A data delivery apparatus including a storage adapted to store limited-access data which associates user data for specifying a user, with data, access to which is permitted or limited to the user; a function determination unit adapted to determine whether a destination device to which the limited-access data is to be transmitted has an access control function of permitting or limiting access to the limited-access data for each user; an authentication unit adapted to, when the limited-access data destination device is determined not to have the access control function, request input of authentication information and performing an authentication process using the input authentication information; and a transmission control unit adapted to, when the authentication process by said authentication unit is successful, transmitting the limited-access data to the destination device.