The Security of Practical Quantum Key Distribution

TL;DR

This paper reviews the current state of practical quantum key distribution (QKD), emphasizing its security guarantees and analyzing the theoretical tools used to assess security across various experimental platforms.

Contribution

It provides a comprehensive review of practical QKD implementations and discusses the theoretical security assessment tools for different quantum communication protocols.

Findings

QKD is mature enough for commercialization

Security can be guaranteed without restricting eavesdropper's power

Theoretical tools are essential for security assessment across platforms

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).