English

Long-distance device-independent quantum key distribution

Quantum Physics 2025-04-01 v1

Abstract

Besides being a beautiful idea, device-independent quantum key distribution (DIQKD) is probably the ultimate solution to defeat quantum hacking. To guarantee security, it requires, however, that the fair-sampling loophole is closed, which results in a very limited maximum achievable distance. To overcome this limitation, DIQKD must be furnished with fair-sampling devices like, for instance, qubit amplifiers. These devices can herald the arrival of a photon to the receiver and thus decouple channel loss from the selection of the measurement settings. Consequently, one can safely postselect the heralded events and discard the rest, which results in a significant enhancement of the achievable distance. In this work, we investigate photonic-based DIQKD assisted by two main types of qubit amplifiers in the finite data block size scenario, and study the resources -- particularly, the detection efficiency of the photodetectors and the quality of the entanglement sources -- that would be necessary to achieve long-distance DIQKD within a reasonable time frame of signal transmission.

Keywords

Cite

@article{arxiv.1905.03591,
  title  = {Long-distance device-independent quantum key distribution},
  author = {Víctor Zapatero and Marcos Curty},
  journal= {arXiv preprint arXiv:1905.03591},
  year   = {2025}
}

Comments

37 pages, 15 figures

R2 v1 2026-06-23T09:01:40.454Z