A contents database 114 memorizes the discriminating information for
discriminating contents and the temporal information as to the time of
content duplication associated with the discriminating information. A
recording program 113 acquires the discriminating information of contents
to be duplicated and duplicates the contents in association with the
acquired discriminating information and with the temporal information
memorized in the contents database 114. This substantially prohibits
duplication in large quantities without significantly impairing the
interests of a user.