References of "State, Radu 50003137"
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See detailBlockchain Governance: An Overview and Prediction of Optimal Strategies Using Nash Equilibrium
Khan, Nida UL; Ahmad, Tabrez; Patel, Anass et al

in 3rd AUE International Research Conference (in press)

Blockchain governance is a subject of ongoing research and an interdisciplinary view of blockchain governance is vital to aid in further research for establishing a formal governance framework for this ... [more ▼]

Blockchain governance is a subject of ongoing research and an interdisciplinary view of blockchain governance is vital to aid in further research for establishing a formal governance framework for this nascent technology. In this paper, the position of blockchain governance within the hierarchy of Institutional governance is discussed. Blockchain governance is analyzed from the perspective of IT governance using Nash equilibrium to predict the outcome of different governance decisions. A payoff matrix for blockchain governance is created and simulation of different strategy profiles is accomplished for computation of all Nash equilibria. We also create payoff matrices for different kinds of blockchain governance, which were used to propose novel mathematical formulae usable to predict the best governance strategy that minimizes the occurrence of a hard fork as well as predicts the behavior of the majority during protocol updates. [less ▲]

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See detailTokenization of Sukuk: Ethereum Case Study
Khan, Nida UL; Kchouri, Bilal UL; Yatoo, Nissar Ahmad et al

in Global Finance Journal (in press)

Sukuk is a financial instrument that provides returns similar to conventional bonds. It has served to cater to the capital requirements of big corporations and governments, while circumventing interest to ... [more ▼]

Sukuk is a financial instrument that provides returns similar to conventional bonds. It has served to cater to the capital requirements of big corporations and governments, while circumventing interest to adhere to the Shariah law. Sukuk can be touted as Shariah-compliant bonds that rank amongst the most successful and the fastest growing financial instrument in the Islamic economy. The sukuk research area is marked by a dearth of quantitative literature, compared to qualitative academic work. This paper seeks to fill this existing gap, and introduces a novel, exploratory analysis of sukuk tokenization based on a case study. The funding needs of small and medium enterprises remains largely unmet through sukuk on account of the high costs involved, among other reasons. As we show in this paper, blockchains can aid to lower the cost incurred through the tokenization of sukuk. We highlight some of the key challenges involved in the issuance of sukuk and discuss their resolution using blockchain. We also provide a taxonomy of blockchain applications in finance, with a particular focus on Islamic finance. Our paper reviews different blockchain architectures to assess their viability for tokenization. We conduct a novel case study on sukuk tokenization by implementing a basic smart contract for Sukuk al-Murabaha on Ethereum. The paper concludes by a conceptual analysis of feasibility concerns, based on a comparison of the conducted cost-benefit analysis of conventional sukuk issuance with tokenization. [less ▲]

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See detailDeep dive into Interledger: Understanding the Interledger ecosystem - Part 4
Trestioreanu, Lucian Andrei UL; Cassagnes, Cyril UL; State, Radu UL

Learning material (2020)

At the technical level, the goal of Interledger is to provide an architecture and a minimal set of protocols to enable interoperability for any value transfer system. The Interledger protocol is literally ... [more ▼]

At the technical level, the goal of Interledger is to provide an architecture and a minimal set of protocols to enable interoperability for any value transfer system. The Interledger protocol is literally a protocol for interledger payments. To understand how is it possible to achieve this goal, several aspects of the technology require a deeper analysis. For this reason, in our journey to become knowledgeable and active contributor we decided to create our own test-bed on our premises. By doing so, we noticed that some aspects are well documented but we found that others might need more attention and clarification. Despite a large community effort, the task to keep information on a fast evolving software ecosystem is tedious and not always the priority for such a project. Therefore, the purpose of this document is to guide, through several hands-on activities, community members who want to engage at different levels. The document consolidates all the relevant information from generating a simple payment to ultimately create a test-bed with the Interledger protocol suite between Ripple and other distributed ledger technology. [less ▲]

