31 research outputs found

    Spread spectrum-based video watermarking algorithms for copyright protection

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    Merged with duplicate record 10026.1/2263 on 14.03.2017 by CS (TIS)Digital technologies know an unprecedented expansion in the last years. The consumer can now benefit from hardware and software which was considered state-of-the-art several years ago. The advantages offered by the digital technologies are major but the same digital technology opens the door for unlimited piracy. Copying an analogue VCR tape was certainly possible and relatively easy, in spite of various forms of protection, but due to the analogue environment, the subsequent copies had an inherent loss in quality. This was a natural way of limiting the multiple copying of a video material. With digital technology, this barrier disappears, being possible to make as many copies as desired, without any loss in quality whatsoever. Digital watermarking is one of the best available tools for fighting this threat. The aim of the present work was to develop a digital watermarking system compliant with the recommendations drawn by the EBU, for video broadcast monitoring. Since the watermark can be inserted in either spatial domain or transform domain, this aspect was investigated and led to the conclusion that wavelet transform is one of the best solutions available. Since watermarking is not an easy task, especially considering the robustness under various attacks several techniques were employed in order to increase the capacity/robustness of the system: spread-spectrum and modulation techniques to cast the watermark, powerful error correction to protect the mark, human visual models to insert a robust mark and to ensure its invisibility. The combination of these methods led to a major improvement, but yet the system wasn't robust to several important geometrical attacks. In order to achieve this last milestone, the system uses two distinct watermarks: a spatial domain reference watermark and the main watermark embedded in the wavelet domain. By using this reference watermark and techniques specific to image registration, the system is able to determine the parameters of the attack and revert it. Once the attack was reverted, the main watermark is recovered. The final result is a high capacity, blind DWr-based video watermarking system, robust to a wide range of attacks.BBC Research & Developmen

    Robust digital image watermarking algorithms for copyright protection

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    Digital watermarking has been proposed as a solution to the problem of resolving copyright ownership of multimedia data (image, audio, video). The work presented in this thesis is concerned with the design of robust digital image watermarking algorithms for copyright protection. Firstly, an overview of the watermarking system, applications of watermarks as well as the survey of current watermarking algorithms and attacks, are given. Further, the implementation of feature point detectors in the field of watermarking is introduced. A new class of scale invariant feature point detectors is investigated and it is showed that they have excellent performances required for watermarking. The robustness of the watermark on geometrical distortions is very important issue in watermarking. In order to detect the parameters of undergone affine transformation, we propose an image registration technique which is based on use of the scale invariant feature point detector. Another proposed technique for watermark synchronization is also based on use of scale invariant feature point detector. This technique does not use the original image to determine the parameters of affine transformation which include rotation and scaling. It is experimentally confirmed that this technique gives excellent results under tested geometrical distortions. In the thesis, two different watermarking algorithms are proposed in the wavelet domain. The first algorithm belongs to the class of additive watermarking algorithms which requires the presence of original image for watermark detection. Using this algorithm the influence of different error correction codes on the watermark robustness is investigated. The second algorithm does not require the original image for watermark detection. The robustness of this algorithm is tested on various filtering and compression attacks. This algorithm is successfully combined with the aforementioned synchronization technique in order to achieve the robustness on geometrical attacks. The last watermarking algorithm presented in the thesis is developed in complex wavelet domain. The complex wavelet transform is described and its advantages over the conventional discrete wavelet transform are highlighted. The robustness of the proposed algorithm was tested on different class of attacks. Finally, in the thesis the conclusion is given and the main future research directions are suggested

    Contribution to the construction of fingerprinting and watermarking schemes to protect mobile agents and multimedia content

