The present invention provides a digital data reproducing device having a simple configuration and being capable of protecting copyright of digital data such as video or audio. Content provider side embeds copyright management information (cumulative number of reproduction times, permissible number of reproduction times, etc.) into digital data that has been degraded by scrambling, and provides it to a content user. A reproducing device of the content user side causes copyright management information detection unit to detect the copyright management information, decreases the data degradation depending on result of the detection, and reproduces by data reproducing unit.