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See detailBlockPGP: A Blockchain-based Framework for PGP Key Servers
Yakubov, Alexander UL; Shbair, Wazen UL; Khan, Nida UL et al

in International Journal of Networking and Computing (2020), 10(1), 1-24

Pretty Good Privacy (PGP) is one of the most prominent cryptographic standards offering end-to-end encryption for email messages and other sensitive information exchange. PGP allows to verify the identity ... [more ▼]

Pretty Good Privacy (PGP) is one of the most prominent cryptographic standards offering end-to-end encryption for email messages and other sensitive information exchange. PGP allows to verify the identity of the correspondent in information exchange as well as the information integrity. PGP implements asymmetric encryption with certificates shared through a network of PGP key servers. In this paper, we propose a new PGP management framework with the key servers infrastructure implemented using blockchain technology. Our approach offers fast propagation of certificate revocation among PGP key servers and elimination of man-in-the-middle risks. It also grants users the required access control to update their own PGP certificates, which is not the case with the current PGP key servers. A prototype has been implemented using Ethereum blockchain and an open source key server, named Hockeypuck. Finally, we evaluated the prototype with extensive experiments. Our results show that our solution is practical and it could be integrated with the existing public PGP key servers infrastructure. [less ▲]

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See detailTowards Usable Protection Against Honeypots
Ferreira Torres, Christof UL; Steichen, Mathis UL; State, Radu UL

in IEEE International Conference on Blockchain and Cryptocurrency, Toronto, Canada 3-6 May 2020 (2020)

The Ethereum blockchain enables the execution of so-called smart contracts. These are programs that facilitate the automated transfer of funds according to a given business logic without the participants ... [more ▼]

The Ethereum blockchain enables the execution of so-called smart contracts. These are programs that facilitate the automated transfer of funds according to a given business logic without the participants requiring to trust one another. However, recently attackers started using smart contracts to lure users into traps by deploying contracts that pretend to give away funds but in fact contain hidden traps. This new type of scam is commonly referred to as honeypots. In this paper, we propose a system that aims to protect users from falling into these traps. The system consists of a plugin for MetaMask and a back-end service that continuously scans the Ethereum blockchain for honeypots. Whenever a user is about to perform a transaction through MetaMask, our plugin sends a request to the back-end and warns the user if the target contract is a honeypot. [less ▲]

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See detailFeasibility of Stellar as a Blockchain-based Micropayment System
Khan, Nida UL; Ahmad, Tabrez; State, Radu UL

in Springer SmartBlock 2019 - 2nd International Conference on Smart Blockchain (2019, November)

The advent of Bitcoin was heralded as an innovation in the global monetary system, that could bring down transaction fees by circumventing the need for third parties and conduct transactions in real time ... [more ▼]

The advent of Bitcoin was heralded as an innovation in the global monetary system, that could bring down transaction fees by circumventing the need for third parties and conduct transactions in real time. The divisibility of a blockchain cryptocurrency to even fractions of a cent, caused microtransactions to become feasible to formerly non-existent denominations. These microtransactions have spurred the development of novel ways of monetizing online resources and hold the potential to aid in alleviation of poverty. The paper conducts a feasibility study on Stellar as a blockchain-based micropayment system. It highlights the computational and other issues that impedes its progress and utilizes a characterization model for micropayment systems to evaluate the efficacy of the Stellar platform. The paper conducts a comparison with the micropayment solutions from Bitcoin, Ethereum and PayPal. The paper analyzes a subset of transactions from the Stellar blockchain to aid in drawing a conclusion on the undertaken study and elaborates on the mitigation tools to enable fraud prevention in online monetary transactions. [less ▲]

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See detailAuto-encoding Robot State against Sensor Spoofing Attacks
Rivera, Sean UL; Lagraa, Sofiane UL; Iannillo, Antonio Ken UL et al

in International Symposium on Software Reliability Engineering (2019, October)

In robotic systems, the physical world is highly coupled with cyberspace. New threats affect cyber-physical systems as they rely on several sensors to perform critical operations. The most sensitive ... [more ▼]

