Usability Assessment in a Multi-Biometric Continuous Authentication System

Multimodal biometric continuous authentication systems allow to improve security, making user identity verification a continuous process rather than a one-time occurrence. Unfortunately, the usability of these systems and their adequacy for working activities are often questioned. This paper presents a usability study for a multimodal biometric continuous authentication system capable of continuously and transparently verifying user identity through face, fingerprint and keystroke traits. We evaluate the system's usability obtained varying configuration parameters. This allows identifying the more suitable parameters configuration for different usability and security requirements. The experimental campaign relies on 60 users performing pre-defined tasks while our continuous authentication system is running. Users' opinions on system usability were collected with a post questionnaire. Our findings show that users were able to complete ordinary tasks securely and without additional effort, and that they have accepted the authentication system, which only requires minimal training.