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    The main characteristic of fingerprinting codes is the need of high error-correction capacity due to the fact that they are designed to avoid collusion attacks which will damage many symbols from the codewords. Moreover, the use of fingerprinting schemes depends on the watermarking system that is used to embed the codeword into the content and how it honors the marking assumption. In this sense, even though fingerprinting codes were mainly used to protect multimedia content, using them on software protection systems seems an option to be considered. This thesis, studies how to use codes which have iterative-decoding algorithms, mainly turbo-codes, to solve the fingerprinting problem. Initially, it studies the effectiveness of current approaches based on concatenating tradicioanal fingerprinting schemes with convolutional codes and turbo-codes. It is shown that these kind of constructions ends up generating a high number of false positives. Even though this thesis contains some proposals to improve these schemes, the direct use of turbo-codes without using any concatenation with a fingerprinting code as inner code has also been considered. It is shown that the performance of turbo-codes using the appropiate constituent codes is a valid alternative for environments with hundreds of users and 2 or 3 traitors. As constituent codes, we have chosen low-rate convolutional codes with maximum free distance. As for how to use fingerprinting codes with watermarking schemes, we have studied the option of using watermarking systems based on informed coding and informed embedding. It has been discovered that, due to different encodings available for the same symbol, its applicability to embed fingerprints is very limited. On this sense, some modifications to these systems have been proposed in order to properly adapt them to fingerprinting applications. Moreover the behavior and impact over a video produced as a collusion of 2 users by the YouTube鈥檚 s ervice has been s tudied. We have also studied the optimal parameters for viable tracking of users who have used YouTube and conspired to redistribute copies generated by a collusion attack. Finally, we have studied how to implement fingerprinting schemes and software watermarking to fix the problem of malicious hosts on mobile agents platforms. In this regard, four different alternatives have been proposed to protect the agent depending on whether you want only detect the attack or avoid it in real time. Two of these proposals are focused on the protection of intrusion detection systems based on mobile agents. Moreover, each of these solutions has several implications in terms of infrastructure and complexity.Els codis fingerprinting es caracteritzen per proveir una alta capacitat correctora ja que han de fer front a atacs de confabulaci贸 que malmetran una part important dels s铆mbols de la paraula codi. D'atra banda, la utilitzaci贸 de codis de fingerprinting en entorns reals est脿 subjecta a que l'esquema de watermarking que gestiona la incrustaci贸 sigui respectuosa amb la marking assumption. De la mateixa manera, tot i que el fingerprinting neix de la protecci贸 de contingut multim猫dia, utilitzar-lo en la protecci贸 de software comen莽a a ser una aplicaci贸 a avaluar. En aquesta tesi s'ha estudiat com aplicar codis amb des codificaci贸 iterativa, concretament turbo-codis, al problema del rastreig de tra茂dors en el context del fingerprinting digital. Inicialment s'ha q眉estionat l'efic脿cia dels enfocaments actuals en la utilitzaci贸 de codis convolucionals i turbo-codis que plantegen concatenacions amb esquemes habituals de fingerprinting. S'ha demostrat que aquest tipus de concatenacions portaven, de forma impl铆cita, a una elevada probabilitat d'inculpar un usuari innocent. Tot i que s'han proposat algunes millores sobre aquests esquemes , finalment s'ha plantejat l'煤s de turbocodis directament, evitant aix铆 la concatenaci贸 amb altres esquemes de fingerprinting. S'ha demostrat que, si s'utilitzen els codis constituents apropiats, el rendiment del turbo-descodificador 茅s suficient per a ser una alternativa aplicable en entorns amb varis centenars d'usuaris i 2 o 3 confabuladors . Com a codis constituents s'ha optat pels codis convolucionals de baix r脿tio amb dist脿ncia lliure m脿xima. Pel que fa a com utilitzar els codis de fingerprinting amb esquemes de watermarking, s'ha estudiat l'opci贸 d'utilitzar sistemes de watermarking basats en la codificaci贸 i la incrustaci贸 informada. S'ha comprovat que, degut a la m煤ltiple codificaci贸 del mateix s铆mbol, la seva aplicabilitat per incrustar fingerprints 茅s molt limitada. En aquest sentit s'ha plantejat algunes modificacions d'aquests sistemes per tal d'adaptar-los correctament a aplicacions de fingerprinting. D'altra banda s'ha avaluat el comportament i l'impacte que el servei de YouTube produeix sobre un v铆deo amb un fingerprint incrustat. A m茅s , s'ha estudiat els par脿metres 貌ptims per a fer viable el rastreig d'usuaris que han confabulat i han utilitzat YouTube per a redistribuir la copia fru茂t de la seva confabulaci贸. Finalment, s'ha estudiat com aplicar els esquemes de fingerprinting i watermarking de software per solucionar el problema de l'amfitri贸 malici贸s en agents m貌bils . En aquest sentit s'han proposat quatre alternatives diferents per a protegir l'agent en funci贸 de si 茅s vol nom茅s detectar l'atac o evitar-lo en temps real. Dues d'aquestes propostes es centren en la protecci贸 de sistemes de detecci贸 d'intrusions basats en agents m貌bils. Cadascuna de les solucions t茅 diverses implicacions a nivell d'infrastructura i de complexitat.Postprint (published version

