基于贝叶斯网络模型和矩阵嵌入的VoIP隐写算法  

A Novel VoIP Steganography Method Based on Bayesian Network and Matrix Embedding

作　　者：高瞻瞻[1] 汤光明[1] 王硕[1] Gao Zhanzhan;Tang Guangming;Wang Shuo(PLA Information and Technology University,Zhengzhou 450001)

机构地区：[1]解放军信息工程大学,郑州450001

出　　处：《计算机研究与发展》2018年第4期854-863,共10页Journal of Computer Research and Development

基　　金：国家自然科学基金项目(61272488);河南省科技攻关项目(122102210047);全军军事类研究生基金项目(2015JY125)~~

摘　　要：网络语音电话(voice over IP,VoIP)已成为目前人们沟通交流的普遍选择.相比文本、图像等传统隐写载体,网络语音数据流隐蔽性好,隐藏空间更大,因而得到越来越多的关注.目前的网络语音隐写研究围绕算法设计展开,已有成果的抗检测性有待进一步加强,且缺乏安全性理论指导.为此,首先分析语音帧的时序性特点,以相对熵的形式定义了基于贝叶斯网络模型的隐写安全性.通过分析语音编码过程,建立了固定码本参数的贝叶斯网络模型并将参数分为二元载体和三元载体2类.应用矩阵嵌入技术确定载体的修改位置,减少修改量;以最小化安全性测度为目标确定三元载体元素的修改方向,降低隐写对载体统计特性的影响.实验表明:在不显著增加计算复杂度的前提下,所提算法取得了比已有算法更好的感知透明性和抗检测能力.Voice over IP(VoIP)call has become our common choice of communication with each other.Compared with traditional steganographic covers such as texts and images,VoIP data flow has better imperceptibility and larger space for secret message embedding.Thus,VoIP steganography has received increasing attention in recent years.So far,the research mainly revolves around the designing of embedding and extracting process.However,the detection resistance of existing methods still needs to be strengthened.And they are lacking in the guidance of steganographic security theory.This paper firstly analyzes time sequence characteristics of speech frames,then defines the steganographic security in the form of relative entropy based on Bayesian network model.By analysing the speech encoding process,a specific Bayesian network model for fixed codebook parameters is established and the parameters are divided into binary cover elements and ternary cover elements.To minimize the change number in the embedding process,matrix embedding is used to determine the change positions in the cover vector.To reduce embedding impacts on the statistical properties of the cover,change directions of the ternary cover elements are determined by minimizing the security measure.Experimental results show that under the premise of limited computational complexity,the novel VoIP steganography method leads to good perceptual transparency and outperforms prior methods in resisting blind steganalysis.

关 键 词：VoIP隐写 贝叶斯网络 矩阵嵌入 固定码本 隐写安全性 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]