Paper accepted at AfricaCrypt 2026

The paper “The Best of Both Worlds: Hybrid Authenticated Key Exchange for QKD(N) without Signatures” was authored by Sebastian Clermont (TU Darmstadt) and UCS researcher Johanna Henrich.

The publication proposes a hybrid authenticated key exchange that completely removes the need for digital signature schemes in order to reduce the cryptographic attack surface and improve crypto-agility. Instead, the protocol combines Post-Quantum Cryptography (PQC) and QKD-based key agreement while leveraging PQC Key Encapsulation Mechanisms (KEMs) for both authentication and key exchange.

In addition, the paper provides a fully modular security analysis and the practical feasibility is demonstrated through benchmark implementations using ML-KEM, FrodoKEM, and Classic McEliece.

The work was carried out in collaboration with TU Darmstadt as part of the ATHENE research project SATURN.

The acceptance at AfricaCrypt 2026 highlights the ongoing research activities of the UCS group in the fields of quantum-secure communication, applied Cryptography and crypto-agility.