1. A system for verifying a face of a user by using a light mask, comprising: a facial feature extraction unit for extracting a facial feature vector from a specific facial image; a non-user Gaussian Mixture Model (GMM) configuration unit for generating a non-user GMM from a non-user facial image of a non-user; a user GMM configuration unit for generating a user GMM by applying light masks to a user facial image of a user; a log-likelihood value calculation unit for inputting the facial feature vector both to the non-user GMM and to the user GMM, thus calculating log-likelihood values; and a user verification unit for comparing the calculated log-likelihood values with a predetermined threshold, thus verifying whether the specific facial image is a facial image of the user.