AMR Steganalysis Based on the Probability of Same Pulse Position

This paper presents a method for detection of adaptive multirate (AMR) audio steganography. AMR audio codec is an audio data compression scheme optimized for speech coding, and widely used in some mobile telecommunications system. The AMR audio steganography schemes are emerging recently and they embed secret messages by modifying the nonzero pulse positions which are determined by fixed codebook search in AMR compression procedure. Those methods have high embedding capacity and good imperceptivity. We have observed that those steganography schemes will cause the probability of same pulse positions in the same track increasing. Based on this phenomenon, this paper presents a set of steganalysis features of the probability of same pulse position. The support vector machine is applied to the proposed features and used as the steganalyzer. The performance of the scheme is tested on a database containing ~140714 audios. Experimental results show that the correct detection rate of our proposed method is 90% when the embedding bit rate is 30% or above, and can reach above 85% for cover audios.