  We propose an enhanced discrimination measurement for tripartite
3-dimensional entangled states in order to improve the discernible number of
orthogonal entangled states. The scheme suggests 3-dimensional Bell state
measurement by exploiting composite two 3-dimensional state measurement setups.
The setup relies on state-of-the-art techniques, a multi-port interferometer
and nondestructive photon number measurements that are used for the
post-selection of suitable ensembles. With this scheme, the sifted signal rate
of measurement-device-independent quantum key distribution using 3-dimensional
quantum states is improved by up to a factor of three compared with that of the
best existing setup.
