An entanglement-based continuous variable (CV) QKD scheme is proposed, performing information reconciliation over an entanglement-assisted link. The same entanglement generation source is used in both raw key transmission and information reconciliation. The entanglement generation source employs only low-cost devices operated in the C-band. The proposed CV-QKD scheme with information reconciliation over an entanglement-assisted link significantly outperforms the corresponding CV-QKD scheme with information reconciliation over an authenticated public channel. It also outperforms the CV-QKD scheme in which a classical free-space optical communication link is used to perform information reconciliation. An experimental demonstration over the free-space optical testbed established at the University of Arizona campus indicates that the proposed CV-QKD can operate in strong turbulence regimes. To improve the secret key rate performance further, adaptive optics is used.
Keywords: QKD; continuous variable; entanglement; entanglement assisted communication; information reconciliation.