An apparatus , comprising: an ultrasonic sensor array ; and a control; system , at least part of which is coupled to the ultrasonic sensor array , the control system configured to: control the ultrasonic sensor array to acquire ultrasonic image data corresponding to at least one reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from a target object during an acquisition time window; extract first fingerprint data from the ultrasonic image data, the first fingerprint data corresponding to a first depth; determine whether the ultrasonic image data includes second fingerprint data that is different from the first fingerprint data, the second fingerprint data corresponding to a second depth that is different from the first depth, wherein a depth difference between the depth of the first fingerprint data and the depth of the second fingerprint data corresponds to at least a threshold time difference of the received ultrasonic waves; and, if it is determined that the ultrasonic image data does not include second fingerprint data that is different from the first fingerprint data and that is corresponding to a second depth that is different from the first depth, perform an authentication process based, at least in part, on the first fingerprint data. an ultrasonic sensor array ; and a control; system , at least part of which is coupled to the ultrasonic sensor array , the control system configured to: control the ultrasonic sensor array to acquire ultrasonic image data corresponding to at least one reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from a target object during an acquisition time window; extract first fingerprint data from the ultrasonic image data, the first fingerprint data corresponding to a first depth; determine whether the ultrasonic image data includes second fingerprint data that is different from the first fingerprint data, the second fingerprint data corresponding to a second depth that is different from the first depth, wherein a depth difference between the depth of the first fingerprint data and the depth of the second fingerprint data corresponds to at least a threshold time difference of the received ultrasonic waves; and, if it is determined that the ultrasonic image data does not include second fingerprint data that is different from the first fingerprint data and that is corresponding to a second depth that is different from the first depth, perform an authentication process based, at least in part, on the first fingerprint data. control the ultrasonic sensor array to acquire ultrasonic image data corresponding to at least one reflected ultrasonic wave received by at least a portion of the ultrasonic sensor array from a target object during an acquisition time window; extract first fingerprint data from the ultrasonic image data, the first fingerprint data corresponding to a first depth; determine whether the ultrasonic image data includes second fingerprint data that is different from the first fingerprint data, the second fingerprint data corresponding to a second depth that is different from the first depth, wherein a depth difference between the depth of the first fingerprint data and the depth of the second fingerprint data corresponds to at least a threshold time difference of the received ultrasonic waves; and, if it is determined that the ultrasonic image data does not include second fingerprint data that is different from the first fingerprint data and that is corresponding to a second depth that is different from the first depth, perform an authentication process based, at least in part, on the first fingerprint data. <EOS>