NDSS

Decentralized Control: A Case Study of Russia

Reethika Ramesh (University of Michigan), Ram Sundara Raman (University of Michgan), Matthew Bernhard (University of Michigan), Victor Ongkowijaya (University of Michigan), Leonid Evdokimov (Independent), Anne Edmundson (Independent), Steven Sprecher (University of Michigan), Muhammad Ikram (Macquarie University), Roya Ensafi (University of Michigan)

Past censorship research has largely focused on blocking in highly centralized networks, such as China's. However, censorship in decentralized networks is on the rise, despite the fact that synchronizing blocking across large regions of hundreds or thousands of ISPs seems prohibitively difficult. In this paper, we systematically show the mechanisms that underlie decentralized information control by focusing on a case-study: Russia. Decentralized information control presents a host of problems for censorship measurement, including difficulty identifying censored content, the requirement for measurement from diverse perspectives, and varied censorship mechanisms that require significant effort to identify in a robust manner. By working with activists on the ground in Russia, we obtained a blocklist signed by the Russian government along with seven years of historical blocklist data. We also obtained access to twenty vantage points within Russia from which to measure, and we augmented this with remote measurement techniques.

Our study shows that decentralized network control results in very different experiences of the Internet for those within Russia. ISPs do not block content consistently, nor do they block in the same ways, utilizing a range of techniques including TCP/IP blocking, DNS poisoning, and HTTP content filtering. The challenges presented in Russia, as well as the patterns we identify, likely reflect the overall trends for decentralized information controls world-wide. Measurement and circumvention will become more difficult as networks continue to fracture and exhibit highly variant behavior based on location. Russia's rise to prominence as a censor is wake up call for censorship researchers, activists, and citizens of the global Internet, and understanding decentralized network controls will be key to continuing to preserve Internet freedom for years to come.