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Q: Quantenoptik
Q 432: Poster: Quanteninformation
Q 432.8: Poster
Donnerstag, 7. März 2002, 16:30–18:30, Schloss
Secure quantum key sharing with Aharonov states — •Aldo Delgado1, Gernot Alber1, and Igor Jex2 — 1Abteilung für Quantenphysik, Universität Ulm, D-89069 Ulm, Germany — 2Department of Physics, FNSPE Czech Technical University Prague, 115 19 Praha, Czech Republic
A new quantum key sharing protocol is presented [1]. It is a generalization of Ekert’s quantum cryptographic protocol [2] to three parties. With this protocol a party can simultaneously create and distribute a random classical key between two other parties in such a way that these two parties have access to this random key only if they share the information that they have received.
Our protocol is based on the use of a total, anti-symmetric three-particle
state,
a so called Aharonov state.
Its security is investigated with respect to some eavesdropping strategies.
In particular, it is shown that
a local, realistic theory cannot be constructed
for a specific choice of measurements so that an
eavesdropper, having total control of the measurement devices, cannot
simulate this
new key sharing protocol with a classical stochastic process.
This work is supported by the DFG within the SPP
‘Quanteninformationsverarbeitung’
and by the DLR.
A.D. and I.J. acknowledge support by the DAAD and by the GA of the Czech
Republic.
[1] A. Delgado, G. Alber, I. Jex (in preparation).
[2] A. K. Ekert, Phys. Rev. Lett. 67, 661 (1991).