基于比特控制的快速矩阵嵌入  

Fast Matrix Embedding Based on Bit-control

作　　者：王超[1] 张卫明[1] 刘九芬[1] 

机构地区：[1]信息工程大学信息工程学院,郑州450002

出　　处：《电子与信息学报》2011年第9期2169-2174,共6页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(60803155)资助课题

摘　　要：为了保证安全和信息传输率,隐写术期望能利用对载体的每个修改嵌入尽可能多的信息,也即提高嵌入效率。矩阵嵌入是最主要的提高嵌入效率的编码方法。Fridrich提出的基于随机线性码的矩阵嵌入方法能达到高的嵌入效率,但是计算复杂度较高。该文利用择多校验法对矩阵嵌入进行改进,首先使用控制比特对载体分组进行异或构造新载体,然后在新载体上执行矩阵嵌入,通过考察控制比特的状态可以快速生成修改量尽可能小的模式。分析和实验表明,该方法可以在嵌入效率和嵌入速度之间灵活的进行折中。与Fridrich的原始方法相比,新方法在保持嵌入效率基本不变的情况下,其计算复杂度随着控制比特数的增加以指数速度降低。与已有的快速矩阵嵌入方法比,新方法能以更快的嵌入速度达到更高的嵌入效率。For good security and large payload in steganography,it is desired to embed as many messages as possible per change of the cover-object,i.e.,to have high embedding efficiency.Matrix embedding is the most popular method for increasing the embedding efficiency.Matrix embedding based on random linear codes,proposed by Fridrich,can achieve high embedding efficiency,but cost high computational complexity.In this paper,Fridrich＇s matrix embedding is improved by majority-vote parity check.First,a new cover is constructed from the original cover block with several control-bits by exclusive-or operations.Second,the matrix embedding is executed on the new cover,and a modification pattern with few changes on the original cover can be fast found by investigating the states of the control-bits.Analysis and experimental results show that the proposed method can flexibly trade embedding efficiency for embedding speed,or vice versa.Comparing with Fridrich＇s method,the computational complexity of the novel method exponentially decreases with increasing the number of the control-bits when embedding efficiency is unchangeable.Comparing with previous fast matrix embedding methods,the proposed method can reach higher embedding efficiency with faster embedding speed.

关 键 词：隐写术 矩阵嵌入 嵌入率 嵌入效率 嵌入速度 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]