Floodlight Quantum Key Distribution: Breaking The One-Photon-Per-Bit Barrier
Quntao Zhuang, Zheshen Zhang, Justin Dove, Franco N. C. Wong, Jeffrey H. Shapiro · arXiv (Cornell University) · 2015
Existing quantum key distribution protocols typically transmit at most one photon per bit, so that the no-cloning theorem ensures their security. As a result, their key rates suffer dramatically in long-distance transmission because of channel loss. We introduce floodlight quantum key distribution (FL-QKD), which breaks the one photon per bit barrier and overcomes loss by exploiting a huge number of optical modes per bit. FL-QKD is capable of 2 Gbps secret-key rates over a 50 km fiber link. Its security follows from employing less than one photon per mode and using photon-coincidence channel monitoring.