A steganographic method based on gain quantization for iLBC speech streams

Abstract

Under the premise of ensuring good speech quality and resistance to steganalysis, how to embed as much information as possible into low-bit-rate speech is a challenge. The existing research mainly focuses on least significant bits in the compressed speech streams or line spectral frequencies in the encoding processes of the G.723.1 and G.729a codecs. In this paper, we are concentrating on steganography in Internet Low Bitrate Codec speech streams. Specifically, we present a novel steganographic method on the basis of the gain quantization (GQS), which is included in the vector quantization of dynamic codebooks. The secret information is embedded by modifying the search range of the gain codebook to quantize the gain value. The experimental results show that the proposed GQS method achieves a higher hiding capacity, less signal distortion, and better resistance to steganalysis.