A patent troll that accused Rackspace of violating a patent merely by selling Linux-based servers has seen its case thrown out. A judge ruled the patent claim invalid because it describes a relatively simple math operation.

The company in question is Uniloc, which has a long history of suing tech vendors. In 2009, a US District Court judge overturned a $388 million verdict Uniloc had won against Microsoft. That litigation was finally settled late last year for an undisclosed sum. Uniloc continues litigating, however, with at least a dozen lawsuits filed just last week.

Uniloc sued Rackspace in June 2012 in US District Court in Eastern Texas (PDF), claiming Rackspace violated its patent "by or through making, using, offering for sale, selling and/or importing servers running Linux Kernel (version 2.6 or higher), which is used to process floating point operations carried out on Rackspace’s servers including those servers used in conjunction with Rackspace’s hosting solutions/products."

Math operations aren't automatically unpatentable, but US District Court Judge Leonard Davis ruled yesterday (PDF) that this one isn't novel enough to deserve patent protection. Why not? Because the "invention" claimed was just a decision to round numbers before, instead of after, an arithmetic computation. Seriously.

Loss comes in patent-friendly court

Uniloc's loss is remarkable for being so decisive—its complaint was tossed before it even reached trial—and because it came in a court notorious for being friendly to patent holders. Davis (whose son is the lawyer for another patent troll with cases in East Texas, Lodsys) is the chief judge in the district and recently upheld a $368.2 million verdict against Apple in a case involving FaceTime.

Uniloc's patent, filed in 1995 and granted in 1999, covers a "Method and apparatus for handling overflow and underflow in processing floating-point numbers." Uniloc acquired this patent in January 2012 from inventor James Brakefield, who works as an expert witness. This is not the primary patent Uniloc uses to sue vendors, so the rest of its lawsuits will not be impeded by Davis's decision.

The patent asserted against Rackspace has 28 claims, with 20 of them being connected to claim #1, the only one Uniloc asserted. The judge's ruling knocks out most of the patent by striking down the first claim, which reads:

A method for processing floating-point numbers, each floating-point number having at least a sign portion, an exponent portion and a mantissa portion, comprising the steps of: converting a floating-point number memory register representation to a floating-point register representation; rounding the converted floating-point number; performing an arithmetic computation upon said rounded number resulting in a new floating-point value; and converting the resulting new floating-point register value to a floating-point memory register representation.

A floating point number is a number with a decimal point and a certain number of significant figures.

Uniloc was seeking a jury trial, but Davis granted Rackspace's motion to dismiss the complaint entirely "for failure to allege infringement of a patentable claim."

Rackspace is a customer of Red Hat, maker of Red Hat Enterprise Linux. Rackspace has said it would "love to get rid of software patents," and Red Hat routinely defends itself and its customers against patent attacks. In this case, Red Hat said it "provided Rackspace’s defense as part of Red Hat’s commitment to standing behind customers through Red Hat’s Open Source Assurance program."

Rackspace argued that the claim is unpatentable and Davis agreed. For one thing, the claim fails the "machine-or-transformation" test because it does not involve a machine, and the "the transformation portion of the test is not satisfied by the conversion of a number from one format to another," the judge wrote.

Rackspace also argued that the patent claim violates a Supreme Court "prohibition against patenting mathematical formulas and abstract ideas."

In describing just how simple the patent claim is, Davis summarized it as follows: “Claim 1 is, in essence, a formula to 'solve mathematical problems of converting one form of numerical representation to another.' Claim 1 recites a four-step method for processing floating-point numbers: (1) convert the floating-point number from a 'memory register representation' to a 'register representation'; (2) round the result; (3) 'perform an arithmetic computation' on the rounded result to obtain a new floating-point number; and (4) convert the result back to a 'memory register representation.'"

The "novelty" of the claim "is the rounding of the floating-point number before, rather than after, the arithmetic computation."

"Claim 1, then, is merely an improvement on a mathematical formula," Davis wrote. "Even when tied to computing, since floating-point numbers are a computerized numeric format, the conversion of floating-point numbers has applications across fields as diverse as science, math, communications, security, graphics, and games. Thus, a patent on Claim 1 would cover vast end uses, impeding the onward march of science. Under Flook, the improvement over the standard is insufficient to validate Claim 1’s otherwise unpatentable subject matter."

"Flook" refers to Parker v. Flook, a 1978 case in which "the Supreme Court found unpatentable claims directed to an improved method for calculating, using a generalized formulation for converting numbers," Davis wrote.

Not Uniloc's only patent—far from it

Unfortunately for the many companies sued by Uniloc, the patent in the Rackspace case is just a small piece of its portfolio containing more than 50 patents. Red Hat told Ars that it is not aware of any other lawsuits based on this patent.

Uniloc's most important patent is #5,490,216, covering a system for software registration designed to prevent software piracy. The '216 patent has been used in dozens of lawsuits.

The company's website promises continued battles based on this patent. "In 2003 Uniloc filed a patent infringement lawsuit against Microsoft for the unauthorized use of a product activation anti-piracy system on Microsoft’s Windows XP and Office XP products," the company states. "In 2009 a Federal Court jury in Rhode Island found Microsoft guilty of willful infringement and ordered Microsoft to pay Uniloc $388 Million in damages. ... Later that year the judge in the case overturned the jury’s verdict. Uniloc has appealed this decision to the US Court of Appeals for the Federal Circuit. Nevertheless, the Court maintained that Uniloc’s patent is valid, so Uniloc will continue to protect its patent and defend its intellectual property." Microsoft and Uniloc settled in March of last year.

Uniloc isn't kidding about pursuing new lawsuits. It filed 12 new suits on March 21 in the Eastern District of Texas against Activision Blizzard, Aspyr Media, Digital River, Electronic Arts, McAfee, Pervasive Software, Sony, Symantec, Gear Software, Sage Software, SolarWinds, and Wildpackets. Those suits are based on the '216 patent asserted against Microsoft.

Uniloc Luxembourg filed 16 suits in the Eastern District in December 2012 and about a dozen in October 2012. Several of those cases have been withdrawn by Uniloc, probably due to settlements.

While Uniloc's litigation days aren't over, Red Hat and Rackspace declared yesterday's ruling to be an important victory against companies that file patent lawsuits despite not making any technology of their own.

“NPE [non-practicing entity] patent lawsuits are a chronic and serious problem for the technology industry," Red Hat Assistant General Counsel Rob Tiller said in an announcement. "Such lawsuits, which are frequently based on patents that should never have been granted, typically cost millions of dollars to defend. ... Courts can help address this problem by determining the validity of patents early and with appropriate care. In this case, Judge Davis did just that, and set a great example for future cases.”

“The early dismissal of this case delivers a clear message that patent assertion entities can’t expect quick settlements on weak claims, a tactic many patent assertion entities use to monetize questionable patents,” Rackspace General Counsel Alan Schoenbaum said. “We salute Red Hat for its outstanding defense and for standing firm with its customers in defeating this patent troll. We hope that many more of these spurious software patent lawsuits will be dismissed on similar grounds."

We've asked Uniloc if it will appeal the case, but we haven't heard back yet.

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