Secrecy content of two-qubit states
Quantum Physics
2016-08-16 v1
Abstract
We analyze the set of two-qubit states from which a secret key can be extracted by single-copy measurements plus classical processing of the outcomes. We introduce a key distillation protocol and give the corresponding necessary and sufficient condition for positive key extraction. Our results imply that the critical error rate derived by Chau, Phys. Rev. A {\bf 66}, 060302 (2002), for a secure key distribution using the six-state scheme is tight. Remarkably, an optimal eavesdropping attack against this protocol does not require any coherent quantum operation.
Cite
@article{arxiv.quant-ph/0411092,
title = {Secrecy content of two-qubit states},
author = {A. Acín and J. Bae and E. Bagan and M. Baig and Ll. Masanes and R. Muñoz-Tapia},
journal= {arXiv preprint arXiv:quant-ph/0411092},
year = {2016}
}
Comments
5 pages, RevTeX