The security of practical quantum key distribution

TLDR

Quantum key distribution is a mature technology that can theoretically guarantee key security without limiting an eavesdropper’s power. The paper seeks to generate a secret key between authorized partners via quantum and authenticated classical channels. It reviews practical QKD and presents theoretical tools for assessing the security of discrete, continuous, and distributed‑phase‑reference protocols.

Abstract

Quantum key distribution (QKD) is the first quantum information task to reach the level of mature technology, already fit for commercialization. It aims at the creation of a secret key between authorized partners connected by a quantum channel and a classical authenticated channel. The security of the key can in principle be guaranteed without putting any restriction on the eavesdropper's power. The first two sections provide a concise up-to-date review of QKD, biased toward the practical side. The rest of the paper presents the essential theoretical tools that have been developed to assess the security of the main experimental platforms (discrete variables, continuous variables and distributed-phase-reference protocols).