From: smb@research.att.com
Date: Wed, 24 Nov 93 11:23:17 PST
To: henry strickland <strick@osc.versant.com>
Subject: Re: <8c> C-source for diffie-hellman?
Message-ID: <9311241920.AA14514@toad.com>
MIME-Version: 1.0
Content-Type: text/plain


	 DH itself is a trivial algorithm.  All you need is a decent
	 multiple precsion math package.    I think all it takes is
	 	-- random numbers
	 	-- primality test
	 	-- gcd
	 	-- raise-to-power-modulo-some-number

One more thing -- you want the base for the exponentiations to be
a generator of the subgroup.  Also, ideally the modulus should be
a prime of the form kp+1, where p is also a prime and k is a small
integer.  Your DH toolkit should include routines to generate the
base and modulus according to those criteria.

	 BTW, schneier is literally a FAQ for cypherpunks.  
	 Fantastic book.  Cough up the money for it...

Indeed, though I've only seen some drafts; my copy of the book itself
hasn't arrived yet.