  We reconsider the strength of the electroweak phase transition (EWPT) in the
inert doublet dark matter model, using a quantitatively accurate form for the
one-loop finite temperature effective potential, taking into account relevant
particle physics and dark matter constraints, focusing on a standard model
Higgs mass near 126 GeV, and doing a full scan of the space of otherwise
unconstrained couplings. We find that there is a significant (although
fine-tuned) space of parameters for achieving an EWPT sufficiently strong for
baryogenesis while satisfying the Xenon100 constraints from direct detection
and not exceeding the correct thermal relic density. We predict that the dark
matter mass should be in the range 60-67 GeV, and we discuss possible LHC
signatures of the charged and CP-odd Higgs bosons, including a 10% decrease of
the h -> 2 photon branching ratio.
