I. Introduction
Physiological and behavioral characteristics have always been used to identify an individual. When we refer to this identification approach, the focus is on biometrics. The development of biometrics happened at a fast pace, starting from technologies based on fingerprint, to those based on iris recognition, facial recognition or even biological rhythm or behavioral characteristics such as specific features of a person’s gait. Because we are in the age of speed and technological progress, biometric authentication has become increasingly common, including in access systems in institutions or in public or private spaces, but also in trade. If biometric technologies can improve our lives, it is no less true that they collect data that falls into the wider sphere of personal data and has as its main purpose the security of the individual.