Fragile Watermarking Research Articles

Protecting the Content Integrity of Digital Imagery with Fidelity Preservation

Fragile watermarking has attracted a lot of attention in the last decade. An interesting approach, presented in 2011 by Lin et al., results in very high quality of the watermarked images. However, after a thorough examination of the paper, a few improvements are proposed in our revised version of the algorithm in order to overcome some shortcomings. In particular, changes to the pseudocode and modifications to deal with pixel saturation are suggested, along with a way to improve the scheme security. Finally, a deeper analysis of the security is presented.

A Fragile Watermarking Algorithm for Hologram Authentication

A fragile watermarking algorithm for hologram authentication is presented in this paper. In the proposed algorithm, the watermark is embedded in the discrete cosine transform (DCT) domain of a hologram. The watermarked hologram is stored in spatial domain with finite precision level. By enhancing the precision for storing the watermarked hologram pixels, the distortion produced by the proposed watermarking scheme can be lowered. While providing high perceptual transparency, the proposed algorithm also attains high performance detection to delivery errors and malicious tampering. Experimental results reveal that the proposed algorithm can be used as an effective filter for blocking polluted or tampered holograms from 3D magnitude and/or phase reconstruction.

Effects of Reversible Watermarking on Iris Recognition Performance

Fragile watermarking has been proposed as a means of adding additional security or functionality to biometric systems, particularly for authentication and tamper detection. In this paper we describe an experimental study on the effect of watermarking iris images with a particular class of fragile algorithm, reversible algorithms, and the ability to correctly perform iris recognition. We investigate two scenarios, matching watermarked images to unmodified images, and matching watermarked images to watermarked images. We show that different watermarking schemes give very different results for a given capacity, highlighting the importance of investigation. At high embedding rates most algorithms cause significant reduction in recognition performance. However, in many cases, for low embedding rates, recognition accuracy is improved by the watermarking process. Keywords—Biometrics, iris recognition, reversible watermarking.

Effects of Reversible Watermarking on Iris Recognition Performance

Fragile watermarking has been proposed as a means of adding additional security or functionality to biometric systems, particularly for authentication and tamper detection. In this paper we describe an experimental study on the effect of watermarking iris images with a particular class of fragile algorithm, reversible algorithms, and the ability to correctly perform iris recognition. We investigate two scenarios, matching watermarked images to unmodified images, and matching watermarked images to watermarked images. We show that different watermarking schemes give very different results for a given capacity, highlighting the importance of investigation. At high embedding rates most algorithms cause significant reduction in recognition performance. However, in many cases, for low embedding rates, recognition accuracy is improved by the watermarking process. Keywords—Biometrics, iris recognition, reversible watermarking.

A Fragile Watermarking Scheme for Temper Detection

A fragile watermarking scheme which can detect the tampered areas of an image is proposed. The proposed scheme is quantization-based and can detect the tapered pixels with high accuracy. DES (Data Encryption Standard) algorithm is applied to generate watermark sequences and a HVS (Human Visual System) model is used to calculate the step size of embedding. Security of the proposed algorithm depends on a secret key. Attackers would not crack the watermark even they know the encrypting algorithm and watermarking scheme. The proposed scheme has high level of imperceptibility and high performance with low computational complexity. Experimental results indicate the effectiveness and efficiency of the proposed scheme.

Self-embedding fragile watermarking based on DCT and fast fractal coding

A self-embedding fragile watermarking scheme is proposed in this paper, which is based on Discrete Cosine Transform and fractal compression coding. To overcome the high computational complexity of fractal coding, a fast coding method is also presented that improves the efficiency of fractal block coding in the watermarking procedure. In our algorithm, three kinds of watermarks are generated for image authentication and recovery, which is based on an interleaved and overlapped 8 ×8 image block structure. This makes our method obtain an authentication granularity of 4 ×4 approximately. At the same time, we take advantage of two levels of mapping to select mapping block for every image block. Three versions of recovery watermarks for each block are embedded in different quadrants, which provides another two chances for block recovery in case one is destroyed. Experimental results demonstrate that the proposed scheme not only outperforms conventional self-embedding fragile watermarking algorithms in tamper recovery, but also improves the security against the various counterfeiting attacks.

A Fragile Watermark Method for Improving Medical Images Security

Aiming at the medical images security problem during storage and transmission, the author provides a fragile watermark method to protect it. And this method can be able to achieve integrity detection and accurate tampering localization. This method adopt s image block, chaotic modulation in watermark information and encryption to set password . The watermark information will be embedded to the least significant bits of original medical image’s sub - block area. Experimental results show that the algorithm has the following features: ( 1 ) T h e watermarked medical images has high and stable quality . ( 2 ) I t is sensitive to manipulations, and any manipulation of any pixel can be detected . ( 3 ) T he tampering localization can be accurate into 2×2 pixel area . ( 4 ) T he algorithm achieves the blind detection with high security.

Two-layer fragile watermarking method secured with chaotic map for authentication of digital Holy Quran.

