2024/06/20 by Florian Kanitschar, Kanitschar, Florian, Hajomer, Adnan A. E. +3
Computer Science · Physics and Astronomy · #Chaos-based Image/Signal Encryption #FOS: Physical sciences #Quantum Mechanics and Applications #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2406.14610
openalex publication_date 2024/06/20 · openalex created_date 2024/06/26 · openalex updated_date 2026/07/28
Establishing scalable, secure quantum networks requires advancing beyond conventional point-to-point quantum key distribution (QKD) protocols toward point-to-multipoint QKD protocols. Here, we generalize a well-established discrete-modulated continuous-variable (CV) QKD protocol from the point-to-point to the point-to-multipoint setting. We present a comprehensive security analysis across four trust scenarios and derive secret key rates for both loss-only and noisy channels, in the asymptotic and composable finite-size regimes. Experimentally, we validate the protocol in a passive optical network with 10 km access links, achieving a composable secure key rate of 2.185 × 10-3 bits per symbol (0.273 Mbit/s) against independent and identically distributed collective attacks. Our results demonstrate that discrete-modulated CV-QKD can support access networks with multiple users while relying solely on cost-efficient, off-the-shelf telecommunication components, paving the way toward practical, scalable, and secure quantum networks.