xref: /freebsd/usr.bin/compress/doc/NOTES (revision 05248206f720394d95c2a7475429311df670a2e9)
1 6dc4364cSPhilippe Charnier
2 9b50d902SRodney W. GrimesFrom: James A. Woods <jaw@eos.arc.nasa.gov>
3 9b50d902SRodney W. Grimes
4 9b50d902SRodney W. Grimes>From vn Fri Dec  2 18:05:27 1988
5 9b50d902SRodney W. GrimesSubject: Re: Looking for C source for RSA
6 9b50d902SRodney W. GrimesNewsgroups: sci.crypt
7 9b50d902SRodney W. Grimes
8 9b50d902SRodney W. Grimes# Illegitimi noncarborundum
9 9b50d902SRodney W. Grimes
10 9b50d902SRodney W. GrimesPatents are a tar pit.
11 9b50d902SRodney W. Grimes
12 9b50d902SRodney W. GrimesA good case can be made that most are just a license to sue, and nothing
13 9b50d902SRodney W. Grimesis illegal until a patent is upheld in court.
14 9b50d902SRodney W. Grimes
15 9b50d902SRodney W. GrimesFor example, if you receive netnews by means other than 'nntp',
16 9b50d902SRodney W. Grimesthese very words are being modulated by 'compress',
17 9b50d902SRodney W. Grimesa variation on the patented Lempel-Ziv-Welch algorithm.
18 9b50d902SRodney W. Grimes
19 9b50d902SRodney W. GrimesOriginal Ziv-Lempel is patent number 4,464,650, and the more powerful
20 9b50d902SRodney W. GrimesLZW method is #4,558,302.  Yet despite any similarities between 'compress'
21 9b50d902SRodney W. Grimesand LZW (the public-domain 'compress' code was designed and given to the
22 9b50d902SRodney W. Grimesworld before the ink on the Welch patent was dry), no attorneys from Sperry
23 9b50d902SRodney W. Grimes(the assignee) have asked you to unplug your Usenet connection.
24 9b50d902SRodney W. Grimes
25 9b50d902SRodney W. GrimesWhy?  I can't speak for them, but it is possible the claims are too broad,
26 9b50d902SRodney W. Grimesor, just as bad, not broad enough.  ('compress' does things not mentioned
27 9b50d902SRodney W. Grimesin the Welch patent.)  Maybe they realize that they can commercialize
28 9b50d902SRodney W. GrimesLZW better by selling hardware implementations rather than by licensing
29 9b50d902SRodney W. Grimessoftware.  Again, the LZW software delineated in the patent is *not*
30 9b50d902SRodney W. Grimesthe same as that of 'compress'.
31 9b50d902SRodney W. Grimes
32 9b50d902SRodney W. GrimesAt any rate, court-tested software patents are a different animal;
33 9b50d902SRodney W. Grimescorporate patents in a portfolio are usually traded like baseball cards
34 9b50d902SRodney W. Grimesto shut out small fry rather than actually be defended before
35 9b50d902SRodney W. Grimesnon-technical juries.  Perhaps RSA will undergo this test successfully,
36 9b50d902SRodney W. Grimesalthough the grant to "exclude others from making, using, or selling"
37 9b50d902SRodney W. Grimesthe invention would then only apply to the U.S. (witness the
38 9b50d902SRodney W. GrimesGenentech patent of the TPA molecule in the U.S. but struck down
39 9b50d902SRodney W. Grimesin Great Britain as too broad.)
40 9b50d902SRodney W. Grimes
41 9b50d902SRodney W. GrimesThe concept is still exotic for those who learned in school the rule of thumb
42 9b50d902SRodney W. Grimesthat one may patent "apparatus" but not an "idea".
43 9b50d902SRodney W. GrimesApparently this all changed in Diamond v. Diehr (1981) when the U. S. Supreme
44 9b50d902SRodney W. GrimesCourt reversed itself.
45 9b50d902SRodney W. Grimes
46 9b50d902SRodney W. GrimesScholars should consult the excellent article in the Washington and Lee
47 9b50d902SRodney W. GrimesLaw Review (fall 1984, vol. 41, no. 4) by Anthony and Colwell for a
48 9b50d902SRodney W. Grimescomprehensive survey of an area which will remain murky for some time.
