An image forgery protection apparatus comprises: one or more memories; and circuitry. The circuitry generates challenge data which change with lapse of time at least in a predetermined period. The circuitry generates a unique response which changes with lapse of time, the unique response corresponding to the challenge data on a basis of a physically unclonable function. The circuitry changes subject image data correspondingly to the unique response, the subject image data obtained by capturing an image of a subject.