  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.