49 9b50d902SRodney W. Grimes
50 9b50d902SRodney W. GrimesUntil the dust clears, how you approach ideas which are patented depends
51 9b50d902SRodney W. Grimeson how paranoid you are of a legal onslaught.  Arbitrary?  Yes.  But
52 *14517324SEitan Adlerthe patent bar of the CCPA (Court of Customs and Patent Appeals)
53 9b50d902SRodney W. Grimesthanks you for any uncertainty as they, at least, stand to gain
54 9b50d902SRodney W. Grimesfrom any trouble.
55 9b50d902SRodney W. Grimes
56 9b50d902SRodney W. Grimes=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
57 9b50d902SRodney W. GrimesFrom: James A. Woods <jaw@eos.arc.nasa.gov>
58 9b50d902SRodney W. GrimesSubject: Re: Looking for C source for RSA (actually 'compress' patents)
59 9b50d902SRodney W. Grimes
60 9b50d902SRodney W. Grimes	In article <2042@eos.UUCP> you write:
61 9b50d902SRodney W. Grimes	>The concept is still exotic for those who learned in school the rule of thumb
62 9b50d902SRodney W. Grimes	>that one may patent "apparatus" but not an "idea".
63 9b50d902SRodney W. Grimes
64 9b50d902SRodney W. GrimesA rule of thumb that has never been completely valid, as any chemical
65 9b50d902SRodney W. Grimesengineer can tell you.  (Chemical processes were among the earliest patents,
66 9b50d902SRodney W. Grimesas I recall.)
67 9b50d902SRodney W. Grimes
68 9b50d902SRodney W. Grimes	ah yes -- i date myself when relaying out-of-date advice from elderly
69 9b50d902SRodney W. Grimes	attorneys who don't even specialize in patents.  one other interesting
70 9b50d902SRodney W. Grimes	class of patents include the output of optical lens design programs,
71 9b50d902SRodney W. Grimes	which yield formulae which can then fairly directly can be molded
72 9b50d902SRodney W. Grimes	into glass.  although there are restrictions on patenting equations,
73 9b50d902SRodney W. Grimes	the "embedded systems" seem to fly past the legal gauntlets.
74 9b50d902SRodney W. Grimes
75 6dc4364cSPhilippe Charnier	anyway, I'm still learning about intellectual property law after
76 6dc4364cSPhilippe Charnier	several conversations from a Unisys (nee sperry) lawyer re 'compress'.
77 9b50d902SRodney W. Grimes
78 9b50d902SRodney W. Grimes	it's more complicated than this, but they're letting (oral
79 9b50d902SRodney W. Grimes	communication only) software versions of 'compress' slide
80 9b50d902SRodney W. Grimes	as far as licensing fees go.  this includes 'arc', 'stuffit',
81 9b50d902SRodney W. Grimes	and other commercial wrappers for 'compress'.  yet they are
82 6dc4364cSPhilippe Charnier	signing up licensees for hardware chips.  Hewlett-Packard
83 6dc4364cSPhilippe Charnier	supposedly has an active vlsi project, and Unisys has
84 6dc4364cSPhilippe Charnier	board-level LZW-based tape controllers.  (to build LZW into
85 9b50d902SRodney W. Grimes	a disk controller would be strange, as you'd have to build
86 9b50d902SRodney W. Grimes	in a filesystem too!)
87 9b50d902SRodney W. Grimes
88 9b50d902SRodney W. Grimes 	it's byzantine
89 6dc4364cSPhilippe Charnier	that Unisys is in a tiff with HP regarding the patents,
90 9b50d902SRodney W. Grimes	after discovering some sort of "compress" button on some
91 6dc4364cSPhilippe Charnier	HP terminal product.  why?  well, professor Abraham Lempel jumped
92 9b50d902SRodney W. Grimes	from being department chairman of computer science at technion in
93 6dc4364cSPhilippe Charnier	Israel to sperry (where he got the first patent), but then to work
94 6dc4364cSPhilippe Charnier	at Hewlett-Packard on sabbatical.  the second Welch patent
95 9b50d902SRodney W. Grimes	is only weakly derivative of the first, so they want chip
96 6dc4364cSPhilippe Charnier	licenses and HP relented.  however, everyone agrees something
97 6dc4364cSPhilippe Charnier	like the current Unix implementation is the way to go with
98 6dc4364cSPhilippe Charnier	software, so HP (and UCB) long ago asked spencer Thomas and i to sign
99 9b50d902SRodney W. Grimes	off on copyright permission (although they didn't need to, it being pd).
