On 18/08/15 19:23, jim bell wrote:
*From:* Peter Fairbrother <[email protected]>
*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 Out of date even when it was made, I think it really represents the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
