Censorship in the wild: Analyzing internet filtering in Syria

Abdelberi Chaabane*, Terence Chen, Mathieu Cunche, Emiliano De Cristofaro, Arik Friedman, Mohamed Ali Kaafar

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contributionpeer-review

51 Citations (Scopus)


Internet censorship is enforced by numerous governments worldwide, however, due to the lack of publicly available information, as well as the inherent risks of performing active measurements, it is often hard for the research community to investigate censorship practices in the wild. Thus, the leak of 600GB worth of logs from 7 Blue Coat SG-9000 proxies, deployed in Syria to filter Internet traffic at a country scale, represents a unique opportunity to provide a detailed snapshot of a real-world censorship ecosystem. This paper presents the methodology and the results of a measurement analysis of the leaked Blue Coat logs, revealing a relatively stealthy, yet quite targeted, censorship. We find that traffic is filtered in several ways: using IP addresses and domain names to block subnets or websites, and keywords or categories to target specific content. We show that keyword-based censorship produces some collateral damage as many requests are blocked even if they do not relate to sensitive content. We also discover that Instant Messaging is heavily censored, while filtering of social media is limited to specific pages. Finally, we show that Syrian users try to evade censorship by using web/socks proxies, Tor, VPNs, and BitTorrent. To the best of our knowledge, our work provides the first analytical look into Internet filtering in Syria.

Original languageEnglish
Title of host publicationProceedings of the 2014 Conference on Internet Measurement Conference
Place of PublicationNew York
PublisherAssociation for Computing Machinery
Number of pages14
ISBN (Electronic)9781450332132
Publication statusPublished - 5 Nov 2014
Externally publishedYes
Event2014 ACM Internet Measurement Conference, IMC 2014 - Vancouver, Canada
Duration: 5 Nov 20147 Nov 2014


Conference2014 ACM Internet Measurement Conference, IMC 2014


  • censorship
  • internet filtering
  • measurements


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