An information extraction method, an information extraction device, a program, a registration device, and a verification device that improve authentication accuracy simultaneously with reduction of the amount of information concerning an identification target are proposed. From a plurality of first images obtained from viewpoints in surroundings of a living body portion, common portions of silhouettes of the living body portion that is shown in the images are generated as a first stereoscopic image in a target space. From a plurality of second images obtained from the viewpoints in the surroundings of the living body portion, common portions of silhouettes of an inner surface image of the living body portion that is shown in the images are generated as a second stereoscopic image in the target space. A value representing a shape of a cross section of the second stereoscopic image that has a predetermined positional relationship with respect to a reference position of the first stereoscopic image is extracted as an identification information item.