Field-trial quantum key distribution between Sicily and Malta

Abstract

Quantum key distribution (QKD) is the first commercial application of the second quantum revolution. Although QKD systems have already been developed and implemented all around the world, some open challenges are limiting the overall deployment of this technology (limited key rate, limited link distance, etc.). By improving the current QKD protocols, it is possible to increase the final secret key generation rate. In this work, we compare 1-decoy with 2-decoy methods in BB84 protocol over an underwater optical fiber link connecting Malta to Italy, showing that 2-decoy can achieve more than twice the key rate of 1-decoy method.

Scalable Implementation of Temporal and Phase Encoding QKD with Phase‐Randomized States

“…The approach is scalable, enabling the implementation of the high‐dimensional generalization of many DV protocols, as proposed in ref. [33]. We experimentally demonstrate it in the case of qubits preparation as we test the bi‐dimensional BB84 protocol with decoy method.…”