Paper 2026/445 Original: eprint.iacr.org/2026/445 ↗

Implementation of a post-quantum hybrid group key exchange protocol

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.