Augmenting Leakage Detection using Bootstrapping

Side-channel leakage detection methods based on statistical tests, such as t-test or chi^2-test, provide high confidence in the presence of leakage with a large number of traces. However, practical limitations on testing time and equipment may set an upper-bound on the number of traces available, turning the number of traces into a limiting factor in side-channel leakage detection. We describe a statistical technique, based on statistical bootstrapping, that significantly improves the effectiveness of leakage detection using a limited set of traces. Bootstrapping generates additional sample sets from an initial set by assuming that it is representative of the entire population. The additional sample sets are then used to conduct additional leakage detection tests, and we show how to combine the results of these tests. The proposed technique, applied to side-channel leakage detection, can significantly reduce the number of traces required to detect leakage by one, or more orders of magnitude. Furthermore, for an existing measured sample set, the method can significantly increase the confidence of existing leakage hypotheses over a traditional (non-bootstrap) leakage detection test. This paper introduces the bootstrapping technique for leakage detection, applies it to three practical cases, and describes techniques for its efficient computation

Energy efficient enabling technologies for semantic video processing on mobile devices

Semantic object-based processing will play an increasingly important role in future multimedia systems due to the ubiquity of digital multimedia capture/playback technologies and increasing storage capacity. Although the object based paradigm has many undeniable benefits, numerous technical challenges remain before the applications becomes pervasive, particularly on computational constrained mobile devices. A fundamental issue is the ill-posed problem of semantic object segmentation. Furthermore, on battery powered mobile computing devices, the additional algorithmic complexity of semantic object based processing compared to conventional video processing is highly undesirable both from a real-time operation and battery life perspective. This thesis attempts to tackle these issues by firstly constraining the solution space and focusing on the human face as a primary semantic concept of use to users of mobile devices. A novel face detection algorithm is proposed, which from the outset was designed to be amenable to be offloaded from the host microprocessor to dedicated hardware, thereby providing real-time performance and reducing power consumption. The algorithm uses an Artificial Neural Network (ANN), whose topology and weights are evolved via a genetic algorithm (GA). The computational burden of the ANN evaluation is offloaded to a dedicated hardware accelerator, which is capable of processing any evolved network topology. Efficient arithmetic circuitry, which leverages modified Booth recoding, column compressors and carry save adders, is adopted throughout the design. To tackle the increased computational costs associated with object tracking or object based shape encoding, a novel energy efficient binary motion estimation architecture is proposed. Energy is reduced in the proposed motion estimation architecture by minimising the redundant operations inherent in the binary data. Both architectures are shown to compare favourable with the relevant prior art

RLIPv2: Fast Scaling of Relational Language-Image Pre-training

Relational Language-Image Pre-training (RLIP) aims to align vision representations with relational texts, thereby advancing the capability of relational reasoning in computer vision tasks. However, hindered by the slow convergence of RLIPv1 architecture and the limited availability of existing scene graph data, scaling RLIPv1 is challenging. In this paper, we propose RLIPv2, a fast converging model that enables the scaling of relational pre-training to large-scale pseudo-labelled scene graph data. To enable fast scaling, RLIPv2 introduces Asymmetric Language-Image Fusion (ALIF), a mechanism that facilitates earlier and deeper gated cross-modal fusion with sparsified language encoding layers. ALIF leads to comparable or better performance than RLIPv1 in a fraction of the time for pre-training and fine-tuning. To obtain scene graph data at scale, we extend object detection datasets with free-form relation labels by introducing a captioner (e.g., BLIP) and a designed Relation Tagger. The Relation Tagger assigns BLIP-generated relation texts to region pairs, thus enabling larger-scale relational pre-training. Through extensive experiments conducted on Human-Object Interaction Detection and Scene Graph Generation, RLIPv2 shows state-of-the-art performance on three benchmarks under fully-finetuning, few-shot and zero-shot settings. Notably, the largest RLIPv2 achieves 23.29mAP on HICO-DET without any fine-tuning, yields 32.22mAP with just 1% data and yields 45.09mAP with 100% data. Code and models are publicly available at https://github.com/JacobYuan7/RLIPv2.Comment: Accepted to ICCV 2023. Code and models: https://github.com/JacobYuan7/RLIPv

A synthetic data set to benchmark anti-money laundering methods

Bank transactions are highly confidential. As a result, there are no real public data sets that can be used to investigate and compare anti-money laundering (AML) methods in banks. This severely limits research on important AML problems such as efficiency, effectiveness, class imbalance, concept drift, and interpretability. To address the issue, we present SynthAML: a synthetic data set to benchmark statistical and machine learning methods for AML. The data set builds on real data from Spar Nord, a systemically important Danish bank, and contains 20,000 AML alerts and over 16 million transactions. Experimental results indicate that performance on SynthAML can be transferred to the real world. As use cases, we present and discuss open problems in the AML literature

