Content data (11), handling limit data (12), and a check program (13) are provided in a data group (10) recorded on an information recording medium (1). The check program (13) causes a reproducing device to read the content data so as to make the reproducing device function as a check device for checking the data state of the handling limit data. Thus, when the handling limit data (12) is tampered, the check program (13) is executed by the reproducing device to find the tamper.