An example electronic device includes memory for storing a program for unlocking the first electronic device using a wearable electronic device; wireless communication circuitry; and one or more processors configured to execute the program stored in the memory to cause the electronic device to at least establish wireless communication, via the wireless communication circuitry, with the wearable electronic device when the wearable electronic device is in a wireless communication range of the first electronic device; determine whether the wearable second electronic device is authenticated for unlocking the first electronic device; determine whether the wearable electronic device is in a specific range of the first electronic device based on a signal transmitted from the wearable electronic device being worn; and unlock the first electronic device based on determining that the wearable electronic device is authenticated and is in the specific range of the electronic device.