A device for transmitting authentication information is disclosed. A device for transmitting authentication information, according to one embodiment of the present invention, comprises: a storage unit for storing authentication information and frequency information corresponding to letters or numbers included in the authentication information; a control unit for generating sound wave signals having a frequency corresponding to the letters or numbers included in the authentication information; and a sound wave output unit for outputting the sound wave signal, wherein the control unit sequentially generates, in the order in which the letters or numbers are enumerated, sound wave signals having a frequency corresponding to the letters or numbers included in the authentication information, and repeatedly generates, a preset number of times, a sound wave signal having a frequency corresponding to each letter or number.