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Capacity of a simultaneous quantum secure direct communication scheme between the central party and other M parties

Ting Gao·Feng-Li Yan·Zhi-Xi Wang·You-Cheng Li
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Abstract

We analyze the capacity of a simultaneous quantum secure direct communication scheme between the central party and other $M$ parties via $M+1$-particle GHZ states and swapping quantum entanglement. It is shown that the encoding scheme should be secret if other $M$ parties wants to transmit $M+1$ bit classical messages to the center party secretly. However when the encoding scheme is announced publicly, we prove that the capacity of the scheme in transmitting the secret messages is 2 bits, no matter how big $M$ is.

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Ting Gao, Feng-Li Yan, Zhi-Xi Wang, You-Cheng Li. 2006-04-18. Capacity of a simultaneous quantum secure direct communication scheme between the central party and other M parties. https://doi.org/10.1088/0256-307x%2F23%2F10%2F009

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