A High Security Buyer-Seller Watermark Protocol based on Iris Biometric

With the development of digital watermarking technology, digital watermarking protocol is now drawing the attention for protecting copyrights of digital products. However, the copyright protection is fully protected by watermark technology if it is employed a suitable protocol between the rights owner and the customer. Therefore, currently, there are a number of buyer-seller watermarking protocols proposed, however, an anonymous problem and collusion problem are still unsolved completely. Thus, this paper proposes a high security watermark protocol based on iris biometric for resolving these problems. In addition, this paper also produces watermarking generation mechanism which aims to improve the efficiency of the whole mechanism. Finally, the investigation indicates that the proposed buyer-seller watermark protocol takes care of the security concerns of all parties involved, and the proposed scheme could also find an illegal copy of the content, the violators can be traced back

Tatouage du flux compressé MPEG-4 AVC

La présente thèse aborde le sujet de tatouage du flux MPEG-4 AVC sur ses deux volets théoriques et applicatifs en considérant deux domaines applicatifs à savoir la protection du droit d auteur et la vérification de l'intégrité du contenu. Du point de vue théorique, le principal enjeu est de développer un cadre de tatouage unitaire en mesure de servir les deux applications mentionnées ci-dessus. Du point de vue méthodologique, le défi consiste à instancier ce cadre théorique pour servir les applications visées. La première contribution principale consiste à définir un cadre théorique pour le tatouage multi symboles à base de modulation d index de quantification (m-QIM). La règle d insertion QIM a été généralisée du cas binaire au cas multi-symboles et la règle de détection optimale (minimisant la probabilité d erreur à la détection en condition du bruit blanc, additif et gaussien) a été établie. Il est ainsi démontré que la quantité d information insérée peut être augmentée par un facteur de log2m tout en gardant les mêmes contraintes de robustesse et de transparence. Une quantité d information de 150 bits par minutes, soit environ 20 fois plus grande que la limite imposée par la norme DCI est obtenue. La deuxième contribution consiste à spécifier une opération de prétraitement qui permet d éliminer les impactes du phénomène du drift (propagation de la distorsion) dans le flux compressé MPEG-4 AVC. D abord, le problème a été formalisé algébriquement en se basant sur les expressions analytiques des opérations d encodage. Ensuite, le problème a été résolu sous la contrainte de prévention du drift. Une amélioration de la transparence avec des gains de 2 dB en PSNR est obtenueThe present thesis addresses the MPEG-4 AVC stream watermarking and considers two theoretical and applicative challenges, namely ownership protection and content integrity verification.From the theoretical point of view, the thesis main challenge is to develop a unitary watermarking framework (insertion/detection) able to serve the two above mentioned applications in the compressed domain. From the methodological point of view, the challenge is to instantiate this theoretical framework for serving the targeted applications. The thesis first main contribution consists in building the theoretical framework for the multi symbol watermarking based on quantization index modulation (m-QIM). The insertion rule is analytically designed by extending the binary QIM rule. The detection rule is optimized so as to ensure minimal probability of error under additive white Gaussian noise distributed attacks. It is thus demonstrated that the data payload can be increased by a factor of log2m, for prescribed transparency and additive Gaussian noise power. A data payload of 150 bits per minute, i.e. about 20 times larger than the limit imposed by the DCI standard, is obtained. The thesis second main theoretical contribution consists in specifying a preprocessing MPEG-4 AVC shaping operation which can eliminate the intra-frame drift effect. The drift represents the distortion spread in the compressed stream related to the MPEG encoding paradigm. In this respect, the drift distortion propagation problem in MPEG-4 AVC is algebraically expressed and the corresponding equations system is solved under drift-free constraints. The drift-free shaping results in gain in transparency of 2 dB in PSNREVRY-INT (912282302) / SudocSudocFranceF

Comparative evaluation of video watermarking techniques in the uncompressed domain

