基于对称W态和身份认证的安全量子通信协议

由于W态纠缠的强鲁棒性，它被认为是更适用于量子信息处理和量子安全通信的信息载体。针对4粒子W态或3粒子非对称W态量子直接通信效率低下或物理实现困难等缺陷，利用3粒子对称W态和量子身份认证机制，提出了一种新的确定型安全量子通信协议。该协议由认证码生成、量子态准备、量子态分发、安全检测与身份认证和消息通信五阶段组成，通信双方只需进行两粒子Bell基、单粒子Z基或X基测量，通信效率也有所提高，即1个3粒子W态传输1经典比特信息。安全分析证明该协议能有效抵抗各类窃听者Eve攻击和伪装攻击，具有较好的安全特性。

Secure quantum communication protocol based on symmetric W state and identity authentication

Due to the better robustness of entangled W state, it is considered to be better qualified as information carrier for quantum information processing and quantum secure communication. Recently, many kinds of quantum direct communication protocols based on four-particle W state or three-particle asymmetric W state have been proposed. However, these protocols either have low communication efficiency or are difficult to be implemented in physics experiment. By utilizing three-particle W state and the mechanism of quantum identity authentication, a new deterministic secure quantum communication protocol was proposed. This protocol consisted of five parts: authentication code generating, quantum states preparation, quantum states distribution, eavesdropping check and identity authentication, and information communication. The two participants only needed to perform the two-particle Bell measurement, the single-particle 〖WTBX〗Z〖WTBZ〗-basis or 〖WTBX〗X〖WTBZ〗-basis measurement, and the communication efficiency was also improved: One W state can transmit one classical bit of information. The security analysis shows that the present protocol is secure against various eavesdropper Eve's attacks and impersonation attacks, so it has better security.