Fundamental limitations on the device-independent quantum conference key agreement
Abstract
We provide several general upper bounds on the rate of a key secure against a quantum adversary in the device-independent conference key agreement (DI-CKA) scenario. They include bounds by reduced entanglement measures and those based on multipartite secrecy monotones such as a multipartite squashed entanglement-based measure, which we refer to as reduced c-squashed entanglement. We compare the latter bound with the known lower bound for the protocol of conference key distillation based on the parity Clauser-Horne-Shimony-Holt game. We also show that the gap between the DI-CKA rate and the device-dependent rate is inherited from the bipartite gap between device-independent and device-dependent key rates, giving examples that exhibit the strict gap.
Keywords
Cite
@article{arxiv.2111.02467,
title = {Fundamental limitations on the device-independent quantum conference key agreement},
author = {Karol Horodecki and Marek Winczewski and Siddhartha Das},
journal= {arXiv preprint arXiv:2111.02467},
year = {2023}
}
Comments
v1: 15 pages, 2 figures. See also the parallel work by Aby Philip, Eneet Kaur, Peter Bierhorst, and Mark M. Wilde titled "Intrinsic Non-Locality and Device-Independent Conference Key Agreement" appearing on arXiv along with this work. v2: Section IV removed as it was redundant, results unchanged, typos corrected