In the case of modifying available copy count information which is contained in distribution data, the distribution data being distributed from a distribution server and stored in a PC which serves as a receiving device, the PC sends a reuse request to the distribution server. Thereafter, the PC receives a reuse information key from the distribution server so as to rewrite the available copy count of the distribution data based on the reuse information key, thereby making it possible to reuse the distribution data already distributed once.