安全传送明文的量子直传实验方案设计

乒乓直传协议是一种新颖的量子直传通信协议。基于量子纠缠特性，乒乓协议允许绝对安全地进行明文直接通信和渐进地进行密钥安全分发。是一种绝对安全的即时通信协议。该量子直传协议将来有望成为安全稳定的光量子通信的主流方式。然而，目前还没有该协议的物理实现方案。分析了乒乓直传协议的工作原理．给出了该协议的流程图，进而分析了协议的物理实现机制，结合纠缠光子源、自由空间单光子路由控制和单光子检测技术，提出了在自由空间中实现乒乓直传协议的实验技术方案，并设计出了乒乓直传协议的实验装置。此实验技术方案为从实验角度进一步研究乒乓协议，以及未来此协议的商业化应用提供了参考。

Experimental Scheme of Secure Plaintext Transmission with Quantum Direct Communication

“Ping-pong” protocol is a novel secure deterministic quantum communication protocol. Based on an entangled pair of qubit, it allows asymptotically secure key distribution and quasi-secure direct communication. Its absolute security has been proved. It is hoped that this kind of quantum deterministic communication will be a main trend of the future quantum optic communication. However, there is no experimental implement of this protocol reported so far. The working scheme of the ping-pong protocol is analyzed and its flow chart is presented. Then the scheme of physical realization of the ping-pong protocol is analyzed. Combining entangled photon resource technique with single photon routing control and single photon detecting technique, an experimental realization in freespace of this protocol and its equipment figure are then proposed. Based on this work, further research of the ping-pong protocol and some practical applications can be taken.