Patent ID: 7617536
Filing Date: 2009-11-10
Classification: G06F,G11B,H04L

Abstract:
1. An unauthorized apparatus detection device connected to an information server capable of having a portable media inserted therein, the portable media further for being inserted into a detection target apparatus, the portable media storing a target apparatus identifier and a corresponding first verification value, and the target apparatus identifier identifying the detection target apparatus, the unauthorized apparatus detection device comprising: a storage unit that stores the target apparatus identifier and the first verification value, the target apparatus identifier and the first verification value being previously received from the information server by the unauthorized apparatus detection device; a generation unit that generates a second verification value that differs from the first verification value that corresponds to the target apparatus identifier, and that overwrites, in the storage unit, the second verification value in place of the first verification value; a transmission/reception unit that transmits to the information server the second verification value, such that the information server writes the second verification value into the portable media when the portable media is inserted into the information server, and such that the detection target apparatus overwrites, in the portable media, the second verification value in place of the first verification value when the portable media is inserted into the detection target apparatus, the transmission/reception unit receiving, from the information server, the target apparatus identifier and the second verification value, as a received verification value, when the portable media, into which the second verification value is overwritten in place of the first verification value by the detection target apparatus, is inserted into the information server; a control unit (i) that, when the received target apparatus identifier matches the stored target apparatus identifier, judges whether or not the received verification value matches the stored second verification value, and (ii) that, when it is judged that the received verification value does not match the stored second verification value, registers the target apparatus identifier on an unauthorized apparatus list; and a title key storage unit that stores a title key for decrypting encrypted content, wherein, when the control unit judges that the received verification value matches the stored second verification value, the control unit transmits the title key to the information server, such that the information server writes the title key into the portable media, and such that the detection target apparatus decrypts the encrypted content using the title key when the portable media storing the title key is inserted into the detection target apparatus.