A novel LWT-based robust watermark strategy for colour images

With the advent of the web and the creation of electronic distribution channels for multimedia objects, there is an increased risk of copyright infringements. Content providers try to alleviate this problem by using copyright protection facilities that often involve watermarking schemes as primitives. Clearly, the intention of the content provider can be subverted if the watermarking scheme is susceptible to intentional attacks, especially to attacks on the robustness of watermarks. It was noted early during the development of watermarking algorithms that the intention of resolving the copyright situation might be subverted entirely without removing any watermark contained in multimedia objects. Indeed, so-called protocol attacks try to introduce some sort of ambiguity during the copyright resolution process. After providing formal definitions for some common protocol attacks, we discuss the possibility of constructing watermarking schemes that are provably secure against ambiguity and copy attacks. Although there were several previous attempts to secure watermarking schemes against protocol attacks, we provide for the first time a formal security proof of our scheme. The security of the construction is based on a cryptographic primitive, namely an unforgeable public-key signature scheme, that is used to constrain the watermarking bits to have a specific form.

Federated learning (FL) has become an emerging distributed framework to build deep learning models with collaborative efforts from multiple participants. Consequently, copyright protection of FL deep model is urgently required because too many participants have access to the joint-trained model. Recently, Secure FL framework is developed to address data leakage issue when central node is not fully trustable. This encryption process has made existing DL model watermarking schemes impossible to embed watermark at the central node. In this paper, we propose a novel client-side Federated Learning watermarking method to tackle the model verification issue under the Secure FL framework. In specific, we design a backdoor-based watermarking scheme to allow model owners to embed their pre-designed noise patterns into the FL deep model. Thus, our method provides reliable copyright protection while ensuring the data privacy because the central node has no access to the encrypted gradient information. The experimental results have demonstrated the efficiency of our method in terms of both FL model performance and watermarking robustness.

The ambiguity attack is to derive a valid watermark from a medium to defeat the ownership claim of the real owner. Most of the research suggests that it is difficult to design a provably secure non-ambiguity watermarking without a trusted third party. Recently, Li and Chang have provided a specific blind additive spread spectrum watermarking scheme as an example that is provably non-ambiguous. However, the proposed watermarking needs the length of watermark n > 3.07 × 10 9 according to our analysis. In this paper, a framework for quantization based watermarking schemes and non-blind spread spectrum watermarking scheme to achieve non-ambiguity is proposed. As a result, many of the existent watermarking schemes can achieve provable non-invertibility via using this framework, and an nonambiguity ownership verification protocol without a trusted third party may be constructed. We have obtained the close form solution of false positive rate for the underlying quantization based schemes and spread spectrum watermarking schemes (both blind and non-blind). The length of key of pseudo-random sequence generator (PRSG) is extended to m = c × n , the cardinality of the valid watermark set is extended to vWv = 2 m = 2 c,n , thus leading to more security to exhaustive searching attack than the Li and Chang's scheme, which has m = sn. In addition, the required length of watermark becomes much shorter than that required in the Li and Chang's scheme. At last, we propose a noninvertible and robust quantization-based watermarking scheme with the length of watermark being n=1024 .

Malicious tampering of digital image content may lead to serious consequences. As image resolution increases and its circulations on the network grows rapidly, images undergo double compression in the following environment: compression (JPEG/JPEG2000) for first release, decoding, application processing (conventional signal processing/security attacks/malicious content tampering), and compression (JPEG2000/JPEG) for rerelease before detection. Effectively determining whether the image content has been tampered and to locate the tampering position in a double-compression environment is an urgent problem. In this paper, a novel watermark expression method based on rotating vector and its modulation algorithm is proposed. Based on this method, a semi-fragile watermarking scheme is established for the image content authentication. The stability of watermarked data is analyzed theoretically, providing the watermark scheme with a theoretical basis. The authentication schemes with feature extraction and reconstruction, watermark embedding and extraction, and tamper detection and localization are mainly elaborated. The robustness of watermark, its security, and related detection performance are analyzed. Theoretical analysis and experiments show that the scheme features a good watermark transparency, good robustness, and stable distribution for different attacks and can effectively distinguish malicious tampering from content-preserving operators and locate tampering area under double-compression environment. In addition, the proposed scheme can resist watermark attacks, collage attacks, and forge attacks. Compared with related schemes, the proposed scheme has superior comprehensive performance and is suitable for content authentication in double-compression environment, which expands the application scope of watermark-based content authentication.

