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Summoning, No-Signalling and Relativistic Bit Commitments

Summoning is a task between two parties, Alice and Bob, with distributed networks of agents in space-time. Bob gives Alice a random quantum state, known to him but not her, at some point. She is required to return the state at some later point, belonging to a subset defined by communications receive...

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Detalles Bibliográficos
Autor principal: Kent, Adrian
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7515023/
https://www.ncbi.nlm.nih.gov/pubmed/33267248
http://dx.doi.org/10.3390/e21050534
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author Kent, Adrian
author_facet Kent, Adrian
author_sort Kent, Adrian
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description Summoning is a task between two parties, Alice and Bob, with distributed networks of agents in space-time. Bob gives Alice a random quantum state, known to him but not her, at some point. She is required to return the state at some later point, belonging to a subset defined by communications received from Bob at other points. Many results about summoning, including the impossibility of unrestricted summoning tasks and the necessary conditions for specific types of summoning tasks to be possible, follow directly from the quantum no-cloning theorem and the relativistic no-superluminal-signalling principle. The impossibility of cloning devices can be derived from the impossibility of superluminal signalling and the projection postulate, together with assumptions about the devices’ location-independent functioning. In this qualified sense, known summoning results follow from the causal structure of space-time and the properties of quantum measurements. Bounds on the fidelity of approximate cloning can be similarly derived. Bit commitment protocols and other cryptographic protocols based on the no-summoning theorem can thus be proven secure against some classes of post-quantum but non-signalling adversaries.
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spelling pubmed-75150232020-11-09 Summoning, No-Signalling and Relativistic Bit Commitments Kent, Adrian Entropy (Basel) Article Summoning is a task between two parties, Alice and Bob, with distributed networks of agents in space-time. Bob gives Alice a random quantum state, known to him but not her, at some point. She is required to return the state at some later point, belonging to a subset defined by communications received from Bob at other points. Many results about summoning, including the impossibility of unrestricted summoning tasks and the necessary conditions for specific types of summoning tasks to be possible, follow directly from the quantum no-cloning theorem and the relativistic no-superluminal-signalling principle. The impossibility of cloning devices can be derived from the impossibility of superluminal signalling and the projection postulate, together with assumptions about the devices’ location-independent functioning. In this qualified sense, known summoning results follow from the causal structure of space-time and the properties of quantum measurements. Bounds on the fidelity of approximate cloning can be similarly derived. Bit commitment protocols and other cryptographic protocols based on the no-summoning theorem can thus be proven secure against some classes of post-quantum but non-signalling adversaries. MDPI 2019-05-25 /pmc/articles/PMC7515023/ /pubmed/33267248 http://dx.doi.org/10.3390/e21050534 Text en © 2019 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Kent, Adrian
Summoning, No-Signalling and Relativistic Bit Commitments
title Summoning, No-Signalling and Relativistic Bit Commitments
title_full Summoning, No-Signalling and Relativistic Bit Commitments
title_fullStr Summoning, No-Signalling and Relativistic Bit Commitments
title_full_unstemmed Summoning, No-Signalling and Relativistic Bit Commitments
title_short Summoning, No-Signalling and Relativistic Bit Commitments
title_sort summoning, no-signalling and relativistic bit commitments
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7515023/
https://www.ncbi.nlm.nih.gov/pubmed/33267248
http://dx.doi.org/10.3390/e21050534
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