An Ear Canal Deformation Based User Authentication Using Ear Wearable Devices

TL;DR

EarDynamic is a novel in-ear wearable authentication system that uses acoustic sensing of ear canal deformation during speech to achieve high accuracy, passively and continuously verifying user identity.

Contribution

It introduces a new biometric modality based on ear canal deformation captured via acoustic signals, enabling passive, continuous user authentication with high accuracy.

Findings

Achieves 97.38% recall and 96.84% F1 score.

Works effectively in noisy environments and during daily activities.

Abstract

Biometric-based authentication is gaining increasing attention for wearables and mobile applications. Meanwhile, the growing adoption of sensors in wearables also provides opportunities to capture novel wearable biometrics. In this work, we propose EarDynamic, an ear canal deformation-based user authentication using in-ear wearables. EarDynamic provides continuous and passive user authentication and is transparent to users. It leverages ear canal deformation that combines the unique static geometry and dynamic motions of the ear canal when the user is speaking for authentication. It utilizes an acoustic sensing approach to capture the ear canal deformation with the built-in microphone and speaker of the in-ear wearable. Specifically, it first emits well-designed inaudible beep signals and records the reflected signals from the ear canal. It then analyzes the reflected signals and extracts fine-grained acoustic features that correspond to the ear canal deformation for user authentication. Our extensive experimental evaluation shows that EarDynamic can achieve a recall of 97.38% and an F1 score of 96.84%. Results also show that our system works well under different noisy environments with various daily activities.