Roger Dingledine: Building Tor and Defending Anonymity

Roger Dingledine spent a summer as an intern at the National Security Agency. He then spent the next two decades building the one piece of software the agency admitted it couldn't beat.

Tor, the anonymity network he co-wrote and named, bounces the traffic of millions of people through volunteer relays around the world. Dissidents use it, journalists use it, and so do drug markets, which is why the FBI, the NSA and the Kremlin have all taken their shots at it.

Dingledine, known online as "arma," has answered every one of them in public, usually on the Tor blog and usually with receipts. The story of Tor is largely the story of him refusing to blink.

Roger Dingledine at a Glance

• Dingledine left MIT in June 2000 with three degrees and a master's thesis on anonymous publishing supervised by Ron Rivest, after stints on MIT's network security team and a summer internship at the NSA.
• In the early 2000s he joined Paul Syverson's onion routing project at the Naval Research Laboratory, brought in his MIT classmate Nick Mathewson and named the software Tor.
• The Tor network went live in October 2002 with free, open-source code; by the end of 2003 it had about a dozen volunteer nodes.
• The 2004 design paper he wrote with Mathewson and Syverson introduced hidden services and later won a USENIX Security Test of Time award; the EFF began funding the work the same year.
• The Tor Project became a nonprofit in 2006, added censorship-beating bridges in 2007 and shipped Tor Browser in 2008; the Arab Spring made it famous.
• Leaked NSA slides titled "Tor Stinks" surfaced in October 2013, and in 2015 Dingledine accused Carnegie Mellon researchers of taking at least $1 million from the FBI to attack Tor users.
• Tor won the EFF Pioneer Award in 2012 and the Levchin Prize in 2021; Dingledine was a Technology Review "35 under 35" pick in 2006 and a Foreign Policy top global thinker in 2012.
• Today he works on community and outreach for the Tor Project, which absorbed the Tails operating system in 2024, and he still headlines DEF CON, most recently with "Stories from a Tor dev" in 2025.

The Life of Roger Dingledine

The MIT Years

Dingledine did MIT the hard way. By June 2000 he'd collected a bachelor's degree in computer science and engineering, a second one in mathematics and a master of engineering, all at once.

His master's thesis, supervised by RSA co-inventor Ronald Rivest, described the Free Haven Project, a design for an anonymous, censorship-resistant data store where documents could be published and read without anyone being able to find and destroy them. It was, in hindsight, a rehearsal.

His resume from those years reads like the opening chapter of a spy novel: MIT's network security team, a graphics supercomputer startup called Integrated Computing Engines, a summer at the NSA. After graduation he took a job at a startup called Reputation Technologies with the title "Security Philosopher."

Onion Routing Gets a Name

Onion routing was born at the US Naval Research Laboratory in 1995, where David Goldschlag, Michael Reed and Paul Syverson asked whether internet connections could be built so that nobody could tell who was talking to whom. The answer was to wrap each message in layers of encryption and peel one off at each hop.

In the early 2000s Dingledine joined Syverson's project, and soon his MIT classmate Nick Mathewson joined too. Several onion routing efforts were appearing at the time, so Dingledine gave this one a name to tell it apart: Tor, for The Onion Routing.

The network went live in October 2002, with the code released as free and open-source software. By the end of 2003 it was running on about a dozen volunteer nodes, nearly all of them in the United States, plus one in Germany.

The Second-Generation Onion Router

In 2004 Dingledine, Mathewson and Syverson published "Tor: The Second-Generation Onion Router" at the USENIX Security Symposium. The paper added perfect forward secrecy, directory servers and configurable exit policies, and it described a design for location-hidden services reachable through rendezvous points, the feature the world would later know as .onion sites.

It also reported something onion routing had never had before: a working international network of more than 30 nodes running on the real internet, with no special privileges or kernel changes needed. A decade later USENIX gave the paper its Test of Time award.

The Electronic Frontier Foundation saw what Tor could mean for digital rights and began funding Dingledine's and Mathewson's work in 2004. In 2006 they set up The Tor Project, Inc. as a 501(c)(3) nonprofit, and the same year Technology Review named Dingledine one of its 35 innovators under 35.

Bridges, Browsers and the Arab Spring

Governments noticed Tor quickly, and some began blocking it. In 2007 the project introduced bridges, unlisted entry points that let users in censored countries reach the network, and Dingledine took the subject to DEF CON with a talk on Tor and blocking resistance.

The bigger leap came in 2008, when work began on Tor Browser, which packaged the network into a single download that anyone could use. When the Arab Spring arrived, Tor was ready, and the network grew to thousands of volunteer relays and millions of users.

Tor's dark side grew with it. Silk Road, the drug market that ran as a Tor hidden service until the FBI shut it down in October 2013, became the example critics reached for, and Dingledine spent years explaining that the anonymity that hides a dealer is the same anonymity that hides a dissident.

Tor Stinks

On October 4, 2013, the Guardian published NSA slides leaked by Edward Snowden. One presentation was titled "Tor Stinks," and it conceded that the agency couldn't unmask all Tor users all of the time.

Dingledine's response went up the same day. The good news, he wrote, was that the NSA had gone after users with a browser exploit, "meaning there's no indication they can break the Tor protocol or do traffic analysis on the Tor network."

The exploit, later identified as EgotisticalGiraffe, used an old, already patched Firefox bug. The lesson Dingledine drew was blunt: Tor's weakest link was the browser, not the network, and users needed to keep their software updated.

The Million-Dollar Attack

In July 2014 the Tor Project discovered a group of relays running a traffic confirmation attack against users of hidden services, and a Black Hat talk by researchers at Carnegie Mellon's Software Engineering Institute was abruptly withdrawn.

Sixteen months later, Dingledine connected the dots in a blog post titled "Did the FBI Pay a University to Attack Tor Users?" The researchers, he wrote, "were paid by the FBI to attack hidden services users in a broad sweep, and then sift through their data to find people whom they could accuse of crimes," for a payment of at least $1 million.

There was no warrant and no apparent review board, he argued, and outsourcing surveillance to academics set a precedent that should worry everyone. It remains one of the sharpest things a nonprofit has ever said about a federal agency.

The Censorship Arms Race

Dingledine's DEF CON talks became an annual report on the fight. In 2017 he introduced the next generation of onion services, in 2019 he described "the Tor censorship arms race," and in 2022 he explained how Russia was trying to block Tor after Moscow moved against the network.

The field caught up with him. In 2021 Tor received the Levchin Prize for Real-World Cryptography, joining the EFF Pioneer Award it'd won in 2012 and the Free Software Foundation's Award for Social Benefit from 2010.

Dingledine Today

Dingledine has held most jobs at the Tor Project, including president and research director, and now works on community and outreach. He moved to New York City in 2019 and is a visiting scholar at New York University.

The Tor Project itself keeps growing. In September 2024 it merged with Tails, the amnesic operating system that routes everything through Tor, under executive director Isabela Fernandes.

And Dingledine still tells the story in person. His DEF CON 33 talk in August 2025, "Stories from a Tor dev," drew well over 100,000 views online, and in 2026 he sat for an ask-me-anything session at FOSSASIA.

Roger Dingledine: Still Peeling the Onion

Tor is an odd thing to have built: a tool funded at various times by the US government, attacked by the US government and relied on by people hiding from governments everywhere.

Dingledine's answer has always been the same. Anonymity isn't a feature you can hand out only to the good guys, so you build it for everyone and defend it in public.

He interned at the NSA. The NSA has been trying to catch up with him ever since.