Paper 2026/445

Implementation of a post-quantum hybrid group key exchange protocol

Samuel Klement, Slovak University of Technology in Bratislava

Zoltán Raffay, Slovak University of Technology in Bratislava

Pavol Zajac, Slovak University of Technology in Bratislava

Abstract

Post-quantum cryptography focuses on research of cryptographic primitives, including public key encryption and signatures, that can resist the attacks mounted by an adversary with an access to a quantum computer. An alternative is to employ quantum cryptography to protect communication links by employing principles of quantum physics to protect security of the key exchange. Recently, a group key establishment protocol that combines these approaches in a secure way was presented by Steinwandt and Gonzales Vasco. We have successfully imple- mented and employed this protocol in a prototype application. In this article we describe the overall architecture and specific details of the implementation that can be of interest for scientific community. We conclude with a discussion of specific challenges, options and open problems that can accompany similar imple- mentation task.

@misc{cryptoeprint:2026/445,
      author = {Tomáš Fabšič and Samuel Klement and Zoltán Raffay and Pavol Zajac},
      title = {Implementation of a post-quantum hybrid group key exchange protocol},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/445},
      year = {2026},
      url = {https://eprint.iacr.org/2026/445}
}