# Secure quantum key distribution with realistic devices

## TL;DR

This paper reviews recent theoretical and experimental advances in securing quantum key distribution (QKD) against practical device imperfections, highlighting progress like measurement-device-independent protocols that enhance real-world security.

## Contribution

It provides a comprehensive overview of how practical security challenges in QKD are addressed through innovative protocols and improved understanding of device imperfections.

## Key findings

- Measurement-device-independent protocols close critical security loopholes.
- Researchers understand and manage practical device imperfections.
- Recent advances enable secure QKD with realistic devices.

## Abstract

In principle, quantum key distribution (QKD) offers information-theoretic security based on the laws of physics. In practice, however, the imperfections of realistic devices might introduce deviations from the idealized models used in security analyses. Can quantum code-breakers successfully hack real systems by exploiting the side channels? Can quantum code-makers design innovative counter-measures to foil quantum code-breakers? This article reviews theoretical and experimental progress in the practical security aspects of quantum code-making and quantum code-breaking. After numerous attempts, researchers now thoroughly understand and are able to manage the practical imperfections. Recent advances, such as the measurement-device-independent protocol, have closed the critical side channels in the physical implementations, paving the way for secure QKD with realistic devices.