Role of anti-squeezing noise in continuous-variable quantum cryptography

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F20%3A73603748" target="_blank" >RIV/61989592:15310/20:73603748 - isvavai.cz</a>

Result on the web

<a href="https://obd.upol.cz/id_publ/333183634" target="_blank" >https://obd.upol.cz/id_publ/333183634</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Role of anti-squeezing noise in continuous-variable quantum cryptography

Original language description

Quadrature squeezing is known to enforce continuous-variable quantum cryptography. However, in practice, squeezed states are never generated perfectly and always contain anti-squeezing quadrature noise concerned with losses in the optical parametric oscillator sources. We therefore address the role of anti-squeezing noise in continuous-variable quantum cryptography over attenuating and noisy quantum channels. We first assume that anti-squeezing noise is trusted, hence, out of control of a potential eavesdropper, capable of collective attacks. In this regime, anti-squeezing noise can be even helpful by tightening the bound on the information leakage in the quantum channel. Moreover, in the asymptotic limit of infinitely strong trusted anti-squeezing noise, the bound can be expressed analytically. We then assume that anti-squeezing noise is controlled by an eavesdropper, thus being a side-channel in the source implementation. In this regime, the anti-squeezing noise leads to the security break both in direct and reverse reconciliation scenarios. We compare the bounds on the untrusted phase-sensitive anti-squeezing noise to the typical phase-insensitive channel excess noise and show that protocols are more robust to the anti-squeezing noise, while the presence of such noise makes the protocol more sensitive to the noise in the main quantum channel. The obtained results reveal the important role of anti-squeezing noise in continuous-variable quantum cryptography and suggest the need of pure squeezed state preparation in the case of untrusted sources.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

20203 - Telecommunications

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

2020 43RD INTERNATIONAL CONFERENCE ON TELECOMMUNICATIONS AND SIGNAL PROCESSING (TSP)

ISBN

978-1-72816-376-5

ISSN

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e-ISSN

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Number of pages

5

Pages from-to

421-425

Publisher name

IEEE Computer Society Press

Place of publication

New York

Event location

Itálie

Event date

Jul 7, 2020

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

000577106400090