In robotic systems, the physical world is highly coupled with cyberspace. New threats affect cyber-physical systems as they rely on several sensors to perform critical operations. The most sensitive targets are their location systems, where spoofing attacks can force robots to behave incorrectly. In this paper, we propose a novel anomaly detection approach for sensor spoofing attacks, based on an auto-encoder architecture. After initial training, the detection algorithm works directly on the compressed data by computing the reconstruction errors. We focus on spoofing attacks on Light Detection and Ranging (LiDAR) systems. We tested our anomaly detection approach against several types of spoofing attacks comparing four different compression rates for the auto-encoder. Our approach has a 99% True Positive rate and a 10% False Negative rate for the 83% compression rate. However, a compression rate of 41% could handle almost all of the same attacks while using half the data. [less ▲]

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See detailMQLV: Optimal Policy of Money Management in Retail Banking with Q-Learning
Charlier, Jérémy Henri J. UL; Ormazabal, Gaston; State, Radu UL et al

in Proceedings of the Fourth Workshop on MIning DAta for financial applicationS (MIDAS 2019) co-located with the 2019 European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML-PKDD 2019) (2019, September)

Reinforcement learning has become one of the best approach to train a computer game emulator capable of human level performance. In a reinforcement learning approach, an optimal value function is learned ... [more ▼]

Reinforcement learning has become one of the best approach to train a computer game emulator capable of human level performance. In a reinforcement learning approach, an optimal value function is learned across a set of actions, or decisions, that leads to a set of states giving different rewards, with the objective to maximize the overall reward. A policy assigns to each state-action pairs an expected return. We call an optimal policy a policy for which the value function is optimal. QLBS, Q-Learner in the Black-Scholes(-Merton) Worlds, applies the reinforcement learning concepts, and noticeably, the popular Q-learning algorithm, to the financial stochastic model of Black, Scholes and Merton. It is, however, specifically optimized for the geometric Brownian motion and the vanilla options. Its range of application is, therefore, limited to vanilla option pricing within the financial markets. We propose MQLV, Modified Q-Learner for the Vasicek model, a new reinforcement learning approach that determines the optimal policy of money management based on the aggregated financial transactions of the clients. It unlocks new frontiers to establish personalized credit card limits or bank loan applications, targeting the retail banking industry. MQLV extends the simulation to mean reverting stochastic diffusion processes and it uses a digital function, a Heaviside step function expressed in its discrete form, to estimate the probability of a future event such as a payment default. In our experiments, we first show the similarities between a set of historical financial transactions and Vasicek generated transactions and, then, we underline the potential of MQLV on generated Monte Carlo simulations. Finally, MQLV is the first Q-learning Vasicek-based methodology addressing transparent decision making processes in retail banking. [less ▲]

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See detailVisualization of AE's Training on Credit Card Transactions with Persistent Homology
Charlier, Jérémy Henri J. UL; Petit, François UL; Ormazabal, Gaston et al

in Proceedings of the International Workshop on Applications of Topological Data Analysis In conjunction with ECML PKDD 2019 (2019, September)

Auto-encoders are among the most popular neural network architecture for dimension reduction. They are composed of two parts: the encoder which maps the model distribution to a latent manifold and the ... [more ▼]

Auto-encoders are among the most popular neural network architecture for dimension reduction. They are composed of two parts: the encoder which maps the model distribution to a latent manifold and the decoder which maps the latent manifold to a reconstructed distribution. However, auto-encoders are known to provoke chaotically scattered data distribution in the latent manifold resulting in an incomplete reconstructed distribution. Current distance measures fail to detect this problem because they are not able to acknowledge the shape of the data manifolds, i.e. their topological features, and the scale at which the manifolds should be analyzed. We propose Persistent Homology for Wasserstein Auto-Encoders, called PHom-WAE, a new methodology to assess and measure the data distribution of a generative model. PHom-WAE minimizes the Wasserstein distance between the true distribution and the reconstructed distribution and uses persistent homology, the study of the topological features of a space at different spatial resolutions, to compare the nature of the latent manifold and the reconstructed distribution. Our experiments underline the potential of persistent homology for Wasserstein Auto-Encoders in comparison to Variational Auto-Encoders, another type of generative model. The experiments are conducted on a real-world data set particularly challenging for traditional distance measures and auto-encoders. PHom-WAE is the first methodology to propose a topological distance measure, the bottleneck distance, for Wasserstein Auto-Encoders used to compare decoded samples of high quality in the context of credit card transactions. [less ▲]

