Feeds

Boffins follow TOR breadcrumbs to identify users

Anonymity? Fuggedaboutit! Watching TOR for months reveals true names

High performance access to file storage

It's easier to identify TOR users than they believe, according to research published by a group of researchers from Georgetown University and the US Naval Research Laboratory (USNRL).

Their paper, Users Get Routed: Traffic Correlation on Tor by Realistic Adversaries, is to be presented in November at November's Conference on Computer and Communications Security (CCS) in Berlin. While it's been published at the personal page of lead author Aaron Johnson of the NRL, it remained under the radar until someone posted a copy to Cryptome.

The paper states simply that “Tor users are far more susceptible to compromise than indicated by prior work”. That prior work provided the framework for what Johnson's group has accomplished: using traffic correlation in the live TOR network to compromise users' anonymity.

“To quantify the anonymity offered by Tor, we examine path compromise rates and how quickly extended use of the anonymity network results in compromised paths”, they write. In some cases, they found that for the patient attacker, some users can be identified with 95 percent certainty.

The compromise isn't something available to the trivial attacker. The models that Johnson developed assume that an adversary has access either to Internet exchange ports, or controls a number of Autonomous Systems (for example an ISP). However, it's probably reasonable to assume that the instruments of the state could deploy sufficient resources to replicate Johnson's work.

At the core of Johnson's work is a Tor path simulator that he's published at github. The TorPS simulator helps provide accurate AS path inference from TOR traffic.

“An adversary that provides no more bandwidth than some volunteers do today can deanonymize any given user within three months of regular Tor use with over 50 percent probability and within six months with over 80 percent probability. We observe that use of BitTorrent is particularly unsafe, and we show that long-lived ports bear a large security cost for their performance needs. We also observe that the Congestion-Aware Tor proposal exacerbates these vulnerabilities,” the paper states.

If the adversary controls an AS or has access to Internet exchange point (IXP) traffic, things are even worse. While the results of their tests depended on factors such as AS or IXP location, “some users experience over 95 percent chance of compromise within three months against a single AS or IXP.”

The researchers also note that different user behaviours change the risk of compromise. Sorry, BitTorrent fans, your traffic is extremely vulnerable over time. ®

High performance access to file storage

More from The Register

next story
Parent gabfest Mumsnet hit by SSL bug: My heart bleeds, grins hacker
Natter-board tells middle-class Britain to purée its passwords
Obama allows NSA to exploit 0-days: report
If the spooks say they need it, they get it
Web data BLEEDOUT: Users to feel the pain as Heartbleed bug revealed
Vendors and ISPs have work to do updating firmware - if it's possible to fix this
Samsung Galaxy S5 fingerprint scanner hacked in just 4 DAYS
Sammy's newbie cooked slower than iPhone, also costs more to build
Snowden-inspired crypto-email service Lavaboom launches
German service pays tribute to Lavabit
One year on: diplomatic fail as Chinese APT gangs get back to work
Mandiant says past 12 months shows Beijing won't call off its hackers
Call of Duty 'fragged using OpenSSL's Heartbleed exploit'
So it begins ... or maybe not, says one analyst
NSA denies it knew about and USED Heartbleed encryption flaw for TWO YEARS
Agency forgets it exists to protect communications, not just spy on them
prev story

Whitepapers

Securing web applications made simple and scalable
In this whitepaper learn how automated security testing can provide a simple and scalable way to protect your web applications.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
HP ArcSight ESM solution helps Finansbank
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.