We apply the methods of the theory of elasticity for two important problems in fingerprint based authentication: (1) registration of deformations up to the level of pixel-wise correspondence of two images; (2) parametric modeling and exact measurement of the natural deformations. The approach is based on the numerical solution of Navier linear PDE, the registration being provided even for the cases of significant losses and errors in the initial correspondences of minutiae that may be caused by various noise and distortion factors. Relatively compact and theoretically grounded model of the deformations is proposed, which allows to obtain the estimations of discrepancies in the most extreme cases.