Biblio

This paper presents secure MatDot codes, a family of evaluation codes that support secure distributed matrix multiplication via a careful selection of evaluation points that exploit the properties of the dual code. We show that the secure MatDot codes provide security against the user by using locally recoverable codes. These new codes complement the recently studied discrete Fourier transform codes for distributed matrix multiplication schemes that also provide security against the user. There are scenarios where the associated costs are the same for both families and instances where the secure MatDot codes offer a lower cost. In addition, the secure MatDot code provides an alternative way to handle the matrix multiplication by identifying the fastest servers in advance. In this way, it can determine a product using fewer servers, specified in advance, than the MatDot codes which achieve the optimal recovery threshold for distributed matrix multiplication schemes.

With the advancement in Generative Adversarial Networks (GAN), it has become easier than ever to generate fake images. These images are more realistic and non-discernible by untrained eyes and can be used to propagate fake information on the Internet. In this paper, we propose a novel method to detect GAN generated fake images by using a combination of frequency spectrum of image and deep learning. We apply Discrete Fourier Transform to each of 3 color channels of the image to obtain its frequency spectrum which shows if the image has been upsampled, a common trend in most GANs, and then train a Capsule Network model with it. Conducting experiments on a dataset of almost 1000 images based on Unconditional data modeling (StyleGan2 - ADA) gave results indicating that the model is promising with accuracy over 99% when trained on the state-of-the-art GAN model. In theory, our model should give decent results when trained with one dataset and tested on another.

This paper reviews the video watermarking schemes resistance against tampering attacks. There are several transform methods which are used for Video Watermarking including Discrete Fourier Transform (DFT), Discrete Cosine Transform (DCT), Discrete wavelet transform (DWT) and are discussed and compared in this paper. The results are presented in a table with a summary of their advantages.

In this first paper of a two-part series, the harmonic plane decomposition is introduced, which is an extension of the vector-space decomposition. In multiphase electrical machines with variable phase-pole configurations, the vector-space decomposition leads to a varying numbers of vector spaces when changing the configuration. Consequently, the model and current control become discontinuous. The method in this paper is based on samples of each single slot currents, similarly to a discrete Fourier transformation in the space domain that accounts for the winding configuration. It unifies the Clarke transformation for all possible phase-pole configurations such that a fixed number of orthogonal harmonic planes are created, which facilitates the current control during reconfigurations. The presented method is not only limited to the modeling of multiphase electrical machines but all kinds of existing machines can be modeled. In the second part of this series, the harmonic plane decomposition will be completed for all types of machine configurations.

In the process of informationization and networking of smart grids, the original physical isolation was broken, potential risks increased, and the increasingly serious cyber security situation was faced. Therefore, it is critical to develop accuracy and efficient anomaly detection methods to disclose various threats. However, in the industry, mainstream security devices such as firewalls are not able to detect and resist some advanced behavior attacks. In this paper, we propose a time series anomaly detection model, which is based on the periodic extraction method of discrete Fourier transform, and determines the sequence position of each element in the period by periodic overlapping mapping, thereby accurately describe the timing relationship between each network message. The experiments demonstrate that our model can detect cyber attacks such as man-in-the-middle, malicious injection, and Dos in a highly periodic network.

This paper deals with a new indoor localization scheme called “CEPHEID” by using ceiling lighting fixtures. It is based on the fact that each lighting fixture has its own characteristic flickering pattern. Then, the author proposes a technique to identify individual light by using simple instruments and DNN classifier. Thanks to the less requirements for hardware, CEPHEID can be implemented by a few simple discrete electronic components and an ordinary smartphone. A prototype “CEPHEID dongle” is also introduced in this paper. Finally, the validity of the author's method is examined by indoor positioning experiments.

Biometry is often used as a part of the multi-factor authentication in order to improve the security of IT systems. In this paper, we propose the palmprint-based solution for user identity verification. In particular, we present a new approach to feature extraction. The proposed method is based both on texture and color information. Our experiments show that using the proposed hybrid features allows for achieving satisfactory accuracy without increasing requirements for additional computational resources. It is important from our perspective since the proposed method is dedicated to smartphones and other handhelds in mobile verification scenarios.

Deep learning techniques have been widely used in intrusion detection, but their application on convolutional neural networks (CNN) is still immature. The main challenge is how to represent the network traffic to improve performance of the CNN model. In this paper, we propose a network intrusion detection algorithm based on representation learning using Fast Fourier Transformation (FFT), which is first exploration that converts traffic to image by FFT to the best of our knowledge. Each traffic is converted to an image and then the intrusion detection problem is turned to image classification. The experiment results on NSL-KDD dataset show that the classification performence of the algorithm in the CNN model has obvious advantages compared with other algorithms.

