittedly Japanese counter-intelligence would likely have drawn the proper conclusion had they seen the story. I should note that if Kernan's account is correct, the danger to American SIGINT efforts were far greater than were realized. Three downed American airmen were rescued by Japanese ships; they were then interrogated and executed. None of them (again, according to Kernan) had had proper training on what they should or should not disclose. If, indeed, the fact of cryptanalysis was common knowledge, it was lucky indeed that the proper questions weren't asked -- or if they were asked, they weren't answered, even though at least one of them did give away more information than he should have. --Steven M. Bellovin, http://www.cs.columbia.edu/~smb - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
A lack of US cryptanalytic security before Midway?
The conventional wisdom is that the successful US cryptanalytic efforts against Japanese naval codes was a closely-held secret. I've just stumbled on a source that disputes that. In The Unknown Battle of Midway: The Destruction of the American Torpedo Squadrons (Alvin Kernan, Yale University Press, 2005), the author states: Rumors began to circulate that the Japanese were planning to invade little Midway Atoll and draw our ships out to fight the great sea battle their strategy had long anticipated. Our information, we heard, at the scuttlebutt, came from code breakers... Unbelievably, the Japanese never tumbled throughout the entire war to the fact that their codes had been broken, and the U.S. Navy, equally blindly, continued to believe that its ability to read one after another of the Japanese codes remained a deep, dark secret from its own sailors. But when the American carriers sailed from Pearl Harbor to the Battle of Midway everyone aboard knew what was in the wind and how we knew it. The source for this statement isn't clear. The author himself was an enlisted sailor on one of the American carriers (he was an ordnanceman for a torpedo squadron), so it may be first person knowledge. Later in the second paragraph, there's a footnote to Prange et al's Miracle at Midway, but I don't have that reference. --Steven M. Bellovin, http://www.cs.columbia.edu/~smb - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