This paper presents a novel watermarking method to facilitate the authentication and detection of the image forgery on the Quran images. Two layers of embedding scheme on wavelet and spatial domain are introduced to enhance the sensitivity of fragile watermarking and defend the attacks. Discrete wavelet transforms are applied to decompose the host image into wavelet prior to embedding the watermark in the wavelet domain. The watermarked wavelet coefficient is inverted back to spatial domain then the least significant bits is utilized to hide another watermark. A chaotic map is utilized to blur the watermark to make it secure against the local attack. The proposed method allows high watermark payloads, while preserving good image quality. Experiment results confirm that the proposed methods are fragile and have superior tampering detection even though the tampered area is very small.

Hamming Code Based Watermarking Scheme for 3D Model Verification

Due to the explosive growth of the Internet and maturing of 3D hardware techniques, protecting 3D objects becomes a more and more important issue. In this paper, a public hamming code based fragile watermarking technique is proposed for 3D objects verification. An adaptive watermark is generated from each cover model by using the hamming code technique. A simple least significant bit (LSB) substitution technique is employed for watermark embedding. In the extraction stage, the hamming code based watermark can be verified by using the hamming code checking without embedding any verification information. Experimental results shows that 100% vertices of the cover model can be watermarked, extracted, and verified. It also shows that the proposed method can improve security and achieve low distortion of stego object.

Scalable fragile watermarking for image authentication

Semi-fragile watermarks are used to detect unauthorised changes to an image, whereas tolerating allowed changes such as compression. Most semi-fragile algorithms that tolerate compression assume that because compression only removes the less visually significant data from an image, tampering with any data that would normally be removed by compression cannot affect a meaningful change to the image. Scalable compression allows a single compressed image to produce a variety of reduced resolution or reduced quality images, termed subimages, to suit the different display or bandwidth requirements of each user. However, highly scaled subimages remove a substantial fraction of the data in the original image, so the assumption used by most semi-fragile algorithms breaks down, as tampering with this data allows meaningful changes to the image content. The authors propose a scalable fragile watermarking algorithm for authentication of scalable JPEG2000 compressed images. It tolerates the loss of large amounts of image data because of resolution or quality scaling, producing no false alarms. Yet, it also protects that data from tampering, detecting even minor manipulations other than scaling, and is secure against mark transfer and collage attacks. Experimental results demonstrate this for scaling down to 1/1024th the area of the original or to 1/100th the file size.

Résultats à 16 semaines d’une étude de Phase III randomisée, contrôlée de l’apremilast, inhibiteur oral de la Phosphodiesterase 4, chez des patients présentant un psoriasis modéré à sévère (ESTEEM 1)

The need for publishing maps in secure digital format, especially guarantees data integrity which motivated us to propose a scheme that detects and locates modification data with high accuracy while ensuring exact recovery of the original content. In particular, using fragile watermarking algorithm based on reversible manner to embed hidden data in 2D vector map for each spatial features. In this paper, a reversible data-hiding scheme is explored based on the idea of difference expansion with Manhattan distances. A set of invertible integer mappings is defined to extract Manhattan distances from coordinates and the hidden data are embedded by modifying the differences between the adjacent distances. Experiments results show that the proposed scheme has good performance in term invisibility and tamper modification ability. The scheme could detect modification data such addition and deletion some features, and exactly recovery the original content of the 2D vector map.

Effective Fragile Watermarking for Image Authentication with High-quality Recovery Capability

In this paper, we propose an effective fragile image watermarking scheme for tampering detection and content recovery. Cover image is divided into a series of non-overlapping blocks and a block mapping relationship is constructed by the secret key. Several DCT coefficients with direct current and lower frequencies of the MSBs for each block are used to generate the reference bits, and different coefficients are assigned with different bit numbers for representation according to their importance. To enhance recovery performance, authentication bits are generated by the MSBs and the reference bits, respectively. After LSB substitution hiding, the embedded watermark bits in each block consist of the information of itself and its mapping blocks. On the receiver side, all blocks with tampered MSBs can be detected and recovered using the valid extracted reference bits. Experimental results demonstrate the effectiveness of the proposed scheme.

Authentication and copyright protection watermarking scheme for H.264 based on visual saliency and secret sharing

This paper proposes a video watermarking scheme based on visual saliency and secret sharing, which can be used for both synchronous authentication and copyright protection. Firstly, video is divided into several different scenes, and region of interest (ROI) for each I frames would be extracted automatically using the proto-object based saliency attention model. Secondly, the robust watermark and fragile watermark are generated according to ROI. The robust watermark is synthesized by copyright information and ROI of the first I frame for each video scene, and the edge map of ROI in each I frame is chosen as the fragile watermark. Finally, the robust watermark and fragile watermark are embedded into I frames of video scenes so that it can achieve video authentication and copyright information simultaneously. Experimental results demonstrate that the proposed method is robust to recompression and frame attack, and is also sensitive to tamper at the same time.