Scan design is a universal design for test (DFT) technology to increase the observability and controllability of the circuits under test by using scan chains. However, it also leads to a potential security problem that attackers can use scan design as a backdoor to extract confidential information. Researchers have tried to address this problem by using secure scan structures that usually have some keys to confirm the identities of users. However, the traditional methods to store intermediate data or keys in memory are also under high risk of being attacked. In this paper, we propose a dynamic-key secure DFT structure that can defend scan-based and memory attacks without decreasing the system performance and the testability. The main idea is to build a scan design key generator that can generate the keys dynamically instead of storing and using keys in the circuit statically. Only specific patterns derived from the original test patterns are valid to construct the keys and hence the attackers cannot shift in any other patterns to extract correct internal response from the scan chains or retrieve the keys from memory. Analysis results show that the proposed method can achieve a very high security level and the security level will not decrease no matter how many guess rounds the attackers have tried due to the dynamic nature of our method.

We propose a spectral scrambling scheme to enhance physical layer security for an underwater VLC system which also simplifies the real-value signal generation procedure. A 1.08-Gb/s PAM-8 encrypted data over 1.2m transmission is experimentally demonstrated.

SDN is a new network framework which can be controlled and defined by software programming, and OpenFlow is the communication protocol between SDN controller plane and data plane. With centralized control of SDN, the network is more vulnerable encounter APT than traditional network. After deeply analyzing the process of APT at each stage in SDN, this paper proposes the APT detection method based on HMM, which can fully reflect the relationship between attack behavior and APT stage. Experiment shows that the method is more accurate to detect APT in SDN, and less overhead.

In this paper, an innovative approach to keyboard user monitoring (authentication), using keyboard dynamics and founded on the concept of time series analysis, is presented. The work is motivated by the need for robust authentication mechanisms in the context of on-line assessment such as those featured in many online learning platforms. Four analysis mechanisms are considered: analysis of keystroke time series in their raw form (without any translation), analysis consequent to translating the time series into a more compact form using either the Discrete Fourier Transform or the Discrete Wavelet Transform, and a "benchmark" feature vector representation of the form typically used in previous related work. All four mechanisms are fully described and evaluated. A best authentication accuracy of 99% was obtained using the wavelet transform.

Scan-based test is commonly used to increase testability and fault coverage, however, it is also known to be a liability for chip security. Research has shown that intellectual property (IP) or secret keys can be leaked through scan-based attacks. In this paper, we propose a dynamically-obfuscated scan design for protecting IPs against scan-based attacks. By perturbing all test patterns/responses and protecting the obfuscation key, the proposed architecture is proven to be robust against existing non-invasive scan attacks, and can protect all scan data from attackers in foundry, assembly, and system developers (i.e., OEMs) without compromising the testability. Furthermore, the proposed architecture can be easily plugged into EDA generated scan chains without having a noticeable impact on conventional integrated circuit (IC) design, manufacturing, and test flow. Finally, detailed security and experimental analyses have been performed on several benchmarks. The results demonstrate that the proposed method can protect chips from existing brute force, differential, and other scan-based attacks that target the obfuscation key. The proposed design is of low overhead on area, power consumption, and pattern generation time, and there is no impact on test time.

We present a neural network technique for the analysis and extrapolation of time-series data called Neural Decomposition (ND). Units with a sinusoidal activation function are used to perform a Fourier-like decomposition of training samples into a sum of sinusoids, augmented by units with nonperiodic activation functions to capture linear trends and other nonperiodic components. We show how careful weight initialization can be combined with regularization to form a simple model that generalizes well. Our method generalizes effectively on the Mackey-Glass series, a dataset of unemployment rates as reported by the U.S. Department of Labor Statistics, a time-series of monthly international airline passengers, and an unevenly sampled time-series of oxygen isotope measurements from a cave in north India. We find that ND outperforms popular time-series forecasting techniques including LSTM, echo state networks, (S)ARIMA, and SVR with a radial basis function.

Information security is crucial to data storage and transmission, which is necessary to protect information under various hostile environments. Cryptography serves as a major element to ensure confidentiality in both communication and information technology, where the encryption and decryption schemes are implemented to scramble the pure plaintext and descramble the secret ciphertext using security keys. There are two dominating types of encryption schemes: deterministic encryption and chaotic encryption. Encryption and decryption can be conducted in either spatial domain or frequency domain. To ensure secure transmission of digital information, comparisons on merits and drawbacks of two practical encryption schemes are conducted, where case studies on the true color digital image encryption are presented. Both deterministic encryption in spatial domain and chaotic encryption in frequency domain are analyzed in context, as well as the information integrity after decryption.

SoCs implementing security modules should be both testable and secure. Oversights in a design's test structure could expose internal modules creating security vulnerabilities during test. In this paper, for the first time, we propose a novel automated security vulnerability analysis framework to identify violations of confidentiality, integrity, and availability policies caused by test structures and designer oversights during SoC integration. Results demonstrate existing information leakage vulnerabilities in implementations of various encryption algorithms and secure microprocessors. These can be exploited to obtain secret keys, control finite state machines, or gain unauthorized access to memory read/write functions.

