Unconsciously Continuous Authentication Protocol in Zero-Trust Architecture Based on Behavioral Biometrics

Zero-trust architecture has received massive attention globally and been a significant development in the field of cybersecurity. Within zero-trust architecture, the continuous authentication (CA) strategy has been proposed to counter the network security threats posed by traditional static authentication mechanisms. However, most studies have focused on either device-to-device authentication or user authentication. This limitation results in risks of identity spoofing or credential theft despite the implementation of the CA mechanism, thus concluding the parity in significance between authenticating users and devices. Furthermore, considering the CA of users, it is essential to face the issue posed by user authentication fatigue. In response to these challenges, this work aims to introduce an unconsciously CA protocol (UCAP) based on zero-trust concepts and behavior biometrics. UCAP utilizes the behavior of keystroke dynamics as a main factor in consistently evaluating the user trust level. This method enables the continual updating of communication keys to preserve robust authentication of both devices and users. The robustness of UCAP has been examined through formal tools, while the experimental outcomes have shown satisfactory performance.