arXiv:2305.03940 · Quantum Information and Computation

A simpler security proof for 6-state quantum key distribution

Kaan Akyuz, Boris Škorić

Published Sep 1, 2023• 1 citation

Abstract

Six-state Quantum Key Distribution (QKD) achieves the highest key rate in the class of qubit-based QKD schemes. The standard security proof, which has been developed since 2005, invokes complicated theorems involving smooth R\'{e}nyi entropies. In this paper we present a simpler security proof for 6-state QKD that entirely avoids R\'{e}nyi entropies. This is achieved by applying state smoothing directly in the Bell basis. We obtain the well known asymptotic rate, but with slightly more favorable finite-size terms. We furthermore show that the same proof technique can be used for 6-state quantum key recycling.

DOI: 10.26421/qic23.11-12-4

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