基于混沌和小波变换的音频加密算法

Audio Encryption Algorithm Based on Chaos and Wavelet Transform

为使音频信息可以在信道中安全传输,提出了一种在MPEG压缩的背景下基于混沌和小波变换的音频加密算法。首先对信号采用随机矩阵进行扩充来改变原信号的幅值,其次在"时域-小波域-时域"利用Logistic混沌映射进行3次音频信号置乱和扩散加密操作,最终得到加密信号。通过分段Logistic映射生成密钥的随机矩阵。理论分析发现,所提算法的密钥空间明显增大。实验结果表明,得到的音频加密信号的直方图分布更均匀,信号间的相关度变小,密钥敏感度增强。因此,提出的音频加密算法具有较高的安全性。

To make audio information broadcast across the Web safely,an audio encryption algorithm based on chaotic systems and the wavelet transform in MPEG background was proposed.Firstly,the signal is added with a random matrix to change the value of signal.Secondly,logistic map is used to scramble and diffuse the position of each signal in time and the wavelet domains for three times.Finally,we can obtain the secure signal.The random matrix used as keys was generated by piecewise Logistic map and the random seeds.The experiment results show the mentioned algorithm not only makes gray histogram uniform and signal correlation weake,but also increases key space and high sensitivity to the keys.Therefore,the audio encryption algorithm has higher security to protect audio information.