  A simple extension of the minimal supersymmetric standard model in which
baryon and lepton numbers are local gauge symmetries spontaneously broken at
the supersymmetry scale is reported. This theory provides a natural explanation
for proton stability. Despite violating R-parity, it contains a dark matter
candidate carrying baryon number that can be searched for in direct detection
experiments. The model accommodates a light active neutrino spectrum and
predicts one heavy and two light sterile neutrinos. It also allows for lepton
number violating processes testable at the Large Hadron Collider.
