Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!ihnp4!houxm!whuxl!whuxlm!akgua!gatech!seismo!harvard!think!mit-eddie!cybvax0!frog!wjr From: wjr@frog.UUCP Newsgroups: net.crypt Subject: Re: Eastern Front/WWII Cryptography Message-ID: <686@frog.UUCP> Date: Fri, 7-Mar-86 02:48:45 EST Article-I.D.: frog.686 Posted: Fri Mar 7 02:48:45 1986 Date-Received: Mon, 10-Mar-86 00:18:40 EST References: <869@spp2.UUCP> <12068@ucbvax.BERKELEY.EDU> Reply-To: wjr@frog.UUCP (Bill Richard) Organization: Superfrog Heaven [ CRDS, Framingham MA ] Lines: 71 [] I too have been following this discussion with some interest and would like to see it continue, so I am going to try to make a few small contributions of my own. About Turing: Some information about the work at Bletchley Park and Turing's role in it can be found in the recent biography 'Alan Turing: the Enigma' by Andrew Hodges. Another book that I have not seen anybody mention yet is "The Wizard War" by R. V. Jones. I believe it was originally published in Britain as "Most Secret War" It has been a few years since I borrowed it from a library so I don't recall the publishing info, sorry. Anyway, Jones was the head of a British group whos job was to coordinate intelligence about German technical innovation and Allied countermeasures. He discusses Ultra among other things. Further comments: >> = ross@spp2.UUCP (Jonathan Ross) > = weemba@brahms.UUCP (Matthew P. Wiener) >> Among the important secrets that still remains classified (at >> least as of the publishing of the book entitled, I believe, "_The >> Radar War_") is the design of the "computer" that Alan Turing used >> to break the German codes. I wish I could go into more detail here >> but I don't have any sources at hand. > >Algorithms to break Enigma have been published in the journal _Cryptologia_. >Is that close enough? Also there is some description of the "bombes" and how they worked in the Turing biography mentioned above. >> With regards disinformation, until a few postings ago, I was >> under the (apparently) mistaken impression that Churchill did allow >> Coventry to be bombed unopposed, in order to keep the British >> cracking of the German code a secret. (note: I'd love to see sources >> on this if anyone knows of any). > >The story is repeated in Winterbotham _The Ultra Secret_ and repudiated >with the correct explanation in Calvocaressi _Top Secret Ultra_. The >British *had* decrypted the relevant messages. But the name of Coventry >was in code ('Korn' if I remember correctly), and no one realized the >urgency of identifying what 'Korn' referred to until it was too late. If I remember correctly the situation was something like this: The British had, from an Enigma decrypt, a list of targets (by code name only) that were to be attacked in the next couple of weeks, but not the exact order or specific dates. They were able from POW interrogations and other means to make up a tentative list of the cities that corresponded to the list of code names, however the list of cities was a bit longer than the list of code names. By the day of the attack on Coventry they had managed to make some match ups of code names and cities, some after the fact, but when they got the message that 'Korn' would be attacked that night all they could say was that it would probably be one of three cities (including Coventry). It was too late to reinforce the anti-aircraft batteries around all of these cities so all they could do was to alert the RAF to expect a raid over central England that night. >It is difficult. Winterbotham's inaccuracy concerning Coventry is just >one example. And he was in on most of Ultra. Again if I remember correctly, Winterbotham was in the group that managed the distribution of Ultra intelligence to the field commanders. So he certainly knew what use was being made of Ultra in the field, but he was not in a position to see the raw decrypts or follow the work of the intelligence analysts at Bletchley Park, and this may explain some of his inaccuracies. ---- William J. Richard @ Charles River Data Systems 983 Concord St. Framingham, MA 01701 Tel: (617) 626-1112 uucp: ...!decvax!frog!wjr