Security architecture for Fog-To-Cloud continuum system

Nowadays, by increasing the number of connected devices to Internet rapidly, cloud computing cannot handle the real-time processing. Therefore, fog computing was emerged for providing data processing, filtering, aggregating, storing, network, and computing closer to the users. Fog computing provides real-time processing with lower latency than cloud. However, fog computing did not come to compete with cloud, it comes to complete the cloud. Therefore, a hierarchical Fog-to-Cloud (F2C) continuum system was introduced. The F2C system brings the collaboration between distributed fogs and centralized cloud. In F2C systems, one of the main challenges is security. Traditional cloud as security provider is not suitable for the F2C system due to be a single-point-of-failure; and even the increasing number of devices at the edge of the network brings scalability issues. Furthermore, traditional cloud security cannot be applied to the fog devices due to their lower computational power than cloud. On the other hand, considering fog nodes as security providers for the edge of the network brings Quality of Service (QoS) issues due to huge fog device’s computational power consumption by security algorithms. There are some security solutions for fog computing but they are not considering the hierarchical fog to cloud characteristics that can cause a no-secure collaboration between fog and cloud. In this thesis, the security considerations, attacks, challenges, requirements, and existing solutions are deeply analyzed and reviewed. And finally, a decoupled security architecture is proposed to provide the demanded security in hierarchical and distributed fashion with less impact on the QoS.Hoy en día, al aumentar rápidamente el número de dispositivos conectados a Internet, el cloud computing no puede gestionar el procesamiento en tiempo real. Por lo tanto, la informática de niebla surgió para proporcionar procesamiento de datos, filtrado, agregación, almacenamiento, red y computación más cercana a los usuarios. La computación nebulizada proporciona procesamiento en tiempo real con menor latencia que la nube. Sin embargo, la informática de niebla no llegó a competir con la nube, sino que viene a completar la nube. Por lo tanto, se introdujo un sistema continuo jerárquico de niebla a nube (F2C). El sistema F2C aporta la colaboración entre las nieblas distribuidas y la nube centralizada. En los sistemas F2C, uno de los principales retos es la seguridad. La nube tradicional como proveedor de seguridad no es adecuada para el sistema F2C debido a que se trata de un único punto de fallo; e incluso el creciente número de dispositivos en el borde de la red trae consigo problemas de escalabilidad. Además, la seguridad tradicional de la nube no se puede aplicar a los dispositivos de niebla debido a su menor poder computacional que la nube. Por otro lado, considerar los nodos de niebla como proveedores de seguridad para el borde de la red trae problemas de Calidad de Servicio (QoS) debido al enorme consumo de energía computacional del dispositivo de niebla por parte de los algoritmos de seguridad. Existen algunas soluciones de seguridad para la informática de niebla, pero no están considerando las características de niebla a nube jerárquica que pueden causar una colaboración insegura entre niebla y nube. En esta tesis, las consideraciones de seguridad, los ataques, los desafíos, los requisitos y las soluciones existentes se analizan y revisan en profundidad. Y finalmente, se propone una arquitectura de seguridad desacoplada para proporcionar la seguridad exigida de forma jerárquica y distribuida con menor impacto en la QoS.Postprint (published version

Augmenting the Student-Teacher Feature Pyramid Matching Method for Better Unsupervised Anomaly Localization

Anomaly detection in images is the machine learning task of classifying inputs as normal or anomalous. Anomaly localization is the related task of segmenting input images into normal and anomalous regions. The output of an anomaly localization model is a 2D array, called an anomaly map, of pixel-level anomaly scores. For example, an anomaly localization model trained on images of non-defective industrial products should output high anomaly scores in image regions corresponding to visible defects. In unsupervised anomaly localization the model is trained solely on normal data, i.e. without labelled training observations that contain anomalies. This is often necessary as anomalous observations may be hard to obtain in sufficient quantities and labelling them is time-consuming and costly. Student-teacher feature pyramid matching (STFPM) is a recent and powerful method for unsupervised anomaly detection and localization that uses a pair of convolutional neural networks of identical architecture. In this thesis we propose two methods of augmenting STFPM to produce better segmentations. Our first method, discrepancy scaling, significantly improves the segmentation performance of STFPM by leveraging pre-calculated statistics containing information about the model’s behaviour on normal data. Our second method, student-teacher model assisted segmentation, uses a frozen STFPM model as a feature detector for a segmentation model which is then trained on data with artificially generated anomalies. Using this second method we are able to produce sharper anomaly maps for which it is easier to set a threshold value that produces good segmentations. Finally, we propose the concept of expected goodness of segmentation, a way of assessing the performance of unsupervised anomaly localization models that, in contrast to current metrics, explicitly takes into account the fact that a segmentation threshold needs to be set. Our primary method, discrepancy scaling, improves segmentation AUROC on the MVTec AD dataset over the base model by 13%, measured in the shrinkage of the residual (1.0 − AUROC). On the image-level anomaly detection task, a variant of the discrepancy scaling method improves performance by 12%