Two-way protocols for quantum cryptography with a nonmaximally entangled qubit pair
Two-way protocols for quantum cryptography with a nonmaximally entangled qubit pair
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DOI：
10.1103/physreva.80.022323
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发表时间：
2009-08
影响因子：
2.9
通讯作者：
K. Shimizu;K. Tamaki;Hiroyuki Fukasaka
中科院分区：
文献类型：
--
作者：
K. Shimizu;K. Tamaki;Hiroyuki Fukasaka
本文提出了一种具有非最大纠缠量子位对的量子密码方案。在类似于量子超密集编码的双向配置中，两位密钥可以通过量子位对中一个粒子的往返来分发，并通过与另一个粒子的适当联合测量来接收。我们方案的安全性基于某些非极大纠缠态之间局部酉变换的量子力学不可能性。虽然窃听者 Eve 总能识别量子态并拦截密钥，但她不可能以单位概率重新发送状态，合法各方不可避免地会发现她。我们的协议还能够实现量子安全直接通信。
This paper proposes a scheme for quantum cryptography with a nonmaximally entangled qubit pair. In a two-way configuration similar to quantum super dense coding, a two-bit key can be distributed by a round trip of one particle of the qubit pair and received by an appropriate joint measurement with the other. The security of our scheme is based on the quantum-mechanical impossibility of local unitary transformation between certain nonmaximally entangled states. Although an eavesdropper, Eve, can always identify the quantum state and intercept the key, it is impossible for her to resend the state with a unity probability and the legitimate parties inevitably detect her. Our protocol is also capable to quantum secure direct communication.