Quantum Secret Broadcast for Wireless Quantum Networks

Abstract

In wireless quantum networks, nodes communicate by means of pre-distribution for entangled pairs and relay path establishment for quantum teleportation. However, simple point-to-point communication seriously restricts the efficiency of quantum communication. Inspired by sharing idea of quantum secret sharing (QSS), which is based on three collaborative nodes with pre-shared GHZ (Greenberger-Horne-Zeilinger) states, we propose a quantum secret broadcast scheme to improve network performance. In a cluster network cored on three parties of QSS, three cluster heads with pre-shared GHZ states are senders, while cluster members are receivers. One cluster head encodes secret messages on auxiliary particles by performing certain operations on them with GHZ particles, then three cluster heads measure their own particles and broadcast measurement results honestly. Based on the specific correlation of measurement results and secret messages, all receivers can recover the secret messages. Furthermore, to prevent eavesdropping, cluster heads can update an encoding key periodically. Analysis shows the proposed scheme is more efficient than previous schemes in wireless quantum networks, especially when the number of receivers is larger. Besides, in the proposed scheme, attacks on quantum channel based on GHZ state can be detected, and eavesdroppers cannot recover messages correctly for lack of suitable decoding key.