Nawal A. El-Fishawy

An Efficient Block-by-Block SVD-Based Image Watermarking Scheme

This paper presents a block based digital image watermarking that is dependent on the mathematical technique of singular value decomposition (SVD). Traditional SVD watermarking already exists for watermark embedding on the image as a whole. In the proposed approach, the original image is divided into blocks, and then the watermark is embedded in the singular values (SVs) of each block separately. This segmentation process and watermarking on a block-by-block basis makes the watermark more robust to the attacks such as noise, compression, cropping and other attacks as the results reveal. Watermark detection is implemented by extracting the watermark from the SVs of the watermarked blocks. Extracting the watermark from one block at least is enough to ensure the existence of the watermark.

An SVD audio watermarking approach using chaotic encrypted images

This paper presents a new approach for audio watermarking using the Singular Value Decomposition (SVD) mathematical technique. The proposed approach can be used for data hiding in the audio signals transmitted over wireless networks and for multi-level security systems as will be stated in the applications section. This approach is based on embedding a chaotic encrypted watermark in the singular values of the audio signal after transforming it into a 2-D format. The selection of the chaotic encryption algorithm for watermark encryption is attributed to its permutation nature, which resists noise, filtering, and compression attacks. After watermark embedding, the audio signal is transformed again into a 1-D format. The transformation between the 1-D and 2-D formats is performed in the well-known lexicographic ordering method used in image processing. The proposed approach can be implemented on the audio signal as a whole or on a segment-by-segment basis. The segment-by-segment implementation allows embedding the same watermark several times in the audio signal, which enhances the detectability of the watermark in the presence of severe attacks. Experimental results show that the proposed audio watermarking approach maintains the high quality of the audio signal and that the watermark extraction and decryption are possible even in the presence of attacks.

PROPOSED MAC PROTOCOL VERSUS IEEE 802.15.3A FOR MULTIMEDIA TRANSMISSION OVER UWB NETWORKS

In this paper, a Medium Access Control (MAC) protocol is proposed to investigate Quality of Service (QoS) for multimedia traffic transmitted over Ultra Wide-Band (UWB) networks and increase the system capacity. This enhancement comes from using Wise Algorithm for Link Admission Control (WALAC) which has three suggested versions. The QoS of multimedia transmission is determined in terms of average delay, admission ratio, loss probability, utilization, and the network capacity. In addition, a new parameter is aroused for the network performance. Comparisons between the IEEE 802.15.3a protocol and the proposed one are done. The proposed protocol shows better results in both sparse and dense networks for real time traffic transmission.

Homomorphic image watermarking with a singular value decomposition algorithm

Information embedding and retrieval in digital images.Digital Watermarking.Image processing. In this paper, a new homomorphic image watermarking method implementing the Singular Value Decomposition (SVD) algorithm is presented. The idea of the proposed method is based on embedding the watermark with the SVD algorithm in the reflectance component after applying the homomorphic transform. The reflectance component contains most of the image features but with low energy, and hence watermarks embedded in this component will be invisible. A block-by-block implementation of the proposed method is also introduced. The watermark embedding on a block-by-block basis makes the watermark more robust to attacks. A comparison study between the proposed method and the traditional SVD watermarking method is presented in the presence of attacks. The proposed method is more robust to various attacks. The embedding of chaotic encrypted watermarks is also investigated in this paper to increase the level of security.

PERFORMANCE EVALUATION OF BLOCK BASED SVD IMAGE WATERMARKING

This paper presents a block based digital image watermarking algorithm that is dependent on the mathematical technique of singular value decomposition (SVD). Traditional SVD watermarking already exists for watermark embedding on the image as a whole. In the proposed approach, the original image is divided into blocks, and then the watermark is embedded in the singular values (SVs) of each block, separately. The watermark embedding on a blockby-block basis makes the watermark more robust to the attacks such as noise, compression, cropping and lowpass filtering as the results reveal. The watermark detection is implemented by extracting the watermark from the SVs of the watermarked blocks. Extracting the watermark from one block at least is enough to ensure the existence of the watermark.

