High-rate multipartite quantum secret sharing with composable security
Abstract
Future quantum communication networks will conceivably support cryptographic tasks that require entanglement among more than two users. Quantum secret sharing is a prime example where entanglement provides a direct means to coordinate untrusted parties with security from eavesdropping in a multi-party setting. However, the canonical GHZ-based protocols can be vulnerable to participant attacks, in which untrusted parties try to learn the secret without collaborating. Here, we experimentally evaluate a discrete-variable (n,n)-threshold quantum secret-sharing protocol whose finite-key analysis provides composable security against general attacks, including participant attacks. Using two domain-engineered entangled photon pair sources, we generate 4-qubit GHZ states at rates above 5×103 fourfold events per second and a maximum asymptotic secret key rate of 750 ± 10 bits per second. We then distribute the state through a 4-arm star network comprising 20km of fibre in total. From the measured event rates and error statistics, we infer that a randomised 24-hour execution with the optimised basis probability would yield a composable finite-key lower bound of 8.7 Mbits, under the assumption that the measured source and device statistics remain stationary.
Related
- Quantum secret sharing in a tripartite superconducting network
- Combinatorial aspects of holographic quantum secret sharing
- Traceable Quantum Secret Sharing
- Quantum Secret Sharing with a Helper and Programmable Access Structures
- Collusion-Secure Semi-Quantum Secret Sharing Scheme using a Quantum Third Party
BibTeX
@misc{brooks2026highrate,
title = {{High-rate multipartite quantum secret sharing with composable security}},
author = {Russell M. J. Brooks and Joseph Ho and Joseph Niblo and Janka Memmen and Anna Pappa and Jens Eisert and Nathan Walk and Alessandro Fedrizzi},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.13367},
eprint = {2609.13367},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.13367},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - High-rate multipartite quantum secret sharing with composable security
AU - Russell M. J. Brooks
AU - Joseph Ho
AU - Joseph Niblo
AU - Janka Memmen
AU - Anna Pappa
AU - Jens Eisert
AU - Nathan Walk
AU - Alessandro Fedrizzi
PY - 2026
DA - 2026/09/11
PB - arXiv
DO - 10.48550/arxiv.2609.13367
UR - https://arxiv.org/abs/2609.13367
AB - Future quantum communication networks will conceivably support cryptographic tasks that require entanglement among more than two users. Quantum secret sharing is a prime example where entanglement provides a direct means to coordinate untrusted parties with security from eavesdropping in a multi-party setting. However, the canonical GHZ-based protocols can be vulnerable to participant attacks, in which untrusted parties try to learn the secret without collaborating. Here, we experimentally evaluate a discrete-variable (n,n)-threshold quantum secret-sharing protocol whose finite-key analysis provides composable security against general attacks, including participant attacks. Using two domain-engineered entangled photon pair sources, we generate 4-qubit GHZ states at rates above 5×10^3 fourfold events per second and a maximum asymptotic secret key rate of 750 ± 10 bits per second. We then distribute the state through a 4-arm star network comprising 20km of fibre in total. From the measured event rates and error statistics, we infer that a randomised 24-hour execution with the optimised basis probability would yield a composable finite-key lower bound of 8.7 Mbits, under the assumption that the measured source and device statistics remain stationary.
ER -