保持直方图特性的最低比特位密写方法  

Least Significant Bit Matching Steganographic Method Resisting Histogram Attacks

作　　者：陈志宏[1] 刘文耀[1] 

机构地区：[1]天津大学精密仪器与光电子工程学院,天津300072

出　　处：《天津大学学报》2008年第1期21-27,共7页Journal of Tianjin University(Science and Technology)

摘　　要：基于对最低比特位Matching密写方法与利用图像直方图进行的密写分析方法的研究,提出了一种可保持直方图特性的LSB Matching密写方法.在密写过程中定义动态改变的密写信息表以记录秘密信息嵌入位的增减,并根据信息表内的记录判断下一次同样灰度值的像素嵌入秘密信息时的增减方向,而总体原则是尽量保证密写后的图像直方图变化最小.实验表明,经该方法密写后的图像直方图基本保持了原有峰值和变化趋势等属性,对一些针对图像直方图攻击方法有很好的效果.A modification to the least significant bit （LSB） matching was proposed. In LSB matching, if the LSB of the next cover pixel matches the next bit of secret data, do nothing; otherwise, choose to add or subtract one from the cover pixel value at random. While in the improved method, a steganographic information table was defined to record histogram change of cover image which was caused by embedded bits. Through the table, the next LSB with the same pixel value will be judged to add or subtract one dynamically in order to ensure the histogram change of cover image was minimized. The experimental results show that the proposed embedding method has better performance against the attacks aiming at histograms than traditional LSB matching method. The histograms of cover image in which the secret information was embedded with the proposed method can maintain their attributes such as peak values and transformation trends to an acceptable degree.

关 键 词：信息安全 信息隐藏 密写 密写分析 最低比特位 直方图 直方图函数 最低比特位Matching 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]