Utility, Innovation and Mathematics
Jo Stanley1
Introduction
The first section of this paper examines the history of the transition from physical (real
world) inventions to ‘virtual’, computer-related ones. It explores the rationale behind the
evolution of ‘hybrid’ inventions: those that embed computer software elements in
physical environments in order to satisfy the demands of the United States Patent Office.
It looks at the distortions engendered by attempts to maintain the ‘physicality’ of
computer-related inventions, and how hybrids bring pathologies of their own.
Section two examines the current definitions of, and assertions about patent utility, and
presents the notion of virtual utility. Although today the battle for ‘virtual innovation’ is
largely won (see recent decisions in State Street and Excel), the author has argued
elsewhere that the judicial decisions that achieved this move are pragmatic and lack
ontological conviction. From an ontological viewpoint little work has been done in the
courts to demonstrate a coherent rationale for the change in policy. Instead, there has
been a switch to utility as the load bearer of patentability in US law. It replaces the s101
patentable categories in importance. The final skirmish in the debate promises to be in
the area of convincing the Patent Office and courts of the ‘virtual utility’ of virtual
inventions. Utility carries strong overtones of physicality that are hard to contradict. This
paper argues that such connotations make no more sense than the old arguments used
against virtual innovation. It suggests that in the real real patent world representative arts
such as software modelling of ‘real world’ systems deserve a place in their role as
representatives.
The final part of the paper looks briefly at the history of some extremely mathematical
patents, those from the field of cryptography. Cryptography constitutes a longestablished class of patentable items in the US Patent Office, yet recently there have
been complaints that some cryptographic inventions are so close to pure mathematics
that they should never have received patents at all. I review some of these patents in the
1
Dr J.A. Stanley, Senior Lecturer Dept of Computer Science Anglia Polytechnic University, and visiting
lecturer at Anglia Law School.
1
light of the thirty-year struggle that less mathematical patents have had to gain
acceptance as patentable subject matter.
2
Part 1
Statute Law and Case Law Developments in Software
Patents
1.1
The Law
35 United States Code, s101 addresses what is patentable. It says this:
Whoever invents or discovers any new and useful process, machine, manufacture,
or composition of matter, or any new and useful improvement thereof may obtain
patent therefor, subject to the conditions and requirements of this title.
Similarly, the corresponding part of the European Patent Convention (paraphrased here)
says this:
A valid patent is given for the candidate invention having:

Novelty (not being anticipated)

Inventive step (not being obvious)

Capability of industrial application (useful to the public)
Both jurisdictions make certain exceptions to patentability. In America these have been
established by judicial decision, in Europe they take the form of an exclusions list barring
amongst other things:
Discoveries, scientific theories and mathematical methods2.
Schemes, rules, methods for performing mental acts … doing business and
programs for computers3.
The American exceptions can be classified as abstracta, and converge closely with their
European equivalents. The US business method exception from patentability was felled
by a recent decision4.
1.2
What is Patentable?
The primary goal of the global patent culture is to foster useful, inventive solutions to
acknowledged technical problems that will benefit the public. The history of computerrelated inventions indicates that for some time they were treated as non-technical
2
3
European Patent Convention (EPC) Art 52 (2)(a).
EPC Art 52 (2)(c).
3
entities5. Computer programs are difficult to classify6 and liable to fall on the abstract
side of patentable7 & 8.
In the 19th century patents were predominantly awarded for useful applications of
‘natural forces’9, mostly as machines10 – highly tangible objects. Processes were
regarded with more suspicion, being intangible until implemented, and being potentially
broad because supportable on many platforms. Mechanical processes were executed by
machinery, hence they must be mere ‘functions of a machine’ rather than innovative
transformations in their own right11. Chemical processes were admitted to be
patentable12. The unpatentable items specified in early American judicial decisions, and
recited in all subsequent decisions on subject matter patentability were these: scientific
truths13, ideas14, properties15 and natural phenomena (such as electricity as such)16.
4
State Street Bank and Trust Company v Signature Financial Group Inc., (149 F3rd [1998] at 1368).
The US example of Johnston. (Appeals Court [1974]), banking software considered to support a ‘liberal
art’. (502 F 2nd 765, 769).
6
They are ‘literary works’, hence subject to copyright, and ‘virtual machines’ hence potentially patentable.
7
The US Patent Office 1968 Guidelines: Examination of Patent Applications on Computers Programs (33
Fed Reg. 15, 609 – 610) barring programs reflect this view. These were hastily rescinded in 1969 (34 Fed
Reg. 15, 724), following the Appeals Court decision in Prater (infra). But see also the subsequent Supreme
Court decision in Gottschalk v Benson, which stigmatised programs as likely to be unpatentable items. This
blight lasted for the next decade, (409 US 63 [1972]).
8
See also UK Banks Committee Report which advocated keeping a watching brief over the patentability of
programs. Few UK cases surfaced at that time.
9
In a German case challenging the patentability of computer programs, the opinion said: ‘All these
methods lack a basic requirement for a patentable invention, namely the creative utilisation of natural
forces. (GRUR Int [1968] at 211).
10
Eli Witney’s cotton gin (patented 1794). As a process example: Charles Goodyear’s sulphur treatment of
rubber to produce vulcanised product (patented 1844).
11
For example, the US decision on Tarcsky-Hornoch’s invention, a pulse counting circuit and method.
(Filed [1960]. Appeal from a decision of the Patent Office, heard in the Appeals Court [1968], 397 F 2 nd at
856). Tarcsky-Hornoch citing the fact that chemical processes did not receive the patentability challenges
applied to mechanical ones. The Tarcsky-Hornoch court concluded that up to that case the law on
patentablity had been ‘..unclear …whether the dividing line marks a difference between means (patentable)
and result (unpatentable) or chemistry and mechanics. (Tarczy-Hornoch at 859). The court explicitly
threw out the allegedly confused prior law.
12
Tilghman v Proctor, (102 US 707 [1881]). Application of the hydrolysis of fats. Infringer did not use
inventor’s apparatus and was therefore deemed not to infringe. The Court did not restrict the process to one
apparatus but allowed it as a genuine process with scope ranging over a number of platforms.
13
Mackay Co v Radio Corps (306 US, 86, 94, [1939]). Invention of V-shaped radio antennae, the angle of
the ‘V’ specified using Abrahams’ Law. The inventor owned to having simplified some mathematical
expression in his disclosure, but did not declare Abrahams’ as being in the prior art. The Court held that the
invention was patentable since it applied a scientific truth.
14
Rubber-Tip Pencil v Howard (87 US 498, 507, [1874]). The Court argued that the idea for erasers
attached to pencils per se is not patentable. Basically, the claim failed for excessive breadth.
15
Le Roy v Tatham, (55 US 156, 175), [1852]. The invention was for improving the making of pipes by
using lead. The pipes were improved by a property of lead: it melted and hardened on cooling. The court
argued that this was a general discovery of a use for that property; not a specific process for exploiting it.
