I. Introduction
Biometric recognition systems can verify the identities of people based on their physiological and/or behavioral personal characteristics, and hence, such systems are widely used as essential safety precautions in various fields such as the military, organizations, universities, banks, airports, as well as in e-commerce. Usually, biometric traits are extracted from facial images, fingerprints, iris images, and palm prints; however, such traits may be easy to steal and copy [1]–[3]. Considering that it is possible to forge authentication systems using stolen data by performing spoofing attacks, it is worthwhile to explore more unique biological signals for biometric authentication purposes. However, several authentication methods do not support the replacement of users in user management systems after authentication considering that users are authenticated only once before system use. Therefore, conventional biometric traits are only used in the begining of user verification process, and hence, such traits may be unsuitable for continuous authentication [4].