Digital Watermarking, Fingerprinting and Compression: An Information-Theoretic Perspective

The ease with which digital data can be duplicated and distributed over the media and the Internethas raised many concerns about copyright infringement.In many situations, multimedia data (e.g., images, music, movies, etc) are illegally circulated, thus violatingintellectual property rights. In an attempt toovercome this problem, watermarking has been suggestedin the literature as the most effective means for copyright protection and authentication. Watermarking is the procedure whereby information (pertaining to owner and/or copyright) is embedded into host data, such that it is:(i) hidden, i.e., not perceptually visible; and(ii) recoverable, even after a (possibly malicious) degradation of the protected work. In this thesis,we prove some theoretical results that establish the fundamental limits of a general class of watermarking schemes. The main focus of this thesis is the problem ofjoint watermarking and compression of images, whichcan be briefly described as follows: due to bandwidth or storage constraints, a watermarked image is distributed in quantized form, using $R_Q$ bits per image dimension, and is subject to some additional degradation (possibly due to malicious attacks). The hidden message carries $R_W$ bits per image dimension. Our main result is the determination of the region of allowable rates $(R_Q, R_W)$, such that: (i) an average distortion constraint between the original and the watermarked/compressed image is satisfied, and (ii) the hidden message is detected from the degraded image with very high probability. Using notions from information theory, we prove coding theorems that establish the rate regionin the following cases: (a) general i.i.d. image distributions,distortion constraints and memoryless attacks, (b) memoryless attacks combined with collusion (for fingerprinting applications), and (c) general---not necessarily stationary or ergodic---Gaussian image distributions and attacks, and average quadratic distortion constraints. Moreover, we prove a multi-user version of a result by Costa on the capacity of a Gaussian channel with known interference at the encoder

Real time DDoS detection using fuzzy estimators

We propose a method for DDoS detection by constructing a fuzzy estimator on the mean packet inter arrival times. We divided the problem into two challenges, the first being the actual detection of the DDoS event taking place and the second being the identification of the offending IP addresses. We have imposed strict real time constraints for the first challenge and more relaxed constraints for the identification of addresses. Through empirical evaluation we confirmed that the detection can be completed within improved real time limits and that by using fuzzy estimators instead of crisp statistical descriptors we can avoid the shortcomings posed by assumptions on the model distribution of the traffic. In addition we managed to obtain results under a 3 sec detection window. © 2012 Elsevier Ltd. All rights reserved

A Relationship between Quantization and Distribution Rates of Digitally Fingerprinted Data

This paper considers a fingerprinting system where$2^{n R_W}$ distinct Gaussian fingerprints are embedded inrespective copies of an $n$-dimensional i.i.d. Gaussian image.Copies are distributed to customers in digital form, using$R_Q$ bits per image dimension.By means of a coding theorem, a rate regionfor the pair $(R_Q, R_W)$ is established such that (i) theaverage quadratic distortion between the original imageand each distributed copy does not exceed a specified level;and (ii) the error probability in decoding the embedded fingerprintin the distributed copy approaches zero asymptotically in $n$

A Relationship Between Quantization and Watermarking Rates in the Presence of Gaussian Attacks

A system which embeds watermarksin n-dimensional i.i.d. Gaussian images and distributesthem in compressed form is studied.The performance of the system in the presence of Gaussianattacks is considered, and the region of achievablewatermarking and quantization rates is establishedunder constraints on image distortion and watermark detectability.The performance of related schemes is also discussed

Morphological Segmentation for Keyword Spotting

We explore the impact of morphological segmentation on keyword spotting (KWS). Despite potential benefits, state-of-the-art KWS systems do not use morphological information. In this paper, we augment a state-of-the-art KWS system with sub-word units derived from supervised and unsupervised morphological segmentations, and compare with phonetic and syllabic segmentations. Our experiments demonstrate that morphemes improve overall performance of KWS systems. Syllabic units, however, rival the performance of morphological units when used in KWS. By combining morphological, phonetic and syllabic segmentations, we demonstrate substantial performance gains.United States. Intelligence Advanced Research Projects Activity (United States. Army Research Laboratory Contract W911NF-12-C-0013

Distance Measures for Reduced Ordering Based Vector Filters

Reduced ordering based vector filters have proved successful in removing long-tailed noise from color images while preserving edges and fine image details. These filters commonly utilize variants of the Minkowski distance to order the color vectors with the aim of distinguishing between noisy and noise-free vectors. In this paper, we review various alternative distance measures and evaluate their performance on a large and diverse set of images using several effectiveness and efficiency criteria. The results demonstrate that there are in fact strong alternatives to the popular Minkowski metrics

Thinking and acting both globally and locally : The Field School in intercultural education as a model for action-research training and civic learning.

We present the Field School model of intercultural civic education, service-learning, action research training, and collaboration (with local academic and community partners) based on field work in applied anthropology. Theoretical and methodological foundations of the Field School also include experiential learning and immersive pedagogy, multiculturalism and cross-cultural communication, international education and study abroad programs, collaborative international development, participatory research, and in-depth knowledge in one’s own specific discipline. The primary goals of these intensive, short-term action research projects in other, less-developed countries or regions are benefits for community partners that are as sustainable as possible and to foster and assess learning experiences of students. The Peabody-Vanderbilt Field School in Intercultural Education began in Ecuador and Argentina, but we focus on Field Schools in China, rural New Mexico, and South Africa. In Guangxi, P.R.C., U.S. and Chinese students learned to navigate political and cultural complexities to study migration, community needs and assets assessment, and health effects of changing diet on children, and assisted English language learning in schools, a university and a factory. Native American students from Gallup, NM, and students from Nashville, TN, travelled to each other’s locale to study the impact of diabetes in each culture and develop health education and other prevention strategies. In Cape Town, SA, students worked on health and education projects in three townships; we focus here on a collaboration with high school staff to study and reduce the high dropout rate. We analyze Field School impacts on local community partners and student-researchers