    Efficient and Robust Video Steganography Algorithms for Secure Data Communication

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    Over the last two decades, the science of secretly embedding and communicating data has gained tremendous significance due to the technological advancement in communication and digital content. Steganography is the art of concealing secret data in a particular interactive media transporter such as text, audio, image, and video data in order to build a covert communication between authorized parties. Nowadays, video steganography techniques are important in many video-sharing and social networking applications such as Livestreaming, YouTube, Twitter, and Facebook because of noteworthy developments in advanced video over the Internet. The performance of any steganography method, ultimately, relies on the imperceptibility, hiding capacity, and robustness against attacks. Although many video steganography methods exist, several of them lack the preprocessing stages. In addition, less security, low embedding capacity, less imperceptibility, and less robustness against attacks are other issues that affect these algorithms. This dissertation investigates and analyzes cutting edge video steganography techniques in both compressed and raw domains. Moreover, it provides solutions for the aforementioned problems by proposing new and effective methods for digital video steganography. The key objectives of this research are to develop: 1) a highly secure video steganography algorithm based on error correcting codes (ECC); 2) an increased payload video steganography algorithm in the discrete wavelet domain based on ECC; 3) a novel video steganography algorithm based on Kanade-Lucas-Tomasi (KLT) tracking and ECC; 4) a robust video steganography algorithm in the wavelet domain based on KLT tracking and ECC; 5) a new video steganography algorithm based on the multiple object tracking (MOT) and ECC; and 6) a robust and secure video steganography algorithm in the discrete wavelet and discrete cosine transformations based on MOT and ECC. The experimental results from our research demonstrate that our proposed algorithms achieve higher embedding capacity as well as better imperceptibility of stego videos. Furthermore, the preprocessing stages increase the security and robustness of the proposed algorithms against attacks when compared to state-of-the-art steganographic methods

    Collusion-resistant fingerprinting for multimedia in a broadcast channel environment

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    Digital fingerprinting is a method by which a copyright owner can uniquely embed a buyer-dependent, inconspicuous serial number (representing the fingerprint) into every copy of digital data that is legally sold. The buyer of a legal copy is then deterred from distributing further copies, because the unique fingerprint can be used to trace back the origin of the piracy. The major challenge in fingerprinting is collusion, an attack in which a coalition of pirates compare several of their uniquely fingerprinted copies for the purpose of detecting and removing the fingerprints. The objectives of this work are two-fold. First, we investigate the need for robustness against large coalitions of pirates by introducing the concept of a malicious distributor that has been overlooked in prior work. A novel fingerprinting code that has superior codeword length in comparison to existing work under this novel malicious distributor scenario is developed. In addition, ideas presented in the proposed fingerprinting design can easily be applied to existing fingerprinting schemes, making them more robust to collusion attacks. Second, a new framework termed Joint Source Fingerprinting that integrates the processes of watermarking and codebook design is introduced. The need for this new paradigm is motivated by the fact that existing fingerprinting methods result in a perceptually undistorted multimedia after collusion is applied. In contrast, the new paradigm equates the process of collusion amongst a coalition of pirates, to degrading the perceptual characteristics, and hence commercial value of the multimedia in question. Thus by enforcing that the process of collusion diminishes the commercial value of the content, the pirates are deterred from attacking the fingerprints. A fingerprinting algorithm for video as well as an efficient means of broadcasting or distributing fingerprinted video is also presented. Simulation results are provided to verify our theoretical and empirical observations

    Digital watermarking methods for data security and authentication

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    Philosophiae Doctor - PhDCryptology is the study of systems that typically originate from a consideration of the ideal circumstances under which secure information exchange is to take place. It involves the study of cryptographic and other processes that might be introduced for breaking the output of such systems - cryptanalysis. This includes the introduction of formal mathematical methods for the design of a cryptosystem and for estimating its theoretical level of securit

    Watermarking techniques for genuine fingerprint authentication.

