新型文本数字水印技术及其典型应用研究

发布时间：2018-03-02 16:49

本文选题：文本数字水印　切入点：拓扑结构　出处：《电子科技大学》2008年博士论文　论文类型：学位论文

【摘要】： 近年来,随着以互联网技术为代表的信息技术的迅猛发展,各种文字、图像、声音、视频等媒体的获取、保存与使用方式发生了很大的变化。这一方面给人们带来了极大的方便,但另一方面,未经版权所有人许可对数字作品的任意复制、修改等盗版行为也日趋严重。因此,如何在互联网环境下进行有效的版权保护等信息安全问题,也就成为了重要的研究课题。在此背景下,数字水印技术作为一种新的多媒体信息安全保护技术应运而生。它将隐藏信息嵌入到各种数字媒体中,结合传统的数据加密技术来实现信息的隐藏通信、访问控制、版权保护等功能,当前,该领域的研究与应用已经相当深入。但令人遗憾的是,由于文字媒体本身的一些特点,作为数字水印技术重要组成部分的文本数字水印技术的进展却是相对滞后的,这与文字是人类传播信息最主要方式的现实情况形成了很大的反差。本文的工作就是要针对现有文本数字水印技术存在的薄弱环节,进行新型的文本数字水印技术及其典型应用的研究。主要的研究内容涉及文本数字水印嵌入算法、水印检测方法、系统实现框架、抗攻击技术及典型应用等该领域的关键问题,取得了如下创新性成果: 1)提出了一种基于字符拓扑结构的文本数字水印技术,通过改变字符或者字符串字形的拓扑结构,设计出语义上相同的字符(串)的多种字形,并对这些字形的拓扑结构进行恰当的编码,利用字符(串)的拓扑结构来携带数字水印信息。同时,给出了鲁棒性和视觉影响试验方法、结果,并分析了水印的抗攻击性能。 2)引入图论作为1)所述的文本数字水印技术的数学基础,将字符字形映射为图论中的“图”,对“图”或者“图”的特征量进行恰当的编码,利用这些编码来表示数字水印。同时,给出了基于图论的水印嵌入、检测方法的数学模型和详细实现过程。 3)提出了一种以符号的冗余编码表示隐藏信息的隐藏数据通信技术,以及与该方法相关的文本数字水印嵌入、检测技术和载体文件的显示技术。这些技术包括:将符号编码成冗余数字代码的若干方法;隐藏通信的数据加载与分离方法;特定字体文件的设计方法;若干对嵌入水印信息的载体文件进行显示的方法。在此基础上,利用冗余编码的原理,还提出了一种利用索引值嵌入隐藏信息的图像数字水印算法。 4)结合基于“字符拓扑结构”和“冗余编码”的文本数字水印技术的特点,提出了文本数字水印系统完整解决方案。给出了两种特殊的字体设计方法,重点描述了在统一的框架体系中,实现在电子文件和印刷品文件上嵌入、检测数字水印的技术。 5)提出了一种新的隐藏通信方法,其原理是改变字符图形与字符编码在各种编码标准规范中已确定的标准映射关系,采用自定义的方法进行字符图形与字符编码的映射,从而使得电子文件显示出的字符图形与电子文件的内在编码分别构成显式通信信道和隐藏通信信道,这两种信道可以独立地进行通信。应用该隐藏通信技术制作成自包含字符图形和编码信息的电子文件,便于利用现有互联网搜索引擎按照文件的属性进行在线搜索。 6)针对同步攻击这一困扰扩频水印技术的难题,研究了一类基于字符特征的文本数字水印技术的编码映射规则,给出了相应的扩频水印加载与检测模型。利用字符语义在水印加载与检测过程中具备的良好鲁棒性,通过载体字符产生伪随机代码,最终生成具有同步错误修正能力的自适应扩频文本水印,仿真实验表明其抗同步攻击性能得到了显著的提高。 7)提出了一种新的数字内容网络出版发行机制,其主要特点是用户可免费获取数字内容,但必须强制性地观看广告,广告与数字产品关联绑定。描述了这种机制的系统体系结构及相关技术协议,给出了实现该机制所需的内容加密、水印嵌入、屏幕字符替换等关键技术。该机制为平衡数字内容价值链中各方的利益提供了一种新的解决途径。
[Abstract]:In recent years, with the rapid development of Internet technology, the information technology represented a variety of text, images, sound, video and other media access, great changes have taken place in the preservation and use. This has brought great convenience to people, but on the other hand, without any copyright license for digital the works of replication, modification of piracy has become more and more serious. Therefore, how to protect the copyright and other information security problems effectively in the Internet environment, has become an important research topic.
Under this background, digital watermarking technology as a new kind of multimedia information security technology came into being. It will hide the information into digital media, communication, hidden combined with traditional data to realize information encryption technology and access control, copyright protection and other functions, the current research and application in this field but has been very thorough. Unfortunately, due to some characters of the media itself, as progress is the text digital watermarking technology is an important part of the digital watermarking technology is lagging behind, this is the reality of human communication of information the main way to form a great contrast with the text.
The work of this paper is to aim at the weak link existing text digital watermarking technology, research on text digital watermarking technology model and its typical applications. The main content of this study relates to a text digital watermarking algorithm, the watermark detection method, system framework, key problems of anti attack technology and the typical applications of the field, are as follows innovative achievements:
1) proposed a text digital watermarking technology character based on topological structure, by changing the topology character string or character, design a semantic same character (string) of the glyphs and the topological structures of these glyphs are using the character encoding, (string) topology to carry digital watermarking information. At the same time, the results are robust and visual impact test method, and analyzes the anti attack capability of the watermark.
