Project Jengo Redux: Cloudflare’s Prior Art Search Bounty Returns

A Familiar Fight, Renewed

Cloudflare is facing its second patent troll lawsuit. On March 15, Sable Networks — a company that hasn't appeared to run a real business in nearly a decade — filed suit against Cloudflare using patents that bear little relation to Cloudflare's business or services. This echoes Cloudflare's 2017 encounter with Blackbird Technologies, where the company decided to fight rather than pay a nuisance settlement.

That earlier fight produced Project Jengo: a crowdsourced effort to find prior art that could invalidate Blackbird's patents. It worked. Cloudflare won the lawsuit, one of Blackbird's other patents was invalidated, and prior art on 31 of Blackbird's patents was published for anyone to use. Blackbird went from being one of the most prolific patent trolls in the US to shrinking its staff and filing far fewer cases. Now Cloudflare is launching the same approach against Sable — and needs public help again.

$100,000 for Prior Art on Ten Patents

Sable is asserting ancient, 20-year-old patents and stretching them far beyond their intended scope. The company has already sued more than a dozen technology companies across a wide range of products. If its claims against Cloudflare succeed, Sable could plausibly extend those claims to mere router users — essentially anyone on the Internet.

Cloudflare is sponsoring a prior-art contest covering all of Sable's active patents. Participants submit evidence that the patented technology was already in use or known before the patent application was filed. Cloudflare will pay out $100,000 total, split among entrants who provide the most useful prior-art references for challenging Sable's patents.

Submissions are open for the duration of the case: Sable Networks, Inc. v. Cloudflare, Inc., No. 6:21-cv-00261-ADA (W.D. Tex.). The window closes when Sable drops the case with prejudice (meaning it can't re-file later), a settlement is reached, or the court resolves the case and appeals are exhausted. Every three months for two years or until the case ends — whichever comes first — Cloudflare will select winners from submissions to date and award a portion of the pool. Final winners will be selected at case end and receive the remaining funds. All relevant submissions will be made public.

Ten Sable patents are at issue. Four are asserted directly against Cloudflare:

The remaining six are also part of the prior-art search:

Publishing prior art on all of Sable's patents should give others a head start and lower the cost of fighting back. The Blackbird experience suggests this approach works: the drop in Blackbird's staffing and filings after Cloudflare published prior art on its patents shows that publicizing prior art can undercut the threat those patents pose.

The first Project Jengo contest received 275 submissions from 155 people covering 49 Blackbird patents, with payments to 18 participants. Community enthusiasm ran high:

Over the years I've been disappointed and angered by a number of patent cases where I feel that the patent system has been abused by so-called 'patent trolls' in order to stifle innovation and profit from litigation. With Jengo in particular, I was a fan of what Cloudflare had done previously with Universal SSL. When the opportunity arose to potentially make a difference with a real patent troll case, I was happy to try and help.

— Adam, Security Engineer

I'm pretty excited, I've never won a single thing in my life before. And to do it in service of taking down evil patent trolls? This is one of the best days of my life, no joke. I submitted because software patents are garbage and clearly designed to extort money from productive innovators for vague and obvious claims. Also, I was homeless at the time I submitted and was spending all day at the library anyway.

— Garrett, San Francisco

Why Sable’s Case Is Built on Twenty-Year-Old Concepts

The patents Sable Networks is asserting against Cloudflare trace back to Caspian Networks, a company founded as Packetcom in 1998 that attempted to commercialize a “flow-based router.” Caspian publicly demonstrated its Apeiro router in 2003, describing it as a conventional router augmented with extra memory and logic to handle packets belonging to the same flow. Caspian’s own 2003 presentation contrasted its design with existing routers in this way:

Caspian went out of business in 2006. Sable Networks then briefly picked up the technology, but its last visible activity appears to date from 2011. Last year, after a long period of inactivity, Sable shifted its focus to monetizing Caspian’s old patents through litigation—a classic patent troll strategy.

In the first round of lawsuits, Sable filed eight infringement cases against companies like Cisco and Juniper that manufacture and sell network equipment. All eight were promptly settled. Notably, those settlements came just before two significant events: Sable would have had to respond to a USPTO administrative proceeding challenging patent validity, and a district court judge was set to determine the proper scope of the patent claims. By settling early, Sable avoided any substantive ruling on its broadly asserted claims.

Shortly after settling those cases, Sable filed six new lawsuits against a new set of technology companies, this time including Cloudflare. Unlike the earlier defendants, Cloudflare does not manufacture or sell routers or switches—making Sable’s infringement allegations much more of a stretch. With Cloudflare, Sable has now found a defendant willing to fight back.

The ’431 Patent and Overreach

All four patents Sable asserts against Cloudflare were filed between 2000 and 2004, a time when dial-up internet access was still common. One example is U.S. Patent No. 6,954,431, titled “Micro-Flow Management,” filed on April 19, 2000. The patent describes a router that labels packets for a given flow and forwards all packets in that flow based on that label:

The patent claims to teach a new switching technology that provides a previously unavailable degree of quality of service—echoing Caspian’s Apeiro router that the market rejected a decade ago. But Sable’s interpretation stretches these patents far beyond their original scope. The claims appear to cover any kind of packet processing, possibly even the “conventional routers” of the early 2000s that handled each packet independently.

This broad interpretation has already been extended to firewalls—both software and devices. If Sable’s logic holds, any person or business using a firewall, or even a WiFi router at home, could be in its crosshairs. The potential targets are not limited to large companies; anyone trying to protect their network from external threats is at risk.

The Incentive Problem Persists

Patent trolls thrive on this distorted incentive structure, driven by the enormous cost of defending even meritless claims. According to the 2019 Report of the Economic Survey by the American Intellectual Property Law Association, the median cost of defending a patent infringement case brought by a non-practicing entity through trial and appeal was $4.5 million for large cases with over $25 million at risk. Even for small cases with less than $1 million at stake, the median defense cost was $750,000.

Since most defendants will settle at a fraction of their expected litigation costs rather than see the case through to a verdict, trolls see only upside in filing as many lawsuits as possible, regardless of the strength of their claims. Their business model relies on taking vague patents from years ago and applying them as broadly as imaginable to new technologies and companies. These entities have no products of their own; they exist solely to extract a tax on others.

After several years of decline, patent litigation rose about 12% in 2020 compared to 2019, and the Electronic Frontier Foundation noted a similar uptick in troll filings, including a case where a troll sued a COVID-19 test maker during the height of the pandemic. The trend has continued: a report noted a 43.3% increase in patent litigation in Q1 2021 compared to the same period a year earlier, with non-practicing entities seeing their busiest first quarter since 2015, fueled by the litigation finance industry’s abundant capital.

Cloudflare remains a strong supporter of the patent system—the company has been issued 160+ patents that allow it to market and deliver its services with confidence. But patent trolls assert fictional uses of their patents without the investment or market risk that real innovators bear. Project Jengo is designed to reintroduce real costs to the filing of meritless patent lawsuits. By finding and submitting strong prior art, you can help send the message that filing the wrong case risks far more than losing a single lawsuit.