An information processing device includes an imaging unit configured to perform imaging of one of the object person and a registrant, a first feature amount calculation unit configured to calculate a feature amount of a face of the registrant, a second feature amount calculation unit configured to calculate time series of feature amount of a lip of the registrant, a registration unit configured to register the time series of feature amount of the lip in a database to be associated with the feature amount of the face of the registrant, an identification unit configured to identify the face of the object person, a recognition unit configured to recognize speech content of the object person, and an authentication unit configured to perform personal authentication of the object person based on an identification result of the face and a recognition result of the speech content of the object person.