Research

My research develops cryptographic protocols that remain secure in a post-quantum setting and distribute trust and power among several participants. I am particularly interested in constructions that are both provably secure and practical enough for real systems.

Projects

I am the lead researcher on SCANDIUM, a ZITiS-funded project investigating privacy-preserving cooperation between German law-enforcement agencies. The project develops secure multiparty computation techniques for detecting overlaps in confidential datasets without revealing the underlying data, helping reduce duplicated investigative work.

I am a collaborator on PiQASO (Post-Quantum Cryptography As-a-Service for Common Transmission Systems and Infrastructures), an EU Digital Europe project developing deployable post-quantum cryptographic services for existing systems and infrastructures. PACY contributes to the design of PQC service abstractions, post-quantum encryption, and associated key-management approaches.

Publications

Distributed Key Generation for NTRU, CANS 2026.
Joint work with Jérôme Nguyen, Caroline Sandsbråten, and Tjerand Silde.

Olingo: Threshold Lattice Signatures with DKG and Identifiable Abort, ACM CCS 2026.
Joint work with Kamil Doruk Gur, Jonathan Katz, Caroline Sandsbråten, and Tjerand Silde.

Collaborative, Segregated NIZK (CoSNIZK) and More Efficient Lattice-Based Direct Anonymous Attestation, Cryptology ePrint Archive, 2024.
Joint work with Liqun Chen and Nada El Kassem.

More Efficient Lattice-Based Electronic Voting from NTRU, Communications in Cryptology, 2024.
Joint work with Caroline Sandsbråten and Tjerand Silde.

More Efficient, Provably-Secure Direct Anonymous Attestation from Lattices, Future Generation Computer Systems, 2019.
Joint work with Nada El Kassem, Liqun Chen, Rachid El Bansarkhani, Ali El Kaafarani, Jan Camenisch, Paulo Martins, and Leonel Sousa.

L-DAA: Lattice-Based Direct Anonymous Attestation, Cryptology ePrint Archive, 2018.
Joint work with Nada El Kassem, Liqun Chen, Rachid El Bansarkhani, Ali El Kaafarani, and Jan Camenisch.

A Lower Bound for Biases Amongst Products of Two Primes, Research in Number Theory, 2017.

DAA Security, Revisited: Property-Based Definitions with UC Endorsement
Joint work with Jan Camenisch, Manu Drijvers, and Anja Lehmann.

Theses

Lattice-Based Privacy-Preserving Protocols with Distributed Trust, PhD thesis, 2024.

A Lower Bound For Biases Amongst Products of Two Primes, Master’s thesis, 2016.