5
4
With the advent of computer technology in the middle of the last century, came an
intensification of the desire of the Patent Office and courts to demarcate unpatentable
‘laws of nature’ and scientific principles from patentable inventions that applied these
principles. Computer programs were seen as being on the cusp of this division.
Computer programs proved elusive – intangible – in the patent context. Implementing
processes as they did, they already incurred a black mark for being less substantial than
machines. Electronic circuits with a useful purpose had no such problems with
intangibility; they could be claimed as apparatus (the synonym for machine in the patent
context)17. Yet software is logically equivalent and physically interchangeable with
hardware18. A designer may choose a hardware implementation for speed19, or a
software implementation for portability or adaptability. In short, the decision is made to
satisfy purely functional criteria; the same broad purpose may be served by either
solution.
Also considered alarmingly radical was the fact that computer programs, dealing only
with data - that pale surrogate for real world activity - should be patentable. The
transformations programs achieve yield values in variables, not actual commodities.
Worse, programs frequently use mathematics to implement their functions20.
When it came to inventions with a mathematical heart to their novelty, the mathematics
involved was allied to a mental process, as well as being too general or abstract to be
patentable. The Patent Office took the ‘point of novelty’ approach, arguing as follows:
1. If a claim is to a process that is solely mental, then it is not patentable.
2. If the novelty of the claimed process resides in the mental steps, and the
associated physical elements are old in the art, then the whole process is
unpatentable.
O’Reilly v Morse (56 US 62, 117). The Court argued that Morse had not invented electro-magnetism, but
only a subset of the machinery that was enabled thereby to print at a distance. His claim therefore
outstripped his actual invention.
17
All Tarcsky-Hornoch’s machine claims were accepted, only the method ones were rejected.
18
Prima facie it is. Many arguments are suppressed, however, by this statement.
19
Most of the early cryptography patents show algorithms implemented as chips.
20
In the past, the Patent Office has even used the argument that the operation of a computer at a level
below that which the claimed computerised solution addresses provides evidence of the mathematical
nature of the solution. Application of Walter, (618 F 2nd [1980] 758, 761). The Patent Office argued in
Walter that a computer operates on binary signals. Base two arithmetic is imposed by the architecture of
the computer itself. Since these manipulations are the way that a computer operates to effect a process,
then this must mean that the claimed process is mathematical.
16
5
3.
If the physical elements are new then the novelty of the mental element is
immaterial, (don’t care), and the process is a candidate for patent21.
The second ‘rule’ above epitomises the point-of-novelty approach. This was Patent
Office policy when the first computer-related inventions started to appear as regular
candidates in the 1950s. Patent examiners frequently strengthened their case by holding
that if a process could be implemented by a mind or a machine then the claims to it were
vague, (even if a machine implementation was described in the patent application22).
The Appeals Court challenged the Patent Office’s point-of-novelty approach in Prater23.
It argued that only purely mental processes were unpatentable24. In Prater no exclusively
human judgement was involved. The Court further argued in Musgrave25 that if any
process showed truth-functional steps (where output relies solely on inputs together with
a clerical procedure) – which a program will - then it is potentially patentable. The Court
discredited the point-of-novelty test, (rule 2 above), on grounds of its illogicality, and held
that it should no longer control computer cases26.
The Appeals Court continued in this vein through a number of seminal cases between
1968 and 1971. Towards the end of this series of cases the Appeals Court was
confidently allowing claims to programs, so long as they were new and useful, simply
because software technology was firmly in the mainstream of ‘the technological arts’27.
21
These are the infamous Abrams Rules. Abrams invention (1950s) was in the field of petroleum
prospecting. There was a calculation using bore-hole pressure readings as input. It determined whether
petrol-bearing strata were likely to be present in the vicinity of the bore-hole. The ‘method’ offered no
actual (real world) way to determine pressures, and consequently the application failed.
22
See Reduction of Data From Spectral Analysis. Charles Prater. (Filed [1961]).
23
First Appeals Court hearing of Application of Charles Prater. (Prater 1, [1968]. 415 F 2nd at 1378).
Rehearing, (Prater 2, [1969], 415 F 2nd at 1393).
24
A purely mental process may well be one that shows a propositional attitude: believing, fearing or hoping
about a proposition. This ‘aboutness’ is expressed as ‘intentionality’ by John Searle, who uses the term to
characterise a human mind as compared to a machine. (Machines do not fear or hope or desire about a
procedure that they carry out). Intentionality: An Essay in the Philosophy of Mind, Searle, [1983]. In any
case, ‘purely mental acts’ are private to the mind that carries them out. They cannot be inspected, let alone
used, by another person. Therefore they cannot have the required utility to be patentable.
25
Corrections for Seismic Data Obtained from Expanding Spread. Filed in 1965. (Appeals Court hearing:
431 F2nd 882 [1970]).
26
Said the court: ‘A given process including both “physical” and “mental” steps could be statutory
during the infancy of the field of technology to which it pertained, when the physical steps were
new, and non-statutory at some later time after the physical steps became old’. That is, the
statutory nature of the invention varies across time, which is clearly false. (Musgrave at 889).
27
That term is used in Foster [March 1971], 438 F 2nd at 1011, Benson, [May 1971], 441 F 2nd at 682, and
McIlroy [May 1971], (three weeks after Benson), 442 F 2 nd at 1397.
6
The Appeals Court then suffered a set-back in developing its jurisprudence. The
Supreme Court reviewed its decision in Benson28. The highest court barred the patenting
of ‘mathematical algorithms’, of which Benson’s number converter was said to be an
example. The definition of ‘mathematical algorithms’ was never that clear to
commentators or to the Appeals Court29. They were conflated with computer programs,
and this was taken by all concerned as a slur on the patentability of programs. Following
Benson, applications for patents on computer programs slumped and remained low for a
decade30.
After the body blow of Benson, the Appeals Court’s new task was to ‘decide around’ that
case, and rescue innovative software where this seemed justifiable.
1.3
Deciding Around Benson
These were some of the strategies the Appeals Court used:
1.3.1
Category Myopia
If software is installed on a hardware platform and claimed as a machine its chances of
patentability are improved. The Benson decision only rejected computation processes,
therefore the court was entitled to cordon off processes embodied by programs and
claimed as such as the only unpatentable category31. But note the uneasiness displayed
by Appeals Court Judge Rich, dissenting in Johnston from approving the machine
claims:
The point is that the machine and process claims are really directed to the same
invention …
28
Gottschalk v Benson, 409 US at 273. [November 1972], reviewing Appeals Court decision (441 F 2 nd
[1971], at 682). Concerning a number converter that changed a number represented in Binary Coded
Decimal (BCD) into pure binary. The use was in a telephone switch station. The benefits of this converter
that were puffed over and above solutions already in the art were these. It cut down the repetitive
computerised stores and retrievals of intermediate data, cut down the overall number of steps taken,
reduced the number of hardware components required, and diminished the chance of error in number
manipulations. Burroughs Corp. subsequently patented a ‘Number Conversion Apparatus’: US 4,342,026
[1982]. Their specification states: ‘many systems for converting between BCD and binary have been
proposed and are well known in the art.’ They cited patents for converters from 1957 (2,814,437) up to
1970 (3,505,675).
