English

Fidelity Bounds for Device-Independent Advantage Distillation

Quantum Physics 2023-03-27 v3

Abstract

It is known that advantage distillation (that is, information reconciliation using two-way communication) improves noise tolerances for quantum key distribution (QKD) setups. Two-way communication is hence also of interest in the device-independent case, where noise tolerance bounds for one-way error correction are currently too low to be experimentally feasible. Existing security proofs for the device-independent repetition-code protocol (the most prominent form of advantage distillation) rely on fidelity-related security conditions, but previous bounds on the fidelity were not tight. We improve on those results by developing an algorithm that returns arbitrarily tight lower bounds on the fidelity. Our results give new insight on how strong the fidelity-related security conditions are, and could also be used to compute some lower bounds on one-way protocol keyrates. Finally, we conjecture a necessary security condition for the protocol studied in this work, that naturally complements the existing sufficient conditions.

Keywords

Cite

@article{arxiv.2105.03213,
  title  = {Fidelity Bounds for Device-Independent Advantage Distillation},
  author = {Thomas A. Hahn and Ernest Y. -Z. Tan},
  journal= {arXiv preprint arXiv:2105.03213},
  year   = {2023}
}

Comments

15 pages, 3 figures. Includes changes made for publication

R2 v1 2026-06-24T01:52:27.857Z