A new structure-preserving quaternion QR decomposition method for color image blind watermarking

Robust watermarking is a valuable methodology used in protecting the copyright and securing digital images. In this paper, new fractional-order multi-channel orthogonal exponent moments (MFrEMs) and their invariants to geometric transformations are derived for the first time. We utilized these highly accurate moments to construct a new robust watermarking algorithm for color images. This algorithm consists of three phases. First, the bits of the binary watermark scrambled by using a 1D Sine chaotic map. Second, the fractional-order MFrEMs are calculated from the host color image. Finally, a quantization process is performed, where the scrambled bits of the binary watermark embedded into the host color image. Various experiments were conducted to test the proposed watermarking algorithm and compare it with the existing robust watermarking algorithms for color images. The obtained results ensure the proposed robust watermarking algorithm's superiority over existing algorithms regarding the visual imperceptibility and robustness against various attacks.

Nowadays, Internet and multimedia is popularly growing fast and is being used in digital communication. With increase in demand, risks are also involved. Thus, digital watermarking is an absolute method to provide authentication and copyright protection to the digital media to protect it from illegal modification and redistribution. In this paper, we have proposed a robust watermarking algorithm using DES, ECC and DCT for color images. The original color image (watermark) and cover image has been separated into three independent color channels (red, green and blue) and their gray scale equivalents are used. Each individual gray scale equivalent of RGB components of original image has been encrypted using Data Encryption Standard (DES). The Henon map is used to generate three different round keys for DES with different initial parameters. After encrypting three different gray scale equivalents, the encrypted images are mapped to the points of elliptic curve. The mapped images so formed are embedded in different gray scale equivalents of RGB components of color image using DCT. The mapped images are hidden into the mid frequency of DCT blocks to avoid it from common attacks. The effectiveness and robustness of the algorithm is shown in the experiments.

In this paper, a wavelet-based watermarking scheme for color images is proposed. The watermarking scheme is based on the design of a color visual model that is the modification of a perceptual model used in the image coding of gray scale images. The model is designed to estimate and utilize the noise detection threshold of each wavelet coefficient in luminance and chrominance components in order to satisfy the transparency and robustness required by color image watermarking techniques. Besides the visual masking given by taking into account the luminance content and the texture, the crossed masking effect and the effect given by the variance within the local region of the target coefficient are investigated such that the estimated noise detection threshold is more close to the real noise detection threshold. In a locally adaptive fashion based on the wavelet decomposition, the thresholds of subband coefficients in each color component are derived to construct a perceptually lossless quantization matrix for embedding watermarks. Performance in terms of robustness and transparency is obtained by embedding the maximum strength watermark while maintaining the perceptually lossless quality of the watermarked color image. Simulation results show that the proposed scheme is more robust than the existing schemes while retaining the watermark transparency.

Now a day's large amount of digital information such as video, audio or image is spread over the internet. So it should be a great challenge for all researchers to provide security to such a type of digital data. Also the piracy and copyright is emerging issue when digital information in the form of video, audio & image is transmitted over the transmission media. So to prevent the problem of piracy and security of digital data such as video, video watermarking techniques has been introduced. There are various watermarking schemes to give the security to videos but they were unable to provide the quality in terms of robustness and security. In this paper optimized and hybrid based robust digital video watermarking scheme has been proposed. The optimization is performed in the proposed system with the help of genetic algorithm. The quality of the proposed watermarking scheme is measured in terms of PSNR and NC values. The PSNR calculated using our approach is off 50.48 db which is far better than existing approaches.

Macrophotography Images (MPIs) have recently emerged as an active topic due to the development of mobile phone camera technology. A large number of MPIs have been rapidly increasing in many rich visual services, such as smartphones or high-definition monitors. MPIs are often composed of sharp macroimage and blur background, which exhibit different perceptual properties that often lead to different just noticeable difference (JND) estimation. Inspired by this, we formulate the blur concealment (BC) as another factor to determine the total masking effect: the interaction is relatively straightforward with a limited masking effect in the sharp regions, and is complicated with a strong masking effect in the blur parts. Furthermore, texture and orientation adaption and color information weighting are separately incorporated into the contrast masking and color masking. Finally, considering both BC and masking effects, a novel robust watermarking framework based on the proposed blur-guided JND model for MPIs, targeting at further improving the MPIs copyright protection performance. Extensive experiments on MP2020 and Blur Detection data sets show that the applicability of the proposed JND model in the scenario of perceptually MPIs watermarking, and our proposed scheme can outperform the state-of-the-art watermarking schemes by providing better robustness performance at the uniform visual quality.

