Patent ID: 7503073

Claim:
An information managing apparatus for managing content, comprising: content retrieving means for retrieving the content; identification information obtaining means for obtaining identification information for identifying the information managing apparatus; content storing means for storing the content and adding the identification information to the content; usage-right storing means for storing a usage right regulating use of the content, the usage right comprising the identification information and information for allowing use of the content on an apparatus having the same identification information as the identification information added to the content, wherein the usage right allows use of the content in a hierarchical tree-based key management system, wherein the apparatus is a device node leaf of the hierarchical tree-based key management system; encryption means for encrypting the content using a content key, wherein the content key is generated based on a root key of the hierarchical tree-based key management system; and means for allowing playback of the content only when the playback is allowed by the usage right and the identification information added to the content and the identification information obtained by the identification information obtaining means correspond.