Methodologies and tools for watermark evaluation and benchmarking facilitate the development of improved watermarking techniques. In this paper, we want to introduce and discuss the integration of audio watermark evaluation methods into the well-known web service Watermark Evaluation Testbed (WET). WET is enhanced by using. A special set of audio files with characterized content and a collection of single attacks as well as attack profiles will help to select special audio files and attacks with their attack parameters.

In this paper we discuss natural language watermarking, which uses the structure of the sentence constituents in natural language textin order to insert a watermark. This approach is different from techniques, collectively referred to as “text watermarking,” which embed information by modifying the appearance of text elements,such as lines, words, or characters. We provide a survey of the current state of the art in natural language watermarking and introduce terminology, techniques, and tools for text processing. We also examine the parallels and differences of the two watermarking domains and outline how techniques from the image watermarking domain may be applicable to the natural language watermarking domain.

Selective encryption is a technique that is used to minimizec omputational complexity or enable system functionality by only encrypting a portion of a compressed bitstream while still achieving reasonable security. For selective encryption to work, we need to rely not only on the beneficial effects of redundancy reduction, but also on the characteristics of the compression algorithm to concentrate important data representing the source in a relatively small fraction of the compressed bitstream. These important elements of the compressed data become candidates for selective encryption. In this paper, we combine encryption and distributed video source coding to consider the choices of which types of bits are most effective for selective encryption of a video sequence that has been compressed using a distributed source coding method based on LDPC codes. Instead of encrypting the entire video stream bit by bit, we encrypt only the highly sensitive bits. By combining the compression and encryption tasks and thus reducing the number of bits encrypted, we can achieve a reduction in system complexity.

Robust watermarks are evaluated in terms of image fidelity and robustness. We extend this framework and apply reliability testing to robust watermark evaluation. Reliability is the probability that a watermarking algorithm will correctly detect or decode a watermark for a specified fidelity requirement under a given set of attacks and images. In reliability testing, a system is evaluated in terms of quality, load, capacity and performance. To measure quality that corresponds to image fidelity, we compensate for attacks to measure the fidelity of attacked watermarked images. We use the conditional mean of pixel values to compensate for valumetric attacks such as gamma correction and histogram equalization. To compensate for geometrical attacks, we use error concealment and perfect motion estimation assumption. We define capacity to be the maximum embedding strength parameter and the maximum data payload. Load is then defined to be the actual embedding strength and data payload of a watermark. To measure performance, we use bit error rate (BER) and receiver operating characteristics (ROC) and area under the curve (AUC) of the ROC curve of a watermarking algorithm for different attacks and images. We evaluate robust watermarks for various quality, loads, attacks, and images.

With the proliferation of cameras in handheld devices that allows users to capture still images and videos, providing users with software tools to efficiently manage multimedia content has become essential. In many cases users desire to organize their personal media content using high-level semantic labels. In this paper we will describe low-complexity algorithms that can be used to derive semantic labels, such as “indoor/outdoor,” “face/not face,” and “motion/not motion” for mobile video sequences. We will also describe a method for summarizing mobile video sequences. We demonstrate the classification performance of the methods and their computational complexity using a typical processor used in many mobile terminals.

In this work we identify vulnerabilities of on-demand multicast routing protocols for multi-hop wireless networks and discuss the challenges encountered in designing mechanisms to defend against hem. We propose BSMR, a novel secure multicast routing protocol that withstands insider attacks from colluding adversaries. Our protocol is a software-based solution and does not require additional or specialized hardware. We present simulation results which demonstrate that BSMR effectively mitigates the identified attacks.

Multi-hop wireless networks rely on node cooperation to provide multicast services. The multi-hop communication offers increased coverage for such services, but also makes them more vulnerable to insider (or Byzantine) attacks coming from compromised nodes that behave arbitrarily to disrupt the network. In this work we identify vulnerabilities of on-demand multicast routing protocols for multi-hop wireless networks and discuss the challenges encountered in designing mechanisms to defend against them. We propose BSMR, a novel secure multicast routing protocol designed to withstand insider attacks from colluding adversaries. Our protocol is a software-based solution and does not require additional or specialized hardware. We present simulation results which demonstrate that BSMR effectively mitigates the identified attacks.

Peer-to-peer streaming systems are becoming highly popular for IP Television (IPTV). Most systems can be categorized as either tree-based or mesh-based, and as either pushbased or pull-based. However, there is a lack of clear understanding of how these different mechanisms perform comparatively in a real-world setting. In this paper, we compare two representative streaming systems using mesh-based and multiple tree-based overlay routing through deployments on the PlanetLab widearea experimentation platform. To the best of our knowledge, this is the first study to directly compare streaming overlay architectures in real Internet settings. Our results indicate that mesh-based systems inject a much higher number of duplicate packets into the network, but they perform better under a variety of conditions. In particular, mesh-based systems give consistently higher application goodput when the number of overlay nodes, or the streaming rates increase. They also perform better under churn and large flash crowds. Their performance suffers when latencies among peers are high, however. Overall, mesh-based systems appear to be a better choice than multi-tree based systems for peer-to-peer streaming at a large scale.

