Content Management System and Content Management Unit

摘要

A content management system which can prevent a content from being copied exceeding the limited number of copies for the content. The content management system includes a first content management device and a second content management device. The first content management device stores period information that indicates an available period during which a first external device is permitted to use a copied content which has been copied from the content, and outputs the period information to the second content management device when the content is moved. Upon receiving the period information from the first content management device, the second content management device judges whether the available period of the copied content has expired, using the received period information, and if it is judges that the available period has not expired, it inhibits the content from being copied to the second external device.