Research Of Audio Steganography Algorithm Based On Wavelet Transform

With widely disseminating of network audio document and the serious situation in the information security field, the audio steganography have been under more and more attention. This paper analyzes and summarized the current research status and existing problems of the audio steganography, then the major focus is around ensuring imperceptibility and robustness to enhance the capacity of hidden information embedded, and designs two kind of audio steganography algorithm in wavelet domain.Firstly, according to the problem that some embeding methods such as plusing directly, quantization coding, modifing the energy ratio and so on are difficult to enhancing the embeding capacity, so the matrix coding is introducted. This method's characteristic is capable of greatly improving the embeding efficiency, so as to achieve the purpose of raising the embeding capacity. And the matrix coding help to reduce the proportion of the original audio changes, thereby reducing the effects of the original audio carrier'imperceptibility when embeded datas. In order to improve the problems as large calculation amount and slow execution speed of the traditional generation wavelet, the algorithm chooses the lifting wavelet transform coefficients to embed datas. Considering ensuring absolute concealment of the secret speech, the algorithm uses MPEG I Audio Psychoacoustic model 1 to compute masking threshold, and controls the embedded frames by masking threshold.Secondly, according to the previous embeding methods's problem of the difficult controling to the wavelet coefficient's floating point numbers caused by processing directly, the PCM quantization coding is introducted to quantify the every segment's mean value of wavelet coefficient to a binary sequence. This method can greatly reduce the quantization error, and have stronger robustness than traditional ordinary single-valued quantization. The algorithm still uses the matrix coding embeding method, but it's for every segment's mean value of wavelet coefficient. Section size set according to application needs, you can achieve the embedding capacity to improve. In order to induce the calculation amount, the algorithm uses the less complex time-frequency analysis of audio signals to select the embedded frame by looking for voiced frame, imperceptibility can also be guaranteed.Through the experimental analysis, the two kinds of wavelet domain audio steganography algorithm presented in this paper have higher embeding capacity than the same kind of algorithms, and guarantee a good robustness and imperceptibility.