29
Note Judge Rich’s comments in Christensen (immediately post-Benson). 478 F 2nd at 1392 [1973], at
1396.
30
Keith Witek’s software patentability index. (Pers com).
31
By ‘judicial exception’. Application of Johnston. Before the Court of Appeals ([1974], 502 F 2 nd 765).
Johnson’s invention was a program that processed bank account transactions. All 5 claims at issue were to
a system (a machine). The Appeals Court over-turned the Patent Office’s rejection of Johnston’s claims.
7
He pointed out that the invention was, in fact:
being sold as a computer program to banks so that they can perform data processing
services.
Once categories are specifically listed, they provide opportunity for misconstruction
of terms when new technological objects confront them. The centralist approach of
Judge Rich sought to expose the actuality of the invention32.
1.3.2
Carving Computational Levels
System software was distinguished from application software in Chatfield33. So long as
software enhances the performance of its platform rather than merely processing data it
may be deemed patentable. This is a mirror of the European ‘technical effect’ argument.
The Chatfield court also distinguished the ‘Benson’ algorithm from the ‘Mainstream’34
algorithm. The former had mathematical content, the latter was ‘just another form of
process’35.
I suggest that this was a seriously wrong turning in the jurisprudential development. In
fact, an algorithm is not ‘just another process’. It has symbolic connotations that ought
not to be misrepresented:
An algorithm can be applied to any of a class of certain symbolic inputs, and in a
finite time and number of steps can eventuate in a result in corresponding symbolic
(Frederick Adams) 36.
output
1.3.3
Holism: the Physical Bookends Argument
If there is sufficient ‘real world’ (that is, physical) activity that uses the results of any
calculations (called post solution activity), a software invention may be patentable37. This
32
Judge Rich subsequently down-played the importance of s101 categorisation in State Street; Judge Plager
even more so in Excel.
33
Application of Chatfield. 545 F 2nd, 152 [1976]. Chatfield invented system software that allocated
resources in a multi-user system. The innovation was that priorities were dynamically assigned while
programs were running, as opposed to being statically predetermined.
34
My term.
35
In Chatfield Judge Markey said: ‘The broader definition of an algorithm is “a step-by-step procedure for
solving a problem” … It is axiomatic that inventive minds seek … step-by-step solutions. (545 F 2nd
[1976]), at 156.
36
‘[An algorithm is] an effective or clerical procedure. It is a step-by-step recipe for computing the value of
a function. It determines what is to be done at each step without requiring any ingenuity of any person, or
any machine, executing it’. (Stewart Shapiro).
8
safe harbour remains in the MPEP Guidelines for computer-related inventions38, and
practising attorneys recommend the use of manoeuvres that meet such demands39. It
stands for the judicial view that the hybridised invention must be treated as a whole, and
not dissected.
Historically, the problem that arose from this mindset was as follows. The ‘diplomatic’
use of real world bookends tacked on to a basically mathematical solution made the
Patent Office and courts very sensitive to the liberties that might be taken in the name of
holism40. At the time, the Patent Office had, to an extent, replaced the point-of–novelty
test by the Blue Pencil Rule41. This strategy allowed a claim to overcome the s101
hurdle as patentable subject matter so long as one statutory (ie physical) element
existed in the claim. It subsequently normalised by ‘pencilling out’ the non-statutory
elements for the purpose of the s102 (novelty) and s103 (non-obviousness) inquiries. If
the mathematics is removed from an invention, what is lost may very well be the prime
source of novelty. What is definitely lost is the interface between the mathematics and
the physical world which may be a source of novelty in its own right. This move is
dissectionist and anti-holistic.
The most extreme (and aberrant) decision in this mindset was Flook42 in the Supreme
Court. In that case not only was the mathematics extirpated from a hydrocarbon cracking
process (which the program embodying the mathematics controlled) at the start of the
analysis, but it was declared a ‘known’ mathematical relation, when there was no
evidence to that effect43.
The Patent Office was developing a test that essentially instructed thus: 1. Identify a
mathematical algorithm in a claim. 2. Delete it from the claim. 3. Ask, does the remainder
The term ‘post solution activity’ was coined in the Appeals Court hearing of Flook (559 F 2nd [1977], at
21). An invention that continually (the innovation) recalculated the alarm limit in a petroleum-cracking
plant.
38
S1V B 2b, citing Diehr.
39
Keith Witek, Developing a Comprehensive Software Claim Drafting Strategy for US Software Patents.
Berkeley J Tec & L, [1996]). Gregory Stobbs, [1996 and 2000 eds] Software Patents.
40
For example: In re Richman 195 USPQ 340 [1977].
41
Carl Moy Statutory Subject Matter and Hybrid Claiming, John Marshall JCIL, 277.
42
Parker v Flook, 437 US, at 451. [Decided June 22nd 1978].
43
According to Chisum that was an illicit manoeuvre that should have been purged as ‘antithetical to
patent law’. The Patentability of Algorithms. University of Pittsburgh Law Review, [1986], 970, at 995.
Carl Moy suggests that the Flook decision shows the Court’s intention to demarcate the domain of
principles and scientific truths (where it considered Flook’s equation belonged), as immune from patent
monopoly.
37
9
of the claim address statutory subject matter44? If so it passes the s101 categorisation
test. This clearly reduces the threshold of s101 as compared to point-of–novelty.
In Flook, the Court asked this question: is the invention minus the maths novel? That is,
is oil refining novel? The answer was, not surprisingly, ‘no’.
In the Appeals Court we see the beginnings of the Freeman, Walter, Abele test for the
‘process with a hole in it’: Any mathematics is removed, the statutory nature of the
residue is tested, then the mathematics is allowed to limit the claim. (See Abele45 and
also Diehr46 in the Supreme Court). During this time the focus was on s101 statutory
subject matter issues. The s102 and 103 inquiries may well have been starved out47.
1.3.4
The Fate of Expert Systems under the Blue Pencil Rule
Under Blue Pencil, expert diagnostic programs and business methods were bound to fail
the patent demand for real-world, structural correlates to any calculations being done by
software. The decision in Meyer illustrates this point48. Meyer’s invention49 was an expert
system to complement a neurologist’s diagnostic skills. A battery of tests was performed
on a patient and the results computed as a probability of normal function or malfunction
of various parts of the patient’s nervous system. Using the ABC pattern of analysis we
split the invention into three phases: A is data gathering (by physiological testing). B is a
mathematical analysis of the test results – the core of the invention. C is a clinical action
taken by a doctor informed by the analysis at B. A was held to be not convincingly ‘real
44
Gable and Leaheey: The Strength of Patent Protection of Computer Products, (17, Rutgers [1991] at
106), citing Barett: Patentable Subject Matter: Mathematical Algorithms and Computer Programs, (1106
Official Gazette PTO [1989]).
