A dark wing of the intelligence supports the Tor Project

Experts working at US and UK Intelligence agencies on monthly base leak Tor vulnerabilities to the developers at the Tor Project.

The BBC reported that the executive director of the Tor Project revealed that both US and UK intelligence agencies share bugs anonymously with Tor developers.

The circumstance is quite surprising considering that both NSA and GCHQ are currently working to de-anonymize Tor users, but the information disclosed by Andrew Leman, in an interview with BBC confirm the existence of groups of experts inside the organizations that anonymously leak information about Tor vulnerabilities in order for the bugs to get patched.

“There’s a lot of groundswell of support as to what is going on, but at the same time there’s the other half of the organization that is: ‘You know what? People shouldn’t have privacy,’ and ‘Let’s go out and attack these things,’”“So there is always a balance between those who protect our freedom and liberty and those who don’t want you to have it.” Lewman said. 

Lewman confirmed that agency insiders ordinary used Tor’s mechanism for anonymous bug submissions which doesn’t request any information to the researchers which provide information on bugs in the Tor network.

According to Lewman in some cases the insiders have also provided the patches to fix the flaws, of course the experts at the Tor Project have carefully analyzed the code submitted. Lewman admitted to have been surprised by the quality of bug reports.

“Sometimes it includes a patch that says: ‘Here’s my code fix.’ And we look through all this stuff very carefully, and we’ve been totally impressed by the quality of bug reports that we get both on the software side, which is a coding error – sometimes very, very subtle – or on the design side, where you know you guys made a design decision here and maybe you want to consider some other use cases.”

Lewman admitted that this secret support provided by insiders is damaging the missions of the agencies to de-anonymize Tor users. The whistleblower Edward Snowden disclosed last year a presentation on a secret NSA project codenamed “Tor Stinks” explaining the effort spent by the agencies to track users on the Tor network.

The internal presentation confirmed the difficulties of the NSA to design an automated solution to de-anonymize Tor users on a large-scale.

“We will never to able to de-anonymize all Tor users all the time. With manual analysis, we can de-anonymize a very small fraction of Tor users.” is reported in the presentation.

The members of the Tor Project receive these submissions on a monthly basis, according to Lewman the insiders that submit the bugs have a deep knowledge of the Tor code and spent a lot of time to discover the bugs.

“Many people – you have to think about the type of people who would be able to do this and have the expertise and time to read Tor source code from scratch for hours, for weeks, for months and find and elucidate these super-subtle bugs or other things that they probably don’t get to see in most commercial software,” “And the fact that we take a completely anonymous bug report allows them to report to us safely.” he added.

The interview published by BBC confirms that intelligence has cyber capabilities to discover flaws in the Tor network, probably also other agencies have the same knowledge. The fact that some of the experts working for the Agency anonymously support the Tor project doesn’t mean that all the bugs are reported and these flaws in the wrong hands are a serious menace for Tor users privacy.

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Pierluigi Paganini

(Security Affairs – Tor project,  Intelligence)