Experimental demonstration of practical high-speed Gaussian coherent state continuous-variable quantum key distribution with real-time parameter monitoring and key distillation

Abstract

Gaussian modulated coherent state continuous variable quantum key distribution protocol is proven to provide high security while being compatible with classical coherent communication equipment. Here, we demonstrate a high-speed Gaussian modulated coherent state continuous variable quantum key distribution with a symbol rate of 40 MHz. Our system is consisted of field deployable data acquisition and processing hardware. We have also developed a software tool chain for recording data and parameter monitoring in real time. The data is then post processed to distill secret keys. We have achieved a secret key rate of 2.3 Mbps after all the post processing stages, at a transmission distance of 25 km.