Then a further conclusion is testified that if the cover and the stego - object are acquainted with the attackers then the security of the system is spoiled 并进一步证明了，若隐秘载体和隐秘对象都为攻击者所知，则隐秘通信系统不安全。
2.
The proposed adaptive watermarking scheme enables more energy of watermark to be embedded with imperceptibility , so the stego mesh can be resilient to higher intensity of attacks than with traditional schemes 这使得本算法能够在嵌入的水印信息不可见的前提下嵌入更大能量的水印,从而保证水印隐藏对象能够承受更大强度的攻击。
3.
The concept of stego - key exchange is first presented . some conditions and a basic protocol of realizing it are first discussed . then a known - secret stego - key exchange scheme and some unknown - secret stego - key exchange schemes are designed 首次对阈下信道中的隐匿密钥协商的概念、实现条件和基本协议进行了讨论，并设计了已知秘密的隐匿密钥协商方案和几个未知秘密的隐匿密钥协商方案。
4.
In this dissertation we make a study of subliminal channels that conclude the progress , the application , the model , the construction , the stego - key , the capacity , the security , the way to realize subliminal - freeness , and so on 本文对阈下信道技术进行了比较全面的总结和研究，包括阈下信道的发展状况，应用前景，阈下信道的模型，构造方法，隐匿密钥，容量，安全性以及封闭方法等。
5.
According to common multimedia earners in the internet , the static images are selected as stego carriers . at first , beginning with typical method in special domain lsb ( least significant bit ) , the relative tests are developed , and the reasonable results are obtained 考虑到网络上最常用的多媒体载体，我们选取静态图像作为信息隐藏的载体，从空域中的典型算法? ?最不重要位( lsb )方法入手，开展相关的试验工作并得一些重要结果。
6.
In order to adapt the scheme to both the color image and the gray image , while embedding the watermarking into the image , the scaling factors are determined by the local luminance feature and texture features of the image . it can improve the embedding strength and the watermarking robustness . from the experimental results , the stego - images are extremely robust to common image processing such as median filter , jpeg compression and denoising after adding the stochastic noises 2 、提出了一种新的基于小波变换和纹理特征的数字水印算法，该算法依据从图像小波域提取出的纹理特征来选取水印的嵌入位置，较好地利用了图像的纹理区域，既能掩蔽较多的噪声，又能较好地抵抗jpeg压缩等一般性攻击，调节了数字水印技术中存在的不可见性与鲁棒性之间的矛盾。
7.
Give precise criterions and descriptions of some important concepts and disposals of data - hiding technique such as cover , stego - object , hiding information , data embedding , data extraction , stego - key , stego - analysis , insensibility , covert communication , digital watermarking , robustness and etc . then propose a general mathematical model of data hiding which cover most models proposed in other papers and establish the basis for further theory analysis 本论文独立完成的主要成果有： ( 1 )对信息隐藏技术中的一些重要概念和处理给出了准确的规范和描述，主要有隐秘载体、隐秘对象、秘密信息、数据嵌入、数据提取、隐秘密钥、隐秘分析、不可感知性、隐秘通信、数字水印、鲁棒性等。
