For your voice only: Exploiting side channels in voice messaging for environment detection

Voice messages are an increasingly well-known method of communication, accounting for more than 200 million messages a day. Sending audio messages requires a user to invest lesser effort compared to texting while enhancing the meaning of the message by adding an emotional context (e.g., irony). Unfortunately, we suspect that voice messages might...

An evaluation of the reentrancy vulnerability on GoQuorum-based smartcontracts

Within the context of the Ethereum blockchain protocol, reentrancy is a well-known and well-researched smart contract vulnerability. However, when considering GoQuorum, an Ethereum soft fork, barely any research discussing smart contract vulnerabilities exists. This report aims to partly fill this research gap by evaluating the reentrancy smart...

Security Evaluation of GoQuorum-based Smart Contracts: A Case Study of Malfunctioning Access Control and Double-Spending

GoQuorum is an enterprise blockchain platform that supports smart contracts and allows for private transactions. Smart contracts enable automated payment while eliminating the need for third-party involvement. Previous attacks on smart contracts have already shown that existing vulnerabilities can lead to great financial losses. Yet, a study...

Revisiting smart contract vulnerabilities in Hyperledger Fabric

Hyperledger Fabric is a permissioned enterprise blockchain allowing organizations to collaborate and automate processes via smart contracts. However, these contracts could contain security vulnerabilities leading to unexpected behavior or other negative consequences. Therefore, this study takes a closer look at three reported smart contract...

Enhancing the privacy and security of Hyperledger Fabric smart contracts using different encryption methods

Blockchain networks have gained recent popularity among organisations that want to make use of the security aspects that blockchain provides. Fabric is one of the most used distributed network technologies, most commonly applied in scenarios that require confidential data to be stored securely and privately. Use case examples are finance,...

Investigating Arbitrageurs and Oracle Manipulators in Ethereum

Smart contracts on Ethereum enable billions of dollars of value to be transacted in a decentralised, transparent and trustless environment. However, adversaries lie await in the Dark Forest, waiting to exploit any and all smart contract vulnerabilities in order to extract profits from unsuspecting victims in this new financial system. As the...

Training and testing the TDNN-OPGRU acoustic model on English read and spontaneous speech

Automatic phoneme recognition (APR) is the process of recognizing phonemes (spoken sounds) in a recording of speech. It can be used for any application requiring fast and accurate transcription, i.e. a courthouse. This research creates such a model using the TDNN-OPGRU architecture and trains it on two datasets of recorded English speech - ...

Test Code Comprehension: Insights from an Eye Tracker

Software maintenance is an essential and time-consuming task during the software development cycle. Readability of test code is a crucial element for performing programming tasks, such as testing, bug fixing and maintaining code. Hence poorly written tests are difficult to maintain and lose their value to developers. In order to overcome this...

Graph-Time Convolutional Neural Network: Learning from Time-Varying Signals defined on Graphs

Time-varying network data are essential in several real-world applications, such as temperature forecasting and earthquake classification. Spatial and temporal dependencies characterize these data and, therefore, conventional machine learning tools often fail to learn these joint correlations from data. On the one hand, hybrid models to learn...

Graph-Adaptive Activation Functions for Graph Neural Networks

Network data are essential in applications such as recommender systems, social networks, and sensor networks. A unique characteristic that these data encompass is the coupling between the data values and the underlying network structure on which these data are defined. Graph Neural Networks (GNNs) have been designed as tools to extend the...

Evaluating Explanations for different Relationship Strengths

People like to travel in groups to visit places. Group recommendation systems can be used to recommend an itinerary of "places of interests" (POIs) in an ordered sequence. The order of POIs in the sequence can be explained to group members to increase acceptance of the recommended items. There is a possibility that explanations which reveal...

Retrieval-Based Open-Domain Question Answering: Exploring The Impact on The Retrieval Component across Datasets

Open-domain question answering (QA) is an important step in Artificial Intelligence and its ultimate goal is to build a QA system that can answer any question posed by humans. The majority of the open-domain QA system is the retrieval-based open-domain QA system, which enables the retrieval component to retrieve relevant documents from a large...

Rotation invariant filters in CNNs: applied to segmentation of aerial images for land-use classification

Convolutional neural networks are showing incredible performance in image classification, segmentation, object detection and other computer vision applications in recent years. But they lack understanding of affine transformations to input data. In this work, we introduce rotational invariant<br/>convolutional neural networks that learn...