基于图像的数据库水印算法研究

【作者】 曹再辉；

【导师】 崔新春；

【作者基本信息】 曲阜师范大学 ， 课程与教学论， 2008， 硕士

【摘要】 随着教育信息化程度的提高,现代远程教育为学习者提供了丰富的数字资源,这些资源很容易复制、修改和传播,大大推进了优质教育资源的共享。作为远程教育资源主要的载体,数据库的版权保护问题更亟待解决。关系数据库水印技术是保护数据库版权的一种有效手段,本文对现有关系型数据库水印算法分析研究的基础上,提出了一种在关系数据库中嵌入图像信息的图像数据库水印算法,主要研究内容及成果如下:首先,本文提出了基于图像的关系数据库水印技术,在关系数据中嵌入一张可识别的图像,用来描述版权信息。该算法实现了基于数据库的部分内容恢复水印信息,且算法具有隐蔽性好,水印恢复不需要原始数据库等特点。其次,在基于图像的关系数据库水印的基础上,通过引入混沌随机序列,利用混沌理论对版权信息进行加密,使所嵌入的水印信息具有保密性,攻击者即使知道水印嵌入算法,也无法知道版权信息的确切信息,水印的检测处理过程是极细微的、安全的、可信的且能够抵抗攻击。最后,本文对基于图像的多重关系数据库水印算法进行了探讨,提出了两种基于图像多重数据库水印的方案,且对多重关系库水印中的主要问题进行了分析并提出了相应的解决方法。本文重点介绍了基于图像的数据库水印算法、基于混沌理论的图像数据库水印算法和基于图像的多重数据库水印算法,水印算法的过程均包括水印信息的生成、水印信息的嵌入和水印的检测三个过程。理论分析和实验表明该算法性能好,抗攻击能力强,在关系数据库的版权保护中具有很好的应用价值,对数据库版权信息的保护具有很好的现实意义和理论意义。更多还原

【Abstract】 With the development of information education, more and more digital educational resources are available on the internet. They are so easy to obtain, to spread even to tamper with that the copyright of these digital resources while sharing them has become a hotspot. As databases act as a major carrier of knowledge, the copyright protection of databases need be solved urgently. Relational database watermarking technique is an effectual method of copyright protection to protect the database. Base on analyzing the existing relational database watermarking algorithms, we present an image based algorithm for watermarking relational databases. The main research content and result are as follows:First, we present an image based algorithm for watermarking relational databases. Insert an identifiable image which can be described the copyright into database. By this algorithm, watermark information can be recovered from only a fraction of tuples of a database. The algorithm bears virtues of sound robustness, high security and bland detecting.Secondly, base on the first step, we use the chaos theory to encrypt copyright information. By introducing chaotic sequence as watermark, the embedded watermark information becomes more confidential. The attacker can’t recover the correct watermark image even he knows the algorithms. Watermark detection process is very subtle, security, credible and able to resist the attack.Finally, we give a discussion on algorithms of watermarking relational database using multiple watermarks. We propose two watermark algorithms, analyze possible problems that multiple database watermark algorithm may encounter and give the corresponding solution.Thus the main contributions of this paper including three parts: an image based algorithm for watermarking relational databases, a chaotic encrypt image based algorithm for watermarking relational databases and an image based algorithm for watermarking relational databases using multiple watermarks. All algorithms consist of three parts: watermark generation, embedding and extraction procedure. The experimental results show that the proposed algorithms give excellent performance.更多还原