  A class of quantum protocols of bit commitment is constructed based on the
nonorthogonal states coding and the correlation immunity of some Boolean
functions. The binding condition of these protocols is guaranteed mainly by the
law of causality and the concealing condition is guaranteed by the
indistinguishability between nonorthogonal quantum states and the correlation
immunity of Boolean functions. We also give out an oblivious transfer protocol
based on two-nonorthogonal states coding and build a bit commitment protocol on
top of it. The relationship between these protocols and the well known no-go
theorem is also discussed in details.
