From: "Brian A. LaMacchia" <bal@martigny.ai.mit.edu>
Date: Fri, 2 Feb 1996 10:30:40 +0800
To: jrochkin@cs.oberlin.edu
Subject: Re: RC2 Source Code - Legal Warning from RSADSI
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   Date: Thu, 1 Feb 1996 18:26:15 -0500
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   From: jrochkin@cs.oberlin.edu (Jonathan Rochkind)
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   Now, copyright might be another matter.    But you can't copyright an
   algorithm, only specific text in fixed form (ie, the source code).  So this
   would mean you couldn't use the particular code posted to sci.crypt, but
   wouldn't stop anyone from using the algorithm, if they wrote their own code
   (to be safe, without having seen the RSA-copyrighted code, only having the
   algorithm described to them by someone else).   

If the source code posted to sci.crypt was in fact a copy of an RSADSI
copyrighted soure code listing, then making copies of that listing is a
copyright violation.  However, copyright protection does not extend to
the underlying algorithm, so unless RSADSI has a patent on the algorithm
the idea is free, and can be reimplemented using a "clean room" or
"Chinese wall" approach.  If the posted source code was *not* a copy of
RSADSI source code but instead produced by disassembling object code
RSADSI's claims are tenuous at best.  RSADSI could conceivably claim
that the disassembled code is a derivative product of their copyrighted
object code, but I think they would have a hard time distinguishing
themselves from the facts in _Sega v. Accolade_.

I fail to see how the legality of "alleged-RC2" is any different than
that of the "alleged-RC4" code which was published last year.

						--bal