Experimental quantum secret sharing

We consider two simple and practical protocols for multiparty communication and show their experimental realization. These protocols deal with the task of secret sharing in which a secret message is split among several parties in a way that its reconstruction requires their mutual collaboration. In the presented schemes the parties solve the problem by two different approaches: The first uses as a resource the multiqubit entangled state broken vertical bar Psi(-)(4)>. As no interferometric setups are required here, contrary to known schemes, involving Greenberger-Horne-Zeilinger states, its implementation is simpler and more stable. In the second scheme only sequential transformations on a single qubit are used. This further tremendously simplifies the method, makes it scalable with regard to the number of participating partners and above all, technologically comparable to quantum key distribution.