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 an entire facial area of 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 non-user DataBase (DB) for storing the non-user GMM; a user GMM configuration unit for generating a user GMM by applying a plurality of varying light masks to a user facial image of a user, wherein the plurality of varying light masks are applied by directing illumination on the user facial image from various directions; a user DB for storing the user GMM; 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.