Client apparatus (10, 11, 12, . . . ) receives, from a server (20) or CD-ROM, content data and first management information that enables trial use of the content data and store the received content data and first management information in an HDD. When a user of the client apparatus desires normal use of the stored content data, the client apparatus (10, 11, 12, . . . ) issues a normal use request to the server (20). Then, the client apparatus receives, from the server, second management information that authorizes the normal use of the content data. Thus, only the client apparatus, to which an authorization for the normal use, is allowed to reproduce the content data in a normal mode with no reproduction function limitation on the basis of the second management information. In this way, the inventive arrangements permit efficient delivery of trial and purchasing content, but also can enhance security against unfair use, such as unauthorized copying, of the content.