45
Abele’s invention allowed reduced exposure of a patient to X-irradiation in a computed tomography
application. Artefacts thrown up by the limited exposure were removed by a mathematical weighting
function. In the Appeals Court (684 F 2 nd, [1982]), Judge Nies conceptually removed the mathematical part
and found the remains to be statutory. The invention was then considered as a whole, and the mathematics
approved as limiting the claims. The Patent Office examiner, however, had operated under the Flook
principle, looked for novelty in the tomography without the maths, and decided it was missing.
46
Diehr’s invention provided a dynamic control for traditional rubber curing. Previously, the total time
allowed to heat rubber in moulds and effect the cure was statically set, and could not be adjusted during the
cure. The cure time was calculated using the Arrhenius equation, which was the mathematics in the
method, and known to be used in the field. (450 US [1981], 175).
47
Diehr’s invention, for example, is just an iterative version of rubber-curing control, and appears to be
rather obvious. Also Judge Newman, dissenting, in Schrader found that ‘the record does not show analysis
in terms of sections 102 and 103. It is not reasonable to believe that the activity described is devoid of
prior art …’.
48
688 F 2nd 789 [1982].
49
Process and Apparatus for Identifying Locations of Probable Malfunction. Filed [1974].
10
world’50, but the mere foddering of variables with values. B is ‘mathematics’ and
therefore unpatentable. C, of course, is beyond the ambit of any patent.
1.4
Recent History by Cases
1.4.1
Iwahashi51
Iwahashi invented ‘An Auto-Correlation Circuit for Use in Pattern Recognition’52. As the
specification put it:
state of the art units for calculation of the auto-correlation coefficients have the
disadvantage of requiring expensive multipliers and also complex circuitry.
Rather than use a multiplication step to get the square of the sum of two numbers, the
Iwahashi unit provided a look-up table, implemented as a ROM.
The Appeals Court allowed that Iwahashi’s invention was patentable because it claimed
the invention as a specific machine. All the hardware was general except for the ROM,
which the Court considered to be ‘specific’, and to make the whole specific thereby.
Iwahashi’s claims were functional (that is, in ‘means-for’ format – each element of
hardware being described as ‘a means for’ implementing a function). Under such format
the examiner is coerced (by s112.6) to scrutinise the invention’s written description to
find, for each function:
corresponding structure … described in the specification and equivalents thereof53.
The Court looked for ‘specific structure’54 and found the ROM.
Iwahashi stands for one of two propositions, according to your viewpoint.
Either that some piece of specific structure supporting a mathematical
innovation ratifies that invention as a proper patentable machine,
Or that a mathematical process supported by a general and non-innovative
platform can be called statutory, thanks one piece of ‘nominal hardware’55 (a
ROM in this case56).
Data gathering was discredited as insufficiently ‘real world’ in Richman, (563 F 2 nd 1026 [1977]).
888 F 2nd, at 1370 [1989].
52
Filed [1982].
53
35 US Code s112.6.
54
The origins of this ‘specific structure’ requirement are questioned by Irah Donner, Throwing Out Baby
Benson, (Jurimetrics Journal [Winter 1993] at 247).
50
51
11
1.4.2
Arrhythmia57
The issue in this case was whether claims to an output of signals that merely represent
physical entities (in this case a patient’s heart condition), as opposed to being physical
entities (beyond being ‘signals’58) are valid.
Arrhythmia’s invention sought to pinpoint exactly which patients recovering from heart
attack were at high risk of the potentially lethal tachycardia (fast heart-rate). If this risk
were known, then ameliorative drugs, (with their strong side effects), could be used in a
focused way and only where necessary. The invention used a mathematical
implementation of a Butterworth filter to suppress noise on the heart signals.
Judge Newman said this:
The resultant output [of the filter] is not an abstract number, but a signal related to
the patient’s heart activity.
Arrhythmia stands for one of two propositions, according to your viewpoint.
Either that signals that represent physical things of claimed origin59 (human
heart rate etc) are legitimate physical entities for patent purposes60,
Or that the bounds of patentability are being pushed back a little further. It is
now sufficient for the mathematical treatment of data (the novel item in
Arrhythmia) to be couched in terms of ‘signals’ that represent physical things
rather being physical things.
1.4.3
Alappat61
It is reported that Francis Gray (internal counsel for Tektronix, the assignee of the
Alappat invention) brought this case for the sole purpose of seeking a ruling on whether
Richard Stern’s term.
The use of a ROM by the way was utterly obvious.
57
Arrhythmia Research Technology Inc v Corazonix Corp. (District Court ND Tex, [1990]). Appeals Court
(958 F 2nd 1053 [1992]).
58
The Patent Office always looked favourably on ‘signals’ as a token of tangibility for patentability.
59
Note also that those claims in Abele that failed to declare the origin of the ‘signals’ as being from Xirradiation of a human body failed to convince the court of their validity.
60
MPEP Guidelines. 1V B 2b.
61
In re Alappat. (33 F 3rd [1994]).
55
56
12
digital circuitry governed by mathematical formulae could be patented62. Alappat, an en
banc decision63, in effect said that it could.
Digital oscilloscopes suffer the flaw of displaying traces that rise or fall steeply as jagged
and discontinuous, an effect called ‘aliasing’.
Although anti-aliasing devices were known in the art before Alappat’s invention 64,
Alappat made the following advance. If the pixels adjacent to the wave trace were
subdued in intensity, (due to a novel mathematical treatment of the data), the eye/brain
axis perceived the trace as ‘smoothed’.
Although the data was derived from, and the benefit was felt in, an oscilloscope, the
oscilloscope was not claimed.
The specification did not disclose, nor was it claimed, where the input data – the
vector list - was to come from or how it was to be generated.65
However, the content of the claim preamble linked into the elements of the claims
sufficiently to satisfy Judge Rich that the data was adequately sourced. Here is the
preamble to claim 15:
A rasteriser for converting vector list data representing sample magnitudes of an
input waveform into anti-aliased pixel illumination intensity data to be displayed
on a display means comprising: …..66
Alappat stands for one of two propositions, according to your viewpoint.
Either, provided sufficient structure (albeit non-specific) is supplied in the
written description pointed to by a means-for claim, there is no reason to bar an
invention with a ‘useful, concrete and tangible result’.
Or, a method of mathematically processing data qua data (representing
numbers of unclaimed physical origin) is patentable if claimed as a (structurally
supported) ‘means machine’.
62
Reported by Gregory Aharohian (Internet Patent News Service).
The full complement of judges, in this case eleven, was present.
64
Patent subsequently issued as patent number 5,440,676, [1995].
65
Comment of the dissent in Alappat, led by Judge Archer, at 1563.
66
Note the link to this claim element:
‘means for outputting illumination intensity data as a pre-determined function of the normalised
vertical distance and elevation.’
63
13
The Alappat dissent saw the majority’s decision as a sacrifice of the s101 hurdle: the
statutory subject matter test, since essentially mathematics had been shown patentable.
We also see the inception of the ‘useful, concrete and tangible result’ triplet, reiterated in
State Street and Excel.
One reading of Alappat is that there is an attempt here to re-unite utility and innovation.
1.4.4
In Memory:
Lowry and Beauregard
A program carried on a disk defines a legitimate ‘manufacture’ for s101 purposes.
