To provide managing method and device and a management system capable of easily expanding the value of basic software of a game, etc.
This management system has a region only for reproduction for storing first information and a write-once type recording region capable of storing expansion information used for the first information. The management system has a step for acquiring and authenticating authentication information from a client who uses an optical disk for storing the authentication information including property information that regulates the availability of the expansion information and a proprietary identifier for identifying the optical disk for a platform through a network, a step for acquiring the property information from the platform and transmitting an available list of the expansion information to the platform, and a step for transmitting to the client the expansion information selected by the client in the list.
SHIMAZAKI KATSUSUKE
YASUI TOSHIAKI
OTSUKA KOICHI
