Lagrange polynomial interpolation..

.. used for hacking online banking systems?
Have you ever think about appointing polynomial to discover singe-use passwords generating model?
Yesterday, my friend run me against it, bothering my head about it. We were discussing problem for couple of minutes, trying to find the best mathematical algorithm..
I think we did it, but it seems to be barely possible ( math. NP-hard problem ) to do it without any aditional conditions ( knowledge of general principles used by banks to pregenerate single-use passwords lists ).
I know some directions, that can simplify ordeal.. but i'm passing it over in silence, attempting to produce resolution by all possible, but non privileged means.


If you bethink onself to do it, you are kindly welcome to renew a debate here.