A Steganography Method for AAC Audio Based on Escape Sequences

An information hiding method on escape sequences of Huffman coding which can embed a great deal of secret information into AAC files is proposed based on the research of AAC coding standard. The proposed algorithm first unpacks the cover AAC file to search for the escape sequences, and then modifies least significant bit (LSB) of the escape sequences with the approach of matrix encoding, to improve the embedding efficiency. This method is low in computational complexity without any changes of the length of AAC coding. Experimental results reveal that the proposed algorithm can achieve higher hidden data capacity for AAC audio at the bitrate of 128kbps or above, furthermore, it has good imperceptibility and can resist the steganalysis to some extent.