BANC: Build­ling A Net­work Cen­sor (SS23)


Various state-actors around the world deploy some degree of censorship. To prevent users from accessing specific websites, they alter, drop, and redirect connection attempts to websites and services they deem malicious. Prevalent censorship techniques target the IP, TCP, and TLS layer. While circumvention techniques exist, they draw their inspiration from existing censors in the wild.

To gain an insight into the creation and difficulties of censorship devices, this Project Group aims to develop and build a Network Censor that censors internet traffic in a lab environment. By designing a censor themselves, students gain an insight into current censorship techniques and recognize limitations of current censors. Ideally, the censor will be highly customizable to be usable as an Integration Testing tool for Censorship Circumvention Tools.

Slides of entry presentation:


Coarse Overview

1. Identify current censorship techniques

2. Define architecture and censorship technique(s) of the censor

2.5 Define optional features for certain subgroups of the project group (feel free to present ideas)

3. Implement the censor

4. Identify and document shortcomings of the censor using a censorship circumvention tool


1. Programming skills

2. Interest in censorship (circumvention)

3. Read and understand papers


Even Censors Have a Backup

Geneva: Evolving Censorship Evasion Strategies

GET /out: Automated Discovery of Application-Layer Censorship Evasion Strategies

Censored Planet: An Internet-wide, Longitudinal Censorship Observatory

For questions and ideas, please contact Niklas Niere