
Jane Fawcett, British Decoder Who Helped Doom the Bismarck, Dies at 95 - aaronbrethorst
http://www.nytimes.com/2016/05/30/obituaries/jane-fawcett-british-decoder-who-helped-doom-the-bismarck-dies-at-95.html
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meric
I had a long read on the Bismarck. At each engagement it was outnumbered. By
the time it sank it took 400 hits. And it sunk not because of those torpedoes
but because it's crew scuttled it. What a ship.

I feel sorrow for the loss of its and Hood's crew. Their crew's valiance and
courage and ingenuity used for their own deaths.

I am grateful for many who survived the war and lived the course of their
lives like the woman in this article. They built the world we live in today.

Edit: Apparently it is Memorial Day.

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samirillian
Sounds like that poor Luftwaffe general/concerned father "doomed" the Bismarck
more directly than someone who happened to transcribe a broken code. I wonder
what his obituary was like.

~~~
Arnt
Nah, he just made a mistake. People make the occasional mistake. Crypto has to
cover that, because it happens.

Another general during WW2 made the mistake of always including the same stock
paragraph in every transmission. That's bad. That's an O(n) mistake, not an
O(1) mistake.

And I suppose someone made an O(n) mistake if the British knew the names of a
significant number of Bismarck crew.

~~~
greenyoda
Another mistake, which had serious consequences to the Germans, was that a
German weather ship in the North Atlantic accidentally transmitted their
weather report using the Enigma key reserved for naval operations rather than
the key used for routine information, noticed the mistake, and then
immediately retransmitted the identical message using the routine key. Since
weather forecasts have predictable content and format (and are thus easier to
decrypt), this error allowed the Bletchley Park people to crack the operations
key much more quickly than they otherwise could have.

This episode is described in the book _Alan Turing: The Enigma_ [1], which was
the basis for "The Imitation Game" film. I highly recommend this book if
you're interested in Turing, cryptography, or the early days of computing.
While Turing is best known today for his work on the theoretical underpinnings
of computer science (due to the Turing Machine that bears his name), he also
worked on the design of one of the early general purpose computers (the
ACE[2]) after the war, on voice encryption hardware, and other interesting
stuff.

[1] [http://www.amazon.com/Alan-Turing-Enigma-Inspired-
Imitation/...](http://www.amazon.com/Alan-Turing-Enigma-Inspired-
Imitation/dp/069116472X)

[2]
[https://en.wikipedia.org/wiki/Automatic_Computing_Engine](https://en.wikipedia.org/wiki/Automatic_Computing_Engine)

~~~
michaelcampbell
> Since weather forecasts have predictable content and format (and are thus
> easier to decrypt),

You can't tell the format from the encrypted data though, right? Would you not
have to know apriori what this message was in order to make use of this
particular weakness?

~~~
Arnt
Metadata. In this case, the broadcaster's general location and the timing and
(I suppose) size of the messages. And perhaps known/guessed plaintext attacks:
if you too have a weather ship in the same area you can guess at the content.

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ENTP
I guess we'll never know the monumental contribution women made during WW2 at
Bletchley. Respect.

~~~
DanBC
Here's a BBC Radio Four programme about some women at Bletchley Park:
[http://www.bbc.co.uk/programmes/b062ktlf](http://www.bbc.co.uk/programmes/b062ktlf)

(I have no idea if they geo-block this, nor what the workarounds are.)

Here's a bit of text to accompany that programme:
[http://www.bbc.co.uk/programmes/articles/Q3lFn2vTv9JMgxX98bR...](http://www.bbc.co.uk/programmes/articles/Q3lFn2vTv9JMgxX98bRhL/the-
bletchley-girls-cracking-women)

~~~
hartpuff
AFAIK, BBC Radio is not blocked outside the UK, perhaps because a TV Licence
is not required for radio, and/or possibly because the BBC may control more
distribution rights for the content of its radio productions than its TV
output.

The link you posted is not blocked though, FWIW.

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gonzo
> The message, passed instantly along the chain of command, was instrumental
> in finding the Bismarck, which was first spotted from the air by a
> seaplane...

My wife's great uncle, Tuck Smith, is the person who spotted the Bismarck.
Since the US had not yet entered the war, his being in the air that day was,
literally, and act of war.

It was years before the truth came out.

He was patrolling in the Pacific on 7 Dec 1941. Looking for the Japanese
fleet.

[https://en.wikipedia.org/wiki/Leonard_B._Smith](https://en.wikipedia.org/wiki/Leonard_B._Smith)

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dankohn1
Wonderful story.

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xyzzy4
No black bar?

