DIGITAL DATA WRITING DEVICE, DIGITAL DATA RECORDING DEVICE AND DIGITAL DATA UTILIZING DEVICE

摘要

PURPOSE: A device is provided to prevent the establishment of an illegal action after backing-up limiting information by obtaining different key information at every transmitting processing, converting data by means of obtained key information and transmitting generated conversion managing information and digital data as one set. CONSTITUTION: A memory card(120) transmits a card ID to a player(140). Session key sharing parts(123,142) exchange a random number or the like and share the different session key at every session using ciphering contents which are recorded in the memory card(120). The memory card(120) executes prescribed data conversion in ciphering management information held in a ciphering management information holding part(125) through the use of a session key and generates conversion management information. The player(140) executes inverse data conversion in received conversion management information by using the session key to generate ciphering management information, decodes the ciphering management information by using the card ID and generating management information.