Ownership Protection

Multimedia security has been the aim point of considerable research activity because of its wide application area. The major technology to achieve copyright protection, content authentication, access control and multimedia security is watermarking which is the process of embedding data into a multimedia element such as image or audio, this embedded data can later be extracted from, or detected in the embedded element for different purposes. In this work, a blind watermarking algorithm based on SVD and circulant matrices has been presented. Every circulant matrix is associated with a matrix for which the SVD decomposition coincides with the spectral decomposition. This leads to improve the Chandra algorithm [1], our presentation will include a discussion on the data hiding capacity, watermark transparency and robustness against a wide range of common image processing attacks.

Watermarking techniques for relational data have been proposed to allow copyright protection and data authenticity, among other things. Almost all proposals depend on the primary key of the database relations for deciding where and how to place the marks. The primary key could be easily updated or deleted if the attacker does not require watermarked data to be placed back in the database. The few techniques trying to avoid this dependency create a virtual primary key through schemes that frequently compute non-unique values, which may cause watermark synchronization problems. Also, the deletion of attributes compromises obtaining same values for the virtual primary key used for the mark embedding. In this paper, we propose a solution that solves the dependency of the primary key, avoiding the problem of non-unique values and showing more resilience against attribute deletion attacks than previous schemes.

Relational data watermarking techniques using virtual primary key schemes try to avoid compromising watermark detection due to the deletion or replacement of the relation’s primary key. Nevertheless, these techniques face the limitations that bring high redundancy of the generated set of virtual primary keys, which often compromises the quality of the embedded watermark. As a solution to this problem, this paper proposes double fragmentation of the watermark by using the existing redundancy in the set of virtual primary keys. This way, we guarantee the right identification of the watermark despite the deletion of any of the attributes of the relation. The experiments carried out to validate our proposal show an increment between 81.04% and 99.05% of detected marks with respect to previous solutions found in the literature. Furthermore, we found out that our approach takes advantage of the redundancy present in the set of virtual primary keys. Concerning the computational complexity ...

With the rapid growth of web base environment and extensive requirement of databases, the databases owners are need to be care full about to maintain their ownership of the databases. Digital watermarking is the effective solution to protecting the copyright of databases from illegal copying by using the inherent properties of relational databases. In this paper We propose an idea to design an algorithms of watermark embedding and detection by using a predefined parameter, embedded proportion for the purpose of random selection of tuples. We incorporate the use of hash function along with owner id for security reason. In detection process a cutoff criterion is designed to verify watermarked database. It is assumed that the database can tolerate some modifications within a certain limit. Some experiments are conducted over watermark embedding and detection algorithm and the results are analyzed to show the robustness of the proposed scheme by conducting the modifying tuples or attributes attack.