  In this paper, we consider continuous-variable quantum key distribution (QKD)
protocols which use non-Gaussian modulations. These specific modulation schemes
are compatible with very efficient error correction procedures, hence allowing
the protocols to outperform previous protocols in terms of achievable range. In
their simplest implementation, these protocols are secure for any linear
quantum channels (hence against Gaussian attacks). We also show how the use of
decoy states makes the protocols secure against arbitrary collective attacks,
which implies their unconditional security in the asymptotic limit.
