Image Forgery Localization via Fine-Grained Analysis of CFA Artifacts

In this paper, a forensic tool able to discriminate between original and forged regions in an image captured by a digital camera is presented. We make the assumption that the image is acquired using a Color Filter Array, and that tampering removes the artifacts due to the demosaicking algorithm. The proposed method is based on a new feature measuring the presence of demosaicking artifacts at a local level, and on a new statistical model allowing to derive the tampering probability of each 2 × 2 image block without requiring to know a priori the position of the forged region. Experimental results on different cameras equipped with different demosaicking algorithms demonstrate both the validity of the theoretical model and the effectiveness of our schem

Cyclostationary Algorithm for Signal Analysis in Cognitive 4G Networks with Spectral Sensing and Resource Allocation

Cognitive Radio (CR) effectively involved in the management of spectrum to perform improved data transmission. CR system actively engaged in the data sensing, learning and dynamic adjustment of radio spectrum parameters with management of unused spectrum in the signal. The spectrum sensing is indispensable in the CR for the management of Primary Users (PUs) and Secondary users (SUs) without any interference. Spectrum sensing is considered as the effective adaptive signal processing model to evaluate the computational complexity model for the signal transmission through Matched filtering, Waveform and Cyclostationary based Energy sensing model. Cyclostationary based model is effective for the energy based sensing model based on unique characteristics with estimation of available channel in the spectrum to extract the received signal in the PU signal. Cyclostationary based model uses the spectrum availability without any periodic property to extract the noise features. This paper developed a Adaptive Cross Score Cyclostationary (ACSCS) to evaluate the spectrum sensing in the CR network. The developed ACSCS model uses the computational complexity with estimation of Signal-to-Interference-and-Noise Ratio (SINR) elimination of cost function. ACSCS model uses the Adaptive Least square Spectral Self-Coherence Restoral (SCORE) with the Adaptive Cross Score (ACS) to overcome the issues in CR. With the derived ACSCS algorithm minimizes the computational complexity based on cost function compared with the ACS algorithm. To minimize the computational complexity pipeline triangular array based Gram-Schmidt Orthogonalization (GSO) structure for the optimization of network. The simulation performance analysis with the ACSCS scheme uses the Rician Multipath Fading channel to estimate detection probability to sense the Receiver Operating Characteristics, detection probability and probability of false alarm using Maximum Likelihood (ML) detector. The ACSC model uses the Square-law combining (SLC) with the moment generation function in the multipath fading channel for the channel sensing with reduced computational complexity. The simulation analysis expressed that ACSC scheme achieves the maximal detection probability value of 1. The analysis expressed that proposed ACSC scheme achieves the improved channel estimation in the 4G communication environment

An Overview on Image Forensics

The aim of this survey is to provide a comprehensive overview of the state of the art in the area of image forensics. These techniques have been designed to identify the source of a digital image or to determine whether the content is authentic or modified, without the knowledge of any prior information about the image under analysis (and thus are defined as passive). All these tools work by detecting the presence, the absence, or the incongruence of some traces intrinsically tied to the digital image by the acquisition device and by any other operation after its creation. The paper has been organized by classifying the tools according to the position in the history of the digital image in which the relative footprint is left: acquisition-based methods, coding-based methods, and editing-based schemes

Exploring the potential of dynamic mode decomposition in wireless communication and neuroscience applications

