1,318 research outputs found
Prochlo: Strong Privacy for Analytics in the Crowd
The large-scale monitoring of computer users' software activities has become
commonplace, e.g., for application telemetry, error reporting, or demographic
profiling. This paper describes a principled systems architecture---Encode,
Shuffle, Analyze (ESA)---for performing such monitoring with high utility while
also protecting user privacy. The ESA design, and its Prochlo implementation,
are informed by our practical experiences with an existing, large deployment of
privacy-preserving software monitoring.
(cont.; see the paper
SETTI: A Self-supervised Adversarial Malware Detection Architecture in an IoT Environment
In recent years, malware detection has become an active research topic in the
area of Internet of Things (IoT) security. The principle is to exploit
knowledge from large quantities of continuously generated malware. Existing
algorithms practice available malware features for IoT devices and lack
real-time prediction behaviors. More research is thus required on malware
detection to cope with real-time misclassification of the input IoT data.
Motivated by this, in this paper we propose an adversarial self-supervised
architecture for detecting malware in IoT networks, SETTI, considering samples
of IoT network traffic that may not be labeled. In the SETTI architecture, we
design three self-supervised attack techniques, namely Self-MDS, GSelf-MDS and
ASelf-MDS. The Self-MDS method considers the IoT input data and the adversarial
sample generation in real-time. The GSelf-MDS builds a generative adversarial
network model to generate adversarial samples in the self-supervised structure.
Finally, ASelf-MDS utilizes three well-known perturbation sample techniques to
develop adversarial malware and inject it over the self-supervised
architecture. Also, we apply a defence method to mitigate these attacks, namely
adversarial self-supervised training to protect the malware detection
architecture against injecting the malicious samples. To validate the attack
and defence algorithms, we conduct experiments on two recent IoT datasets:
IoT23 and NBIoT. Comparison of the results shows that in the IoT23 dataset, the
Self-MDS method has the most damaging consequences from the attacker's point of
view by reducing the accuracy rate from 98% to 74%. In the NBIoT dataset, the
ASelf-MDS method is the most devastating algorithm that can plunge the accuracy
rate from 98% to 77%.Comment: 20 pages, 6 figures, 2 Tables, Submitted to ACM Transactions on
Multimedia Computing, Communications, and Application
Persistent Homology Tools for Image Analysis
Topological Data Analysis (TDA) is a new field of mathematics emerged rapidly since the first decade of the century from various works of algebraic topology and
geometry. The goal of TDA and its main tool of persistent homology (PH) is to provide topological insight into complex and high dimensional datasets. We take this
premise onboard to get more topological insight from digital image analysis and quantify tiny low-level distortion that are undetectable except possibly by highly trained persons. Such image distortion could be caused intentionally (e.g. by morphing and steganography) or naturally in abnormal human tissue/organ scan images as a result of onset of cancer or other diseases.
The main objective of this thesis is to design new image analysis tools based on persistent homological invariants representing simplicial complexes on sets of pixel landmarks over a sequence of distance resolutions. We first start by proposing innovative automatic techniques to select image pixel landmarks to build a variety of
simplicial topologies from a single image. Effectiveness of each image landmark selection demonstrated by testing on different image tampering problems such as morphed face detection, steganalysis and breast tumour detection.
Vietoris-Rips simplicial complexes constructed based on the image landmarks at an increasing distance threshold and topological (homological) features computed at each threshold and summarized in a form known as persistent barcodes. We vectorise the space of persistent barcodes using a technique known as persistent binning where we demonstrated the strength of it for various image analysis purposes. Different machine learning approaches are adopted to develop automatic detection of tiny
texture distortion in many image analysis applications. Homological invariants used in this thesis are the 0 and 1 dimensional Betti numbers. We developed an innovative approach to design persistent homology (PH) based
algorithms for automatic detection of the above described types of image distortion. In particular, we developed the first PH-detector of morphing attacks on passport face biometric images. We shall demonstrate significant accuracy of 2 such morph detection algorithms with 4 types of automatically extracted image landmarks: Local Binary patterns (LBP), 8-neighbour super-pixels (8NSP), Radial-LBP (R-LBP) and centre-symmetric LBP (CS-LBP). Using any of these techniques yields several persistent barcodes that summarise persistent topological features that help gaining insights into complex hidden structures not amenable by other image analysis methods. We shall also demonstrate significant success of a similarly developed PH-based universal steganalysis tool capable for the detection of secret messages hidden inside digital images. We also argue through a pilot study that building PH records from digital images can differentiate breast malignant tumours from benign tumours using digital mammographic images. The research presented in this thesis creates new opportunities to build real applications based on TDA and demonstrate many research challenges in a variety of image processing/analysis tasks. For example, we describe a TDA-based exemplar image inpainting technique (TEBI), superior to existing exemplar algorithm, for the reconstruction of missing image regions
A taxonomy framework for unsupervised outlier detection techniques for multi-type data sets
The term "outlier" can generally be defined as an observation that is significantly different from
the other values in a data set. The outliers may be instances of error or indicate events. The
task of outlier detection aims at identifying such outliers in order to improve the analysis of
data and further discover interesting and useful knowledge about unusual events within numerous
applications domains. In this paper, we report on contemporary unsupervised outlier detection
techniques for multiple types of data sets and provide a comprehensive taxonomy framework and
two decision trees to select the most suitable technique based on data set. Furthermore, we
highlight the advantages, disadvantages and performance issues of each class of outlier detection
techniques under this taxonomy framework
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