D 2018

Secure Certification of Mixed Quantum States with Application to Two-Party Randomness Generation

DUPONT DUPUIS, Frédéric, Serge FEHR, Philippe LAMONTAGNE and Louis SALVAIL

Basic information

Original name

Secure Certification of Mixed Quantum States with Application to Two-Party Randomness Generation

Authors

DUPONT DUPUIS, Frédéric (124 Canada, guarantor, belonging to the institution), Serge FEHR, Philippe LAMONTAGNE and Louis SALVAIL

Edition

Cham, 16th International Theory of Cryptography Conference (TCC 2018), p. 282-314, 33 pp. 2018

Publisher

Springer

Other information

Language

English

Type of outcome

Stať ve sborníku

Field of Study

10201 Computer sciences, information science, bioinformatics

Country of publisher

Switzerland

Confidentiality degree

není předmětem státního či obchodního tajemství

Publication form

printed version "print"

Impact factor

Impact factor: 0.402 in 2005

RIV identification code

RIV/00216224:14330/18:00118583

Organization unit

Faculty of Informatics

ISBN

978-3-030-03809-0

ISSN

UT WoS

000594194600011

Keywords in English

STRONG CONVERSE; COIN

Tags

International impact, Reviewed
Změněno: 5/11/2021 15:01, RNDr. Pavel Šmerk, Ph.D.

Abstract

V originále

We investigate sampling procedures that certify that an arbitrary quantum state on n subsystems is close to an ideal mixed state phi(circle times n) for a given reference state phi, up to errors on a few positions. This task makes no sense classically: it would correspond to certifying that a given bitstring was generated according to some desired probability distribution. However, in the quantum case, this is possible if one has access to a prover who can supply a purification of the mixed state. In this work, we introduce the concept of mixed-state certification, and we show that a natural sampling protocol offers secure certification in the presence of a possibly dishonest prover: if the verifier accepts then he can be almost certain that the state in question has been correctly prepared, up to a small number of errors. We then apply this result to two-party quantum coin-tossing. Given that strong coin tossing is impossible, it is natural to ask "how close can we get". This question has been well studied and is nowadays well understood from the perspective of the bias of individual coin tosses. We approach and answer this question from a different-and somewhat orthogonal-perspective, where we do not look at individual coin tosses but at the global entropy instead. We show how two distrusting parties can produce a common high-entropy source, where the entropy is an arbitrarily small fraction below the maximum.