From: Paul Bradley <paul@fatmans.demon.co.uk>
Date: Tue, 10 Jun 1997 08:09:40 +0800
To: "Mark M." <markm@voicenet.com>
Subject: Re: PGP Key generation
In-Reply-To: <Pine.LNX.3.96.970608211659.3887A-100000@purple.voicenet.com>
Message-ID: <Pine.LNX.3.91.970609194807.2934A-100000@fatmans.demon.co.uk>
MIME-Version: 1.0
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> There are a few shortcuts you could take.  For instance, instead of finding
> two random, prime numbers for every key, just keep one prime constant and
> generate another random prime for each key.  This has the disadvantage
> that any one key factored would allow the other keys to be factored
> trivially.  I know there are other ways, but I'm not very good with number
> theory.

This would actually not save as much time as it trivially appears to, the 
main time eater in pgp key generation is a. getting random seeds and 
mixing to distill randomness, and b. executing the extended euclidean 
algorithm to find modular inverses. 

Does anyone know any other speedups? - I`m sure I could think of a few 
but I`m really not in the mood ;-)...

        Datacomms Technologies data security
       Paul Bradley, Paul@fatmans.demon.co.uk
  Paul@crypto.uk.eu.org, Paul@cryptography.uk.eu.org    
       Http://www.cryptography.home.ml.org/
      Email for PGP public key, ID: FC76DA85
     "Don`t forget to mount a scratch monkey"