Lossless Watermarking Scheme Research Articles

LRW-CRDB: Lossless Robust Watermarking Scheme for Categorical Relational Databases

In 2002, Agrawal and Kiernan defined six basic requirements, including preventing illegal watermark embedding and authentication, reversibility, robustness, and others, which must be satisfied when a reversible watermark is designed for relational databases. To meet these requirements, in this paper, a lossless watermarking scheme for a categorical relational database called LRW-CRDB (lossless robust watermarking for categorical relational databases) is proposed. In our LRW-CRDB scheme, the database owner needs to generate two secret embedding keys, K1 and K2, in advance. Then, two reference sets are generated based on two different secret embedding keys and a symmetry-based data hiding strategy, and then these are used for the watermark embedding phases. Experimental results confirmed that our LRW-CRDB scheme successfully detects 100% of hidden watermarks, even when more than 95% of the watermarked relational database has been deleted. In other words, the robustness of our proposed LRW-CRDB scheme outperforms other existing schemes under a variety of possible attacks, such as alteration, sorting, deletion, and mix-match attacks.

A lossless digital watermarking scheme based on a new 3D-hyper chaotic map

To protect owner's visual multimedia data, several watermarking techniques are proposed in the last few years. A 2D discrete cosine transform mathematical tool is used for host colour image copyright protection with new 3D discrete hyper chaotic map for creating watermark which is used for identification. In this research paper, a 3D discrete hyper chaotic map was proposed, which was used in the creation of secret keys and randomness in the image. It makes the system more robust and adds security to the system. The chaotic pattern generated by a chaotic map is applied to improve the protection of the watermark image. The experiments were conducted to check various common image processing attacks and watermark extraction process generates high quality image after different attacks.

Color medical image lossless watermarking using chaotic system and accurate quaternion polar harmonic transforms

Abstract With the increasingly widespread use of medical images in medical institutions and networks, the copyright protection of medical images has become increasingly urgent. Since traditional embedded watermarking technology degrades the quality of the original images, it is not suitable for medical images. In addition, most medical watermarking algorithms are aimed at grayscale images; therefore, a smaller number of color medical image watermarking algorithms are available. In this paper, we propose a lossless watermarking scheme for color medical image copyright protection based on a chaotic system and quaternion polar harmonic transforms (QPHTs), which is a quaternion orthogonal moment method. In watermark embedding, we compute the QPHTs for the original color medical image and select accurate coefficients to construct a zero-watermark image. Then, the zero-watermark image is stored in the intellectual property right (IPR) database. Experimental results show that the proposed scheme is robust to geometric attacks and common attacks and that it has better performance than similar lossless watermarking schemes. In addition, this paper details the selection of accurate coefficients for QPHTs and compares stability with different choices of unit pure quaternions.

A Lossless Watermarking for 3D STL Model Based on Entity Rearrangement and Bit Mapping

With the wide application of 3D STL model in 3D printing, much attention has been paid to its content security and copyright protection. Based on entity rearrangement and bit mapping, a lossless and high capacity watermarking scheme is proposed for 3D STL model. Experimental results and analysis show that the average capacity is improved 0.71bits/facet compared with the original entity rearrangement method, and the capacity is 0.247 bits/entity larger than that of the optimal capacity of the standard entity rearrangement method. It can achieve good efficiency and it is robust against translation, rotation and even scaling. It has potential application in secret communication and copyright protection of 3D STL model.

Artificial bee colony optimized robust-reversible image watermarking

The ownership verification of digital images is possible by the help of image watermarking. Watermarking make the image secure towards unlawful use; but at the same time, it causes some information loss too. Medical and defense are few fields, where even a small change in data can be very problematic. So there is need of reliable and lossless watermarking schemes. The present study is focused on the development of lossless watermarking method that can fulfill five basic requirements (robustness, reversibility, invisibility, security and capacity) of ideal lossless watermarking scheme maximally. Arnold transformed watermark is embedded into the host to restrict any unauthorized access of watermark even after extraction. Slantlet transformed coefficients are known to be quite robust towards image processing attacks; so block wise Slantlet transform is employed to resist the maximum attacks and to ensure a decent capacity. Mean values of transformed coefficients are used for embedding to increase the robustness and imperceptibility. The spatial domain overflow/underflow (due to embedding) is taken care by a post processing to satisfy the reversibility requirements. The embedding strength of watermarking is controlled with the help of artificial bee colony (ABC) in order to get an optimal tradeoff between invisibility and robustness. The proposed scheme is applied to a range of images to show its applicability to different domains.

