Towards a Comprehensive Understanding of Russian Transit Censorship

Towards a Comprehensive Understanding of Russian Transit Censorship

Abstract: Within the past decade, Russia has significantly increased its censorship efforts. This raises the question as to whether Russian ISPs are applying their censorship policies not only to traffic terminating in Russia, but also to traffic that simply transits Russia. Evidence of this “collateral damage” in central Asia due to filtering by upstream Russian network providers has been noticed in previous research, but the full extent of it has yet to be studied. In this work, we present first steps toward a comprehensive study of the collateral damage of Russian censorship. We scan the IP address spaces of 18 countries surrounding Russia while attempting to elicit responses from Russian censors. We identify Russian collateral damage affects at least some of the traffic for 9 of these 18 countries, and that at least 7 ASes are responsible for censorship of transit traffic. Our results highlight the need for further study of collateral damage globally.