Lowry’s invention67 concerned an object-oriented data structure. Claims 1 to 5 were
directed to the ‘memory’ that stored the data structure.
The court maintained that:
The claims require specific electronic structural elements which impart a physical
organisation on the information stored in memory. Lowry’s invention manages
information. … Thus Lowry’s claims define functional characteristics of the
memory68.
More than mere abstraction, the data structures are specific electrical or magnetic
structural elements in memory.
While this is true as far as it goes, a software engineer would simply regard a data
structure as part of a program in which the program declaration pledges that memory will
be used in a specified manner in response to program instructions. Any notion of
electrical or magnetic structure is beside the point.
Beauregard’s invention69 was a program, claimed on a disk, that overcame the graphical
complexity of filling in a complex polygon, such as might be found on a map of
Norwegian fjords. Complicated algorithms for filling such shapes were already in the
prior art, but these were slow to execute. The essential novelty of the program was that it
initially inspected the shape to fill, classified it, and selected the fastest fill algorithm for a
member of that class.
67
Data Processing System Having a Data Structure with a Single Simple Primitive. Assignee was DEC. In
re Lowry. Appeals Court [1994]. (32 F 3rd at 1579).
68
Lowry at 1583.
69
System and Method for Utilising Fast Polygon Fill Routine in a Graphic Display. US patent 4,962,468,
[1990]. Assignee: IBM.
14
Jeffrey Draeger70 argues that the Patent Office Guidelines and the courts part company
in their views of what it is allowable to claim on a disk. The Examination Guidelines state
that patentable subject matter of the ilk of programs and data structures must:
Become structurally AND functionally interrelated to the carrier medium71.
Lowry approved what was perceived to be the physical stamp of organisation that a data
structure lays upon memory. It is an actual enablement that allows more efficient access
to data. For Draeger a program is a different matter to a data structure. It is only stored
in memory of necessity, prior to its animation; it leaves no structural imprint on memory.
According to Draeger, the claim of the disk-carried program to patentability is as a
functional component of the machine system as a whole72. Hence the Guidelines go
beyond Lowry, the seminal decision, yet they do not carry the legal weight that the court
decisions carry. The most the Guidelines ought to stipulate, claims Draeger, should be:
structural OR functional interrelation [between program and disk].
Thus Lowry does not warrant Beauregard. In this mindset you cannot argue for the
functional entity (the program) on the strength of the structural one (the data
structure).
Beyond these issues lies the problem that if a disk is claimed, there is no new utility in
the fact that a program (or anything else, music, for instance73) is committed to disk, or
the way the material is committed to disk, or the way the machine reads it.
Neither is a disk a functional entity without the co-operation of a machine. Lee Hollaar
makes a distinction between kinds of memory. He separates executable from repository
memory74. He objects that a program on media only has the potential for function (for
utility). It needs to be integrated with a hardware/software platform, provided with linking
loaders and other software, in order to display its intended transformation of values
‘kinetically’ (my term). He says:
The only memory where information is functional is executable memory.
Are Beauregard’s Claims Really Valid, John Marshall JCIL [Fall 1998].
Guidelines Part 1V.B.1. See the grounding of the program-substrate interaction argument in the printed
matter exception.
72
Id, at 361. This is the ‘cam for the machine’ argument offered by IBM in Beauregard.
73
The US Patent Office has been obliged by the carrier medium solution to distinguish, in the [1996]
Guidelines, non-functional descriptive material (music, play readings etc) from functional descriptive
material (computer programs).
70
71
15
A program on a disk, from his viewpoint, is just data, and might as well be music.
Although current MPEP Examination Guidelines75 allow transitive (on-a-disk) function as
actual function to cover this case, they also say that media-borne programs are only
patentable if the underlying process is also patentable.
A drawback to a memory claim is loss of scope, since media rapidly go out of style, and
a claim needs to be as broad as possible. On the other hand, to claim ‘any and every
medium’ risks getting default treatment as a process, whose claim to patentability is in
any event less robust.
Richard Stern76 has suggested that a disk claim should only be valid if the corresponding
process is valid. Stern suggests the carrier disk claim must match a ‘hypothetical’
process or machine counterpart77 under this test. But if the process claim would have
been patentable, then the chief benefit in the carrier disk claim strategy appears to be to
extend the reach of a direct infringement action78.
1.4.5
State Street: Tangible Assets
Commentators hold out State Street79 as the case that swept away the business method
exception, yet a careful reading of the case indicates that it was the mathematical
algorithm argument that was most significantly quenched80.
Signature wrote software called the ‘Hub and Spoke’ financial management system. It
was designed to implement economies of scale in administration, but primarily to make
tax savings. License negotiations with State Street broke down and State Street tried to
have Signature’s claims invalidated.
74
Justice Douglas was Right (AIPLA Quart J, [1996]).
Part 1V.B.1. They speak of ‘functional descriptive material’ which ‘imparts functionality when encoded
on computer-readable media’, and give no patentable weight to non-functional descriptive material
(traditional literary texts and music).
76
An Attempt to Rationalise Floppy Disk Claims. John Marshall JCIL [Fall 1998]).
77
Stern supra at 198.
78
If software is claimed as a process then only the end-user may be sued for direct infringement. The
copyist distributor is, at worst, a contributory or indirect infringer. The same applies to software installed
on a machine, if execution of the software is an inherent requirement voiced in the claim. But if the copyist
distributor has a product – a disk – in his hand, then he infringes directly, and liability is strict.
79
State Street Bank and Trust Company v Signature Financial Group Inc., (149 F3rd [1998] at 1368).
Signature’s Patent: no 5,193,0536. Filed [1991]. Issued [1993].
80
The business method move by Judge Rich was a reiteration of Judge Newman’s suggestion in Schrader
that ‘a method of doing business’ was a ‘fuzzy concept’ which should be ‘discarded as error-prone,
redundant and obsolete’. This followed her detailed analysis of so-called business method precedent cases.
She demonstrates that their BM aspect was tangential to the main thrust of the decisions. Yet they were
habitually cited in any business method context. (22 F3rd [1994], 290, at 298).
75
16
One important fact in the case was that Signature’s claims were to a machine, using
means-for language. Judge Rich had only to use the technique he had already used in
Alappat and Iwahashi of coupling each means-claimed function to a structural element
present in the written description of the invention, to demonstrate sufficient structural
support to validate the claim.
In State Street the significance of the s101 patentable categories was minimised:
The question of whether a claim encompasses statutory subject matter should not
focus on which of the four categories of subject matter a claim is directed to ….81
The court’s conclusion was that:
the transformation of data, representing discrete dollar amounts, by a machine
through a series of mathematical calculations into a final share price, constitutes a
practical application of a mathematical algorithm, formula or calculation,
because it produces ‘a useful, concrete and tangible result’.
State Street stands for one of two propositions, according to your viewpoint.
Either that a useful, concrete and tangible result has evolved to override
considerations of s101 type, judicial exceptions and all
Or that the force of technological expansion in the software art has coerced the
courts to abandon their Canutist stance; they can no longer sustain the
recruitment of ancillary artefacts to produce a specious hybrid out of software.