Protection of Health Imagery by Region Based Lossless Reversible Watermarking Scheme.

Providing authentication and integrity in medical images is a problem and this work proposes a new blind fragile region based lossless reversible watermarking technique to improve trustworthiness of medical images. The proposed technique embeds the watermark using a reversible least significant bit embedding scheme. The scheme combines hashing, compression, and digital signature techniques to create a content dependent watermark making use of compressed region of interest (ROI) for recovery of ROI as reported in literature. The experiments were carried out to prove the performance of the scheme and its assessment reveals that ROI is extracted in an intact manner and PSNR values obtained lead to realization that the presented scheme offers greater protection for health imageries.

Ontology-guided distortion control for robust-lossless database watermarking: application to inpatient hospital stay records.

In this paper, we propose a new semantic distortion control method for database watermarking. It is based on the identification of the semantic links that exist in-between attribute's values in tuples by means of an ontology. Such a database distortion control provides the capability for any watermarking scheme to avoid incoherent records and consequently ensures: i) the normal interpretation of watermarked data, i.e. introducing a watermark semantically imperceptible; ii) prevent the identification by an attacker of watermarked tuples. The solution we present herein successfully combines this semantic distortion control method with a robust lossless watermarking scheme. Experimental results conducted on a medical database of more than one half million of inpatient hospital stay records also show a non-negligible gain of performance in terms of robustness and database distortion.

A publicly verifiable lossless watermarking scheme for copyright protection and ownership assertion

In this paper, a discrete cosine transform based copyright protection scheme that does not require the original image for logo verification is proposed. Features of logistic map and discrete cosine transform are used to generate the verification map. Digital signature and timestamp are used to make copyright proving publicly verifiable. We have combined cryptographic tools and digital watermarking, in order to enhance the security and reliability of copyright protection. In addition, chaotic map is used to generate a chaotic pattern image, which can be used as secret key to improve the security of proposed algorithm. Experiments are conducted to show the robustness and effectiveness of the proposed algorithm. Experimental results show that our scheme outperforms related works in most of the cases.

Design and implementation of a block-based lossless watermarking scheme

High capacity reversible watermarking method based on block difference expansion is presented. The proposed scheme relies upon redundancy analysis for image authentication and tamper localisation. The performance of such scheme is compared with that of Tian. While Tian's algorithm is a pixel-based embedding scheme, the proposed method is a block-based embedding technique. Thus, it can be used with the following advantages: (1) possibility of providing more capacity for authentication data (2) no compression is needed (as in case of Tian's scheme) and (3) low time cost because of its reasonable complexity. To find out the embedding capacity both information and redundancy are examined for the underlying image. In addition a corresponding difference image is defined, its histogram is determined and its entropy and redundancy are computed. The proposed scheme creates an extra space for the authentication payload by making use of block difference expansion.

Lossless Watermarking for Verifying the Integrity of Medical Images with Tamper Localization

Given the ease of alteration of digital data, integrity verification and tamper detection for medical images are becoming ever more important. In this paper, instead of using the conventional irreversible block-based watermarking approach to achieve tamper localization, we propose to incorporate such functionality into the region-based lossless watermarking scheme. This is achieved by partitioning an image into certain non-overlapping regions and appending the associated local authentication information directly into the watermark payload. A region of authentication, which can be flexibly specified by the user, is partitioned into small regions in a multilevel hierarchical manner. Such hierarchical structure allows the user to easily adjust the localization accuracy, and makes the tamper detection efficient. Experimental results demonstrate the effectiveness of tamper localization.

A region-based lossless watermarking scheme for enhancing security of medical data.

This paper presents a lossless watermarking scheme in the sense that the original image can be exactly recovered from the watermarked one, with the purpose of verifying the integrity and authenticity of medical images. In addition, the scheme has the capability of not introducing any embedding-induced distortion in the region of interest (ROI) of a medical image. Difference expansion of adjacent pixel values is employed to embed several bits. A region of embedding, which is represented by a polygon, is chosen intentionally to prevent introducing embedding distortion in the ROI. Only the vertex information of a polygon is transmitted to the decoder for reconstructing the embedding region, which improves the embedding capacity considerably. The digital signature of the whole image is embedded for verifying the integrity of the image. An identifier presented in electronic patient record (EPR) is embedded for verifying the authenticity by simultaneously processing the watermarked image and the EPR. Combining with fingerprint system, patient's fingerprint information is embedded into several image slices and then extracted for verifying the authenticity.