摘要
我们分析在经由 M +1 粒子 GHZ 的中央聚会和另外的 M 聚会之间的安全直接通讯计划说的同时的量和交换量纠纷的能力。如果另外的 M 聚会想要播送 1 位古典的 M + ，编码计划应该是秘密的，这被显示出到中心的消息秘密地狂欢。然而，当编码计划公开被宣布时，我们证明在播送秘密的计划的能力在 2 位中发送消息，不管 M 怎么大。
We analyse 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 centre 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 large M is.
基金
Supported by the Natural Science Foundation of Hebei Province under Grant Nos A2004000141 and A2005000140, and the Natural Science Foundation of Hebei Normal University.
