Authentication of the QKD classical channel through Post-Quantum Cryptography in a multi-site 5G/6G quantum-safe communication network
Asier Atutxa, Ane Sanz, Eire Salegi, Maider Huarte, Jasone Astorga, Eduardo Jacob · 2025
Breakthroughs in the field of quantum computing are forcing society to adapt the systems it employs to future threats. Telecommunications networks are no exception, and technologies such as Quantum Key Distribution (QKD) have been developed to establish secure and confidential mechanisms for quantum-safe key distribution. However, the lack of flexibility and scalability of this technology hinders its implementation in 5G/6G networks. In this context, this paper presents the design and development of a QKD classical channel authentication system based on Post-Quantum Cryptography (PQC) algorithms for securing multi-site 5G/6G networks. It also presents the deployment in an experimental infrastructure with a 5G core securization use case, and a comprehensive validation and performance evaluation, measuring key parameters such as protocol timing, error rate, and keyrate. Results show that the PQC authentication offers a similar performance compared to the inflexible, vendor-specific authentication mechanism, obtaining Quantum Bit Error Rate (QBER) measurements ranging from 2.5% to 3.5% in both cases, while only reducing the keyrate 4.53% (from 525.27 bps to 501.44 bps).