Optical discs on which enciphered data is recorded include first recording areas, where enciphered contents data is recorded, and second recording areas provided at the position where a read-out operation is carried out ahead of the first recording areas and including a first area portion, where cipher key data for decoding enciphered contents data is recorded, and a second area portion, where identification data for identification of the recording medium modulated by a modulation system different from that of at least the first area portion is recorded.