  Quantun non-demolition (QND) variables are generlized to the nonlocal ones by
proposing QND measurement networks of Bell states and multi-partite GHZ states,
which means that we can generate and measure them without any destruction. One
of its prospective applications in the quantum authentication system of the
Quantum Security Automatic Teller Machine (QSATM) which is much more reliable
than the classical ones is also presented.
