Subject: Re: 1024 bit key considered insecure (sshd)
To: Karsten W. Rohrbach <karsten@rohrbach.de>
From: David Schultz <dschultz@uclink.Berkeley.EDU>
List: tech-security
Date: 08/29/2002 02:35:08
Thus spake Karsten W. Rohrbach <karsten@rohrbach.de>:
> Perry E. Metzger(perry@piermont.com)@2002.08.29 02:08:27 +0000:
> > I do. If someone with millions of dollars to spend on custom designed
> > hardware wants to break into your computer, I assure you that
> > increasing the size of your ssh keys will not stop them. Nor, for that
> 
> 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.

I believe his point is that increasing the costs of the hardware
required to break your key from 1 million dollars to 1 trillion
dollars is not worthwhile because the process is effectively
infeasible either way.  Though it's true that the performance
penalty of larger keys isn't too bad, you're going to break lots
of older software for essentially no good reason.