Experimental demonstration of quantum secret sharing - art. no. 042301

We present a setup for quantum secret sharing based on energy-time entangle ment. In opposition to known implementations using three particle Greenberg er-Horne-Zeilinger (GHZ) states, our idea takes advantage of only two entan gled photons created via parametric down conversion. However, the system co mprising the pump plus the two down-converted photons bare the same quantum correlation and can be used to mimic three entangled qubits. The relativel y high coincidence count rates found in our setup enable for the first time an application of a quantum communication protocol based on more than two qubits.