Tailpiece
The Signature patent application failed in Europe82. The grounds were that the invention
lacked technical character. Beresford expresses the view that this might have been
mended by the submission of specific algorithms for solving the complex administrative
tasks. These tasks would presumably comprise the technical problem83.
1.4.6
Excel84: Utility Dominates Subject Matter
The word ‘useful’ occurs fourteen times in the Excel Opinion as the primary justification
for the patentability of an invention with mathematical content. For instance:
81
State Street at 1375.
European application number: 92908680.9-2201.
83
E-commerce and Business Method Patents in Europe (IBC Conference [October 2000]).
84
AT&T Corp. v Excel Communications, Inc. (172 F 3rd [1999] 1352).
82
17
Even though a mathematical algorithm is not patentable in isolation, a process that
applies an equation to a new and useful end is at the very least not barred at the
threshold by s101’.
AT&T were the holders of US Patent 5,333,184, for an invention concerned with billing
long distance calls. A customer can choose which interexchange carrier (IXC) they will
principally use (their ‘PIC’). Records are passed to a message accumulation system for
processing and billing.
AT&T’s invention added a field to the record expressing a correlation between the
recipient’s and the caller’s IXCs, to enable differential billing. The essence of the claimed
method was to set values in the PIC record, apply a function and modify the bill figure.
Judge Plager emphasised the ‘mainstream algorithm’ approach85:
the judicially-defined proscription against patenting a ‘mathematical algorithm’, to
the extent such a proscription still exists, is narrowly limited to mathematical
algorithms in the abstract.
The judge justified State Street as following Diehr. But Diehr had kept a sharp eye on the
host process of rubber curing, and the holistic nature of the claims. State Street blatantly
used the tangible hardware platform as just that; the focus of the invention was the
calculating software. Excel approved State Street as ending the bar on numberoutputting inventions if there was a ‘useful concrete and tangible result’.
Alappat had said that the invention claims should be assessed as a whole. Alappat had
claimed a ‘means machine’, though the focus was the mathematics. The Excel court
confronted claims to a method, unsupported by tangible artefacts. Hence Judge Plager
strongly opined that the form of the claim was immaterial86.
According to the court, the AT&T PIC indicator ‘represents information about PICs’. Its
utility is in the achievement of a tuned billing method. Said the court: it neither claims nor
pre-empts the Boolean functions it uses:
AT&T’s claimed process employs … PICs as data, applies Boolean algebra to those
data to determine the value of the PIC indicator, and applies that value through
switching and recording mechanisms to create a signal useful for billing purposes.
85
Background Section B.
18
The ‘mechanisms’ and ‘signals’ presumably fulfil the tangibility requirement.
Excel had argued that there was no physical transformation in AT&T’s invention. The
Federal Circuit answered that point, citing Arrhythmia:
The steps [in Arrhythmia] transformed physical, electrical signals from one form into
another form – a number representing a signal related to the patient’s heart activity,
a non-abstract output. … Arrhythmia’s method claims satisfied s101 because the
algorithm … [produced] a number which had a specific meaning87.
The Appeals Court reversed the District Court, remanding the claims for consideration
under sections 102, 103, and 112.
Tailpiece
Although comprising patentable subject matter, the AT&T billing method was
subsequently found obvious in light of MCI’s ‘Friends and Family’ program.
Conclusion
This review of case law shows some of the problems created by the introduction of
artefacts and linguistic euphemisms designed to implicate tangibility in claims for virtual
inventions.
What is at issue here is to show a proof of specific utility in a virtual device. In this paper
it is taken as a given that such utility will redound in the real world as a human benefit.
Where utility finds a focus in incidental artefacts, it loses its focus in the very novelty
being claimed, yet we know that the condition of patentability is conjunct: novelty AND
utility. An holistic view of the invention, expressed in the claims, and assessed in the
Patent Office and Courts is often a valuable and appropriate strategy. However, there
comes a point when that approach runs out of road; certainly the merger of novel virtual
solutions with artefacts becomes distorting. That point seems to be where so-called
virtual inventions service a virtual world used for great benefit by humans.
The next section explores what is understood by utility.
Also citing State Street (at 1372): ‘for the purposes of s101 analysis, it is of little relevance whether claim
1 is directed to a “machine” or a “process”…’
87
But note the words of Newman in Schrader:
All mathematical algorithms transform data, and thus serve as a process to convert initial conditions or
inputs into solutions or outputs…Data representing bid prices … do not differ … from data representing
electrocardiogram signals… or parameters in a process for rubber curing, (at 297).
86
19
Part 2
2.1
The Nature of Utility
Attempting to Define Utility
Here are two dictionary definitions of utility:
1.
Ability, capacity or power of action, to satisfy needs or gratify desires of the
majority, or of the human race as a whole. (OED).
2.
Fitness for some purpose; profitability for some desired end. Serviceableness.
(Websters).
The general rule for laws of nature (embracing mathematics), as expressed in Mackay
Radio v Telegraph Co88 says this:
while a scientific truth, or mathematical expression of it, is not a patentable
invention, a novel and useful structure created with [its] aid may be.
Many would hold that the utility requirement of patent law demands corporeality in the
invention. In the rule that follows, the implication is that corporeality is opposed to
abstraction, and allied to use:
an idea of itself is not patentable.89
The corporeality of a computer program is frugally satisfied by the presence of signals
on the wire. Beyond that, a particular use can be specified. In the European case of
Vicom, the Board of Appeal complained that:
‘a method of digitally filtering data’ remains an abstract so long as it is not specified
what physical entity is represented by the data and forms the subject of a technical
process90.
Yet the ‘physical entity’ referred to the Vicom turns out to be a satellite-transmitted
picture which can be sharpened by using mathematical procedures.
The grant of a patent is rightly viewed as a contract between grantee and government91 &
92
. There must exist, at the time of claiming an invention, some expressed utility for the
public:
88
306 US [1939], 86, at 94.
Rubber Tip Pencil v Howard. 87 US (20 Wall.), [1874], 498, at 507.
90
Decision T208/84 [1986] (2 EPOR [1987], 74 at 79). The claim was amended to ‘image data’ and was
passed.
91
Genesis of Copyright and Patent Law Bugbee, at 10.
89
20
‘a patent is not a hunting licence’93.
In Brenner94, the Supreme Court cited Justice Story, reading him as describing the entry
level for utility as: not doing damage. The Brenner court went on to demand ‘specific
utility’ otherwise there was just a ‘monopoly of knowledge’, which was impermissible:
The basic quid pro quo contemplated by the Constitution and Congress for granting
a monopoly is the benefit derived by the public from an invention with substantial
utility.
Chisum’s Treatise spells out these elements for the utility of an invention:
 First it must be operable and capable of use to perform the functions and secure
the result intended.95
 Second it must operate to achieve some minimum human purpose.
 Third, it must achieve a human purpose that is not illegal, immoral or contrary to
public policy96.
There seems to be nothing in these three elements of the core definition to challenge the
specific utility found in certain mathematical relations.
