In today’s lecture, we’ll discuss two threats to the Internet that have emerged over the last few years: network surveillance and network censorship. Network surveillance is the act of monitoring a user’s network activity (e.g., who the user is talking to, what the user is talking about, and when the user is talking). Network surveillance is typically done in secret so that the user being monit...

The tug-of-war on the Internet between censor and anti-censor technologies is intensifying. With an aim to raise awareness on Internet censorship and its circumvention, this paper and its companion Part II present a conceptual study of Internet censorship and anti-censorship. This first paper focuses on Internet censorship. It outlines an historical account of censorship through the lens of new...

A proof of strong cosmic censorship is presented for a class of solutions of the Einstein-Maxwell equations, those with polarized Gowdy symmetry. A key element of the argument is the observation that by means of a suitable choice of variables the central equations in this problem can be written in a form where they are identical to the central equations for general (i.e. non-polarized) vacuum G...

Analysing censorship incidents targeting popular circumvention tools such as Tor can be a tedious task. Access to censoring networks is typically difficult to obtain and remote analysis is not always possible. Analysis is however feasible if users behind the censoring networks are given the opportunity to help. In this paper, we propose a lightweight censorship analyser for Tor which is meant t...

Internet censorship is on the rise as websites around the world are increasingly blocked by government-level firewalls. Although popular anonymizing networks like Tor were originally designed to keep attackers from tracing people’s activities, many people are also using them to evade local censorship. But if the censor simply denies access to the Tor network itself, blocked users can no longer ...

We design DNS-sly, a counter-censorship system which enables a covert channel between a DNS client and server. To achieve covertness and deniability in the upstream direction, DNS-sly applies user personalization, adapting to individual behaviors. In the downstream direction, it utilizes CDN-related DNS responses to embed data, while retaining statistical covertness. We show DNS-sly achieves do...

A brief review is given of three recent results concerning classical solutions of gravitational theories: (1) With asymptotically anti de Sitter boundary conditions, there are matter theories satisfying the positive energy theorem which violate cosmic censorship. (2) Despite supersymmetry, there are solutions to N = 8 supergravity in which the total gravitational energy is arbitrarily negative....

Despite the high perceived value and increasing severity of online information controls, a data-driven understanding of the phenomenon has remained elusive. In this paper, we consider two design points in the space of Internet censorship measurement with particular emphasis on how they address the challenges of locating vantage points, choosing content to test, and analyzing results. We discuss...

Both Lowe and Tsai have presented their own versions of the theory that both indicative subjunctive conditionals are strict conditionals. We critically discuss we find each version wanting.