Proximax: Measurement-driven proxy dissemination

Abstract

Many people currently use proxies to circumvent government censorship that blocks access to content on the Internet. Unfortunately, the dissemination channels used to distribute proxy server locations are increasingly being monitored to discover and quickly block these proxies. This has given rise to a large number of ad hoc dissemination channels that leverage trust networks to reach legitimate users and at the same time prevent proxy server addresses from falling into the hands of censors. To address this problem in a more principled manner, we present Proximax, a robust system that continuously distributes pools of proxies to a large number of channels. The key research challenge in Proximax is to distribute the proxies among the different channels in a way that maximizes the usage of these proxies while minimizing the risk of having them blocked. This is challenging because of two conflicting goals: widely disseminating the location of the proxies to fully utilize their capacity and preventing (or at least delaying) their discovery by censors. © 2012 Springer-Verlag.