Behaviors Speak More: Achieving User Authentication Leveraging Facial Activities via mmWave Sensing

It's common to use the face or fingerprint to unlock the smartphone or log into an app. While convenient, these methods can be fooled. Researchers have shown that things like high-quality photos, 3D-printed masks, or fake fingerprints can trick these systems [10]. To prevent this, developers often add extra security steps, like asking you to blink your eyes during a face scan [4]. Existing research has explored the integration of user authentication and liveness detection, such as speech-induced facial vibration [7]. However, those designs even require sophisticated hardware design or specialized sensors [10]. Even worse, among those using the onboard camera for collecting sensitive facial information as biometrics [2], users' privacy is inevitably compromised.