The Death of the Password: A Deep Dive into Biometrics, Behavioral Analytics, and the Zero-Trust Future

Passwords have long been the cornerstone of digital authentication, but their inherent limitations—such as vulnerability to phishing, weak user choices, and the burden of management—have created critical security gaps. This systematic literature review explores the emerging paradigm of Passwordless authentication, analyzing its core components: biometrics, behavioral analytics, and the overarching principle of Zero-Trust Architecture (ZTA). The objective is to provide a comprehensive overview of how these technologies are converging to create more secure and user-friendly authentication systems. The review finds that biometric methods (like fingerprints and facial recognition) offer strong security but rais significant privacy concerns and are not foolproof. Behavioral analytics, which continuously verify users based on patterns like keystroke dynamics or mouse movements, provide a passive, persistent layer of security that is difficult to mimic. Crucially, these methods are most effective when integrated within a Zero-Trust framework, which operates on the principle of "never trust, always verify," thereby eliminating inherent trust from any network. The key contribution of this review is a synthesized analysis demonstrating that the future of authentication is not a single technology replacing the password, but a multifaceted, adaptive system. The outlook points toward a future where continuous, risk-based authentication, combining biometrics and behavioral analytics under a Zero-Trust model, will render the static password obsolete, creating a more resilient security posture.