AUTHENTICATION SYSTEM AND AUTHENTICATION TARGET DEVICE

An authentication system includes an authentication target device used in an authentication target and a plurality of portable devices each carried by a user. The authentication target device performs wireless communication with each of the plurality of portable devices and controls the authentication target by a verification via the wireless communication. The authentication target device includes an authentication target transmitter configured to transmit a radio wave carrying a signal, an authentication target receiver configured to receive a radio wave carrying a signal, and a registration unit configured to register the plurality of portable devices that are genuine. Each of the plurality of portable devices includes a portable device transmitter configured to transmit the radio wave carrying the signal and a portable device receiver configured to receive the radio wave carrying the signal.