2-7 June 2019
Simon Fraser University
America/Vancouver timezone
Welcome to the 2019 CAP Congress Program website! / Bienvenue au siteweb du programme du Congrès de l'ACP 2019 !

32 - Localizing and excluding quantum information; or, how to share a quantum secret in spacetime

4 Jun 2019, 16:59
SWH 9082 + AQ South-East Corner / coin sud-est (Simon Fraser University)

SWH 9082 + AQ South-East Corner / coin sud-est

Simon Fraser University

Poster Competition (Graduate Student) / Compétition affiches (Étudiant(e) 2e ou 3e cycle) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) DCMMP Poster Session & Student Poster Competition Finals (10) | Session d'affiches DPMCM et finales du concours d'affiches étudiantes (10)


Alex May (University of British Columbia)


When can quantum information be localized to each of a collection of spacetime
regions, while also excluded from another collection of regions? We answer this question by defining and analyzing the localize-exclude task, in which a state must be localized to a collection of authorized regions while also being excluded from a set of unauthorized regions. This task is a spacetime analogue of quantum secret sharing, with authorized and unauthorized regions replacing authorized and unauthorized sets of parties. Our analysis yields the first quantum secret sharing scheme for arbitrary access structures for which the number of qubits required scales polynomially with the number of parties. We also study a second related task called state-assembly, in which shares of a quantum state are requested at sets of spacetime points. We fully characterize the conditions under which both the localize-exclude and state-assembly tasks can be achieved, and give explicit protocols. Finally, we propose a cryptographic application of these tasks which we call party-independent transfer.

Primary author

Alex May (University of British Columbia)

Presentation Materials