Characterization of Collective Gaussian Attacks and Security of Coherent-State Quantum Cryptography

TL;DR

This paper characterizes the most general collective Gaussian attacks in continuous-variable quantum cryptography and analyzes the achievable secret-key rates with coherent states under these attacks.

Contribution

It provides a simple description of collective Gaussian attacks and evaluates secret-key rates in the presence of such attacks using coherent states.

Findings

Characterization of the most general collective Gaussian attack

Analysis of asymptotic secret-key rates with coherent states

Implications for security in continuous-variable quantum cryptography

Abstract

We provide a simple description of the most general collective Gaussian attack in continuous-variable quantum cryptography. In the scenario of such general attacks, we analyze the asymptotic secret-key rates which are achievable with coherent states, joint measurements of the quadratures and one-way classical communication.