<span>This paper presents a watermarking scheme for grayscale images, in which lifting wavelet transform and singular value decomposition are exploited based on multi-objective artificial bee colony optimization to produce a robust watermarking method. Furthermore, for increasing security encryption of the watermark is done prior to the embedding operation. In the proposed scheme, the actual image is altered to four sub-band over three levels of lifting wavelet transform then the singular value of the watermark image is embedded to the singular value of LH sub-band of the transformed original image. In the embedding operation, multiple scaling factors are utilized on behalf of the single scaling element to get the maximum probable robustness without changing watermark lucidity. Multi-objective artificial bee colony optimization is utilized for the determination of the optimal values for multiple scaling components, which are examined against various types of attacks. For making the proposed scheme more secure, the watermark is encrypted chaotically by logistic chaotic encryption before embedding it to the host (original) image. The experimental results show excellent imperceptibility and good resiliency against a wide range of image processing attacks.</span>

In this paper we propose a watermarking scheme to ensure copyright protection in video distribution systems. This research is focused on provide a low computational cost solution that allows embedding a robust and imperceptible watermarking signal in the video content, such that the original video transmission rate will not be affected. Our proposal accomplishes this challenge by introducing a fast and effective method based on spatio-temporal Human Visual System properties that allow improving imperceptibility along video sequence and at the same time, enhancing robustness. Extensive experiments were performed to prove that the proposed algorithm satisfies quickness, invisibility and robustness against several real-world video processing issues. The proposed scheme has the advantages of robustness, simplicity and flexibility, allowing it to be considered a good solution in practical situations since it can be adapted to different video distribution systems.

We present and analyze an approach to improve the performance of a broad class of watermarking schemes through attack characterization. Traditional robust watermarking methods use little information concerning the way in which the image is tampered to estimate the embedded watermark. In our novel scheme we propose adding two types of watermarks: reference and robust. The reference watermark is used to assess the way in which the marked image has been modified so that the robust watermark can be optimally extracted to maximize security. Analysis and simulation results are provided to demonstrate the significant performance improvement when the proposed approach is employed in an existing watermarking scheme.

CRT was a widely used algorithm in the development of watermarking methods. The algorithm produced good image quality but it had low robustness against compression and filtering. This paper proposed a new watermarking scheme through dual band IWT to improve the robustness and preserving the image quality. The high frequency sub band was used to index the embedding location on the low frequency sub band. In robustness test, the CRT method resulted average NC value of 0.7129, 0.4846, and 0.6768 while the proposed method had higher NC value of 0.7902, 0.7473, and 0.8163 in corresponding Gaussian filter, JPEG, and JPEG2000 compression test. Meanwhile the both CRT and proposed method had similar average SSIM value of 0.9979 and 0.9960 respectively in term of image quality. The result showed that the proposed method was able to improve the robustness and maintaining the image quality.

This paper presents a watermarking algorithm to embed robust watermark and fragile authentication data into color satellite images. The aim of this watermarking algorithm is to protect the copyright and image originality. This algorithm doesn't require the original image in the extraction process and it is a blind algorithm. The algorithm contains two watermarks, one for the copyright and another one for the image authenticity. The first watermark is embedded in the frequency domain using the discrete cosine transform while the second watermark is embedded in the spatial domain which consists of hash functions using MD5 and Hex formats. The fragile watermark is inserted in one row of each one of the RGB channels. The distortion caused by the embedding is assessed using peak signal to noise ratio (PSNR) and similarity structure index measure (SSIM). Robustness against different types of attacks have been assessed using Stirmark and by introducing small modifications to the satellite images. The robust watermarking scheme survived many attacks such as JPEG compression and filtering. The fragile watermark is very sensitive and any small modification to the image can be detected. It was found that embedding in the green channel offers better performance compared to red and blue channels. In addition the embedding in the Y channel offers better robustness against attacks.