Steganography for MP3 audio by exploiting the rule of window switching

MP3 audio is a promising carrier format for covert communication because of its popularization. In this paper, we propose an MP3 steganographic method by exploiting the rule of window switching during encoding. The method carries out embedding by establishing a mapping relationship between the secret bit and the encoding parameter, namely window type. The proposed algorithm is fully compliant with MP3 compression standard and the distortion caused by steganography can be controlled automatically by the distortion adjustment mechanism of the encoder. Experimental results demonstrate that the proposed method introduces insignificant perceptual distortion and is statistically undetectable for the attack of block size analysis.