  Measurement-device-independent quantum key distribution (MDI-QKD), leaving
the detection procedure to the third partner and thus being immune to all
detector side-channel attacks, is very promising for the construction of
high-security quantum information networks. We propose a scheme to implement
MDI-QKD, but with continuous variables instead of discrete ones, i.e., with the
source of Gaussian-modulated coherent states, based on the principle of
continuous-variable entanglement swapping. This protocol not only can be
implemented with current telecom components but also has high key rates
compared to its discrete counterpart; thus it will be highly compatible with
quantum networks.
