Experimental quantum secret sharing

Abstract

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 |Ψ 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. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.