Ph.D. Tezi Görüntüleme

      Rapid developments in Information Technologies have eased data sharing through the Internet recently. Right to access and use data stored in centralized or distributed databases are served to authenticated users through applications. Copying or modification of digital data without permission and sharing by unauthorized users have brought copyright protection problem. Even though cryptography can be used to share sensitive information securely, it can not be used to protect copyright since encrypted information can not be associated with the original. Digital watermarking methods are used lately in digital rights management. Methods to hide specially crafted secret information or watermark into digital media provide additional security mechanism in protecting the data and determining the ownership information. The digital watermarking algorithms proposed for rights management in multimedia files can not be applied directly on databases. Researchers have suggested special methods for database watermarking to prevent problems with the protection of digital rights. Most of the studies in the literature can be applied to a specific data type that the database contains. In the works has been done in thesis, it is proposed watermarking methods which are resistant to attack and have high watermark capacity for different data types. Proposed methods have high watermark capacity and superior results than similar methods in the literature against different attacks, as can be observed from the results.