Oblivious data hiding : a practical approach

This dissertation presents an in-depth study of oblivious data hiding with the emphasis on quantization based schemes. Three main issues are specifically addressed: 1. Theoretical and practical aspects of embedder-detector design. 2. Performance evaluation, and analysis of performance vs. complexity tradeoffs. 3. Some application specific implementations. A communications framework based on channel adaptive encoding and channel independent decoding is proposed and interpreted in terms of oblivious data hiding problem. The duality between the suggested encoding-decoding scheme and practical embedding-detection schemes are examined. With this perspective, a formal treatment of the processing employed in quantization based hiding methods is presented. In accordance with these results, the key aspects of embedder-detector design problem for practical methods are laid out, and various embedding-detection schemes are compared in terms of probability of error, normalized correlation, and hiding rate performance merits assuming AWGN attack scenarios and using mean squared error distortion measure. The performance-complexity tradeoffs available for large and small embedding signal size (availability of high bandwidth and limitation of low bandwidth) cases are examined and some novel insights are offered. A new codeword generation scheme is proposed to enhance the performance of low-bandwidth applications. Embeddingdetection schemes are devised for watermarking application of data hiding, where robustness against the attacks is the main concern rather than the hiding rate or payload. In particular, cropping-resampling and lossy compression types of noninvertible attacks are considered in this dissertation work

Security issues in watermarking applications - a deeper look

Although it is clear that security is an important issue in digital watermarking applications, the main concerns ad-dressed by the current literature are robustness, capacity and imperceptibility. The inadequacy of the prevailing de-sign paradigm in tackling security issues is mainly due to an incomplete assessment of the threat model. The goal of this paper is to take a detailed and rigorous look at the threat model for a variety of watermarking applications. In this extended abstract, we outline the security requirements for a few common watermarking applications and explore in more detail the threat model for a specific application that involves establishing ownership of multimedia content

ABSTRACT Watermarking and Ownership Problem: A Revisit

Watermarking technologies have been envisioned as a potential means for establishing ownership on digital media objects. However, achievable robustness and false-positive rates of the state-of-the-art watermarking techniques raise doubts about applicability of watermarking to ownership problem. With this perspective, we address the security weaknesses common to most watermarking techniques and assess the role of watermarking in construction of ownership assertion systems. We identify the requirements of a watermarking based ownership assertion system. Also, we provide a basic functional outline of a practical version of such a system and identify its potential vulnerabilities. To mitigate these vulnerabilities, we aim at reducing the false positive rate of the watermark detection scheme. For this purpose, we propose embedding multiple watermarks as opposed to single watermark embedding while constraining the embedding distortion. The crux of the proposed method lies in watermark generation which deploys a family of one-way functions. We incorporate the multiple watermark embedding idea with the additive watermarking technique [1] and present results to illustrate the potential of this approach in reducing the false-positive rate of the watermark detection scheme

April 22, 2004 1:49 WSPC/Lecture Notes Series: 9in x 6in MAIN Image Steganography: Concepts and Practice

In the last few years, we have seen many new and powerful steganography and steganalysis techniques reported in the literature. In the following tutorial we go over some general concepts and ideas that apply to steganography and steganalysis. We review and discuss the notions of steganographic security and capacity. Some of the more recent image steganography and steganalysis techniques are analyzed with this perspective, and their contributions are highlighted. 1

Content security in digital multimedia

xv, 252 p. : ill. ; 30 cm