Controller Area Network (CAN) is the main bus network that connects electronic control units in automobiles. Although CAN protocols have been revised to improve the vehicle safety, the security weaknesses of CAN have not been fully addressed. Security threats on automobiles might be from external wireless communication or from internal malicious CAN nodes mounted on the CAN bus. Despite of various threat sources, the security weakness of CAN is the root of security problems. Due to the limited computation power and storage capacity on each CAN node, there is a lack of hardware-efficient protection methods for the CAN system without losing the compatibility to CAN protocols. To save the cost and maintain the compatibility, we propose to exploit the built-in CAN fault confinement mechanism to detect the masquerade attacks originated from the malicious CAN devices on the CAN bus. Simulation results show that our method achieves the attack misdetection rate at the order of 10-5 and reduces the encryption latency by up to 68% over the complete frame encryption method.

In this paper, a new approach based on Sub-sampled Inverse Fast Fourier Transform (SSIFFT) for efficiently acquiring compressive measurements is proposed, which is motivated by random filter based method and sub-sampled FFT. In our approach, to start with, we multiply the FFT of input signal and that of random-tap FIR filter in frequency domain and then utilize SSIFFT to obtain compressive measurements in the time domain. It requires less data storage and computation than the existing methods based on random filter. Moreover, it is suitable for both one-dimensional and two-dimensional signals. Experimental results show that the proposed approach is effective and efficient.

A novel short-time Fourier transform (STFT) domain adaptive filtering scheme is proposed that can be easily combined with nonlinear post filters such as residual echo or noise reduction in acoustic echo cancellation. Unlike normal STFT subband adaptive filters, which suffers from aliasing artifacts due to its poor prototype filter, our scheme achieves good accuracy by exploiting the relationship between the linear convolution and the poor prototype filter, i.e., the STFT window function. The effectiveness of our scheme was confirmed through the results of simulations conducted to compare it with conventional methods.

This paper proposes a modified empirical-mode decomposition (EMD) filtering-based adaptive dynamic phasor estimation algorithm for the removal of exponentially decaying dc offset. Discrete Fourier transform does not have the ability to attain the accurate phasor of the fundamental frequency component in digital protective relays under dynamic system fault conditions because the characteristic of exponentially decaying dc offset is not consistent. EMD is a fully data-driven, not model-based, adaptive filtering procedure for extracting signal components. But the original EMD technique has high computational complexity and requires a large data series. In this paper, a short data series-based EMD filtering procedure is proposed and an optimum hermite polynomial fitting (OHPF) method is used in this modified procedure. The proposed filtering technique has high accuracy and convergent speed, and is greatly appropriate for relay applications. This paper illustrates the characteristics of the proposed technique and evaluates its performance by computer-simulated signals, PSCAD/EMTDC-generated signals, and real power system fault signals.

Discrete fractional Fourier transform (DFRFT) is a generalization of discrete Fourier transform. There are a number of DFRFT proposals, which are useful for various signal processing applications. This paper investigates practical solutions toward the construction of unconditionally secure communication systems based on DFRFT via cross-layer approach. By introducing a distort signal parameter, the sender randomly flip-flops between the distort signal parameter and the general signal parameter to confuse the attacker. The advantages of the legitimate partners are guaranteed. We extend the advantages between legitimate partners via developing novel security codes on top of the proposed cross-layer DFRFT security communication model, aiming to achieve an error-free legitimate channel while preventing the eavesdropper from any useful information. Thus, a cross-layer strong mobile communication secure model is built.
 

The statistical fingerprints left by median filtering can be a valuable clue for image forensics. However, these fingerprints may be maliciously erased by a forger. Recently, a tricky anti-forensic method has been proposed to remove median filtering traces by restoring images' pixel difference distribution. In this paper, we analyze the traces of this anti-forensic technique and propose a novel counter method. The experimental results show that our method could reveal this anti-forensics effectively at low computation load. According to our best knowledge, it's the first work on countering anti-forensics of median filtering.

A slow-paced persistent attack, such as slow worm or bot, can bewilder the detection system by slowing down their attack. Detecting such attacks based on traditional anomaly detection techniques may yield high false alarm rates. In this paper, we frame our problem as detecting slow-paced persistent attacks from a time series obtained from network trace. We focus on time series spectrum analysis to identify peculiar spectral patterns that may represent the occurrence of a persistent activity in the time domain. We propose a method to adaptively detect slow-paced persistent attacks in a time series and evaluate the proposed method by conducting experiments using both synthesized traffic and real-world traffic. The results show that the proposed method is capable of detecting slow-paced persistent attacks even in a noisy environment mixed with legitimate traffic.