11 research outputs found

    Tatouage numérique des images dans le domaine des ondelettes basé sur la décomposition en valeurs singulières et l'optimisation multi-objective

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    Depuis l'extraordinaire révolution technique de l'analogique vers le numérique à la fin du 20ième siècle, les documents numériques sont devenus de plus en plus utilisés à cause de leur diffusion peu coûteuse et extrêmement rapide. Cependant ce passage de l'analogique vers le numérique ne s'est pas fait sans engendrer des inquiétudes en terme des droits d'auteurs. Des personnes non autorisées peuvent s'approprier des documents numériques pour faire des profits au dépends des propriétaires légitimes ayant les droits initiaux, puisque son contenu peut être facilement copié, modifié et distribué sans risque d'être détérioré. Dans cette optique, au début des années 1990, une nouvelle technique a été introduite qui s'inspire principalement de la cryptographie et la stéganographie : elle consiste à inscrire une marque dans un document numérique. Cette technique est nommée le tatouage numérique, en anglais digital watermarking. Cette thèse présente cinq différentes contributions relatives au domaine du tatouage numérique et du traitement d'image. La première contribution est la proposition de deux solutions au problème de la détection positive fausse de la marque constatée dans certains algorithmes de tatouage numérique basés sur la décomposition en valeurs singulières. L'une des solutions est basée sur les fonctions de hachage et l'autre sur le cryptage d'image. La deuxième contribution est la proposition d'un algorithme de cryptage d'image basé sur le principe du cube Rubik. La troisième contribution est la conception d'un algorithme de tatouage numérique basé sur la transformée en ondelettes à base du schéma de lifting (LWT) et la décomposition en valeurs singulières (SVD). Un facteur scalaire unique est utilisé pour contrôler l'intensité de l'insertion de la marque, et permet ainsi de trouver le meilleur compromis entre la robustesse et l'imperceptibilité du tatouage numérique. Cependant, l'utilisation des facteurs scalaires multiples au lieu d'un facteur scalaire unique est plus intéressante [CKLS97]. Toutefois, la détermination des valeurs optimales des facteurs scalaires multiples est un problème très difficile et complexe. Afin de trouver ces valeurs optimales, on a utilisé séparément l'optimisation multi-objective par algorithme génétique (MOGAO) et l'optimisation multi-objective par l'algorithme de colonie de fourmis (MOACO) qui sont considérés comme la quatrième et la cinquième contributions de cette thèse

    An Improved Secure Image Encryption Algorithm Based on Rubik's Cube Principle and Digital Chaotic Cipher

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    A recently proposed secure image encryption scheme has drawn attention to the limited security offered by chaos-based image encryption schemes (mainly due to their relatively small key space) proposing a highly robust approach, based on Rubik's cube principle. This paper aims to study a newly designed image cryptosystem that uses the Rubik's cube principle in conjunction with a digital chaotic cipher. Thus, the original image is shuffled on Rubik's cube principle (due to its proven confusion properties), and then XOR operator is applied to rows and columns of the scrambled image using a chaos-based cipher (due to its proven diffusion properties). Finally, the experimental results and security analysis show that the newly proposed image encryption scheme not only can achieve good encryption and perfect hiding ability but also can resist any cryptanalytic attacks (e.g., exhaustive attack, differential attack, statistical attack, etc.)

    Ambiguity attacks on robust blind image watermarking scheme based on redundant discrete wavelet transform and singular value decomposition

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    Among emergent applications of digital watermarking are copyright protection and proof of ownership. Recently, Makbol and Khoo (2013) have proposed for these applications a new robust blind image watermarking scheme based on the redundant discrete wavelet transform (RDWT) and the singular value decomposition (SVD). In this paper, we present two ambiguity attacks on this algorithm that have shown that this algorithm fails when used to provide robustness applications like owner identification, proof of ownership, and transaction tracking. Keywords: Ambiguity attack, Image watermarking, Singular value decomposition, Redundant discrete wavelet transfor

    Robust Additive Watermarking in the DTCWT Domain Based on Perceptual Masking

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    In this paper, a robust additive image watermarking system operating in the Dual Tree Complex Wavelet Transform (DTCWT) domain is proposed. The system takes advantage of a new perceptual masking model that exploits the Human Visual System (HVS) characteristics at the embedding stage. It also uses an efficient watermark detection structure, called the Rao-test, to verify the presence of the candidate watermark. This structure relies on the statistical modeling of high frequency DTCWT coefficients by the Generalized Gaussian distribution. Experimental results show that the proposed system outperforms related state-of-the-art watermarking systems in terms of imperceptibility and robustness

    On the Security of Robust Image Watermarking Algorithm based on Discrete Wavelet Transform, Discrete Cosine Transform and Singular Value Decomposition

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    Among emergent applications of digital watermarking, owner identification, proof of ownership and transaction tracking are applications that protect data by embedding the owner’s information (watermark) in it. Recently, a robust image watermarking scheme based on discrete wavelet transform, discrete cosine transform and singular value decomposition was proposed by Hu et al. [1]. However, this scheme has shown some drawbacks. In this paper, we present two ambiguity attacks that clearly demonstrate the ineffectiveness of the above scheme some watermarking applications, such as proof of ownership, transaction tracking and data authentication

    A New Reliable Optimized Image Watermarking Scheme Based on the Integer Wavelet Transform and Singular Value Decomposition for Copyright Protection

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    Although image watermarking schemes based on singular value decomposition (SVD) demonstrate high robustness and imperceptibility, they are exposed to the false positive problem (FPP). This drawback mostly occurs when embedding steps depend on singular values while singular vectors are used as secret keys. In this study, a new reliable SVD-based image watermarking scheme that uses integer wavelet transform (IWT) is proposed to overcome FPP and fulfil all watermarking requirements. Unlike in other schemes, the S and V matrices of the watermark are used as secret keys, whereas the S singular vector of the watermark is embedded into the singular values of the host image. The additional secret key is obtained from the watermarked image during the embedding process to increase security and avoid FPP completely. To improve the robustness, as well as achieve balance between robustness and imperceptibility, multi-objective ant colony optimization (MOACO) is utilized to find the optimal scaling factors, namely, multiple zooming factors. Results of the robustness, imperceptibility, and reliability tests demonstrate that the proposed IWT-SVD-MOACO scheme outperforms several previous schemes and avoids FPP completely
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