Improved finite-size effects in QKD protocols with applications to decoy-state QKD

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Kamin, Lars, Tupkary, Devashish, Lütkenhaus, Norbert
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866909483928649728
author Kamin, Lars
Tupkary, Devashish
Lütkenhaus, Norbert
author_facet Kamin, Lars
Tupkary, Devashish
Lütkenhaus, Norbert
contents We present a finite-size security proof for generic quantum key distribution protocols against independent and identically distributed collective attacks and extend it to coherent attacks using the postselection technique. This work introduces two significant improvements over previous results. First, we achieve tighter finite-size key rates by employing refined concentration inequalities in the acceptance testing phase. Second, we improve second-order correction terms in the key rate expression, by reducing them to scale with the number of sifted rounds rather than the total number of protocol rounds. We apply these advancements to compute finite-size key rates for a qubit and decoy-state BB84 protocol, accommodating arbitrary protocol parameters. Finally, we extend our finite-size security proof to coherent attacks and variable-length protocols and present our results for the decoy-state 4-6 protocol incorporating imperfections such as unequal intensity settings.
format Preprint
id arxiv_https___arxiv_org_abs_2502_05382
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Improved finite-size effects in QKD protocols with applications to decoy-state QKD
Kamin, Lars
Tupkary, Devashish
Lütkenhaus, Norbert
Quantum Physics
We present a finite-size security proof for generic quantum key distribution protocols against independent and identically distributed collective attacks and extend it to coherent attacks using the postselection technique. This work introduces two significant improvements over previous results. First, we achieve tighter finite-size key rates by employing refined concentration inequalities in the acceptance testing phase. Second, we improve second-order correction terms in the key rate expression, by reducing them to scale with the number of sifted rounds rather than the total number of protocol rounds. We apply these advancements to compute finite-size key rates for a qubit and decoy-state BB84 protocol, accommodating arbitrary protocol parameters. Finally, we extend our finite-size security proof to coherent attacks and variable-length protocols and present our results for the decoy-state 4-6 protocol incorporating imperfections such as unequal intensity settings.
title Improved finite-size effects in QKD protocols with applications to decoy-state QKD
topic Quantum Physics
url https://arxiv.org/abs/2502.05382