On 18/08/15 19:23, jim bell wrote:
*From:* Peter Fairbrother <peter@m-o-o-t.org>
*Subject:* Re: Recommended Movie: "Sebastian" 1968.
On 18/08/15 03:46, jim bell wrote:
Since people seem to be recommending things, I recommend the movie "Sebastian". Dirk Bogarde, Susannah York. https://www.youtube.com/watch?v=bIK3OYnD9MY
Out of date even when it was made, I think it really represents the cryptography situation as of the 1930's.
Based on a screenplay by Leo Marks - author of Between Silk and Cyanide: A Codemaker's War 1941-1945. Essential reading. Leo was the codemaker for SOE. All hand ciphers and agents. He wasn't at Bletchley - who called him "the one who got away" - though, and so no machine ciphers. The Silk in the title was for OTPs which could be hidden in clothing from Gestapo/SS searches. As I said, essential reading.
The tv show 60 Minutes spilled the beans about Enigma in 1975. http://www.cbsnews.com/videos/the-ultra-secret/
Not sure that was the one to spill the beans. I thought it was Winterbotham's 1974 book of the same name which first got the idea across to the public; though there was a French book in 1973 as well. Like Winterbotham's book, which the TV show seems to be based on, it's also a bit confused and/or inaccurate. Much of what they tell - the conversations between Hitler and his generals, "knowing Hitler's most secret thoughts", and Hitler's message re Anzio which Gen Clark read - came from the breaking of the Lorentz SZ40, not the Enigma. Colossus, not Bombe. And the Coventry story is fiction [1]. Churchill could not have been told the target from ULTRA decrypts. The ULTRA decrypts are now available in public records, and they do not mention Coventry. [1] My theory: Probably it began as a story made up to impress the need to keep the ULTRA secret - "hey if the man at the door with the revolver who just threatened to shoot you doesn't impress you, Churchill allowed [2] the bombing of Coventry in order to keep the secret". Later the story became an accusation, then a rumour, then a play - though by the time it became a play it was becoming obvious that ULTRA wasn't involved, and the motive for allowing the bombing changed to "Impressing the Americans" [3]. I can easily imagine someone telling Winterbotham the story (Winterbotham was the one who first told the Coventry story in public). I can also imagine Winterbotham repeating the story, in confidence, in order to impress the listener with the need to keep the secret (and with W himself) so often that he didn't know whether it was true or not (he didn't claim to be personally involved). Good story, and Churchill was probably capable of it - but it ain't true. [2] not that there was anything he could have done to stop the bombing, but for the sake of the narrative .. [3] requiring an even wilder suspension of belief, IME
What most people didn't realize was that the controversy was due to the fact that rotor-driven cipher machines had been continued to be sold in the post-WWII era, without their weakness being recognized. This allowed the CIA/GCHQ to continue to decrypt enciphered messages for decades afterwards.
Yes - but Leo Marks wasn't involved in that. He ~ stopped being a cryptographer when SOE was broken up at the end of the war. What he did was hand ciphers, for agents in occupied countries - they couldn't carry cipher machines. There is nothing else like Between Silk and Cyanide in the crypto literature. Crypto at the cutting edge, where a mistake is a painful death, and likely worse. More, it is about how a cryptographer and his work interact with the world. I would not like to have been Leo (I met him once), but hell if I don't respect him. There is a TV documentary about him, called "A Very British Psycho" - an apt title. -- Peter Fairbrother