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See detailDeep dive into Interledger: Understanding the Interledger ecosystem - Part 3
Trestioreanu, Lucian Andrei UL; Cassagnes, Cyril UL; State, Radu UL

Learning material (2019)

At the technical level, the goal of Interledger is to provide an architecture and a minimal set of protocols to enable interoperability for any value transfer system. The Interledger protocol is literally ... [more ▼]

At the technical level, the goal of Interledger is to provide an architecture and a minimal set of protocols to enable interoperability for any value transfer system. The Interledger protocol is literally a protocol for interledger payments. To understand how is it possible to achieve this goal, several aspects of the technology require a deeper analysis. For this reason, in our journey to become knowledgeable and active contributor we decided to create our own test-bed on our premises. By doing so, we noticed that some aspects are well documented but we found that others might need more attention and clarification. Despite a large community effort, the task to keep information on a fast evolving software ecosystem is tedious and not always the priority for such a project. Therefore, the purpose of this document is to guide, through several hands-on activities, community members who want to engage at different levels. The document consolidates all the relevant information from generating a simple payment to ultimately create a test-bed with the Interledger protocol suite between Ripple and other distributed ledger technology. [less ▲]

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See detailDeep dive into Interledger: Understanding the Interledger ecosystem - Part 2
Trestioreanu, Lucian Andrei UL; Cassagnes, Cyril UL; State, Radu UL

Learning material (2019)

At the technical level, the goal of Interledger is to provide an architecture and a minimal set of protocols to enable interoperability for any value transfer system. The Interledger protocol is literally ... [more ▼]

At the technical level, the goal of Interledger is to provide an architecture and a minimal set of protocols to enable interoperability for any value transfer system. The Interledger protocol is literally a protocol for interledger payments. To understand how is it possible to achieve this goal, several aspects of the technology require a deeper analysis. For this reason, in our journey to become knowledgeable and active contributor we decided to create our own test-bed on our premises. By doing so, we noticed that some aspects are well documented but we found that others might need more attention and clarification. Despite a large community effort, the task to keep information on a fast evolving software ecosystem is tedious and not always the priority for such a project. Therefore, the purpose of this document is to guide, through several hands-on activities, community members who want to engage at different levels. The document consolidates all the relevant information from generating a simple payment to ultimately create a test-bed with the Interledger protocol suite between Ripple and other distributed ledger technology. [less ▲]

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See detailDeep dive into Interledger: Understanding the Interledger ecosystem - Part 1
Trestioreanu, Lucian Andrei UL; Cassagnes, Cyril UL; State, Radu UL

Learning material (2019)

At the technical level, the goal of Interledger is to provide an architecture and a minimal set of protocols to enable interoperability for any value transfer system. The Interledger protocol is literally ... [more ▼]

At the technical level, the goal of Interledger is to provide an architecture and a minimal set of protocols to enable interoperability for any value transfer system. The Interledger protocol is literally a protocol for interledger payments. To understand how is it possible to achieve this goal, several aspects of the technology require a deeper analysis. For this reason, in our journey to become knowledgeable and active contributor we decided to create our own test-bed on our premises. By doing so, we noticed that some aspects are well documented but we found that others might need more attention and clarification. Despite a large community effort, the task to keep information on a fast evolving software ecosystem is tedious and not always the priority for such a project. Therefore, the purpose of this document is to guide, through several hands-on activities, community members who want to engage at different levels. The document consolidates all the relevant information from generating a simple payment to ultimately create a test-bed with the Interledger protocol suite between Ripple and other distributed ledger technology. [less ▲]

