“…Biometrics have been gradually replacing traditional methods that recognize people according to what they own, such as cards or keys, or what they know, such as passwords [1]. Iris, face, odor, fingerprint, ear structure, and hand geometry are examples of anatomical characteristics, while voice, walking manner, or signature are behavioral characteristics [2,3]. These biometric modalities should be worldwide, unchangeable, exclusive, and attainable.…”