Konrad Kohbrok's Homepage


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Work and Research

Current Place of Work

I’m currently working at Phoenix R&D, where Raphael, Julian and I are working on security and privacy enhancing technologies in the secure messaging space.

Together with our friends at Cryspen, we are also maintaing OpenMLS, a free and open source implementation of the messaging layer security protocol written in rust.

Research Interests

Research-wise, I’m interested in cryptographic protocols for real-world applications with a focus on key exchange protocols in general and secure (group) messaging protocols in particular.

Besides the academic treatment of such protocols, I’m also interested in protocol design and implementations (with a focus on Rust). More concretely, I’m actively involved in the MLS and MIMI working groups at the IETF.


State-Separating Proofs: A Reduction Methodology for Real-World Protocols
Chris Brzuska and Antoine Delignat-Lavaud and Konrad Kohbrok and Markulf Kohlweiss
ePrint (Published at AsiaCrypt 2018)

The Complexities of Healing in Secure Group Messaging: Why Cross-Group Effects Matter
Cas Cremers and Britta Hale and Konrad Kohbrok
ePrint (Extended abstract published at USENIX Security ‘21)

Bringing State-Separating Proofs to EasyCrypt - A Security Proof for Cryptobox
François Dupressoir and Konrad Kohbrok and Sabine Oechsner
ePrint (Published at CSF 2022)

Cryptographic Security of the MLS RFC, Draft 11
Chris Brzuska and Eric Cornelissen and Konrad Kohbrok
ePrint (Published at IEEE S&P 2022)

Key-schedule Security for the TLS 1.3 Standard
Chris Brzuska and Antoine Delignat-Lavaud and Christoph Egger and Cédric Fournet and Konrad Kohbrok and Markulf Kohlweiss
ePrint (Published at AsiaCrypt 2022)

State-Separating Proofs and Their Applications (Article-based PhD Thesis)
Konrad Kohbrok
Aalto Doc