PIRANTI PEREKAMAN, MEMORI DAN PENGGUNAAN DATA DIGITAL UNTUK PENGUBAH INFORMASI MANAGEMEN DIMANA MEMUAT PEMBATAS; PENGGUNAAN INFORMASI SUATU KUNCI YANG BERBEDA TIAP PEMBAHASAN PENERIMAAN/PENGIRIMAN INFORMASI MANAGEMEN

摘要

In each digital content utilize session, a memory card generates conversion key information for specifying a data conversion, while a player generates inverse conversion key information for specifying an inverse data conversion. The memory card then performs the data conversion specified by the conversion key information on management information stored therein, and sends the converted management information and digital content stored therein to the player. The player performs the inverse data conversion specified by the inverse conversion key information on the converted management information to restore the management information, and utilizes the digital content in accordance with restrictions set in the restored management information to limit the use of the digital content.