基于G.729语音编码非零脉冲位置信息的隐藏算法

VoIP以语音流为传输媒介，具有传输数据量大和应用广泛的优点。但VoIP系统也面临数据安全和隐私泄露的安全威胁。针对编码标准G.729固定码本搜索的非遍历特性和具有一定冗余性的特点，该文提出基于G.729语音编码非零脉冲位置信息的隐藏算法。该算法在固定码本搜索过程中，利用秘密信息控制码本的搜索过程，并在非零脉冲位置和秘密信息之间构建函数进行信息隐藏。在搜索过程中利用最不重要脉冲替换思想并采用最小化失真准则控制由秘密信息的嵌入带来的音质失真。实验结果表明:算法隐藏容量可达400 bit/s，算法具有良好的隐蔽性(PESQ平均值约为3.45)。

An Hiding Algorithm of Nonzero Pulses Position Information Based on G.729 Speech Coding

VoIP (Voice over Internet Protocol) is based on voice stream, which has the advantages of large data transmission and wide application. But the VoIP system is confronted with the security threats of data security and privacy disclosure. Thus, according to nonergodicity and redundancy of the fixed codebook search, an information hiding algorithm based on fixed codebook search process is proposed. This information hiding algorithm is carried out by a functional relationship between the nonzero pulse positions and secret information. The idea of least significant pulse replacement is used in the search process and a distortion minimization criterion is proposed to control the distortion of speech quality caused by the embedding of secret information. The experimental results show that the hiding capacity of the proposed algorithm is up to 400 bit/s and the average PESQ score is 3.45 which indicate that the algorithm has good imperceptibility.