PROBLEM TO BE SOLVED: To improve authentication accuracy of biometric authentication regardless of external light environment.SOLUTION: An acquisition unit 311 acquires feature information of an image of a living body to be authenticated that is photographed by irradiating a living body to be authenticated with first illumination light or second illumination light. The first illumination light includes light with a first wavelength and the second illumination light includes light with the first wavelength and light with a second wavelength different from the first wavelength. A readout unit 312 reads out the feature information of the image of the living body that is photographed by emitting the illumination light with which the living body to be authenticated is irradiated, from a storage unit that stores first feature information of an image of a first living body and second feature information of an image of a second living body. The image of the first living body is an image of a living body that is photographed by irradiating a living body to be registered with the first illumination light, and the image of the second living body is an image of a living body that is photographed by irradiating a living body to be registered with the second illumination light. A calculation unit 313 calculates similarity between the feature information of the image of the living body to be authenticated and the feature information that the readout unit 312 reads out, an authentication unit 314 authenticates the living body to be authenticated on the basis of the similarity calculated by the calculation unit 313.SELECTED DRAWING: Figure 3【課題】外光環境によらずに生体認証の認証精度を向上させる。【解決手段】取得部３１１は、第１照明光又は第２照明光を認証対象の生体に照射して撮影した認証対象生体画像の特徴情報を取得する。第１照明光は、第１波長の光を含み、第２照明光は、第１波長の光と第１波長と異なる第２波長の光とを含む。読出部３１２は、第１生体画像の第１特徴情報と第２生体画像の第２特徴情報とを記憶する記憶部から、認証対象の生体に照射された照明光を照射して撮影した生体画像の特徴情報を読み出す。第１生体画像は、登録対象の生体に第１照明光を照射して撮影した生体画像であり、第２生体画像は、登録対象の生体に第２照明光を照射して撮影した生体画像である。計算部３１３は、認証対象生体画像の特徴情報と読出部３１２が読み出した特徴情報との間の類似
