计算机软件的法律保护

从计算机软件产业的基本概念和特征出发，介绍了世界上几种主要计算机软件保护模式，并对我国的计算机软件保护做出相应介绍，从而针对现阶段存在的不足，提出自已的看法。     

Effective watermarking scheme in the encrypted domain for buyer-seller watermarking protocol

In most watermarking schemes for copyright protection, a seller usually embeds a watermark in multimedia content to identify a buyer. When an unauthorized copy is found by the seller, the traitor’s identity can be traced by the embedded watermark. However, it incurs both repudiation issue and framing issue. To solve these problems, some buyer-seller watermarking protocols have been proposed based on watermarking scheme in the encrypted domain. In this paper, an enhanced watermarking scheme is presented. Compared with Solanki et al.’s scheme, the enhanced scheme increases effective watermarking capacity, avoids additional overhead and overcomes an inherent flaw that watermarking capacity depends on the probability distribution of input watermark sequence. Based on the security requirements of buyer-seller watermarking protocols, a new watermarking scheme in the encrypted domain with flexible watermarking capacity is proposed. It improves the robustness of watermark sequence against image compressions and enables image tampering detection. Watermark extraction is blind, which employs the same threshold criterion and secret keys as watermark embedding. Experimental results demonstrate that the enhanced watermarking scheme eliminates the drawbacks of Solanki et al.’s scheme and that the proposed watermarking scheme in the encrypted domain outperforms Kuribayashi and Tanaka’s scheme.     

网络内容安全分发与版权保护技术

信息的传播从印刷煤体内电子煤体过渡。首先简要讨论了网络上知识产权保护的问题以及相关的重要的产品,同时比较了几种基本的技术。对网络上的知识产权保护的计算结构给出了一个整体的概述。     

数字水印技术在印刷品防伪中的应用

防伪技术一直是人们关注的一个热点,针对印刷品盗版特定场合防伪存在成本较高的问题,在分析印刷扫描给电子图象带误差的基础上提出了一种用于印刷品防伪的数字水印技术,该方法中水印的添加采用了线性运算,而水印的提取则采用了阈值判断法,在提高算法的鲁棒性方面,水印的构造采用了简单但非常有效的重复构造法,另外,为了保证实验结果的稳定性,算法还采用了CIElab色彩空间,实验结果表明,在对参数优化后,该算法能较好的满足防伪的一般要求,同时与其他防伪技术相比,不仅大大减少了防伪成本,而且该算法还可用于普通证件的防伪。     

一种基于小波变换域的有意义图像盲水印算法

提出了一种基于小波变换域的有意义图像盲水印算法。算法中利用乘性隐藏方法在原始图像小波高频系数中嵌入一幅二值图像信息，通过拉普拉斯分布对原始图像小波变换域高频系数的统计分布特性进行建模，然后采用最大似然(ML)法推导得出了一个盲水印检测器，并且利用该检测器实现了一个有意义图像的盲水印算法。实验表明该算法具有较好的隐蔽性和鲁棒性。     

数字水印技术在数字水印数码相机中的应用

数字水印数码相机的问世引起了数码相机业的一场轰动,同时也拓宽了数码照片的用途。然而,数字水印相机作用的发挥又依赖于所使用的水印算法。阐述了数字水印数码相机的特点和数字水印技术在此种相机中的应用过程,并提出了一种新的图像水印算法,实验结果证明了这种算法的有效性和可行性。     

基于混沌加密的小波域音频水印算法

将混沌理论引入到音频水印系统的研究中,设计了一种包含版权信息和密钥的二值图像作为水印,利用混沌序列将其加密后嵌入到原始音频信号的DWT域中。该水印方案包含的版权信息量大,且具有双重的安全性,很难提取出水印信号;即使提取出水印信号,如果不知道密钥,也很难恢复出原始水印图像。对一般的信号处理进行了仿真实验,水印具有很强的鲁棒性。     

Independent component analysis in the blind watermarking of digital images

We propose a new method for the blind robust watermarking of digital images based on independent component analysis (ICA). We apply ICA to compute some statistically independent transform coefficients where we embed the watermark. The main advantages of this approach are twofold. On the one hand, each user can define its own ICA-based transformation. These transformations behave as “private-keys” of the method. On the other hand, we will show that some of these transform coefficients have white noise-like spectral properties. We develop an orthogonal watermark to blindly detect it with a simple matched filter. We also address some relevant issues as the perceptual masking of the watermark and the estimation of the detection probability. Finally, some experiments have been included to illustrate the robustness of the method to common attacks and to compare its performance to other transform domain watermarking algorithms.     

基于小波树的鲁棒—脆弱图像水印技术

为了实现数字图像的版权保护和篡改检测功能,提出一种鲁棒-脆弱水印算法.在小波变换后的图像中,由逼近子带的系数构造特征水印,并根据小波零树思想,嵌入到重要小波树的第一主分量中.提取的特征与水印进行比较不仅可确定图像的版权,而且可证明内容的完整性.实验表明,此算法不仅可以抵抗滤波、压缩、加噪、重量化等常见的图像处理操作,且在人的参与下,可以较好的定位图像的篡改.     

数字水印——原理、实现方法及安全性

数字水印是信息安全领域一个年轻而又发展迅速的研究方向。本文对数字水印技术的原理、实现方法进行介绍,并对数字水印遇到的攻击及对策进行了讨论。