From: John McCormac (jmcc at domain hackwatch.com)
Date: Mon 17 Sep 2001 - 07:10:02 IST
Ronan Cunniffe wrote:
>
> > The British and the French thought the same thing about enigma, til the
> > Poles found two massive weaknesses in it...and didn't tell the people
> > using the tech (the germans) that it was insecure.
>
> It *wasn't* insecure. They were using it incorrectly (according to
> Singh's book). Things like encoding the message key twice at the
I would not tend to regard Singh as an authority on crypto - there are a
lot of better books about Enigma codebreaking around. The Enigma that
was cracked by the Poles was an early version (three rotor if I
remember correctly). Enigma had a flaw that no letter in plaintext
mapped onto itself in ciphertext. (The Poles also had a model of Enigma
to work from I think.) Another was that the patch panel was wired
sequentially as a German typewriter - something that drove the British
cryppies crazy until one of the Poles explained it. There was also the
case of the spy Hans Thilo-Schmidt who was feeding a lot of good
technical information on it to the French.
> beginning of the message, allowing the operator to choose the message key,
> occasionally sending a message in an older or weaker code because the
> recipient didn't have the latest codebooks, 'cribs' (guessed plaintext,
> e.g. "Heil Hitler"[1]), etc.
There is a world of difference between theoretically cracking a crypto
system and doing what was done to Enigma during WWII and before. There
was no general solution for Enigma and each break largely was due to
concentrating on deriving particular keys. Some keys remained unbroken.
What Singh was referring to was the reuse of old keys, propagation of
errors, the use of weaker keys, and the parallel encryption of the same
message in a weaker system (which led the to sinking of the Bismark).
Such things generally will occur in wartime. If you have every had to
break crypto systems, then you will appreciate the achievements of the
people who broke Enigma and Purple.
> There's no guarantees in crypto, but as the public crypto effort gets
> close to the military crypto in scale, the chance of the NSA or GCHQ or
> whoever being *way* out in front drops.
There is one reasonable guarantee - any system can be broken given the
right resources.
> [1] That's *me* in Echelon's black book anyway....
Nah you have to do utter some cosmic magic words to get in there. :-)
Regards...jmcc
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