Internet Censorship in China: Where Does the Filtering Occur?

Xu, Xueyang; Mao, Zeyu; Halderman, J. Alex

doi:10.1007/978-3-642-19260-9_14

Cited by 89 publications

(76 citation statements)

References 2 publications

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“…They also proposed ConceptDoppler, a system for monitoring which keywords are filtered over time. In more recent work on censorship in China [76], Xueyang Xu et al explored the AS-level topology of China's network and probed the firewall to find the locations of filtering devices. They found that two major ISPs in China had different approaches to the placement of filtering devices, either decentralized or in the backbone.…”

Section: Related Workmentioning

confidence: 99%

Analysis of country-wide internet outages caused by censorship

Dainotti

Squarcella

Aben³

et al. 2011

Proceedings of the 2011 ACM SIGCOMM Conference on Internet Measurement Conference

181

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In the first months of 2011, Internet communications were disrupted in several North African countries in response to civilian protests and threats of civil war. In this paper we analyze episodes of these disruptions in two countries: Egypt and Libya. Our analysis relies on multiple sources of large-scale data already available to academic researchers: BGP interdomain routing control plane data; unsolicited data plane traffic to unassigned address space; active macroscopic traceroute measurements; RIR delegation files; and MaxMind's geolocation database. We used the latter two data sets to determine which IP address ranges were allocated to entities within each country, and then mapped these IP addresses of interest to BGP-announced address ranges (prefixes) and origin ASes using publicly available BGP data repositories in the U.S. and Europe. We then analyzed observable activity related to these sets of prefixes and ASes throughout the censorship episodes. Using both control plane and data plane data sets in combination allowed us to narrow down which forms of Internet access disruption were implemented in a given region over time. Among other insights, we detected what we believe were Libya's attempts to test firewall-based blocking before they executed more aggressive BGP-based disconnection. Our methodology could be used, and automated, to detect outages or similar macroscopically disruptive events in other geographic or topological regions.

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Section: Related Workmentioning

confidence: 99%

Analysis of country-wide internet outages caused by censorship

Dainotti

Squarcella

Aben³

et al. 2011

Proceedings of the 2011 ACM SIGCOMM Conference on Internet Measurement Conference

181

View full text Add to dashboard Cite

show abstract

“…China has received the most attention [4,18,47,67,70]. Similar studies have been published for Iran [6], Pakistan [44,45], and Turkey [45].…”

Section: Previous Workmentioning

confidence: 82%

Topics of Controversy: An Empirical Analysis of Web Censorship Lists

Weinberg

Sharif

Szurdi

et al. 2016

Proceedings on Privacy Enhancing Technologies

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Studies of Internet censorship rely on an experimental technique called probing. From a client within each country under investigation, the experimenter attempts to access network resources that are suspected to be censored, and records what happens. The set of resources to be probed is a crucial, but often neglected, element of the experimental design. We analyze the content and longevity of 758,191 webpages drawn from 22 different probe lists, of which 15 are alleged to be actual blacklists of censored webpages in particular countries, three were compiled using a priori criteria for selecting pages with an elevated chance of being censored, and four are controls. We find that the lists have very little overlap in terms of specific pages. Mechanically assigning a topic to each page, however, reveals common themes, and suggests that handcurated probe lists may be neglecting certain frequentlycensored topics. We also find that pages on controversial topics tend to have much shorter lifetimes than pages on uncontroversial topics. Hence, probe lists need to be continuously updated to be useful. To carry out this analysis, we have developed automated infrastructure for collecting snapshots of webpages, weeding out irrelevant material (e.g. site "boilerplate" and parked domains), translating text, assigning topics, and detecting topic changes. The system scales to hundreds of thousands of pages collected.

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“…They also proposed ConceptDoppler, a system for monitoring which keywords are filtered over time. In more recent work on censorship in China [64], Xueyang Xu et al explored the AS-level topology of China's network and probed the firewall to find the locations of filtering devices. They found that two major ISPs in China had different approaches to the placement of filtering devices, either decentralized or in the backbone.…”

Section: Related Workmentioning

confidence: 99%

Analysis of Country-Wide Internet Outages Caused by Censorship

Dainotti

Squarcella

Aben³

et al. 2014

IEEE/ACM Trans. Networking

View full text Add to dashboard Cite

In the first months of 2011, Internet communications were disrupted in several North African countries in response to civilian protests and threats of civil war. In this paper we analyze episodes of these disruptions in two countries: Egypt and Libya. Our analysis relies on multiple sources of large-scale data already available to academic researchers: BGP interdomain routing control plane data; unsolicited data plane traffic to unassigned address space; active macroscopic traceroute measurements; RIR delegation files; and MaxMind's geolocation database. We used the latter two data sets to determine which IP address ranges were allocated to entities within each country, and then mapped these IP addresses of interest to BGP-announced address ranges (prefixes) and origin ASes using publicly available BGP data repositories in the U.S. and Europe. We then analyzed observable activity related to these sets of prefixes and ASes throughout the censorship episodes. Using both control plane and data plane data sets in combination allowed us to narrow down which forms of Internet access disruption were implemented in a given region over time. Among other insights, we detected what we believe were Libya's attempts to test firewallbased blocking before they executed more aggressive BGP-based disconnection. Our methodology could be used, and automated, to detect outages or similar macroscopically disruptive events in other geographic or topological regions.

show abstract

Internet Censorship in China: Where Does the Filtering Occur?

Cited by 89 publications

References 2 publications

Analysis of country-wide internet outages caused by censorship

Analysis of country-wide internet outages caused by censorship

Topics of Controversy: An Empirical Analysis of Web Censorship Lists

Analysis of Country-Wide Internet Outages Caused by Censorship

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