A content playback apparatus comprising: a storage unit operable to store usage permission information including a usable time period for which content is usable; a measurement unit operable to measure time; a malfunction detection unit operable to detect whether or not a malfunction exists in the measurement unit in order to determine whether or not the time measured by the measurement unit is within the usable time period; and a determination unit operable to, when the malfunction detection unit has not detected the malfunction, determine that playback of the content is possible when the time measured by the measurement unit is within the usable time period; the content playback apparatus characterized by further comprising a request unit operable to, when the malfunction detection unit detects the malfunction and that communication via a network is possible, issue a request to a permission server apparatus that permits usage of the content and is connected to the content playback apparatus via the network, and receive a response to the issued request from the permission server apparatus; a restriction unit operable to, when the malfunction detection unit detects the malfunction, place a restriction on the playback of the content until the request unit receives the response; and a playback unit operable to play back the content in accordance with a result of the determination made by the determination unit and the restriction placed by the restriction unit; wherein, when the malfunction detection unit detects the malfunction, the restriction unit (i) judges whether or not a predetermined condition relating to a malfunctioning-state playback is met, and (ii) when connection to the permission server apparatus via the network is possible and the predetermined condition is judged to be met, controls the restriction of the playback of the content so as to permit the playback of the content until the request unit receives the response from the permission server apparatus, and (iii) when connection to the permission server apparatus via the network is not possible and the predetermined condition is judged to be met, controls the restriction of the playback of the content so as to permit the playback of the content. a storage unit operable to store usage permission information including a usable time period for which content is usable; a measurement unit operable to measure time; a malfunction detection unit operable to detect whether or not a malfunction exists in the measurement unit in order to determine whether or not the time measured by the measurement unit is within the usable time period; and a determination unit operable to, when the malfunction detection unit has not detected the malfunction, determine that playback of the content is possible when the time measured by the measurement unit is within the usable time period; the content playback apparatus characterized by further comprising a request unit operable to, when the malfunction detection unit detects the malfunction and that communication via a network is possible, issue a request to a permission server apparatus that permits usage of the content and is connected to the content playback apparatus via the network, and receive a response to the issued request from the permission server apparatus; a restriction unit operable to, when the malfunction detection unit detects the malfunction, place a restriction on the playback of the content until the request unit receives the response; and a playback unit operable to play back the content in accordance with a result of the determination made by the determination unit and the restriction placed by the restriction unit; wherein, when the malfunction detection unit detects the malfunction, the restriction unit (i) judges whether or not a predetermined condition relating to a malfunctioning-state playback is met, and (ii) when connection to the permission server apparatus via the network is possible and the predetermined condition is judged to be met, controls the restriction of the playback of the content so as to permit the playback of the content until the request unit receives the response from the permission server apparatus, and (iii) when connection to the permission server apparatus via the network is not possible and the predetermined condition is judged to be met, controls the restriction of the playback of the content so as to permit the playback of the content.