1 2From: James A. Woods <jaw@eos.arc.nasa.gov> 3 4>From vn Fri Dec 2 18:05:27 1988 5Subject: Re: Looking for C source for RSA 6Newsgroups: sci.crypt 7 8# Illegitimi noncarborundum 9 10Patents are a tar pit. 11 12A good case can be made that most are just a license to sue, and nothing 13is illegal until a patent is upheld in court. 14 15For example, if you receive netnews by means other than 'nntp', 16these very words are being modulated by 'compress', 17a variation on the patented Lempel-Ziv-Welch algorithm. 18 19Original Ziv-Lempel is patent number 4,464,650, and the more powerful 20LZW method is #4,558,302. Yet despite any similarities between 'compress' 21and LZW (the public-domain 'compress' code was designed and given to the 22world before the ink on the Welch patent was dry), no attorneys from Sperry 23(the assignee) have asked you to unplug your Usenet connection. 24 25Why? I can't speak for them, but it is possible the claims are too broad, 26or, just as bad, not broad enough. ('compress' does things not mentioned 27in the Welch patent.) Maybe they realize that they can commercialize 28LZW better by selling hardware implementations rather than by licensing 29software. Again, the LZW software delineated in the patent is *not* 30the same as that of 'compress'. 31 32At any rate, court-tested software patents are a different animal; 33corporate patents in a portfolio are usually traded like baseball cards 34to shut out small fry rather than actually be defended before 35non-technical juries. Perhaps RSA will undergo this test successfully, 36although the grant to "exclude others from making, using, or selling" 37the invention would then only apply to the U.S. (witness the 38Genentech patent of the TPA molecule in the U.S. but struck down 39in Great Britain as too broad.) 40 41The concept is still exotic for those who learned in school the rule of thumb 42that one may patent "apparatus" but not an "idea". 43Apparently this all changed in Diamond v. Diehr (1981) when the U. S. Supreme 44Court reversed itself. 45 46Scholars should consult the excellent article in the Washington and Lee 47Law Review (fall 1984, vol. 41, no. 4) by Anthony and Colwell for a 48comprehensive survey of an area which will remain murky for some time. 49 50Until the dust clears, how you approach ideas which are patented depends 51on how paranoid you are of a legal onslaught. Arbitrary? Yes. But 52the patent bar of the CCPA (Court of Customs and Patent Appeals) 53thanks you for any uncertainty as they, at least, stand to gain 54from any trouble. 55 56=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= 57From: James A. Woods <jaw@eos.arc.nasa.gov> 58Subject: Re: Looking for C source for RSA (actually 'compress' patents) 59 60 In article <2042@eos.UUCP> you write: 61 >The concept is still exotic for those who learned in school the rule of thumb 62 >that one may patent "apparatus" but not an "idea". 63 64A rule of thumb that has never been completely valid, as any chemical 65engineer can tell you. (Chemical processes were among the earliest patents, 66as I recall.) 67 68 ah yes -- i date myself when relaying out-of-date advice from elderly 69 attorneys who don't even specialize in patents. one other interesting 70 class of patents include the output of optical lens design programs, 71 which yield formulae which can then fairly directly can be molded 72 into glass. although there are restrictions on patenting equations, 73 the "embedded systems" seem to fly past the legal gauntlets. 74 75 anyway, I'm still learning about intellectual property law after 76 several conversations from a Unisys (nee sperry) lawyer re 'compress'. 77 78 it's more complicated than this, but they're letting (oral 79 communication only) software versions of 'compress' slide 80 as far as licensing fees go. this includes 'arc', 'stuffit', 81 and other commercial wrappers for 'compress'. yet they are 82 signing up licensees for hardware chips. Hewlett-Packard 83 supposedly has an active vlsi project, and Unisys has 84 board-level LZW-based tape controllers. (to build LZW into 85 a disk controller would be strange, as you'd have to build 86 in a filesystem too!) 87 88 it's byzantine 89 that Unisys is in a tiff with HP regarding the patents, 90 after discovering some sort of "compress" button on some 91 HP terminal product. why? well, professor Abraham Lempel jumped 92 from being department chairman of computer science at technion in 93 Israel to sperry (where he got the first patent), but then to work 94 at Hewlett-Packard on sabbatical. the second Welch patent 95 is only weakly derivative of the first, so they want chip 96 licenses and HP relented. however, everyone agrees something 97 like the current Unix implementation is the way to go with 98 software, so HP (and UCB) long ago asked spencer Thomas and i to sign 99 off on copyright permission (although they didn't need to, it being pd). 100 Lempel, HP, and Unisys grumbles they can't make money off the 101 software since a good free implementation (not the best -- 102 i have more ideas!) escaped via Usenet. (Lempel's own pascal 103 code was apparently horribly slow.) 104 i don't follow the IBM 'arc' legal bickering; my impression 105 is that the pc folks are making money off the archiver/wrapper 106 look/feel of the thing [if ms-dos can be said to have a look and feel]. 107 108 now where is telebit with the compress firmware? in a limbo 109 netherworld, probably, with sperry still welcoming outfits 110 to sign patent licenses, a common tactic to bring other small fry 111 into the fold. the guy who crammed 12-bit compress into the modem 112 there left. also what is transpiring with 'compress' and sys 5 rel 4? 113 beats me, but if sperry got a hold of them on these issues, 114 at&t would likely re-implement another algorithm if they 115 thought 'compress' infringes. needful to say, i don't think 116 it does after the above mentioned legal conversation. 117 my own beliefs on whether algorithms should be patentable at all 118 change with the weather. if the courts finally nail down 119 patent protection for algorithms, academic publication in 120 textbooks will be somewhat at odds with the engineering world, 121 where the textbook codes will simply be a big tease to get 122 money into the patent holder coffers... 123 124 oh, if you implement LZW from the patent, you won't get 125 good rates because it doesn't mention adaptive table reset, 126 lack thereof being *the* serious deficiency of Thomas' first version. 127 128 now i know that patent law generally protects against independent 129 re-invention (like the 'xor' hash function pleasantly mentioned 130 in the patent [but not the paper]). 131 but the upshot is that if anyone ever wanted to sue us, 132 we're partially covered with 133 independently-developed twists, plus the fact that some of us work 134 in a bureaucratic morass (as contractor to a public agency in my case). 135 136 quite a mess, huh? I've wanted to tell someone this stuff 137 for a long time, for posterity if nothing else. 138 139james 140 141