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 transportable recording medium assigned to the current user from among a plurality of transportable recording media that are assigned to users of the first apparatus, each of the plurality of transportable recording media has recorded thereon a media identifier unique thereto, and the transportable recording medium includes a non-secure data area for storing encrypted user information which is generated by encrypting user information assigned to the current user based on the media identifier, the 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, when the transportable recording medium of the current user is locally connected to the first apparatus, the second apparatus reading the media identifier unique to the transportable recording medium assigned to the current user and the encrypted user information assigned to the current user, from the transportable recording medium locally connected to the first apparatus via the network, the user information assigned to the current user being associated with the media identifier unique to the transportable recording medium assigned to the current user by encrypting the user information based on the media identifier, the encrypted user information associating the user information assigned to the current user with the media identifier unique to the transportable recording medium assigned to the current user, the transportable recording medium including a secure data area and the non-secure data area, the encrypted user information being stored in the non-secure data area, the media identifier being stored in the secure data area and requiring an authentication between the first apparatus and the transportable recording medium in order to access the media identifier; and a service providing operation of the second apparatus of (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.