An authenticated portable terminal (3a) retains device information indicating a portable terminal (3b) for which playback of content has been permitted. On the basis of restricted authentication information allowing playback of content under a predetermined condition, which has been imparted to the permitted portable terminal (3b) from the portable terminal (3a), playback of the content is requested by the portable terminal (3b). In the case in which the portable terminal (3b) is determined using the retained device information, in accordance with the request from the portable terminal (3b), content provided from a media server (2) is played back under the predetermined condition.