Spoof detection is a security mechanism used by biometric authentication systems to determine whether an input sample originates from a genuine, living person or a fraudulent imitation. In biometric applications such as facial, fingerprint, or voice recognition, it identifies presentation attacks where an unauthorized individual attempts to deceive the system using synthetic or recorded artifacts, including printed photographs, video replays, silicone masks, or synthesized media. By analyzing distinguishing indicators such as liveness cues, surface textures, depth information, and dynamic biological responses, spoof detection prevents unauthorized access and ensures the integrity of automated identity verification.