HT-Auth: Secure VR Headset Authentication via Subtle Head Tremors

While Virtual Reality (VR) applications have gained popularity in recent years, efficiently identifying users on VR devices remains challenging. Current solutions, such as passwords and digital PINs, relying on handheld controllers or in-air hand gestures, are time-consuming and far less convenient than typing on touchscreens or physical keyboards. Even worse, the entry process can be observed by others in proximity, raising security concerns. In this paper, we propose HT-Auth, a novel authentication method for VR devices based on subtle head tremors. These tremors, occurring during active force exertion, are intrinsic and inevitable for human beings, which can be easily captured by inertial sensors built-in commodity VR headsets. We thus derive neck muscular biometrics from the tremor signal for secure VR device authentication. Our experiments, conducted with both standalone and mobile VR headsets, achieve a commendable balanced accuracy of 97.22% with just 10 registration samples, proving its efficacy and resilience against potential threats. Our source code is available at https://anonymous.4open.science/r/HT-OpenSource-10C3/.