The device-independent approach to quantum key distribution (QKD) aims to establish a secret key between two or more parties with untrusted devices, potentially under full control of a quantum adversary. The performance of a QKD protocol can be quantified by the secret key rate, which can be lower bounded via the violation of an appropriate Bell inequality in a setup with untrusted devices. We study secret key rates in the device-independent scenario for different quantum repeater setups and compare them to their device-dependent analogon. The quantum repeater setups under consideration are the original protocol by Briegel et al. and the hybrid quantum repeater protocol by van Loock et al.. For a given repeater scheme and a given QKD protocol, the secret key rate depends on a variety of parameters, such as the gate quality or the detector efficiency. We systematically analyze the impact of these parameters and suggest optimized strategies.
@article{arxiv.1711.06072,
title = {Device-independent secret-key-rate analysis for quantum repeaters},
author = {Timo Holz and Hermann Kampermann and Dagmar Bruß},
journal= {arXiv preprint arXiv:1711.06072},
year = {2018}
}