Source-linked AI summary
Characterization of Collective Gaussian Attacks and Security of Coherent-State Quantum Cryptography
Stefano Pirandola, Samuel L. Braunstein, Seth Lloyd
TL;DR
The paper characterizes general collective Gaussian attacks in continuous-variable QKD and analyzes asymptotic secret-key rates for coherent-state protocols. It reduces the attack description to channel parameters and identifies canonical attacks as extremal for the resulting bounds.
Problem
The work addresses the need to characterize general collective Gaussian attacks and analyze coherent-state cvQKD security under such attacks.
Method
It decomposes one-mode Gaussian channels into canonical forms, constructs Stinespring dilations, and analyzes coherent-state protocols with heterodyne detection, tomography, and one-way reconciliation.
Results
Asymptotic secret-key rates are bounded by quantities depending only on the three parameters {τ, w, η}, with canonical attacks extremal for these bounds.
Takeaways & Limitations
The characterization supports general security analyses of cvQKD protocols without assumptions on Eve’s interaction.
Takeaways & Limitations
The cryptographic scenario assumes the whole environment is under Eve’s control.
Abstract
from arXiv · showhide
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.