新颖的音频信息隐藏算法

基于混沌映射和改进Patchwork算法的DWT（discrete wavelet transform）域音频信息隐藏技术，实现保密语音在音频信号中的隐藏与恢复。利用混沌序列保密性高和容易再生的特性，保证了算法的安全性；新颖的Patchwork算法，修改部分小波系数，使其统计特征产生相反方向偏移，实现保密语音码流的隐藏。混沌序列的使用与小波系数修改的隐蔽性，加强了算法的安全性；在保证隐藏量的同时，实现了隐藏信息的盲提取。实验表明，隐藏信息后载体音频SNR在50dB左右；在载体音频失真可容忍的情况下，提取的保密语音码流BER均小于0．1％，能够保证隐藏音频的听觉质量和隐藏信息的安全。

Novel audio information hiding algorithm

An audio information hiding technology in DWT(discrete wavelet transform) domain based on chaotic map and modified Patchwork algorithm is presented.A piece of secret speech is hidden in the host audio signal,and can be recovered without loss.Two important characteristics of the chaotic sequence,high secrecy and easy reproducibility,are used to ensure operation security.In the modified Patchwork algorithm,a portion of DWT coefficients has been modified to make a shift of their statistical characteristic in order to hide the bit sequence of audio signals.The application of chaos and privacy of modification to DWT coefficients enhance the security of the algorithm.Blind recovery of the speech information is realized while keeping larger capacity of privacy information.Experimental results show that the SNR of the carrier audio after hiding is around 50dB,and the BER of the recovered bit stream is below 0.1%.This method is capable of ensuring audible quality of the carrier audio and the security of audio signals.