Experimental device-independent quantum key distribution between distant users

Device-independent quantum key distribution (DIQKD) is the art of using untrusted devices to establish secret keys over an untrusted channel. So far, the real-world implementation of DIQKD remains a major challenge, as it requires the demonstration of a loophole-free Bell test across two remote loca...

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Bibliographic Details
Published inarXiv.org
Main Authors Zhang, Wei, Tim van Leent, Redeker, Kai, Garthoff, Robert, Schwonnek, Rene, Fertig, Florian, Eppelt, Sebastian, Scarani, Valerio, Lim, Charles C -W, Weinfurter, Harald
Format Paper Journal Article
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 01.10.2021
Subjects
Error analysis
Physics - Quantum Physics
Quantum cryptography
Quantum entanglement
Rubidium
Security
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Summary:Device-independent quantum key distribution (DIQKD) is the art of using untrusted devices to establish secret keys over an untrusted channel. So far, the real-world implementation of DIQKD remains a major challenge, as it requires the demonstration of a loophole-free Bell test across two remote locations with very high quality entanglement to ensure secure key exchange. Here, we demonstrate for the first time the distribution of a secure key -- based on asymptotic security estimates -- in a fully device-independent way between two users separated by 400 metres. The experiment is based on heralded entanglement between two independently trapped single Rubidium 87 atoms. The implementation of a robust DIQKD protocol indicates an expected secret key rate of r=0.07 per entanglement generation event and r>0 with a probability error of 3%. Furthermore, we analyse the experiment's capability to distribute a secret key with finite-size security against collective attacks.
ISSN:2331-8422
DOI:10.48550/arxiv.2110.00575