Abstract: A portable personal server connectable through a network with a PC connected with an external network that permits communication with the PC only when user's fingerprint information read out by means of a fingerprint authentication unit matches registered information. In order to communicate through the network, the portable personal server and the PC acquires an address, preferably using APIPA, so that the collision of address does not take place in the external network. Consequently, the portable personal server also functions as a network server on the external network. A portable personal server exhibiting high confidentiality of data and suitable for central management of data can thereby be realized.

Abstract: A portable personal server connectable through a network with a PC connected with an external network that permits communication with the PC only when user's fingerprint information read out by means of a fingerprint authentication unit matches registered information. In order to communicate through the network, the portable personal server and the PC acquires an address, preferably using APIPA, so that the collision of address does not take place in the external network. Consequently, the portable personal server also functions as a network server on the external network. A portable personal server exhibiting high confidentiality of data and suitable for central management of data can thereby be realized.

Abstract: The communication terminal of a communication system comprises a virtual network switch which can forcibly alter the destination of data being transmitted/received between the communication terminal and a network. Data is transmitted/received between the network and the communication terminal through a portable electronic device. Various functions, including a security function, can be supplemented by providing the function in software mounted on the portable electronic device. Even if a communication terminal connected directly with the network is not provided with such functions as a VPN, firewall or virus check, high-safety communication is ensured utilizing these security ensuring means mounted on the portable electronic device.

Abstract: In a card settlement system using a portable electronic device having a fingerprint sensor, a credit card and a portable electronic device (5) having a fingerprint sensor are issued to a person who has made application.