  The Greenberger-Horne-Zeilinger (GHZ) entanglement, originally introduced to
uncover the extreme violation of local realism against quantum mechanics, is an
important resource for multiparty quantum communication tasks. But the low
intensity and fragility of the GHZ entanglement source in current conditions
have made the practical applications of these multiparty tasks an experimental
challenge. Here we propose a feasible scheme for practically distributing the
post-selected GHZ entanglement over a distance of more than 100 km for
experimentally accessible parameter regimes. Combining the decoy-state and
measurement-device-independent protocols for quantum key distribution, we
anticipate that our proposal suggests an important avenue for practical
multiparty quantum communication.
