Modern technologies have eased the way for adversaries to bypass the conventional identity authentication and identification processes; hence security systems have been developed to a great extent for protection of privacy and security of identities in different applications. The focus of this thesis is digital watermarking, security and privacy, as well as the ability to employ electrocardiogram as a method to enhance the security and privacy level. A high capacity reversible multiple watermarking scheme is introduced to mainly target the medical images. Furthermore, the use of ECG biometric signals in the form of the embedded watermark is studied. Experimental results indicate that the reversible data hiding scheme outperforms other approaches in the literature in terms of payload capacity and marked image quality. Results from the ECG mark embedding also show that no major degradation in performance is noticeable compared to the case where no watermarking is needed.

Chen Benrong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 125-130). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- What' s Watermarking --- p.1 / Chapter 1.2 --- "Information Hiding, Steganography, and Watermarking" --- p.3 / Chapter 1.3 --- History of Watermarking --- p.5 / Chapter 1.4 --- Importance of Digital Watermarking --- p.8 / Chapter 1.5 --- Objectives of the Thesis --- p.9 / Chapter 1.6 --- Thesis Outline --- p.10 / Chapter 2 --- Applications and Properties of Audio Watermarking --- p.12 / Chapter 2.1 --- Applications --- p.13 / Chapter 2.1.1 --- Ownership Identification and Proof --- p.13 / Chapter 2.1.2 --- Broadcast Monitoring --- p.16 / Chapter 2.1.3 --- Other Applications --- p.18 / Chapter 2.2 --- Properties --- p.19 / Chapter 2.2.1 --- Transparency --- p.20 / Chapter 2.2.2 --- Robustness --- p.20 / Chapter 2.2.3 --- Other Properties --- p.21 / Chapter 3 --- Possible Methods for Audio Watermarking --- p.24 / Chapter 3.1 --- Overview of Digital Audio Watermarking System --- p.25 / Chapter 3.2 --- Review of Current Methods --- p.27 / Chapter 3.2.1 --- Low Bit Coding --- p.27 / Chapter 3.2.2 --- Phase Coding --- p.28 / Chapter 3.2.3 --- Echo Coding --- p.29 / Chapter 3.2.4 --- Spread Spectrum Watermarking --- p.30 / Chapter 3.3 --- Other Related Approaches --- p.31 / Chapter 3.4 --- Outline of Proposed New Method --- p.33 / Chapter 4 --- Audio Watermarking System Based on Spread Spectrum --- p.36 / Chapter 4.1 --- Introduction --- p.36 / Chapter 4.2 --- Embedding and Detecting Information Bit --- p.39 / Chapter 4.2.1 --- General Embedding Process --- p.39 / Chapter 4.2.2 --- General Detection Process --- p.43 / Chapter 4.2.3 --- Pseudorandom Bit Sequences (PRBS) --- p.45 / Chapter 4.3 --- An Optimal Embedding Process --- p.48 / Chapter 4.3.1 --- Objective Metrics for Embedding Process --- p.48 / Chapter 4.3.2 --- Content Adaptive Embedding --- p.52 / Chapter 4.3.3 --- Determination of Frame Length L --- p.57 / Chapter 4.4 --- Requirement For Transparency Improvement --- p.58 / Chapter 5 --- Sample and Frame Selection For Transparency Improvement --- p.60 / Chapter 5.1 --- Introduction --- p.60 / Chapter 5.2 --- Sample Selection --- p.61 / Chapter 5.2.1 --- General Sample Selection --- p.62 / Chapter 5.2.2 --- Objective Evaluation Metrics --- p.65 / Chapter 5.2.3 --- Sample Selection For Transparency Improvement --- p.66 / Chapter 5.2.4 --- Theoretical Analysis of Sample Selection --- p.87 / Chapter 5.3 --- Frame Sclcction --- p.90 / Chapter 5.3.1 --- General Frame Selection --- p.91 / Chapter 5.3.2 --- Frame Selection For Transparency Improvement --- p.94 / Chapter 5.4 --- Watermark Information Retrieve --- p.103 / Chapter 6 --- Psychoacoustic Model For Robustness Verification --- p.105 / Chapter 6.1 --- Introduction of Human Auditory System --- p.106 / Chapter 6.1.1 --- Absolute Hearing Threshold --- p.106 / Chapter 6.1.2 --- Critical Bands --- p.108 / Chapter 6.1.3 --- Masking Effect --- p.111 / Chapter 6.2 --- Psychoacoustic Model of Human Auditory System --- p.112 / Chapter 6.3 --- Robustness Verification by Psychoacoustic Model Analysis --- p.117 / Chapter 7 --- Conclusions and Suggestions For Future Research --- p.121 / Chapter 7.1 --- Conclusions --- p.121 / Chapter 7.2 --- Suggestions For Future Research --- p.123 / Bibliography --- p.125

Developing a robust method of image watermarking that resists rotation, scaling and/or translation (RST) transformations is widely considered to be a more challenging task than developing a method resistant to other attacks. Altering the orientation or size of the image, even only slightly, reduces the receiver¡¦s ability to retrieve the watermark. Protecting against both geometric distortion and signal processing with blind detection is even more problematic. This investigation proposes a novel approach, based on the properties of histograms to measure the numerous global features of all pixels in a cover image and to construct the three-dimensional feature space. The feature space is dynamically partitioned to identify several blocks used to embed the watermark. One feature of the pixels is modified to form a specially distributed histogram for embedding the watermark in a blind digital watermarking method that can be applied to color images. Experimental results demonstrate the robustness of the proposed method against common geometric attacks and signal processing.

