From: "James A. Tunnicliffe" <Tunny@inference.com>
Date: Fri, 1 Nov 1996 07:41:03 -0800 (PST)
To: "'Hal Finney'" <hal@rain.org>
Subject: RE: Discrete logs 1
Message-ID: <c=US%a=_%p=Inference%l=LANDRU-961101154011Z-9245@landru.novato.inference2.com>
MIME-Version: 1.0
Content-Type: text/plain


[...Interesting discussion of logarithms deleted...]
The discrete logs used in crypto have very different mathematical
properties than regular logarithms, but I thought this bit of history
would spark some memories in old-timers and give a new perspective for
younger people.

Hal

As an apparent old-timer (calculators weren't common until my college days, 
which puts me a couple of years before you, I guess) I enjoyed the 
retrospective, and I even recall the joke that goes with the punchline you 
quoted.  It's amazing to realize that only a few years ago, we were 
calculating orbital trajectories using logarithms by lining up marks on 
little sticks of wood!  I have to admit, though, that I was a little 
disappointed after your opening paragraph, because what I was really hoping 
to hear was a straightforward explanation of discrete logs, which, as you 
say, are entirely different.  A simple layman's explanation of what they 
are and how they're useful in crypto would be nice, especially since PGP is 
moving toward this (just when I was beginning to get a handle on RSA!).

Now that I have an interest in all this, I wish Rich Schroeppel still 
worked here (he worked at Inference when I started here in '88, and has 
since done a lot of pioneering work on discrete logs).  Me, I'm still 
trying to figure out what sort of seed is best to plant in a Galois 
field...

Tunny
======================================================================
 James A. Tunnicliffe   | WWWeb: http://www.inference.com/~tunny
 Inference Corporation  | PGP Fingerprint:   CA 23 E2 F3 AC 2D 0C 77
 tunny@Inference.com    |                    36 07 D9 33 3D 32 53 9C
======================================================================



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