The exponential growth of available experimental, simulation, and historical data from modern systems, including those typically considered divergent (e.g., Neuroscience procedures and wireless networks), has created a persistent need for effective data mining and analysis techniques. Most systems can be characterized as high-dimensional, dynamical, exhibiting rich multiscale phenomena in both space and time. Engineering studies of complex linear and non-linear dynamical systems are especially challenging, as the behavior of the system is often unknown and complex. Studying this problem of interest necessitates discovering and modeling the underlying evolving dynamics. In such cases, a simplified, predictive model of the flow evolution profile must be developed based on observations/measurements collected from the system. Consequently, data-driven algorithms have become an essential tool for modeling and analyzing complex systems characterized by high nonlinearity and dimensionality. The field of data-driven modeling and analysis of complex systems is rapidly advancing. Associated investigations are poised to revolutionize the engineering, biomedical, and physical sciences. By applying modeling techniques, a complex system can be simplified using low-dimensional models with spatial-temporal structures described using system measurements. Such techniques enable complex system modeling without requiring knowledge of dynamic equations governing the system's operation. The primary objective of the work detailed in this dissertation was characterizing, identifying, and predicting the behavior of systems under analysis. In particular, characterization and identification entailed finding patterns embedded in system data; prediction required evaluating system dynamics. The thesis of this work proposes the implementation of dynamic mode decomposition (DMD), which is a fully data-driven technique, to characterize dynamical systems from extracted measurements. DMD employs singular value decomposition (SVD), which reduces high-dimensional measurements collected from a system and computes eigenvalues and eigenvectors of a linear approximated model. In other words, by rather estimating the underlying dynamics within a system, DMD serves as a powerful tool for system characterization without requiring knowledge of the governing dynamical equations. Overall, the work presented herein demonstrates the potential of DMD for analyzing and modeling complex systems in the emerging, synthesized field of wireless communication (i.e., wireless technology identification) and neuroscience (i.e., chemotherapy-induced peripheral neuropathy [CIPN] identification for cancer patients). In the former, a novel technique based on DMD was initially developed for wireless coexistence analysis. The scheme can differentiate various wireless technologies, including GSM and LTE signals in the cellular domain and IEEE802.11n, ac, and ax in the Wi-Fi domain, as well as Bluetooth and Zigbee in the personal wireless domain. By capturing embedded periodic features transmitted within the signal, the proposed DMD-based technique can identify a signal’s time domain signature. With regard to cancer neuroscience, a DMD-based scheme was developed to capture the pattern of plantar pressure variability due to the development of neuropathy resulting from neurotoxic chemotherapy treatment. The developed technique modeled gait pressure variations across multiple steps at three plantar regions, which characterized the development of CIPN in patients with uterine cancer. Obtained results demonstrated that DMD can effectively model various systems and characterize system dynamics. Given the advantages of fast data processing, minimal required data preprocessing, and minimal required signal observation time intervals, DMD has proven to be a powerful tool for system analysis and modeling

UGR’16: A New Dataset for the Evaluation of Cyclostationarity-Based Network IDSs

The evaluation of algorithms and techniques to implement intrusion detection systems heavily rely on the existence of well designed datasets. In the last years, a lot of efforts have been done towards building these datasets. Yet, there is still room to improve. In this paper, a comprehensive review of existing datasets is first done, making emphasis on their main shortcomings. Then, we present a new dataset that is built with real traffic and up-to-date attacks. The main advantage of this dataset over previous ones is its usefulness for evaluating IDSs that consider long-term evolution and traffic periodicity. Models that consider differences in daytime/night or weekdays/weekends can also be trained and evaluated with it. We discuss all the requirements for a modern IDS evaluation dataset and analyze how the one presented here meets the different needs

A Survey of Blind Modulation Classification Techniques for OFDM Signals

Blind modulation classification (MC) is an integral part of designing an adaptive or intelligent transceiver for future wireless communications. Blind MC has several applications in the adaptive and automated systems of sixth generation (6G) communications to improve spectral efficiency and power efficiency, and reduce latency. It will become a integral part of intelligent software-defined radios (SDR) for future communication. In this paper, we provide various MC techniques for orthogonal frequency division multiplexing (OFDM) signals in a systematic way. We focus on the most widely used statistical and machine learning (ML) models and emphasize their advantages and limitations. The statistical-based blind MC includes likelihood-based (LB), maximum a posteriori (MAP) and feature-based methods (FB). The ML-based automated MC includes k-nearest neighbors (KNN), support vector machine (SVM), decision trees (DTs), convolutional neural networks (CNNs), recurrent neural networks (RNNs), and long short-term memory (LSTM) based MC methods. This survey will help the reader to understand the main characteristics of each technique, their advantages and disadvantages. We have also simulated some primary methods, i.e., statistical- and ML-based algorithms, under various constraints, which allows a fair comparison among different methodologies. The overall system performance in terms bit error rate (BER) in the presence of MC is also provided. We also provide a survey of some practical experiment works carried out through National Instrument hardware over an indoor propagation environment. In the end, open problems and possible directions for blind MC research are briefly discussed