  We develop a scheme for fault-tolerant quantum computation based on
asymmetric Bacon-Shor codes, which works effectively against highly biased
noise dominated by dephasing. We find the optimal Bacon-Shor block size as a
function of the noise strength and the noise bias, and estimate the logical
error rate and overhead cost achieved by this optimal code. Our fault-tolerant
gadgets, based on gate teleportation, are well suited for hardware platforms
with geometrically local gates in two dimensions.
