Biometric authentication has undergone a paradigm shift from single-modal physical characteristics to sophisticated multimodal systems incorporating behavioral traits, continuous authentication, and advanced presentation attack detection. This evolution is driven by the increasing need for robust, adaptive, and user-centric identity verification mechanisms in digitally connected ecosystems. With global losses from identity fraud exceeding $50 billion in 2024 and deepfake incidents quadrupling between 2023 and 2024, the security community faces unprecedented challenges in verifying digital identity.These developments highlight the critical importance of integrating advanced detection and mitigation strategies into authentication pipelines. .