A content usage control apparatus prevents a content managed by an end user from being illegally used. To prevent a content from being used by an apparatus or user other than an authorized apparatus or user, a content usage control apparatus registers the authorized apparatus or user and determines, before providing the content, whether the content is going to be provided to the authorized apparatus or user. The content usage control apparatus also has the capability of imposing a limitation on rewriting of registration. The above-described capabilities of the content usage control apparatus make it possible to protect copyright of information to be provided. A specific example of the content usage control apparatus is a server which stores contents such as movie contents or music contents, and may be used in a system in which a content is provided in response to a request from a client such as a portable telephone, a TV set, or a personal computer, connected to the server.