An optical disk according to the present invention is the optical disk on which secret information on unique information given to a specific optical disk manufacturer or a specific optical disk and information recorded on an infringement disk list of identifying an illegitimate optical disk manufacturer or an illegitimate optical disk are recorded in advance, and the optical disk has an area in which reproduction-only encrypted data encrypted based on the secret information and the information on the infringement disk list is recorded in advance or an area capable of recording the encrypted data to be encrypted based on the secret information and the information on the infringement disk list.