[Cryptography] List of Proven Secure Ciphers / Hashes

[R. Hirschfeld]

> Date: Tue, 09 Sep 2014 16:49:20 +1200
> From: Peter Gutmann <pgut001 at cs.auckland.ac.nz>
> 
> John Denker <jsd at av8n.com> writes:
> 
> >I've seen any number of hand-wavy arguments that "P = NP" would spell the end
> >of public-key crypto, or worse.  However, all of these arguments seem
> >seriously flawed to me.
> 
> Same here, but the reasoning is much simpler.  Let's say aliens land tomorrow
> and announce "There was another gunman on the grassy knoll, we were
> responsible for the Mary Celeste (sorry about that), oh, and also P = NP.  See
> you in another billion years".
> 
> How does this affect practical usage of PKC in any conceivable way?  Every 
> textbook on crypto *theory* will need to be updated (not to mention a bunch of 
> other books), but what actual, *real-world* effect does it have on the 
> security of RSA, DH, Elgamal, and others?

Showing P = NP (unlikely!) might indeed have little immediate impact
on crypto practice.  It depends on the nature of the proof.  If it's
by giving a practical efficient poly-time algorithm for an NP-complete
problem, that's a game changer.  If on the other hand you only know
that there exist poly-time algorithms for factoring and discrete log
but can't find them (or if you can find them but the degree and/or
coefficients are enormous), that's another matter.

Ray