Abstract: Techniques and apparatuses are described that implement hand-grip location detection using ultrasound. In particular, an ultrasonic sensor determines a location that a user's hand grips a user device. While gripping the user device, the hand creates an additional aperture area, which amplifies ultrasonic signals that are received by one or more transducers of the ultrasonic sensor that are proximate to the user's hand. By analyzing the amplitude (or power) of received ultrasonic signals, the ultrasonic sensor can detect if the user's hand is proximate to a particular transducer. In some implementations, the ultrasonic sensor utilizes speakers and/or microphones that are present within the user device. In this way, the ultrasonic sensor can have a relatively small footprint and fit within space-constrained devices.

Abstract: Techniques and apparatuses are described that implement face authentication anti-spoofing using interferometry-based coherence. In particular, a face-authentication system uses ultrasound to distinguish between a real human face and a presentation attack that uses instruments to present a version of a human face. The face-authentication system includes or communicates with an ultrasonic sensor, which can detect a presentation attack and notify the face-authentication system. In general, the ultrasonic sensor uses interferometry to evaluate an amount of coherence (or similarity) between reflections observed by two or more transducers. In this way, the ultrasonic sensor can prevent unauthorized actors from using the presentation attack to gain access to a user's account or information.

Abstract: Techniques and apparatuses are described that implement face authentication anti-spoofing using ultrasound. In particular, a face-authentication system uses ultrasound to distinguish between a real human face and a presentation attack that uses instruments to present a version of a human face. The face-authentication system includes or communicates with an ultrasonic sensor, which can detect a presentation attack and notify the face-authentication system. In general, the ultrasonic sensor analyzes characteristics of a presented object and determines whether the object represents a human face or a presentation attack instrument. In this way, the ultrasonic sensor can prevent unauthorized actors from using the presentation attack to gain access to a user's account or information.

Abstract: Techniques and apparatuses are described that implement hand-grip location detection using ultrasound. In particular, an ultrasonic sensor determines a location that a user's hand grips a user device. While gripping the user device, the hand creates an additional aperture area, which amplifies ultrasonic signals that are received by one or more transducers of the ultrasonic sensor that are proximate to the user's hand. By analyzing the amplitude (or power) of received ultrasonic signals, the ultrasonic sensor can detect if the user's hand is proximate to a particular transducer. In some implementations, the ultrasonic sensor utilizes speakers and/or microphones that are present within the user device. In this way, the ultrasonic sensor can have a relatively small footprint and fit within space-constrained devices.

Abstract: Techniques and apparatuses are described that implement face authentication anti-spoofing using ultrasound. In particular, a face-authentication system uses ultrasound to distinguish between a real human face and a presentation attack that uses instruments to present a version of a human face. The face-authentication system includes or communicates with an ultrasonic sensor, which can detect a presentation attack and notify the face-authentication system. In general, the ultrasonic sensor analyzes characteristics of a presented object and determines whether the object represents a human face or a presentation attack instrument. In this way, the ultrasonic sensor can prevent unauthorized actors from using the presentation attack to gain access to a user's account or information.

Abstract: Techniques and apparatuses are described that implement face authentication anti-spoofing using interferometry-based coherence. In particular, a face-authentication system uses ultrasound to distinguish between a real human face and a presentation attack that uses instruments to present a version of a human face. The face-authentication system includes or communicates with an ultrasonic sensor, which can detect a presentation attack and notify the face-authentication system. In general, the ultrasonic sensor uses interferometry to evaluate an amount of coherence (or similarity) between reflections observed by two or more transducers. In this way, the ultrasonic sensor can prevent unauthorized actors from using the presentation attack to gain access to a user's account or information.

Abstract: Techniques and apparatuses are described that implement face authentication anti-spoofing using ultrasound. In particular, a face-authentication system uses ultrasound to distinguish between a real human face and a presentation attack that uses instruments to present a version of a human face. The face-authentication system includes or communicates with an ultrasonic sensor, which can detect a presentation attack and notify the face-authentication system. In general, the ultrasonic sensor uses power-spectra to evaluate an amount of variance observed over time within at least one receive channel. In this way, the ultrasonic sensor can prevent unauthorized actors from using the presentation attack to gain access to a user's account or information.