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+ $FreeBSD: src/usr.bin/compress/doc/NOTES,v 1.3 2011/10/16 14:30:28 eadler Exp $
+
+From: James A. Woods <jaw@eos.arc.nasa.gov>
+
+>From vn Fri Dec 2 18:05:27 1988
+Subject: Re: Looking for C source for RSA
+Newsgroups: sci.crypt
+
+# Illegitimi noncarborundum
+
+Patents are a tar pit.
+
+A good case can be made that most are just a license to sue, and nothing
+is illegal until a patent is upheld in court.
+
+For example, if you receive netnews by means other than 'nntp',
+these very words are being modulated by 'compress',
+a variation on the patented Lempel-Ziv-Welch algorithm.
+
+Original Ziv-Lempel is patent number 4,464,650, and the more powerful
+LZW method is #4,558,302. Yet despite any similarities between 'compress'
+and LZW (the public-domain 'compress' code was designed and given to the
+world before the ink on the Welch patent was dry), no attorneys from Sperry
+(the assignee) have asked you to unplug your Usenet connection.
+
+Why? I can't speak for them, but it is possible the claims are too broad,
+or, just as bad, not broad enough. ('compress' does things not mentioned
+in the Welch patent.) Maybe they realize that they can commercialize
+LZW better by selling hardware implementations rather than by licensing
+software. Again, the LZW software delineated in the patent is *not*
+the same as that of 'compress'.
+
+At any rate, court-tested software patents are a different animal;
+corporate patents in a portfolio are usually traded like baseball cards
+to shut out small fry rather than actually be defended before
+non-technical juries. Perhaps RSA will undergo this test successfully,
+although the grant to "exclude others from making, using, or selling"
+the invention would then only apply to the U.S. (witness the
+Genentech patent of the TPA molecule in the U.S. but struck down
+in Great Britain as too broad.)
+
+The concept is still exotic for those who learned in school the rule of thumb
+that one may patent "apparatus" but not an "idea".
+Apparently this all changed in Diamond v. Diehr (1981) when the U. S. Supreme
+Court reversed itself.
+
+Scholars should consult the excellent article in the Washington and Lee
+Law Review (fall 1984, vol. 41, no. 4) by Anthony and Colwell for a
+comprehensive survey of an area which will remain murky for some time.
+
+Until the dust clears, how you approach ideas which are patented depends
+on how paranoid you are of a legal onslaught. Arbitrary? Yes. But
+the patent bar the CCPA (Court of Customs and Patent Appeals)
+thanks you for any uncertainty as they, at least, stand to gain
+from any trouble.
+
+=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
+From: James A. Woods <jaw@eos.arc.nasa.gov>
+Subject: Re: Looking for C source for RSA (actually 'compress' patents)
+
+ In article <2042@eos.UUCP> you write:
+ >The concept is still exotic for those who learned in school the rule of thumb
+ >that one may patent "apparatus" but not an "idea".
+
+A rule of thumb that has never been completely valid, as any chemical
+engineer can tell you. (Chemical processes were among the earliest patents,
+as I recall.)
+
+ ah yes -- i date myself when relaying out-of-date advice from elderly
+ attorneys who don't even specialize in patents. one other interesting
+ class of patents include the output of optical lens design programs,
+ which yield formulae which can then fairly directly can be molded
+ into glass. although there are restrictions on patenting equations,
+ the "embedded systems" seem to fly past the legal gauntlets.
+
+ anyway, I'm still learning about intellectual property law after
+ several conversations from a Unisys (nee sperry) lawyer re 'compress'.
+
+ it's more complicated than this, but they're letting (oral
+ communication only) software versions of 'compress' slide
+ as far as licensing fees go. this includes 'arc', 'stuffit',
+ and other commercial wrappers for 'compress'. yet they are
+ signing up licensees for hardware chips. Hewlett-Packard
+ supposedly has an active vlsi project, and Unisys has
+ board-level LZW-based tape controllers. (to build LZW into
+ a disk controller would be strange, as you'd have to build
+ in a filesystem too!)
+
+ it's byzantine
+ that Unisys is in a tiff with HP regarding the patents,
+ after discovering some sort of "compress" button on some
+ HP terminal product. why? well, professor Abraham Lempel jumped
+ from being department chairman of computer science at technion in
+ Israel to sperry (where he got the first patent), but then to work
+ at Hewlett-Packard on sabbatical. the second Welch patent
+ is only weakly derivative of the first, so they want chip
+ licenses and HP relented. however, everyone agrees something
+ like the current Unix implementation is the way to go with
+ software, so HP (and UCB) long ago asked spencer Thomas and i to sign
+ off on copyright permission (although they didn't need to, it being pd).
+ Lempel, HP, and Unisys grumbles they can't make money off the
+ software since a good free implementation (not the best --
+ i have more ideas!) escaped via Usenet. (Lempel's own pascal
+ code was apparently horribly slow.)
+ i don't follow the IBM 'arc' legal bickering; my impression
+ is that the pc folks are making money off the archiver/wrapper
+ look/feel of the thing [if ms-dos can be said to have a look and feel].
+
+ now where is telebit with the compress firmware? in a limbo
+ netherworld, probably, with sperry still welcoming outfits
+ to sign patent licenses, a common tactic to bring other small fry
+ into the fold. the guy who crammed 12-bit compress into the modem
+ there left. also what is transpiring with 'compress' and sys 5 rel 4?
+ beats me, but if sperry got a hold of them on these issues,
+ at&t would likely re-implement another algorithm if they
+ thought 'compress' infringes. needful to say, i don't think
+ it does after the above mentioned legal conversation.
+ my own beliefs on whether algorithms should be patentable at all
+ change with the weather. if the courts finally nail down
+ patent protection for algorithms, academic publication in
+ textbooks will be somewhat at odds with the engineering world,
+ where the textbook codes will simply be a big tease to get
+ money into the patent holder coffers...
+
+ oh, if you implement LZW from the patent, you won't get
+ good rates because it doesn't mention adaptive table reset,
+ lack thereof being *the* serious deficiency of Thomas' first version.
+
+ now i know that patent law generally protects against independent
+ re-invention (like the 'xor' hash function pleasantly mentioned
+ in the patent [but not the paper]).
+ but the upshot is that if anyone ever wanted to sue us,
+ we're partially covered with
+ independently-developed twists, plus the fact that some of us work
+ in a bureaucratic morass (as contractor to a public agency in my case).
+
+ quite a mess, huh? I've wanted to tell someone this stuff
+ for a long time, for posterity if nothing else.
+
+james
+