2.2
Utility and the Statute
Two sections of the US Code address the utility requirement:
S101:
‘new and useful’.
S112:
The specification shall contain a written description of the
invention, and of the manner and process of making and using
it, in such full, clear, concise and exact terms as to enable any
92
A monopoly, on the other hand, has the connotation of taking out of public usewhat they once had
automatic right to. (Comment of Chief Justice Taney in Charles Rivers v Warren Bridge [1837]. Coke
(1628) traces this usage). Patent and monopoly are currently used interchangeably.
93
Fortas J in Brenner v Manson, (Supreme Court. 383, US 519 [1966]).
94
Brenner v Manson, 383 US 519 [1966].
95
Having designated functionality. An example where this was not the case was a purported ‘perpetual
motion machine’ which, under trials by the National Bureau of Standards failed in its goal of running
perpetually. (Newman v Quigg, 877 F 2nd 1575 [1989]).
96
As Justice Story put it, a patent must not achieve utility to ‘poison people, or promote debauchery, or
facilitate private assassination’. Example case decisions include: a one-armed bandit machine denied a
patent (Ex parte Murphy, 200 USPQ 801 [1977]), a toy racecourse denied a patent [1889], (encouraged
betting), and a pinball machine allowed a patent, [1941] (did not necessarily promote gambling).
21
person skilled in the art to which it pertains … to make and use
the same …
S101’s use of the term ‘useful’ is considered to be mainly historic and general.
S112, on the other hand, demands sufficient description for the skilled artisan to make
and use the invention. The relevant rule97 states that a specific embodiment of the
precise invention claimed must be described. It is the invention claimed that must
have the utility.
The updated MPEP Guidelines [2002] cryptically say this (2106):
Usefulness ‘requires significant functionality’.
‘the mere fact that the claim may satisfy the utility requirement of s101 does not
mean that a useful result is achieved under the practical application requirement as
expressed by the useful, concrete and tangible (UTC) result.
The Guidelines go on to admit that ‘the courts have yet to define the terms useful,
concrete and tangible’.
2.3
The Notion of Virtual Utility
Rochelle Dreyfuss has commented that:
Both patent law and copyright distinguish between principles and instantiations of
those principles. An instantiation can be privately owned, but an abstraction must
go into the public domain.
This begs the following questions, which I deal with in detail elsewhere98:
1. What if the instantiation of a theoretical/explanatory law or principle (abstract) is
in fact a local/phenomenological law (also ‘abstract’), with a highly specific
application in a patentable invention? This has the appearance of an abstraction
with utility.
2. Is specific mathematics ‘technical’ or non-technical?
3. What is ‘technical’ anyhow?
2.4
97
Machines99: a Class of Useful Things
The Code of Federal Regulations: CFR s1.71.
22
In 1967 Minsky said this:
‘Machine’ cannot usefully be defined as ‘a member of [a certain class of
physical objects]’. For the decision as to whether something is a machine
depends on what that thing is actually used for, and not just its
composition or structure.
I suggest that a more flexible approach to the term ‘machine’ would have assisted the
transition between conceptualising the machine as heavy, industrial plant and conceiving
of it as the software virtual machine.
Computer Science is grounded in ideas of the ‘levelled machine’100. Each level has its
own concerns, each takes input, processes it and produces output for another level to
consume and process.
A software machine is able to function on variable thickness platforms: (that is hardware
or a hardware/software mix).
2.5
Software as a Process
If software is viewed as a process it is seen as a platform-independent transformer of
input into output. Cochrane v Deener101 is considered the lead case that made the oneto-many relation between process and platform explicit, and liberated the process from
its platform. The legacy of that case in software decisions, unfortunately, has been that
courts took a valid process to be always one that treats of a physical input. It was
therefore argued by the Patent Office in the early software cases that the input to
software, being data, was insufficiently 'physical'. The language used in the Cochrane
reasoning has no connotations of physicality, and the notion that it meant physicality has
been challenged (see the early software cases). Moy102, however, maintains that the
physicality constraint has tended to act as ‘a bulwark’ against the expansion of the
patent system beyond its traditional limits, Recent software decisions effectively refute
98
J.A. Stanley, Thesis: Invention and Representation. Also see J.A. Stanley, Are the Laws of Nature
Patentable After All? (SLS Conference, September 2003).
99
The Turing machine has been described as ‘the most famous abstract model of a computer’
(Representation and Reality, Introduction, Hilary Putnam, [1988], MIT).
100
Two examples are (1) the ISO OSI 7-layered model for networking, and (2) Tanenbaum’s own levelled
model for conceptualising software in levels from user to hardware. Structured Computer Organisation,
Andrew Tanenbaum.
101
94 US 780 [1876].
102
Revision to Deller on Patents.
23
the physicality approach, reasoning that data represent actual things, which seems only
to be a convenient truism.
2.6
Claim Structure in the Service of Virtual Utility: The Substitution of Physical
Constraints by Virtual Ones
If software is a representative, then surely all its elements - the properties of its data
substrate and the its output - ought to be accepted as virtual.
Alappat was controversial for this very reason. The Federal Circuit dissent in that case
complained that the provenance of the data (the oscilloscope) was unspecified in the
claims, as was its target use103. Similarly in State Street the data was simply numerical,
only constrained so far as it represented ‘dollar amounts’104.
I suggest that the physical book-ends of a claim to an algorithm could be removed
(though this is not prescriptive) if these claiming devices were used:
1.
Data type, range and the specific source of input data, also the target use of the
output of an algorithm should all be delineated in an enhanced preamble to the
claim, which is a definite part of the claim.
2.
In support of point 1, the intra-claim nature of the preamble can be confirmed, as
in Alappat, by strategies such as reference between the preamble and the elements
of the claim body.
2.7
Field of Use
At the moment, a claim’s preamble is used principally to express the ‘field of use’. Its
possible range of roles seems at the moment uncertain105. There are, however, two
recent straws in the wind that indicate its possible range of scope.
103
Although its data derived from an oscilloscope, and its output was used by one, the oscilloscope itself
was not claimed.
104
Which led the District Court to reject State Street’s action, and declare the claims invalid through
insufficient mapping to structural correlates under the prevalent Freeman Walter Abele test, subsequently
thrown out by the Federal Circuit in its hearing of State Street.
105
Chisum comments on preamble (at s8.06[1][d]): ‘if the preamble is a limitation, it defines the scope of
the claimed subject matter. It can be relied on to distinguish the claim from the prior art.
Rosenberg says that the preamble can be made directed to the inventor’s own work (as opposed to the prior
art context – which is the usual thing) by an explanation of the fact (Reading v Baker 748 F 2nd 645 [1984].)
Otherwise, preamble is not considered part of the claim. He concludes that there is ‘no litmus test either
way’. (Citing Judge Nies in Corning Glass v Sumitomo [1989] CAFC. See also Patent Law in
Biotechnology, Chemical sand Pharmaceuticals, Harold Wegner (2nd ed.)