2) 1) introduction of graph theory as the mathematical basis of the text digital watermarking technology, the character glyph mapping for the term "graph", proper encoding of the "map" or "map" feature, use the encoding to represent digital watermarking. At the same time, the watermark embedding is proposed based on graph theory the detection method, the mathematical model and the realization of the process in detail.
3) presents a redundancy encoding symbols of hidden data communication technology of information hiding, and associated with the method of text digital watermarking, display technology, detection technology and vector files. These technologies include: the symbol encoding method into several redundant digital code; loading and separation method of data hiding communication; the design method of specific font file; display method of vector file embedded watermark information. On this basis, using the principle of redundancy encoding, proposes a binary image digital watermarking algorithm to embed hidden information by using the index.
4) based on the character of topological structure and redundancy encoding of text digital watermarking technology, proposed a complete text digital watermarking system solution is given. Two kinds of special font design method, described in the uniform framework, the realization of the embedded in electronic and print files. Detection of digital watermarking technology.
5) proposed a new hidden communication method, its principle is the standard mapping change character graphic and character encoding standard in various encoding has been identified, the mapping method of custom character graphic and character encoding, the encoding characters and graphics and electronic documents so that electronic documents show the respectively. The explicit communication channel and hidden communication channel, the two channel can independently communicate. Application of the self made electronic file containing the character graphics and encoding information hiding communication technology, to facilitate the use of the existing Internet search engine according to the properties of the files to search.
6) in order to solve the problem of synchronization attacks that plagued the spread spectrum watermarking technology, study a class of mapping rules encoding text digital watermarking technology based on character features, gives a spread spectrum watermarking loading and corresponding detection models. Using the character semantic good robustness in embedding and detecting processes for generating pseudo-random code through. Vector of character, the generated text watermarking adaptive spread spectrum synchronization with error correction capability, simulation results show that the anti synchronization attack performance has been significantly improved.
7) proposed a new digital content network publishing mechanism, its main characteristic is that users can free access to digital content, but should be forced to watch the ads, advertising and digital products related to binding. The description of the system architecture of this mechanism and related technical agreement, the implementation of the mechanism for content encryption the key technology of watermark embedding, screen character replacement. This mechanism provides a new solution for the balance of the digital content value chain parties in interests.

【学位授予单位】：电子科技大学
【学位级别】：博士
【学位授予年份】：2008
【分类号】：TP309.7

【引证文献】