关键词: 量子通信, Cluster态, 幺正变换, 测量基, 最优化非相干攻击

Abstract:

Cluster state quantum dialogue is proposed, which enables both legitimate parties to exchange their 4 bit secret messages in a direct way.Compared with the there-particle W states, The shemes have the following advantages. After two-step security check, four-bit secret message can be transmitted to each other by transmitting of single particle with the aid of two-bit classical information. The scheme can discard the drawback the intercept-resend-attack, the entangle-measure attack, and the optimal incoherent attack.

Key words: quantum communication, cluster state, unitary transformations, measuring basis, optimal incoherent attack