1. Introduction
Face recognition (FR) systems have become one of the most widely used biometric modalities, ranging from security to identification applications in government offices, law enforcement, and visa management. These systems are highly effective in preventing unauthorized access while maintaining low false rejection and acceptance rates, placing them among the best methods to reduce security vulnerabilities [1] – [3]. However, these systems still have susceptibilities, notably in the presence of face-morphing attacks. Face morphing attacks aim to exploit the intrinsic nature of FR classifiers that map biometric templates to a singular identity in a one-to-one map. To achieve this, an attacker creates a single morphed face image incorporating the biometric traits and facial landmarks of two different identities. The morphed image can cause an FR system to incorrectly register a false accept with both identities [3] – [7].