UCL logo

UCL Discovery

UCL home » Library Services » Electronic resources » UCL Discovery

Do You See What I See? Differential Treatment of Anonymous Users

Khattak, S; Fifield, D; Afroz, S; Javed, M; Sundaresan, S; Paxson, V; Murdoch, SJ; (2016) Do You See What I See? Differential Treatment of Anonymous Users. In: Proceedings of the NDSS Symposium 2016. Internet Society Green open access

[img]
Preview
Text
ndss16_tor_differential.pdf - ["content_typename_Published version" not defined]

Download (2MB) | Preview

Abstract

The utility of anonymous communication is undermined by a growing number of websites treating users of such services in a degraded fashion. The second-class treatment of anonymous users ranges from outright rejection to limiting their access to a subset of the service’s functionality or imposing hurdles such as CAPTCHA-solving. To date, the observation of such practices has relied upon anecdotal reports catalogued by frustrated anonymity users. We present a study to methodically enumerate and characterize, in the context of Tor, the treatment of anonymous users as second-class Web citizens. We focus on first-line blocking: at the transport layer, through reset or dropped connections; and at the application layer, through explicit blocks served from website home pages. Our study draws upon several data sources: comparisons of Internetwide port scans from Tor exit nodes versus from control hosts; scans of the home pages of top-1,000 Alexa websites through every Tor exit; and analysis of nearly a year of historic HTTP crawls from Tor network and control hosts. We develop a methodology to distinguish censorship events from incidental failures such as those caused by packet loss or network outages, and incorporate consideration of the endemic churn in web-accessible services over both time and geographic diversity. We find clear evidence of Tor blocking on the Web, including 3.67% of the top-1,000 Alexa sites. Some blocks specifically target Tor, while others result from fate-sharing when abuse-based automated blockers trigger due to misbehaving Web sessions sharing the same exit node.

Type: Proceedings paper
Title: Do You See What I See? Differential Treatment of Anonymous Users
Event: NDSS Symposium’16
Location: San Diego, CA, US
Dates: 21 February 2016 - 24 February 2016
ISBN: 1-891562-41-X
Open access status: An open access version is available from UCL Discovery
DOI: 10.14722/ndss.2016.23342
Publisher version: http://dx.doi.org/10.14722/ndss.2016.23342
Language: English
Additional information: This version is the published version. For information on re-use, please refer to the publisher’s terms and conditions.
UCL classification: UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Computer Science
URI: http://discovery.ucl.ac.uk/id/eprint/1472066
Downloads since deposit
94Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item