Portable authentication apparatus and authentication method using the same

PURPOSE: A portable authentication device and an authenticating method using the same are provided to perform an authentication process and a mutual authentication process with a system by storing the information needed for the authentication and linking with the system having a settlement function through a communication interface. CONSTITUTION: A contactless and a contact communication interface(102,112) communicate the data used for the authentication process and the mutual authentication process with a target system through a contactless or a contact mode. An MCU(Main Control Unit)(106) performs the processes between the portable authentication device and the target system. A memory(116) stores the data related to the authentication process, the data related to a user, and a program for performing the processes. A biometric recognizer(118) generates biometric data by recognizing a fingerprint, an iris, a vein, and a face of the user. An instruction input part(110) includes a switch, a button, or a keypad to enable the user to input an ID, a password, the data related to the user, and the selection of a function of the portable authentication device.