Disclosed is an authentication method and system for a device using a Bluetooth technology. A method for performing authentication by a first device, using Bluetooth low energy (LE), according to an embodiment of the present invention comprises: authenticating a user on the basis of ID information of the user; and authenticating a device by comparing information acquired from a user input with information acquired using an exchanged public key. The authentication scheme for a device is determined according to the input/output capability of the device.