  A new commitment scheme based on position-verification and non-local quantum
correlations is presented here for the first time in literature. The only
credential for unconditional security is the position of committer and
non-local correlations generated; neither receiver has any pre-shared data with
the committer nor does receiver require trusted and authenticated
quantum/classical channels between him and the committer. In the proposed
scheme, receiver trusts the commitment only if the scheme itself verifies
position of the committer and validates her commitment through non-local
quantum correlations in a single round. The position-based commitment scheme
bounds committer to reveal valid commitment within allocated time and
guarantees that the receiver will not be able to get information about
commitment unless committer reveals. The scheme works for the commitment of
both bits and qubits and is equally secure against committer/receiver as well
as against any third party who may have interests in destroying the commitment.
Our proposed scheme is unconditionally secure in general and evades Mayers and
Lo-Chau attacks in particular.
