From: Ulf_Moeller@public.uni-hamburg.de (Ulf Moeller)
Date: Mon, 15 Jan 96 13:53:41 PST
To: cypherpunks@toad.com
Subject: Re: Bignum support added to XLISP 2.1h
Message-ID: <m0tbwbX-00007PC@ulf.mali.sub.org>
MIME-Version: 1.0
Content-Type: text/plain


Rick Busdiecker <rfb@lehman.com> writes:
    
>    it is quite easy to write cryptographic algorithms that use very large
>    numbers without adding extra support. The downside is that the language is

>Yup.  I've written some code that generates large numbers, tests for
>primality and does RSA.  The basic RSA enclode is just (mod-expt m e
>n) and decrypt is (mod-expt c d n) where mod-expt is just an optimized
>version of (mod (expt x p) n), ala Schneier, page 200 (1st edition).

Actually, there is a modexpt (and a Fermat test) implementation
in chapter 1 of Abelson/Sussman, with a footnote mentioning
cryptography.

I do wonder if they have an export license... :)