Re: 1024 bit key considered insecure (sshd)

From: 'Karsten W. Rohrbach' (
Date: 08/29/02

Date: Thu, 29 Aug 2002 11:20:48 +0200
From: "'Karsten W. Rohrbach'" <>
To: "George F. Costanzo" <>

George F. Costanzo( 18:57:18 +0000:
> > you missed the concept behind crypto in general, i think. it's not
> > about stopping someone from accessing private resources, but rather
> > making that approach to make access to these resources /very/
> > unattractive, by increasing the amount of time (and thus $$$) an
> > attacker has to effort to get access.
> Yes, to increase the time/cost in breaking the key to outweigh the cost
> of the information that will be gained.

one might remark, as a sidenote, that crypto is just one of the building
blocks to system security. what if the crypto in use is really tough,
but the software framework employing it is full of bugs, or misdesigned
is one question. the other question (as raised in the verious
discussions around pgp/gpg in the last years) is, that - if somebody
wants to access encrypted resources - it might be a better approach for
him to get access by brute (physical) force.

> If the information you're trying to protect is worth that much to you,
> you'll take the extra steps needed to increase key length. Otherwise,
> the default will be fine for most users.

seconded, whereas the security measures need to go a little further if
the resources protected really are /that/ valuable ;-)

> Schneier is blowing this out of proportion a little, quoting Lucky's
> decision throughout. Lucky is overly paranoid and Schneier knows it. He
> also uses the article to bring up (read: plug) his pretty accurate key
> length estimates. Schneier's motives have been slightly dubious for
> awhile.



> A Puritan is someone who is deathly afraid that someone, somewhere, is
> having fun.
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