# Advances in Quantum Cryptography

## TL;DR

This paper reviews recent theoretical and experimental advances in quantum cryptography, covering protocols, security, device independence, satellite challenges, and future directions like quantum networks and cryptographic primitives.

## Contribution

It provides a comprehensive overview of the latest developments in quantum cryptography, integrating both theoretical protocols and experimental progress.

## Key findings

- Progress in quantum key distribution protocols
- Advances in device-independent security methods
- Development of quantum networks and repeaters

## Abstract

Quantum cryptography is arguably the fastest growing area in quantum information science. Novel theoretical protocols are designed on a regular basis, security proofs are constantly improving, and experiments are gradually moving from proof-of-principle lab demonstrations to in-field implementations and technological prototypes. In this review, we provide both a general introduction and a state of the art description of the recent advances in the field, both theoretically and experimentally. We start by reviewing protocols of quantum key distribution based on discrete variable systems. Next we consider aspects of device independence, satellite challenges, and high rate protocols based on continuous variable systems. We will then discuss the ultimate limits of point-to-point private communications and how quantum repeaters and networks may overcome these restrictions. Finally, we will discuss some aspects of quantum cryptography beyond standard quantum key distribution, including quantum data locking and quantum digital signatures.