100 6dc4364cSPhilippe Charnier	Lempel, HP, and Unisys grumbles they can't make money off the
101 9b50d902SRodney W. Grimes	software since a good free implementation (not the best --
102 6dc4364cSPhilippe Charnier	i have more ideas!) escaped via Usenet.  (Lempel's own pascal
103 9b50d902SRodney W. Grimes	code was apparently horribly slow.)
104 6dc4364cSPhilippe Charnier	i don't follow the IBM 'arc' legal bickering; my impression
105 9b50d902SRodney W. Grimes	is that the pc folks are making money off the archiver/wrapper
106 9b50d902SRodney W. Grimes	look/feel of the thing [if ms-dos can be said to have a look and feel].
107 9b50d902SRodney W. Grimes
108 9b50d902SRodney W. Grimes	now where is telebit with the compress firmware?  in a limbo
109 9b50d902SRodney W. Grimes	netherworld, probably, with sperry still welcoming outfits
110 9b50d902SRodney W. Grimes	to sign patent licenses, a common tactic to bring other small fry
111 6dc4364cSPhilippe Charnier	into the fold.  the guy who crammed 12-bit compress into the modem
112 9b50d902SRodney W. Grimes	there left.  also what is transpiring with 'compress' and sys 5 rel 4?
113 9b50d902SRodney W. Grimes	beats me, but if sperry got a hold of them on these issues,
114 9b50d902SRodney W. Grimes	at&t would likely re-implement another algorithm if they
115 9b50d902SRodney W. Grimes	thought 'compress' infringes.  needful to say, i don't think
116 9b50d902SRodney W. Grimes	it does after the above mentioned legal conversation.
117 9b50d902SRodney W. Grimes	my own beliefs on whether algorithms should be patentable at all
118 9b50d902SRodney W. Grimes	change with the weather.  if the courts finally nail down
119 9b50d902SRodney W. Grimes	patent protection for algorithms, academic publication in
120 9b50d902SRodney W. Grimes	textbooks will be somewhat at odds with the engineering world,
121 9b50d902SRodney W. Grimes	where the textbook codes will simply be a big tease to get
122 9b50d902SRodney W. Grimes	money into the patent holder coffers...
123 9b50d902SRodney W. Grimes
124 6dc4364cSPhilippe Charnier	oh, if you implement LZW from the patent, you won't get
125 9b50d902SRodney W. Grimes	good rates because it doesn't mention adaptive table reset,
126 6dc4364cSPhilippe Charnier	lack thereof being *the* serious deficiency of Thomas' first version.
127 9b50d902SRodney W. Grimes
128 9b50d902SRodney W. Grimes	now i know that patent law generally protects against independent
129 9b50d902SRodney W. Grimes	re-invention (like the 'xor' hash function pleasantly mentioned
130 9b50d902SRodney W. Grimes	in the patent [but not the paper]).
131 9b50d902SRodney W. Grimes	but the upshot is that if anyone ever wanted to sue us,
132 9b50d902SRodney W. Grimes	we're partially covered with
133 9b50d902SRodney W. Grimes	independently-developed twists, plus the fact that some of us work
134 6dc4364cSPhilippe Charnier	in a bureaucratic morass (as contractor to a public agency in my case).
135 9b50d902SRodney W. Grimes
136 6dc4364cSPhilippe Charnier	quite a mess, huh?  I've wanted to tell someone this stuff
137 9b50d902SRodney W. Grimes	for a long time, for posterity if nothing else.
138 9b50d902SRodney W. Grimes
139 9b50d902SRodney W. Grimesjames
140 9b50d902SRodney W. Grimes
141