Analysis of untrusted-node quantum key distribution from a geostationary satellite

Tue, 09 Dec 2025 00:00:00 +0000

In pursuit of a global quantum key distribution (QKD) network, a service based on untrusted nodes on geostationary satellites could offer wide coverage, continuous operation, and enhanced security compared to the trusted node alternative. Although this scenario has been studied for entanglement-based protocols, such an approach would require large-area telescopes both on the ground and in space. In this work, we analyze the performance of two QKD protocols well adapted to this scenario, namely twin-field (TF) and mode-pairing (MP) QKD, which exhibit high resilience to high-loss channels. Leveraging an in-depth simulation of communication channels corrected with adaptive optics, we assess the expected secret key rates for both protocols in a configuration involving two 50 cm telescopes on board the satellite and ground-based telescopes ranging from 20 cm to 1 m in aperture. Our results show that, in the best case and considering realistic detectors, it is possible to achieve secret key rates on the order of a few hundred bit/s for both TF and MP-QKD. We show, notably, that secret key generation is potentially feasible even with 20 cm ground telescopes, highlighting the high scalability potential of such a configuration.

Thomas Liege

Tue, 09 Dec 2025 00:00:00 +0000

Réseaux de communication quantiques à nœuds non fiables : stratégies pour surmonter les déficiences des canaux en espace libre

PhD in the experimentalist team. Broadly interested in quantum communication outbreaks and quantum cryptography. My work focuses on studying and optimizing a Continuously Variable Quantum Key Distribution (CV-QKD) device on an optical link simulating atmospheric disturbances.

Thomas Liege | LIP6 - Équipe QI

Analysis of untrusted-node quantum key distribution from a geostationary satellite

Thomas Liege

Réseaux de communication quantiques à nœuds non fiables : stratégies pour surmonter les déficiences des canaux en espace libre