Device-independent quantum key distribution with random key basis

verfasst von
René Schwonnek, Koon Tong Goh, Ignatius W. Primaatmaja, Ernest Y.Z. Tan, Ramona Wolf, Valerio Scarani, Charles C.W. Lim
Abstract

Device-independent quantum key distribution (DIQKD) is the art of using untrusted devices to distribute secret keys in an insecure network. It thus represents the ultimate form of cryptography, offering not only information-theoretic security against channel attacks, but also against attacks exploiting implementation loopholes. In recent years, much progress has been made towards realising the first DIQKD experiments, but current proposals are just out of reach of today’s loophole-free Bell experiments. Here, we significantly narrow the gap between the theory and practice of DIQKD with a simple variant of the original protocol based on the celebrated Clauser-Horne-Shimony-Holt (CHSH) Bell inequality. By using two randomly chosen key generating bases instead of one, we show that our protocol significantly improves over the original DIQKD protocol, enabling positive keys in the high noise regime for the first time. We also compute the finite-key security of the protocol for general attacks, showing that approximately 108–1010 measurement rounds are needed to achieve positive rates using state-of-the-art experimental parameters. Our proposed DIQKD protocol thus represents a highly promising path towards the first realisation of DIQKD in practice.

Organisationseinheit(en)
QuantumFrontiers
Externe Organisation(en)
National University of Singapore
ETH Zürich
Typ
Artikel
Journal
Nature Communications
Band
12
ISSN
2041-1723
Publikationsdatum
01.12.2021
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Allgemeine Chemie, Allgemeine Biochemie, Genetik und Molekularbiologie, Allgemeine Physik und Astronomie
Elektronische Version(en)
https://doi.org/10.1038/s41467-021-23147-3 (Zugang: Offen)