Quantum key distribution using three states in equiangular configuration combines a security threshold comparable with the one of the Bennett-Brassard 1984 protocol and a quantum bit error rate (QBER) estimation that does not need to reveal part of the key. We implement an entanglement-based version of the Renes 2004 protocol, using only passive optic elements in a linear scheme for the measurement POVM, generating an asymptotic secure key rate of more than 10 kbit/s, with a mean QBER of 1.6%. We then demonstrate its security in the case of finite key and evaluate the key rate for both collective and general attacks.
@article{arxiv.1603.07605,
title = {Experimental realization of equiangular three-state quantum key distribution},
author = {Matteo Schiavon and Giuseppe Vallone and Paolo Villoresi},
journal= {arXiv preprint arXiv:1603.07605},
year = {2016}
}