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