A method for operating an electronic device includes transmitting a first message including a first partial security key being a portion of a first security key to a first network; outputting a sound into which a second partial security key being a remaining portion of the first security key is loaded, after transmitting the first message; receiving a second message including a second security key from a second network; and establishing a link for connecting the electronic device and an external device through the second network if the second security key corresponds to the first security key.