Thesis (MScEng)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Electronic watermarking is a method whereby information can be imperceptibly embedded into electronic media, while ideally being robust against common signal manipulations and intentional attacks to remove the embedded watermark. This study evaluates the characteristics of uncompressed video watermarking techniques in terms of visual characteristics, computational complexity and robustness against attacks and signal manipulations. The foundations of video watermarking are reviewed, followed by a survey of existing video watermarking techniques. Representative techniques from different watermarking categories are identified, implemented and evaluated. Existing image quality metrics are reviewed and extended to improve their performance when comparing these video watermarking techniques. A new metric for the evaluation of inter frame flicker in video sequences is then developed. A technique for possibly improving the robustness of the implemented discrete Fourier transform technique against rotation is then proposed. It is also shown that it is possible to reduce the computational complexity of watermarking techniques without affecting the quality of the original content, through a modified watermark embedding method. Possible future studies are then recommended with regards to further improving watermarking techniques against rotation.AFRIKAANSE OPSOMMING: ’n Elektroniese watermerk is ’n metode waardeur inligting onmerkbaar in elektroniese media vasgelê kan word, met die doel dat dit bestand is teen algemene manipulasies en doelbewuste pogings om die watermerk te verwyder. In hierdie navorsing word die eienskappe van onsaamgeperste video watermerktegnieke ondersoek in terme van visuele eienskappe, berekeningskompleksiteit en weerstandigheid teen aanslae en seinmanipulasies. Die onderbou van video watermerktegnieke word bestudeer, gevolg deur ’n oorsig van reedsbestaande watermerktegnieke. Verteenwoordigende tegnieke vanuit verskillende watermerkkategorieë word geïdentifiseer, geïmplementeer en geëvalueer. Bestaande metodes vir die evaluering van beeldkwaliteite word bestudeer en uitgebrei om die werkverrigting van die tegnieke te verbeter, spesifiek vir die vergelyking van watermerktegnieke. ’n Nuwe stelsel vir die evaluering van tussenraampie flikkering in video’s word ook ontwikkel. ’n Tegniek vir die moontlike verbetering van die geïmplementeerde diskrete Fourier transform tegniek word voorgestel om die tegniek se bestandheid teen rotasie te verbeter. Daar word ook aangetoon dat dit moontlik is om die berekeningskompleksiteit van watermerktegnieke te verminder, sonder om die kwaliteit van die oorspronklike inhoud te beïnvloed, deur die gebruik van ’n verbeterde watermerkvasleggingsmetode. Laastens word aanbevelings vir verdere navorsing aangaande die verbetering van watermerktegnieke teen rotasie gemaak

Image authentication using Zernike moment watermarking

The rapid development of internet and digital image editing softwares facilitated the access and illegal usage of digital images. Digital watermarking emerged as a unique tool to protect the authenticity of the image. It is a technique of insertion of a message into a cover media imperceptibly. In this thesis, the main objective is to design and develop a watermarking system for image authentication. A semi-fragile watermarking system using content-based techniques is proposed in this work to solve the problems with the previously proposed methods which are not robust against normal image processing operations such as rotation, scale, translation, noise addition and JPEG compression. The Zernike moments and Sobel edge map are used as watermarks to provide malicious attack classification and locating tampered area. The Zernike moments are chosen due to special characteristics such as robustness against rotation, scale, translation (RST) and noise. Also an image can be reconstructed from the extracted Zernike moments. These watermarks are generated from the approximation component of discrete wavelet decomposition in third level. The Sobel edge map is fused in wavelet coefficients of the corresponding component, and Zernike moments vector is fused in Sobel edge point of the original image. A comparison between recovered Zernike moments and generated Zernike moments form watermarked image at receiver determine the authenticity of the image. In case of authenticity failure, a comparison between recovered Sobel edge map and recently obtained Sobel edge map from the watermarked image detect the location of tampered areas. The results from the test show that the proposed algorithm has good performance in discriminating the malicious from non-malicious modifications which is the main character of an image authentication algorithm. This work significantly improves the robustness of semi-fragile characteristics of watermarking. It accepts scale, translation, noise pollution, rotation and JPEG compression modifications on the watermarked images,so it can solve the problem with previous methods with flaw of discrimination between malicious and non-malicious attacks. The adding or replacing a portion of the image is regarded as malicious attacks and rejected by this algorithm. Using two different watermarks lead to a good classification of incidental and malicious modifications and locating the tampered areas. Experimental results showed that this algorithm achieves better bit error rate against JPEG compression, rotation, scale and noise attacks in comparison with other reviewed schemes in this work. A great improvement is also achieved in the capacity of the watermarking system as shown in chapter Four. This scheme also offers better classification of malicious modifications over the other reviewed schemes in this work