Implementation of continuous-variable quantum key distribution with composable and one-sided-device-independent security against coherent attacks.

Tobias Gehring,Jörg Duhme,Reinhard F Werner,Christoph Pacher,Roman Schnabel,Torsten Franz,Vitus Händchen,Fabian Furrer

doi:10.1038/ncomms9795

Abstract

Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein–Podolsky–Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components.

Highlights

Secret communication over public channels is one of the central pillars of a modern information society
Using continuous variables (CVs) 1sDI quantum key distribution (QKD) has been recently proven secure for collective attacks and infinitely many quantum state distributions[13] as well as with finite-size, composable security against coherent attacks under the same assumption of a memoryless untrusted device[14]
Gaussian collective attacks are in the limit of an infinite number of distributed quantum states as strong as coherent attacks, it is currently not known whether this holds for a realistic finite key length protocol

Summary

Introduction

Secret communication over public channels is one of the central pillars of a modern information society. Our implementation is based on the distribution of continuous-variable Einstein–Podolsky–Rosen entangled light It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Using continuous variables (CVs) 1sDI QKD has been recently proven secure for collective attacks and infinitely many quantum state distributions[13] as well as with finite-size, composable security against coherent attacks under the same assumption of a memoryless untrusted device[14]. We report a continuous-variable QKD implementation that generates a finite and composable key that is secure against coherent attacks and whose security is 1sDI under memoryless assumption. Highly efficient error reconciliation algorithm was developed to enable the generation of the secret key

Methods

Results

Conclusion