The EU’s Quantum Strategy includes plans to develop secure quantum communication infrastructure across the region ...

In this paper, we investigate a terrestrial relay-assisted scheme for a free-space quantum key distribution (QKD) system based on BB84 protocol. We consider the deployment of passive relays which ...

Continuous variable quantum key distribution (CV-QKD) protocol has drawn much attention due to its compatibility with existing optical communication systems. In this paper, we propose a quaternary ...