  The role of squeezing in quantum key distribution with continuous variables
based on homodyne detection and post-selection is investigated for several
specific eavesdropping strategies. It is shown that amplitude squeezing creates
strong correlations between the signals of the legitimate receiver and a
potential eavesdropper. Post-selection of the received pulses can therefore be
used to reduce the eavesdropper's knowledge of the raw key, which increases the
secret key rate by orders of magnitude over large distances even for modest
amounts of squeezing.