  In this thesis we investigate applications of natural language processing (NLP) techniques to information security problems. We present our results in this direction for two important areas: password authentication, and information hiding in natural language text. We have limited this thesis to the realm of language engineering, i.e., our emphasis is on adapting the existing NLP techniques for our purposes, rather than in developing new NLP techniques. Our password mnemonics system helps users to remember random passwords, hence making it possible to implement organizational policies that mandate strong password choices by users. Moreover, in our system password changes do not necessitate a new mnemonic, thereby further easing the users’ task of memorizing their respective mnemonics. Our robust natural language text watermarking system can avoid the removal of the watermark text by an automated adversary, in the same way used by authentication systems to avoid an automated adversary’s compromise of the password string hidden within the password mnemonic. We have also laid the groundwork for followup research in this area.

  Contributing our own creativity (in the form of text, image, audio, and video) to the pool of online information is fast becoming an essential part of online experience. However, it is still an open question as to how we, as authors, can control the way that the information we create is distributed or re-used.
  Rights management problems are serious for text since it is particularly easy for other people to download and manipulate copyrighted text from the Internet and later re-use it free from control. There is a need for a rights protection system that “travels with the content”. Digital watermarking is a mechanism that embeds the copyright information in the document. besides traveling with the content of the documents, digital watermarks can also be imperceptible to the user, which makes the process of removing them from the document challenging.
  The goal of this thesis is to design practical and resilient natural language watermarking systems. I have designed and implemented several natural language watermarking algorithms that use the linguistic features of the cover text in order to embed information. Using linguistic features provides resilience through making the message an elemental part of the content of the text, and through the judicious use of ambiguity in the usage of natural language and richness of features of natural language constituents. In this thesis, I propose several practical and resilient natural language watermarking systems for a variety of genres of text (short, long, edited and cursory text) and analyze their resilience and feasibility.

Wireless mesh networks (WMNs) have emerged as a promising technology for providing low-cost community wireless services.  Despite recent advancement in securing wireless networks, the problem of secure group communication on wireless networks has received relatively little attention. Characteristics specific to WMNs, such as limited communication range and high link error rate, raise unique challenges in designing such protocols.

In this paper we focus on providing data confidentiality for group communications on WMNs.  First, we propose W-LKH, a protocol that combines centralized key management and reliable key delivery, to address the less robust communication present in wireless networks. Next, we introduce WSOM, a new protocol framework designed specifically for the WMNs to overcome the performance and security limitations of W-LKH. Simulation results show that all of the proposed protocols can provide good performance to the upper layer applications, while the WSOM protocols incur smaller overhead and are more responsive than W-LKH. Finally, we suggest the applicability of each of the proposed protocols under different application requirements.

Virtual coordinate system (VCS) based routing provides a practical, efficient and scalable means for point-to-point routing in wireless sensor networks.  Several VCS-based routing protocols have been proposed in the last few years, all assuming that nodes are cooperative. However, malicious nodes may violate this assumption, making VCS-based routing protocols vulnerable to numerous attacks. Thus, it is critical to provide security mechanisms for these protocols to ensure correct operations in adversarial deployment environments.
    In this work, we study the security of VCS-based routing protocols. We identify new attacks targeting the accuracy and stability of virtual coordinates that VCS-based routing relies on and propose several defense mechanisms against the identified attacks. We evaluate the impact of the attacks and the effectiveness of our defense mechanisms using a well-known VCS-based routing protocol, BVR.

The internet and related technologies have made multidomain collaborations a reality. Collaboration enables domains to effectively share resources; however it introduced several security challenges. Managing security in the absence of a central mediator is even more challenging. in this dissertation, we propose a distributed secure interoperability framework for mediator-free collaboration environments.

Losses due to information security breaches are notoriously difficult to measure. An event study of the effect of such breaches on financial performance found that they do not earn significantly negative abnormal returns. To verify whether this finding resulted from the aggregation of data across different characteristics (e.g., the nature of the breaches, the types of firms, the time periods of the study) the impact of each characteristic was analyzed. Again the results were not significantly negative. The study found that a negative bias followed the events of September 11, 2001. It also found that there was a difference in investor reactions to events during the dot-com era, when firms earned higher negative abnormal returns, and after the dot-com era. The implications are discussed.