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    Fingerprints have been used to authenticate people remotely and allow them access to a system. However, the fingerprint-capture sensor is cracked easily using false fingerprint features constructed from a glass surface. Fake fingerprints, which can be easily obtained by attackers, could cheat the system and this issue remains a challenge in fingerprint-based authentication systems. Thus, a mechanism that can validate the originality of fingerprint samples is desired. Watermarking techniques have been used to enhance the fingerprint-based authentication process, however, none of them have been found to satisfy genuine person verification requirements. This thesis focuses on improving the verification of the genuine fingerprint owner using watermarking techniques. Four research issues are being addressed to achieve the main aim of this thesis. The first research task was to embed watermark into fingerprint images collected from different angles. In verification systems, an acquired fingerprint image is compared with another image, which was stored in the database at the time of enrolment. The displacements and rotations of fingerprint images collected from different angles lead to different sets of minutiae. In this case, the fingerprint-based authentication system operates on the ‘close enough’ matching principle between samples and template. A rejection of genuine samples can occur erroneously in such cases. The process of embedding watermarks into fingerprint samples could make this worse by adding spurious minutiae or corrupting correct minutiae. Therefore, a watermarking method for fingerprint images collected from different angles is proposed. Second, embedding high payload of watermark into fingerprint image and preserving the features of the fingerprint from being affected by the embedded watermark is challenging. In this scenario, embedding multiple watermarks that can be used with fingerprint to authenticate the person is proposed. In the developed multi-watermarks schema, two watermark images of high payloads are embedded into fingerprints without significantly affecting minutiae. Third, the robustness of the watermarking approach against image processing operations is important. The implemented fingerprint watermarking algorithms have been proposed to verify the origin of the fingerprint image; however, they are vulnerable to several modes of image operations that can affect the security level of the authentication system. The embedded watermarks, and the fingerprint features that are used subsequently for authentication purposes, can be damaged. Therefore, the current study has evaluated in detail the robustness of the proposed watermarking methods to the most common image operations. Fourth, mobile biometrics are expected to link the genuine user to a claimed identity in ubiquitous applications, which is a great challenge. Touch-based sensors for capturing fingerprints have been incorporated into mobile phones for user identity authentication. However, an individual fake fingerprint cracking the sensor on the iPhone 5S is a warning that biometrics are only a representation of a person, and are not secure. To make thing worse, the ubiquity of mobile devices leaves much room for adversaries to clone, impersonate or fabricate fake biometric identities and/or mobile devices to defraud systems. Therefore, the integration of multiple identifiers for both the capturing device and its owner into one unique entity is proposed

    Hardware realization of discrete wavelet transform cauchy Reed Solomon minimal instruction set computer architecture for wireless visual sensor networks

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    Large amount of image data transmitting across the Wireless Visual Sensor Networks (WVSNs) increases the data transmission rate thus increases the power transmission. This would inevitably decreases the operating lifespan of the sensor nodes and affecting the overall operation of WVSNs. Limiting power consumption to prolong battery lifespan is one of the most important goals in WVSNs. To achieve this goal, this thesis presents a novel low complexity Discrete Wavelet Transform (DWT) Cauchy Reed Solomon (CRS) Minimal Instruction Set Computer (MISC) architecture that performs data compression and data encoding (encryption) in a single architecture. There are four different programme instructions were developed to programme the MISC processor, which are Subtract and Branch if Negative (SBN), Galois Field Multiplier (GF MULT), XOR and 11TO8 instructions. With the use of these programme instructions, the developed DWT CRS MISC were programmed to perform DWT image compression to reduce the image size and then encode the DWT coefficients with CRS code to ensure data security and reliability. Both compression and CRS encoding were performed by a single architecture rather than in two separate modules which require a lot of hardware resources (logic slices). By reducing the number of logic slices, the power consumption can be subsequently reduced. Results show that the proposed new DWT CRS MISC architecture implementation requires 142 Slices (Xilinx Virtex-II), 129 slices (Xilinx Spartan-3E), 144 Slices (Xilinx Spartan-3L) and 66 Slices (Xilinx Spartan-6). The developed DWT CRS MISC architecture has lower hardware complexity as compared to other existing systems, such as Crypto-Processor in Xilinx Spartan-6 (4828 Slices), Low-Density Parity-Check in Xilinx Virtex-II (870 slices) and ECBC in Xilinx Spartan-3E (1691 Slices). With the use of RC10 development board, the developed DWT CRS MISC architecture can be implemented onto the Xilinx Spartan-3L FPGA to simulate an actual visual sensor node. This is to verify the feasibility of developing a joint compression, encryption and error correction processing framework in WVSNs

    Digital watermarking and novel security devices

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    EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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