University of Twente Student Theses


Quantum-safe TOR, post-quantum cryptography

Tujner, Zsolt (2019) Quantum-safe TOR, post-quantum cryptography.

[img] PDF
Abstract:Nowadays there is vast information publicly available on the internet and it is ever-expanding. This knowledge should be available to anyone, but some governments or organizations consider the knowledge gained by information unwanted. They can abuse their power by blocking access to the websites on the internet thus, depriving people of their free will. These oppressive regimes also monitor internet traffic and people who are out of line may be severely punished. The Onion Router (TOR) network aims to grant people in such abusive areas anonymity on the internet, but with the emerge of quantum computers this anonymity is threatened. In this work, we give insight into a quantum-safe TOR network that grants anonymity in the quantum world. To do so, we examined which parts of TOR would become vulnerable in a quantum world. We identified that the symmetric key, and the long-term, medium-term keys generated by asym- metric cryptography are the most concerning cryptographic challenges TOR faces in order to preserve forward secrecy. We suggest changes to these parts and predict drawbacks regarding the changes. To prove our predictions, in our experiments we used an existing implementation that simulates the behaviour of TOR. For benchmarking, an implementation called SweetOnions was used, later this implementation was updated by adding quantum-safe schemes. Purely quantum-safe and hybrid imple- mentations were both tested. The experiments performed measured CPU cycles required for key generation, message encapsulation and decapsula- tion, and circuit creation. Message sizes were also measured to see how quantum-safe cryptography impacts network traffic. Message sizes pose the biggest challenge for TOR, because sending too many packets can cripple the whole network. Finally, based on our results, we show that quantum-safe TOR is possible and suggest two versions - one that can be used in a purely quantum-safe setting, and one that can be used in a hybrid setting.
Item Type:Essay (Master)
Faculty:EEMCS: Electrical Engineering, Mathematics and Computer Science
Subject:54 computer science
Programme:Computer Science MSc (60300)
Link to this item:
Export this item as:BibTeX
HTML Citation
Reference Manager


Repository Staff Only: item control page