Digital watermarking technology is a potential future technology, which uses to protect copyright. Traditional digital watermarking is usually suffered from the limited information capacity and imperceptibility deficiency. In this research, we present the method to increase the capacity of the traditional watermarking techniques, which can be used broadly in present digital watermarking techniques by using the relation between the information in the cover-media. We use two kinds of digital watermarking techniques to analysis. The experiment result show that the proposed method can increase the capacity of embedding information without involves significant quality degradation in cover-media.

There has been a growing interest in reversible watermarking of medical images re- cently for security reasons. Typically, humans are assumed to be the end user of watermarked images, however in many cases machine vision processes may be addi- tional consumers. Therefore, any watermarking performed on these images must be imperceptible to not only human users, but also these machine vision processes. The objective of this thesis is to understand the extent to which reversible water- marking affects the ability of computer vision algorithms to perform correctly. We address both the effect on primitive feature detection and on complete machine vi- sion processes, and investigate the ability to predict these effects using Image Quality Metrics (IQMs). Additionally, we describe the development of a new watermarking algorithm. We perform primitive feature detection on original and watermarked images, com- paring the output feature maps. Subsequently we use statistical modelling to allow prediction of feature map differences based on various IQMs of a watermarked image. We then conduct a similar experiment using manually specified feature maps and edge detectors across their full parameter space. Watermarking algorithms showing the least impact are highlighted and prediction of poorer performance a priori is investigated. In many cases watermarking is shown to cause a significant difference in the output feature map, however prediction of the difference is possible with excellent discrim- ination in many cases. A validation system for utilising these results in practical applications is presented. Three machine vision processes are investigated using a range of watermarking al- gorithms and embedding capacities – iris recognition, medical image registration, and diabetic retinopathy assessment. Significant differences are found in some cases, however at low capacities the iris and retinopathy processes show no significant dif- ferences. In addition, prediction of erroneous results for the retinopathy process was possible with excellent discrimination.

隨著網際網路發展，眾多的數位內容在網際網路上散播。因此，數位內容以及影像的安全性逐漸變成一項重要的議題。由於數位內容的特性極容易經由網際網路傳播與複製，故數位內容所有權人的權力將受到極大的威脅。然而就算市場上有許多保護資料安全性的產品，對一般的使用者來說那些商品還是都過於昂貴。 本研究著重於隱形浮水印技術於影片的檔案格式之中，利用的線上免費公開的隱形浮水印技術工具實作一項服務，提供眾多的一般使用者能於網頁上進行資料的加解密步驟，保護其所需要加解密的檔案。此外本研究也提供了主動式的驗證機制於數位內容中，有別於以往的被動式驗證。 / With the digitalization of media, the improvement of video compression technique and the adaptation of the Internet, videos have become one of the most prominent mediums in the network age. However, due to its nature to be easily copied and distributed, creative workers easily become victims to the piracy. While corporations use proprietary digital rights management (DRM) to guarantee fair use of intellectual properties, individuals are seldom able to afford huge royalty. In this work, we investigate invisible watermarking techniques, discuss their properties, and apply cryptography and steganography techniques to data hiding in digital contents. Specifically, we develop a new public online service of data hiding in digital contents with the aim of proving content owners the ability to claim digital ownership. The current technique used to embed messages in video satisfies integrity but cannot resist attacks/modifications on the video. Also, we proposed a generic active authentication framework via hiding programs in digital contents, giving the developer the possibility to design their own variant from passive authentication to active code execution.

Thesis (Ph.D.)--University of Texas at Dallas, 2007. / Includes vita. Includes bibliographical references.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 70-72). Also available in electronic version. Access restricted to campus users.

Thesis (M.S.)--Rochester Institute of Technology, 2007. / Typescript. Includes bibliographical references (leaves 41-42).

This thesis investigates the problem of optimal design of binary joint watermarking and scalar quantization (JWSQ) systems that are robust under additive Gaussian attacks. A binary JWSQ system consists of two quantizers with disjoint codebooks. The joint quantization and embedding are performed by choosing the quantizer corresponding to the embedded message. The optimal JWSQ design for both fixed-rate and variable-rate cases was considered in the past, but the solution approaches exhibited high computational complexity. In this thesis, we propose faster binary JWSQ design algorithms for both the fixed-rate and variable-rate scenarios. We achieve the speed up by mapping the corresponding optimization problem to a minimum weight path problem in a certain weighted directed acyclic graph (with a constraint on the length of the path in the fixed-rate case). For this mapping to be possible we discretize the quantizer space and use an approximation for the probability of decoding error. The proposed solution algorithms have $O(LN^3)$ and $O(N^4)$ time complexity in the two cases respectively, where $N$ is the size of discretized source alphabet, and in the fixed-rate scenario $L$ is the number of cells in each quantizer. The effectiveness of the proposed designs is assessed through extensive experiments on a Gaussian source. Our results show that our algorithms are able to achieve performance very close to the prior existing schemes, but only at a small fraction of their running time. / Thesis / Master of Applied Science (MASc)