Image tamper detection scheme based on chaotic system and fragile watermarking

In order to solve the shortage of the method based on fragile watermarking,a new chaotic system and fragile watermarking based image tamper detection algorithm was proposed.Firstly,the method used Arnold cat map k times to scramble the original image,and then chose the Least Significant Bit(LSB) plane of the scrambled image as the embedding position.The actual watermark information was formed by using exclusive-or operation between a random binary sequence produced by Logistic map and the original watermark,and the LSB replacement method was utilized to embed watermark.Finally,the watermarked image was obtained by utilizing Arnold cat map T-k times.The experimental results show that,the introduction of chaotic system to a great extend improves the security of the proposed scheme.In addition,the proposed method achieves superior tamper detection and localization accuracy under different common attacks.

A blind fragile watermarking method for 3D models based on geometric properties of triangles

In this paper, a blind fragile watermarking method is presented for 3D triangular mesh models. In the proposed algorithm, watermark data displace medians of the mark triangle instead of embedding them into the vertices, based on the method which is explained. The displacement leads to a new triangle. The proposed method embeds data into the middle of three sides of mark triangle in spherical coordinates. It is performed by fixing one component of the center of neighboring vertices to mark triangle by small and controlled changes. It also increases the number of mark triangles in their selection process and thereby it increases the embedding capacity. The proposed method is invariant to affine transformation including translation, rotation and uniform scaling, due to the use of the normalization process before the embedding and also detection stages. Simulation results show that the proposed method has higher embedding capacity compared to the similar algorithms with the capability of detecting destructive attacks. [Figure not available: see fulltext.]

Digital Watermarking for Image Tamper Detection using Block-Wise Technique

Fragile watermarking has the characteristics where the inserted watermark should be easily breakable for a trivial tampering of the image. So, fragile watermarking technique is proposed for the purpose of authentication or tamper detection. In this paper, we propose an efficient image tamper detection method using block-wise technique which is able to detect the tamper locations. In the proposed method, a digital signature is generated from the hash code of the blocks of the final level where the watermark is inserted and the blocks of the upper level where those blocks are included in the image division process and this signature is used as the watermark, which is randomly inserted into selected image blocks. As the result of experiment, the proposed method was confirmed to be able to detect the tampered parts of the image without testing the entire block of the watermarked image.

A New Fragile Watermarking Based on Chaos

For existing airspace fragile authentication watermarking algorithm positioning accuracy and security issues, this paper presents a fully-fragile watermarking based on chaos for the integrity of the image content authentication and tamper localization. The algorithm uses the original image block, the calculation of each pixel in the image block high-bit gray value as the image feature watermark information. The chaotic sequence is encrypted and determines the position of the watermark bit is embedded watermark information, tampering with the positioning accuracy of an image block of 2 × 2 pixels. Experimental results show that the algorithm is simple, safe, with good practice.

A Semantic Watermarking Technique for Authenticating Video of H.264

A novel watermarking technique to authenticate video of H.264 is presented in this paper, using Uniform Content Locator (UCL) to semantically indexing video content and dual watermarks to preserve and enhance video content integrity and authentication. UCL index information is firstly extracted from video content and is formatted as semantic watermark to be embedded in video content. The UCL watermark is regarded as robust watermark and is then embedded into medium frequencies of DCT-coefficients of H.264 video I-frames in order to protect video attributes property (e.g., video author, copyright, content category). Features information obtained from the previously watermarked DCT-coefficients are treated as fragile watermark and are embedded into the motion vectors of H.264 video P-frames in order to ensure video secrecies (e.g., video integrity, authentication). Experiments demonstrate that this proposed technique can fulfill the requirements of H.264 video authentication and has negligible effects on video code rate change and content distortion.

Binomial Transform Based Image Authentication (BTIA)

In this paper, a fragile watermarking technique based on Binomial transform (BT) has been proposed for color image authentication (BTIA). An initial adjustment is applied to adjust the pixel values. The Binomial transform (BT) is applied to convert each pair of pixel components into transform domain in row major order. Two bits of the authenticating watermarks, starting from the least significant bit position are embedded into each component of transformed pair. A post-embedding adjustment has also been incorporated to keep the embedded component values closest to the original without hampering the embedded watermark bits. The inverse Binomial transform (IBT) is applied on each adjusted pair to regenerate the pixel components which successively produce the watermarked image. At the receiving end, the whole watermark can be extracted by the reverse procedure which can be verified for authentication by obtaining a message digest. Experimental results conform that the proposed technique offers a higher payload and PSNR over existing techniques [7, 9].

A Grayscale Image Fragile Watermark Authentication System in Spatial-Domain

This study deals with devising and implementing a novel technique for image authentication and secured message transmission based on hiding large volume of data into gray scale images. A grayscale image fragile watermark authentication system in spatial-domain is proposed. First it preprocesses the watermark image and resizes it to a quarter of the size of the original image. Then, it generates a random key matrix K and 128bit message authentication code from the original image. It replaces the 128bit message authentication code for the former 128bit of K to obtain a new key matrix KH. Then, it calculates the embedded position P=KHi xor (b7,b6,b5.b4) i MOD 3. b7,b6,b5,b4 are the high 4 bits of the original images pixel. It embeds the watermark image according to P value to the lower 4 bits of the original images pixel. The system is made in experiment. The result shows the system has good imperceptibility.