24
In the case of Rowe v Dror, a general purpose ‘balloon catheter’, already in the art, was
compared to an invention which was a ‘balloon angioplasty catheter’, and referenced in
the preamble to a claim106. In construing the application, the Federal Circuit picked up
the fact that the claim, limited by the pre-amble referred to equipment that had to cope
with the extra functionality of expanding an arterial stenosis, which a standard balloon
catheter does not. The preamble provided the required functional specificity and
therefore constituted a proper limitation on the claim107.
Secondly Alappat’s claim 15 preamble gave the field of use of the rasteriser:
A rasteriser for converting vector list data representing sample
magnitudes of an input waveform into anti-aliased pixel illumination
intensity data to be displayed on a display means comprising ...
Section 3: How did Cryptography Get Away with it For So Long?
3.0
Introduction
The art of cryptography allows the development of methods to transmit messages
securely on an insecure channel. The best of the encryption algorithms run very slowly.
A variety of hardware and software implementations are usually available for any of
them.
Ciphers are coded representations of representatives. The representatives are words
and numbers in binary format. Thus the real world is very far removed from these
objects. Yet cryptography has been a well-established patentable class for at least 25
years. Under the US Patent Office Classification108 it is ‘Class 380, CRYPTOGRAPHY’.
Subclass 28 concerns algorithms encoding ‘signals’. Subclass 30 (which is indented
within subclass 28) concerns public key encryption specifically.
I will briefly outline the content and benefit of three cryptographic algorithms, considering
the utility of each. They are, the RSA public key patent109, Schlafly’s patent110, and
Hoffstein’s patent.111 & 112
106
Rowe v Dror, (112 F 3rd 473 [1997].
The claim was therefore patentably distinguishable from the prior art (ie unobvious) on the basis of
what the preamble said.
108
Refer to the Classification Definitions [Dec 2000], US PTO web site.
109
Rivest, Shamir and Adleman: US Pat# 4,405,829 (Class 380/30). Filed [December 1977], issued
[September 1983]. Assignee MIT.
107
25
3.1
The RSA Public Key Patent
The most secure method of encryption rests on the notion that the key used to decrypt a
message is not a direct inverse of the key used to encrypt it, (the asymmetric solution).
For this purpose a one-way function is necessary. The unpredictable behaviour of prime
numbers under functions such as exponentiation and modular reduction make them
peculiarly fitted to these methods. A user creates a public key (two numbers N and e, a
modulus and an exponent respectively). These the user releases to the public who might
wish to correspond with her. Also in the public domain is the one-way function that will
be needed to encrypt the message. The N number, however, is a composite; it is made
by multiplying two large prime numbers (p and q) together. The user does not release
these two numbers, but can generate her deciphering key from them. Once she has
done this, p and q can be discarded. The deciphering key (d) is a function of the same
broad sort as the enciphering key, involving an exponentiation and a modular reduction.
The success of the method relies on the difficulty of factoring N to try to find p and q and
hence d. This is notoriously difficult to do, and any attack on privacy relies on brute force
trial and error in detecting p and q. Such an attack is so impotent because of the
computation time needed to run the attacking algorithms (10s or 100s of years).
Therefore the encryption method can be called ‘computationally infeasible to break’. This
is the benefit of the RSA patent. There is no guarantee that one day an alternative attack
(not using factoring) will not succeed against RSA.
Whitfield Diffie held out the principle of just such an asymmetric solution to the encoding,
decoding problem113, he could not, however, implement such a solution. Rivest, Shamir
and Adleman114 were able to implement it in their RSA Public Key patent, issued in
1983.
Twenty-six of the forty RSA claims are to a cryptographic communications system; in
other words, a machine. There are references to ‘channels’, ‘lines’ and ‘registers’, and
other general physical elements.
110
Roger Schlafly: US Pat# 5,373,560. (Class 380/28). Filed [August 1993], issued [December 1994].
Jeffrey Hoffstein et al: US Pat# 6,081,597 (Class 380/28). Filed [August 1997], issued [June 2000].
Assignee NTRU Cryptosystems.
112
For technical details, see the works of Bruce Schneier and William Stallings. See also Monopoly,
Mathematics and Nomological Machines, J. Stanley, forthcoming submission to Jurimetrics Journal,
[2004].
113
New Directions in Cryptography, Diffie et al, IEEE Trans Info Theory, Vol IT-22, num 6 [Nov,1976].
Stanford group.
111
26
How was it that the piece of specific mathematics that RSA embodies was not regarded
as a ‘mathematical algorithm’ and rejected in the Patent Office? The two relevant
Supreme Court decisions of the time of RSA’s filing and search were Benson and Flook.
Both were deeply unpromising one would have thought. Yet the patent issued. This is
what Flinn and Jordan wrote in 1997, when RSA had run its patent period:
Meeting the FWA test involved reciting the cryptographic algorithm as an element
within a physical device. In the RSA patent, this approach is stretched near if not
beyond the breaking point. The only elements of the physical device which are not
descriptions of the algorithm are ‘communications channels’, ‘an encoding means’
and ‘a decoding means’115.
The authors comment that this strategy comes ‘as close as possible to claiming the
algorithm by claiming the use of the algorithm in essentially all possible machines or with
all possible processes’.
Had the mathematics of the algorithm been examined as such, perhaps some notion of
where mathematics is too broad to claim could have been developed in the Office.
3.2
Roger Schlafly’s Patent
Since encryption relies on modular reduction, any method to make this more efficient is
welcome in the art. Roger Schafly’s invention was a method to reduce the number of
data-manipulations in a public key system without jeopardising the veracity of the output.
The method depended, amongst other things on the specific properties of the numbers
used as moduli. Schafly’s method is not more mathematical than RSA, but Schafly’s
patent has attracted criticism for claiming two prime numbers albeit in a specific utility
context. Individual primes vary in their specific properties, some lend themselves to such
a method as Schlafly claimed, others do not. Two of Schlafly’s claims indicate setting an
input port to specific primes in order to achieve the patent’s goal. The question again is:
‘if the claims are to specific mathematics – even numbers themselves - for particular use
are they still too broad to succeed’?
3.3
Hoffstein’s Patents116
114
MIT group.
CyberLaw [July 9th 1997].
116
In addition to the patent mentioned above, also consider US Patent 6,298,137. Also see Hoffstein’s
NTRUE web site.
115
27
Jeffrey Hoffstein elucidated mathematics to generate easily created, shorter encryption
keys, and provided an algorithm that allowed a speed of encryption and decryption up to
two orders of magnitude faster than the prior art. Was the method too general for
patentability, as certain contributors to the Internet Patent News have suggested?
Conclusions
1. The diffusion of the focus of invention in software to include physical artefacts is a
solution that baffles the central question of whether a mathematical claim is
excessively broad and ought not to be allowed, or whether it is so specific as to be
allowable within its utility ambit.
2. Utility ought to be located at the very focus of invention, even if that is mathematical.
3. Specific utility voiced within a claim, and made explicit in the claim preamble, rather
than reliant on added artefacts, is the best protection of patent quality.
4. Nowhere is the possible development of the role of the claim preamble discussed as
a methodology that might help to solve the problem discussed here.
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