Recommended Movie: "Sebastian" 1968.
peter at m-o-o-t.org
Tue Aug 18 23:52:56 PDT 2015
On 18/08/15 19:23, jim bell wrote:
> *From:* Peter Fairbrother <peter at 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 Out of date even when it was made, I think it really represents the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
> >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.
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,
And the Coventry story is fiction . 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.
 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
 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" .
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.
 not that there was anything he could have done to stop the bombing,
but for the sake of the narrative ..
 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
There is a TV documentary about him, called "A Very British Psycho" - an
-- Peter Fairbrother
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