Re: Using SSL private key for cookie's HMAC

[Peter Conrad <conrad () tivano de>]

Hi,

On Mon, Sep 06, 2004 at 05:25:35PM -1000, Jason Coombs PivX Solutions wrote:
> Peter Conrad wrote:
> > erm... factoring is better than brute force, isn't it?
>
> Which is more difficult, to factor n quickly when you find out what it 
> is, or to locate n in your precomputed product-of-all-primes dictionary?

the lookup, of course. However, that doesn't mean that any sensible attacker
would use that approach, because

 - it's completely impractical (even more impractical than factorization,
   for reasonably large n)
 - the precomputation cost only amortizes if you want to break *many* RSA
   keys, which was not the original question in this thread.

> If you're going to break codes, you may as well break them all at once 
> to conserve energy, and then publish the lookup table for all to see.

Except that nobody could actually see it, because the required disk array
would collapse into a massive black hole. ;-)

Bye,
        Peter
-- 
Peter Conrad                        Tel: +49 6102 / 80 99 072
[ t]ivano Software GmbH             Fax: +49 6102 / 80 99 071
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