AI
Backdoors, Subpoenas, and Distributed Trust
In 2005, EFF introduced Roger Dingledine to Department of Justice lawyers in Los Angeles. Twenty Secret Service agents lined the back wall, sunglasses on, silent throughout. The central debate: why Tor cannot have a backdoor. One DOJ lawyer raised his hand and asked for one. A second challenge: another DOJ lawyer asked why Tor couldn’t comply like Anonymizer.com, which did answer subpoenas. The answer is architecture. Anonymizer held user data and promised not to misuse it. Tor’s distributed trust model means no single point in the system knows who did what.
Why Tor Needs Allies Inside Law Enforcement
Dingledine argues Tor’s security depends on diverse users. Egyptian activists need cover traffic from governments, corporations, and ordinary people sharing the same network. A former FBI contact once stopped a DOJ meeting from drafting a law to ban Tor, simply by standing up and saying he used it daily for his job. Relay operators who get abuse complaints from ISPs need a contact already inside law enforcement. Nothing a relay operator says at that moment will be believed. The ally has to be in the room before the crisis starts.
The Extortionist Who Offered a Cut
In 2021, a Russian operator extorted dark web marketplaces via DDoS. The collateral traffic slowed Tor broadly. After Dingledine patched a rate-limiting fix, the attacker pivoted to hammering Tor’s nine directory authorities through 5,000 exit relays, pulling those relays onto ISP blocklists. A week of scrambling ended when the attacker showed up on IRC at 7 a.m., admitted he ran an extortion operation, and offered a profit cut to leave bugs unfixed. He then sent $10,000 in Monero as good faith. Tor burned it by forwarding the funds to the zero public key.
Censorship Engineering: Iran’s DPI Block and Russia’s Azure Accident
In 2011, Iran blocked Tor without touching all of TLS. A community DPI engineer found the fingerprint: Tor used a Diffie-Hellman prime from the DNSSEC RFC, not the same prime Firefox used with Apache. Same protocol, different parameter P. That attack was not on anyone’s prediction list. When Russia blocked Tor in December 2021, it hit public relays, default bridges, and Snowflake’s domain fronting. Snowflake had used ajax.aspnetcdn.com as its cover domain. Russia blocked it by IP. Azure shares addresses globally, so Russia accidentally took down all of Azure.
When the Wrong Tool Gets You Killed
An Iranian activist trainer taught people to use open proxies, VPNs, and Tor. He later realized that everyone he had taught anything other than Tor was dead or in jail. Dingledine ties this to the US: governments improve at surveillance gradually, and waiting until the threat becomes visible means leaving a data trail. The same pattern appeared at a New York NFT party Dingledine attended. A Pussy Riot member said the group used Tor while evading Russian secret police for three weeks. The day one member stopped using Tor, she was arrested.
37 Universities Now Running Tor Relays
EFF launched a campaign to get Tor relays running in universities. It started with 8 schools two years before this talk. At the time of the talk, 37 institutions had joined, including UCSD, MIT, CMU, University of Michigan, and UNC Chapel Hill. Morocco’s National Research and Education Network runs a relay. A junior high in Switzerland runs an exit relay because the sysadmin there set it up. Dingledine asked anyone connected to an educational institution to contact him and help grow the campaign.
Notable Quotes
Can I have a back door? DOJ lawyer · ▶ 3:48
Ah, so extortion. Roger Dingledine · ▶ 20:02
Well, more really. Extortionist · ▶ 20:05
I am the law. Plug it in. Emirati official (as recounted) · ▶ 33:01
Key Takeaways
- Tor’s distributed architecture holds no user data, making backdoor requests architecturally meaningless rather than just policy violations.
- Anonymity networks need diverse users, including governments and corporations, or activists lose the cover traffic that hides them.
- Censors consistently surprise defenders with blocking vectors that no prediction list anticipates; community debugging finds answers faster.
About the Speaker(s)
Roger Dingledine is co-founder and original developer of the Tor Project, a nonprofit that develops free and open source software to protect people from tracking, censorship, and surveillance online. He works with journalists and activists on many continents to help them understand and defend against the threats they face, and he is a lead researcher in the online anonymity field. EFF awarded him a Pioneer Award, and Foreign Policy magazine named him one of its top 100 global thinkers.