Multi-Biometric Systems: A State of the Art Survey and Research Directions

Multi-biometrics is an exciting and interesting research topic. It is used to recognizing individuals for security purposes; to increase security levels. The recent research trends toward next biometrics generation in real-time applications. Also, integration of biometrics solves some of unimodal system limitations. However, design and evaluation of such systems raises many issues and trade-offs. A state of the art survey of multi-biometrics benefits, limitations, integration strategies, and fusion levels are discussed in this paper. Finally, upon reviewing multi-biometrics approaches and techniques; some open points are suggested to be considered as a future research point of interest.

Performance of the audio signals transmission over wireless networks with the channel interleaving considerations

This article studies a vital issue in wireless communications, which is the transmission of audio signals over wireless networks. It presents a novel interleaver scheme for protection against error bursts and reduction the packet loss of the audio signals. The proposed technique in the article is the chaotic interleaver; it is based on chaotic Baker map. It is used as a randomizing data tool to improve the quality of the audio over the mobile communications channels. A comparison study between the proposed chaotic interleaving scheme and the traditional block and convolutional interleaving schemes for audio transmission over uncorrelated and correlated fading channels is presented. The simulation results show the superiority of the proposed chaotic interleaving scheme over the traditional schemes. The simulation results also reveal that the proposed chaotic interleaver improves the quality of the received audio signal. It improves the amount of the throughput over the wireless link through the packet loss reduction.

An efficient resource utilization technique for consolidation of virtual machines in cloud computing environments

The problem of migrating virtual machines (VMs) among different physical hosts is vital for resource utilization and carbon dioxide (CO2) minimization in cloud data centers. The proposed technique CPU Utilization Variance (CUV) is based on selecting the best VMs from overutilized servers and migrating them into other servers to save the utilized resources and not to violate the Service Level Agreements established between the end users and cloud service provider. CUV also chooses the most appropriate host to allocate these VMs by calculating the minimum variance of all CPU utilization between all physical servers. CUV is implemented in a large-scale data center composed of 800 physical hosts and the results obtained by CloudSim tool in terms of energy consumption in KW/hour, performance in Million Instructions per Second (MIPS), number of VM migrations and Service Level Agreement Violation are reported. Further, a comparative study is performed between CUV and recently researches for evaluating it, which achieved high performance and lower energy consumption without violating the service level agreements in a large-scale data centers.

Modified cross-layer scheduling for mobile WiMAX networks

The IEEE 802.16 standard defines wireless broadband access technology called Worldwide Interoperability for Microwave Access (commonly called fixed WiMAX). WiMAX introduces several interesting advantages including variable and high data rate, last mile wireless access, point to multipoint communication, large frequency range, and Quality of Service (QoS) for various types of applications. IEEE 802.16e amendment defines mobile WiMAX which includes the fixed WiMAX features plus other features like mobility. However, the actual version of the standard does not define a Medium Access Control (MAC) scheduling architecture in uplink as well as downlink direction. Efficient scheduling design is left for designers and thus providing QoS for IEEE 802.16 Broadband Wireless Access (BWA) system is a challenge for system developers. A scheduling algorithm should take into account the WiMAX QoS classes and service requirements. Cross-layer scheduler which designed for WiMAX networks assign a priority function for every service. The priority functions take into account many parameters like channel conditions, service classes, delay, and throughput. In this paper, the scheduling algorithms will be classified, and a modification in cross-layer scheduling algorithm will be proposed to improve the scheduling performance.

Image transmission over mobile Bluetooth networks with enhanced data rate packets and chaotic interleaving

Bluetooth is a wireless personal area network. This type of networks is widely used for image communication. This paper presents a study for the transmission of images over mobile Bluetooth networks. It presents a novel chaotic interleaving scheme for this purpose. In this scheme, the chaotic Baker map is used for bit interleaving and enhanced data rate packets are used for data transmission. In the proposed scheme, the chaotic interleaver can be applied on the whole bit stream or on a packet-by-packet basis. The proposed scheme is applied with 2DH1, 2DM1, 3DH5, and 3DM5 packets. A comparison study between the proposed scheme and the traditional interleaving schemes for image transmission over correlated and uncorrelated fading channels is presented. The simulation results show the superiority of the proposed scheme over the traditional schemes. The proposed scheme also adds a degree of security to data transmission.