Abstract: A server device for safely managing information is configured to store prescribed character codes and converted character codes in correlation with each other, said server device being connected, via a network (N), to a terminal device for receiving a converted character code string corresponding to a character string indicating personal information stored in a storage unit device. Responsive to the reception of a prescribed character code string corresponding to a character string indicating an item included in the personal information by the terminal device, the server device converts each of prescribed character codes included in the prescribed character code string to a corresponding converted character code, thereby generating a converted character code string corresponding to the character string indicating the item.