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. Countries facilitate censorship by inspecting protocols like IP, TPC, HTTP, DNS, TLS, and VPNs. The sophistication of censors varies as much as the techniques they use. Overall, this leads to a diverse landscape of censorship around the world. In recent years, the analysis of censorship has increased greatly. Automated tools for global censorship analysis and circumvention have been introduced together with country-specific in-depth analyses.
To aid in this acquisition of knowledge, we want to ascertain censorship techniques and the circumventability of censorship around the globe. This includes both country-specific analyses and new circumvention or analysis techniques. Below, we gather potential thesis topics:
Censorship Circumvention Tools Comparison. There are many existing censorship circumvention tools like GoodybeDPI, GreenTunnel, or DPYProxy. Your task is to compile an extensive list of existing circumvention tools while analyzing the specific functionalities that the tools provide. The tools should then be categorized based on their functionality and integrated into our existing censorship probe scanning framework as possible recommendations when specific manipulations work to access a website (the code exists for this). An optimal solution would include specific parameters for the recommended tools and/or setup instructions such that the specific manipulation can be applied by a user without existing knowledge about the tools.
Fragmentation Analysis [MA]. One common set of circumvention techniques that works against a lot of censors is fragmentation-based techniques. Fragmentation techniques can be applied on the TCP and TLS layer (TCP segmentation and TLS record fragmentation). The reason for the success is that many censors struggle to reassembly the fragmented parts correctly, leading to the censor not recognizing the data as to-be-censored. This limitation of censors could stem from performance or storage limitations as the reassembly takes additional time and state holding. While fragmentation techniques are known to be successful, there is a lack of an extensive study that analyzes the behavior of different censors regarding their reassembly mechanism. One could look at different fragmentation points, number of fragments, size of fragments, different offsets, fragmentation overlap, and swapping fragments to infer what the reassembly mechanism of the censor can handle.
Censorship in Marginally Analyzed Countries [BA]. In recent years, some countries have been analyzed more thoroughly than others. Prime examples are the censors of Russia, China, and India. However, censorship occurs in many countries around the globe. In this thesis, you will focus censorship analysis on one or a few countries that have not been analyzed thoroughly up until now. You will also compare the censorship techniques you encounter with those of more thoroughly analyzed censors.
None of these topics interest you, but you still want to analyze censorship in your thesis? Feel free to contact us with your own ideas. We can try to find a topic together!
Requirements (usually):
- Programming, Java, Kotlin, Python
- Knowledge of DNS, HTTP, Network Stack (TCP/IP)
- Interest in censorship (circumvention)
