From: thad@hammerhead.com (Thaddeus J. Beier)
Date: Mon, 5 Feb 1996 11:30:01 +0800
To: cypherpunks@toad.com
Subject: RC2 protected by copyright?
Message-ID: <199602050211.SAA18120@hammerhead.com>
MIME-Version: 1.0
Content-Type: text/plain



RSA issued a statement claiming that anyone using RC2(TM) would be in
violation of various laws.  I think that they might have a point.

You can't protect an idea with trade secrets, certainly not a software
idea, if you intend to sell the software.  It is easy to reverse
engineer it; this is probably what happened with RC2.

But, what about copyright?   Now, copyrights cannot protect ideas, only
the expression of those ideas.  An algorithm is clearly an idea, you could
write a program that would implement it in a completely different way,
not just by translating it (translations are still protected by
copyright). 

RC2, though, as 256 bytes of seemingly random data at the head of it,
in a permutation table.  This is clearly not any idea, but a bit of
text.  This text would have to be copied to any interoperable RC2.
(You could surely use some different permutation, and probably most
of the 256! permutations would be equally secure, but would not
interoperate with RC2).  I would expect that this copying of text be
held to be a violation of copyright.

Some might argue that 256 bytes is so small that perhaps it couldn't
be copyrighted.  Copyright clearly can't protect use of a word, or
a short phrase (1000 points of light, say).  If the permutation table
at the beginning was 65536 16-bit numbers, instead of 256 bytes, then
the copyright protection be that much stronger and less open to debate.

Do any of the real lawyers on the list want to take a crack at this?
Has anybody heard any noise from RSA describing exactly how they
intend to go after people?

thad
-- Thaddeus Beier                     thad@hammerhead.com
   Technology Development                   408) 286-3376
   Hammerhead Productions        http://www.got.net/~thad