My research is primarily focused on authenticated key exchange protocols. Specifically, I work in the field of provable security, where mathematics is used to prove that a particular construction meets certain security standards. In my research, I make these proofs and analyse what they mean in a real-world context. These proofs can be quite esoteric and difficult to apply to complex protocols, so I am developing techniques in this field to answer questions on important real-world protocols such as SSL/TLS and Signal Protocol.
My latest publications have been on the provable security guarantees gained by introducing shared state to authenticated key exchange protocols, and the first ever analysis and proof of security of Signal Protocol. This affects billions of people as it has recently been implemented in WhatsApp, Facebook Messenger and Google Allo amongst others.
I also teach my own undergraduate cryptography course at St Catherine's College, which I very much enjoy.
I am currently in the third year of my DPhil in the Information Security Group here. Before this, I took the MSc in Mathematics and the Foundations of Computer Science.
A Formal Security Analysis of the Signal Messaging Protocol
Katriel Cohn−Gordon‚ Cas Cremers‚ Benjamin Dowling‚ Luke Garratt and Douglas Stebila
In 2nd IEEE European Symposium on Security and Privacy. IEEE. 2017.
On Post−Compromise Security
Katriel Cohn−Gordon‚ Cas Cremers and Luke Garratt
In 29th Computer Security Foundations Symposium (CSF). IEEE. 2016.