Zero Watermarking Research Articles

A fragile zero watermarking schema to check integrity of relational databases based on discrete cosines transform

A fragile zero watermarking schema to check integrity of relational databases based on discrete cosines transform

The Contourlet Domain Comic Zero Watermarking Algorithm based on Discrete Cosine Transform and Singular Value Decomposition

Through to analyze the characteristics of the digital cartoon image, proposed a based on discrete cosine transform (DCT) and singular value decomposition (SVD) combined contourlet transform with zero watermarking algorithm, the algorithm first for image contourlet transform and then make the low-frequency subband DCT and SVD decomposition again after operation block, the largest singular value as the image feature extracting for zero watermarking structure. In order to improve the security of the algorithm, introducing into visual cryptography processing the watermark image, the zero watermarking features obtained and secret sharing for the logic operation is zero watermarking characteristics of the final value.. The simulation results show that the algorithm has strong robustness.

Distortion-Free Watermarking Approach for Relational Database Integrity Checking

Nowadays, internet is becoming a suitable way of accessing the databases. Such data are exposed to various types of attack with the aim to confuse the ownership proofing or the content protection. In this paper, we propose a new approach based on fragile zero watermarking for the authentication of numeric relational data. Contrary to some previous databases watermarking techniques which cause some distortions in the original database and may not preserve the data usability constraints, our approach simply seeks to generate the watermark from the original database. First, the adopted method partitions the database relation into independent square matrix groups. Then, group-based watermarks are securely generated and registered in a trusted third party. The integrity verification is performed by computing the determinant and the diagonal’s minor for each group. As a result, tampering can be localized up to attribute group level. Theoretical and experimental results demonstrate that the proposed technique is resilient against tuples insertion, tuples deletion, and attributes values modification attacks. Furthermore, comparison with recent related effort shows that our scheme performs better in detecting multifaceted attacks.

Grid-line watermarking: A novel method for creating a high-performance text-image watermark

This study aims to discover an effective method to watermark any text image in any language. The ultimate goal of this work is to generate invisible and more robust watermarks, increase the hiding capacity, and identify any change in the original text. Generally these are the limitations of most text-image watermarking methods. Using a grid of horizontal and vertical lines is one of the most effective methods to overcome these limitations. These grid lines run across text- image character-skeleton lines to finely mark and detect watermarks on these line-character intersection points; there is one intersection for one specific zero watermark pixel. Each intersection point is defined by one hiding bit of the watermark such that the more reference horizontal and vertical lines of grid pattern are plotted, the more points of intersection are obtained. This approach increases the hiding-bit capacity to watermark embedding, which is a disadvantage shared by many text-image watermarking methods. In addition, if all positions of all intersection points are collected, these points will act as the identity reference points of all original characters to verify their integrities after they are modified.

A New Image Zero Watermark Algorithm Based on SVD

A New Image Zero Watermark Algorithm Based on SVD