  We present a bit commitment protocol based on quantum nonlocality that seems
to bring ever-lasting unconditional security. Although security is not
rigorously proved, physical arguments and numerical simulations support this
conclusion. The key point is that the proof of the commitment is forced to
become classical data uncorrelated with anything else. This allows us to
circumvent previous impossibility proofs in which it is assumed that classical
data can be replaced by quantum data that may be entangled with the committer.
The proposed protocol also recovers two features missing in recent
"relativistic" quantum bit commitment protocols: (i) the committer can decide
if and when she wants to reveal the commitment and (ii) the security of the
commitment lasts for arbitrary long time.
