ScanRing: Hybrid Authentication System in a Ring Device Using a Distance Sensor and an IMU Sensor MHCI026

Smart rings are used for contactless payment, smart lock operation, and health monitoring. For applications such as electronic payment and unlocking smart locks, the implementation of a user authentication system in smart rings is essential; however, some challenges remain. Fingerprint authentication is sensitive to fingertip conditions, while face authentication faces difficulties with miniaturization, power efficiency, and privacy. This study proposes ScanRing, a hybrid authentication system using a distance sensor and an IMU sensor in a smart ring. By moving the ring device laterally in front of the face, the distance sensor captures facial structure data, while the IMU sensor records the user’s motion characteristics. These combined datasets enable robust user authentication without relying on cameras, which enhances privacy while supporting a compact and power-efficient design. A user study (N = 30) demonstrated that ScanRing achieved an average authentication accuracy of 98.41 \(\%\) under stable conditions.