1. A service providing method of providing a current user of a first apparatus with each service provided by one or more other apparatuses via a network, wherein the first apparatus is able to communicate with each of the one or more other apparatuses via the network and is locally connectable to a recording medium from among recording media that are uniquely assigned to users of the first apparatus, each recording medium has a media identifier as a unique identifier recorded thereon and is transportable, and each recording medium includes an area for storing encrypted user information which is generated by encrypting user information that is inherent to a user assigned thereto, said service providing method comprising: a service requesting operation of the first apparatus requesting a second apparatus to provide a service desired by the current user, the second apparatus being one of the one or more other apparatuses; a reading operation of, if a recording medium of the current user is locally connected to the first apparatus, the second apparatus reading the media identifier and the encrypted user information in the locally recording medium via the first apparatus and the network; and a service providing operation of the second apparatus (i) generating a decryption key based on the media identifier read in said reading operation, (ii) generating user information by decrypting the encrypted user information read in said reading operation by using the generated decryption key, (iii) customizing the desired service according to the generated user information, and (iv) transmitting the customized service to the first apparatus.