At least one set of revocation information for identifying electronic
appliances that should be revoked for content protection and master
revocation information for identifying electronic appliances that have
special permission to update the revocation information are recorded in
advance into a special storage region on a storage medium. When the
storage medium is loaded into an electronic appliance indicated by the
master revocation information, the revocation information can be updated.
However, when the storage medium is loaded into an electronic appliance
indicated by the revocation information, the electronic appliance is
revoked and so the protection of contents is improved.