标题： 基于二维交替量子行走和真实单粒子纠缠态的双消息系统量子密码协议 显示英文标题

标题： Quantum cryptographic protocols with dual messaging system via 2D alternate quantum walks and genuine single particle entangled states

摘要： 单粒子纠缠态（SPES）可以比多粒子对应态提供更安全的量子信息编码和处理方式。 通过从初始分离态出发的二维交替量子行走设置生成的SPES可以是三重纠缠或双重纠缠。 这封信表明，生成的真实三重纠缠和非局域双重纠缠SPES可以用作加密密钥，同时安全地编码两个不同的消息。 我们详细说明了消息加密解密步骤，并展示了基于三重和双重SPES的加密协议对窃听者攻击（如截获和重发以及中间人攻击）的鲁棒性。 我们还详细说明了如何使用单光子实验实现这些协议，三个自由度分别为轨道角动量、路径和偏振。 这些协议在量子通信任务中具有无与伦比的安全性。 利用生成的SPES同时编码两个不同消息的能力展示了所提出的加密协议的多功能性和效率。 这种能力可以显著提高量子通信系统的吞吐量。 显示英文摘要

摘要： Single-particle entangled states (SPES) can offer a more secure way of encoding and processing quantum information than their multi-particle counterparts. The SPES generated via a 2D alternate quantum-walk setup from initially separable states can be either 3-way or 2-way entangled. This letter shows that the generated genuine three-way and nonlocal two-way SPES can be used as cryptographic keys to securely encode two distinct messages simultaneously. We detail the message encryption-decryption steps and show the resilience of the 3-way and 2-way SPES-based cryptographic protocols against eavesdropper attacks like intercept-and-resend and man-in-the-middle. We also detail how these protocols can be experimentally realized using single photons, with the three degrees of freedom being OAM, path, and polarization. These have unparalleled security for quantum communication tasks. The ability to simultaneously encode two distinct messages using the generated SPES showcases the versatility and efficiency of the proposed cryptographic protocol. This capability could significantly improve the throughput of quantum communication systems.