On the inversion of biometric templates by an example

In this paper we analyze practical issues related to an adversarial inversion of biometric templates constructed without any cryptographically-secure protection features. The inversion in most cases is considered an ill-defined problem as the template captures only a small subset of the physical presence of a specific biometric trait. We apply our practical approach to an existing iris-based biometric system and demonstrate that “inverted” iris images pass matching tests even when encoded like barcodes.