A configuration is provided for a process in which appropriate content code corresponding to apparatuses and applications of various model types and versions is selected to be performed. In a configuration in which content code recorded on an information recording medium is obtained, and processing, such as a security check in accordance with the content code, conversion of the content data, and embedding of player information into the content, is performed, at least a portion of the content code is set as encrypted data, and as an encryption key, a node key set so as to correspond to a node of a key tree having a hierarchical structure is used.