A device that can be attached to an image-forming apparatus includes a memory including first and second storage areas, control circuitry, and a connection interface for connecting to an information processing apparatus at a time of remanufacturing the device. The first storage area stores first information specific to the device. The second storage area stores second information read out and used by the image-forming apparatus and a digital signature generated based on the first and second information. At a time of the remanufacturing, the control circuitry receives the second information, the digital signature, and authentication information from the information processing apparatus via the connection interface, and allows the second information and the digital signature to be written to the second storage area if verification of the second information based on the authentication information is successful.