  This paper conducts an extensive review of biometric user authentication
literature, addressing three primary research questions: (1) commonly used
biometric traits and their suitability for specific applications, (2)
performance factors such as security, convenience, and robustness, and
potential countermeasures against cyberattacks, and (3) factors affecting
biometric system accuracy and po-tential improvements. Our analysis delves into
physiological and behavioral traits, exploring their pros and cons. We discuss
factors influencing biometric system effectiveness and highlight areas for
enhancement. Our study differs from previous surveys by extensively examining
biometric traits, exploring various application domains, and analyzing measures
to mitigate cyberattacks. This paper aims to inform researchers and
practitioners about the biometric authentication landscape and guide future
advancements.
