  Four-wave mixing in atomic vapor allows for the generation of
multi-spatial-mode states of light containing many pairs of two-mode entangled
vacuum beams. This in principle can be used to send independent secure keys to
multiple parties simultaneously using a single light source. In our experiment,
we demonstrate this spatial multiplexing of information by selecting three
independent pairs of entangled modes and performing continuous-variable
measurements to verify the correlations between entangled partners. In this
way, we generate three independent pairs of correlated random bit streams that
could be used as secure keys. We then demonstrate a classical four-party secret
sharing scheme as an example for how this spatially multiplexed source could be
used.
