Image-based Database Watermarking Algorithm

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.