Authentication of fingerprint scanners

Fingerprint scanners have unique patterns that can be used to distinguish one scanner from another one. The pattern, which we call scanner pattern, stems from the variability of device characteristics at silicon level and is caused by imperfections of the conversion from the input to the scanner (i.e., the object applied to it) to its output (i.e., the digital image). The scanner pattern is a sufficiently unique and persistent intrinsic characteristic of the fingerprint scanners even to those of the same technology, manufacturer, and model. We propose a simple and extremely accurate algorithm that is able to distinguish the pattern of one scanner from the pattern of another scanner of exactly the same model by extracting the pattern from a single image, acquired with each scanner. In this way, the scanner pattern can be used to enhance the security of a bio metric system by authenticating the scanner, used to acquire a particular fingerprint image, and thus detect attacks on the scanner. Combining the biometric authentication with a scanner authentication leads to a two-part authentication, which we call bipartite authentication, that verifies both the identity of the user and the "identity" of the fingerprint scanner.