CS590B690B Detecting network interference Lecture 10 Phillipa Gill – umasS Amherst

Where we are Last time: Case study: Iran + Pakistan Questions? Revisit hands on activity … RIPEstat page for AS 12880: https://stat.ripe.net/AS12880#tabId=at-a-glance Try looking up other Iranian networks NDT data in Google http://www.google.com/publicdata/explore?ds=e9krd11m38onf_&ctype=l&str ail=false&bcs=d&nselm=h&met_y=download_throughput&scale_y=lin&ind_y =false&rdim=country&idim=country:364&ifdim=country&ind=false OOKLA Speed test: http://www.google.com/publicdata/explore?ds=z8ii06k9csels2_&ctype=l&met _y=avg_download_speed

Test your knowledge (Iran) How did the government assert control over the Internet in 2001? What were the conflicting goals of Iran in implementing censorship? What was the end result of these? What is the `campaign for halal Internet’? Why did people fear this? What is the purpose of IP addresses designated in RFC1918? What are two techniques used by Anderson to map an internal 10.x.x.x address to an external IP? What is the idea of “dimming the Internet”? How can “dimming” be measured? How did the pseudonymous paper identify filtering based on the host header? What type of proxy did they find?

Test your knowledge (Pakistan) Why is censorship in Pakistan well known? Which protocol allowed collateral damage when they censored YouTube? How does the ISP Lens paper differ from other papers we’ve studied in the class? What types of filtering does the ISP lens paper identify and how? What was the impact of filtering? On user behavior? On content providers? On service providers?

Today Case Study: China Background (ONI report) Great Cannon Locating the censors (Xu et al.) http://pam2011.gatech.edu/papers/pam2011--Xu.pdf

background China: one-party state, ruled by the Chinese Communist Party (CCP) Conflict between IT development and ability to contain sensitive or threatening information Several milestones challenged gov’t control: Anniversary of Tibetan Uprising in 2008: Protests in Lhasa 2008 Beijing Olympics, pressures to lessen censorship Foreign reporters had unprecedented access within the country Domestic news still highly restricted Unfettered Internet access for foreign journalists restricted to “games-related” Web sites 2009 Riots in Urumqi led to Internet restrictions to “quench the riot … and prevent violent” State sponsored Web site access (31 sites) slowly restored but Internet access in Xinjiang was effectively severed for 10 months

Background 2 2010 Google refuses to comply with legal requirements of content filtering in China Attempts to hack gmail accounts of human rights activists Google wanted to establish a truly free and open search engine or officially close Google.cn Google’s actions placed PRC’s censorship practices in the international spotlight China’s population means that even at 28.9% Internet penetration the country has the most Internet users in the world Mobile networking is important for bridging the rural/urban divide 10% of users access the Internet only on a mobile device Widespread use of Internet has led to a change in the public discourse and exposing corruption of government officials and even dismissal of senior officials

Internet filtering in china Initial project: Green Dam Youth Escort project Filtering at the level of the user’s computer Analysis by ONI + StopBadware showed that it wasn’t effective in blocking all pornography and would unpredictably block political and religious content Follow on project: “Blue Dam” with more features mandated to be installed by ISPs Server side/ISP-level blocking of content deemed to be inappropriate Blog services are also responsible for policing content on their sites Must install keyword filters + delete accounts of violating users More on this in the online social networking lecture …

Today’s readings Great Cannon Internet Censorship in China: Where Does the Filtering Occur? Xu et al. 2011

Hands on activity Online reports of Chinese censorship: https://en.greatfire.org/ http://www.herdict.org/explore/indepth?fc=CN http://www.google.com/transparencyreport/traffic/explorer/?r=CN &l=EVERYTHING China Chats data: https://china-chats.net/ Video chat censorship: https://www.usenix.org/sites/default/files/conference/protected- files/foci15_slides_knockel.pdf