  The Higgs sector of the Standard Model offers a unique probe of the hidden
sector. In this work, we explore the possibility of renormalizable Higgs
couplings to the hidden sector vector fields which can constitute dark matter
(DM). Abelian gauge sectors with minimal field content, necessary to render the
gauge fields massive, have a natural Z_2 parity. This symmetry ensures
stability of the vector fields making them viable dark matter candidates, while
evading the usual electroweak constraints. We illustrate this idea with the
Stueckelberg and Higgs mechanisms. Vector DM is consistent with the WMAP,
XENON100, and LHC constraints, while it can affect significantly the invisible
Higgs decay. Due to the enhanced branching ratio for the Higgs decay into the
longitudinal components of the vector field, the vector Higgs portal provides
an efficient way to hide the Higgs at the LHC. This could be the reason why the
latest combined ATLAS/CMS data did not bring evidence for the existence of the
Higgs boson.
