A computer-readable recording medium which records an Internet connection information registration application program for providing a user service for registering Internet connection information for Internet connection on a portable recording medium having a secret area accessible only by a private procedure, where media identification information unique to the portable recording medium is stored, and a public area which can be arbitrarily externally accessed, comprising:
- means for causing a user to perform operation of selecting a desired Internet provider;
- means for receiving information necessary for Internet connection from a terminal of the Internet provider selected by the user operation;
- means for performing mutual authentication with the portable recording medium and exchanging authentication keys while the portable recording medium is being connected to a write terminal;
- means for acquiring the media identification information encrypted by the authentication key from the portable recording medium;
- and
- means for, while the acquired media identification information is decrypted by the authentication key, generating Internet connection information for Internet connection on the basis of the received information, encrypting the Internet connection information by the decrypted media identification information, and registering the Internet connection information on the portable recording medium.