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See detailStandardising smart contracts: Automatically inferring ERC standards
Norvill, Robert UL; Fiz Pontiveros, Beltran UL; State, Radu UL et al

in Proceedings of 2019 IEEE International Conference on Blockchain and Cryptocurrency (2019)

Ethereum smart contracts have become common enough to warrant the need for standards to ensure ease of use. The most well known standard was created for the emerging token ecosystem and the exchanges ... [more ▼]

Ethereum smart contracts have become common enough to warrant the need for standards to ensure ease of use. The most well known standard was created for the emerging token ecosystem and the exchanges serving it: the ERC20 standard. In this work we use the function selectors present in Ethereum smart contract bytecode to define contract purpose. Contracts are clustered according to the selectors they have. A Reverse look-up from selectors to function names is used to label clusters. We use the function names in clusters to suggest candidates for ERC standardisation. [less ▲]

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See detailWhispering Botnet Command and Control Instructions
Steichen, Mathis UL; Ferreira Torres, Christof UL; Fiz Pontiveros, Beltran UL et al

in 2nd Crypto Valley Conference on Blockchain Technology, Zug 24-26 June 2019 (2019, June 25)

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See detailDeep dive into Interledger: Understanding the Interledger ecosystem
Trestioreanu, Lucian Andrei UL; Cassagnes, Cyril UL; State, Radu UL

Learning material (2019)

At the technical level, the goal of Interledger is to provide an architecture and a minimal set of protocols to enable interoperability for any value transfer system. The Interledger protocol is literally ... [more ▼]

At the technical level, the goal of Interledger is to provide an architecture and a minimal set of protocols to enable interoperability for any value transfer system. The Interledger protocol is literally a protocol for interledger payments. To understand how is it possible to achieve this goal, several aspects of the technology require a deeper analysis. For this reason, in our journey to become knowledgeable and active contributor we decided to create our own test-bed on our premises. By doing so, we noticed that some aspects are well documented but we found that others might need more attention and clarification. Despite a large community effort, the task to keep information on a fast evolving software ecosystem is tedious and not always the priority for such a project. Therefore, the purpose of this document is to guide, through several hands-on activities, community members who want to engage at different levels. The document consolidates all the relevant information from generating a simple payment to ultimately create a test-bed with the Interledger protocol suite between Ripple and other distributed ledger technology. [less ▲]

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See detailPHom-GeM: Persistent Homology for Generative Models
Charlier, Jérémy Henri J. UL; State, Radu UL; Hilger, Jean UL

in The 6th Swiss Conference on Data Science (2019)

Generative neural network models, including Generative Adversarial Network (GAN) and Auto-Encoders (AE), are among the most popular neural network models to generate adversarial data. The GAN model is ... [more ▼]

Generative neural network models, including Generative Adversarial Network (GAN) and Auto-Encoders (AE), are among the most popular neural network models to generate adversarial data. The GAN model is composed of a generator that produces synthetic data and of a discriminator that discriminates between the generator’s output and the true data. AE consist of an encoder which maps the model distribution to a latent manifold and of a decoder which maps the latent manifold to a reconstructed distribution. However, generative models are known to provoke chaotically scattered reconstructed distribution during their training, and consequently, incomplete generated adversarial distributions. Current distance measures fail to address this problem because they are not able to acknowledge the shape of the data manifold, i.e. its topological features, and the scale at which the manifold should be analyzed. We propose Persistent Homology for Generative Models, PHom-GeM, a new methodology to assess and measure the distribution of a generative model. PHom-GeM minimizes an objective function between the true and the reconstructed distributions and uses persistent homology, the study of the topological features of a space at different spatial resolutions, to compare the nature of the true and the generated distributions. Our experiments underline the potential of persistent homology for Wasserstein GAN in comparison to Wasserstein AE and Variational AE. The experiments are conducted on a real-world data set particularly challenging for traditional distance measures and generative neural network models. PHom-GeM is the first methodology to propose a topological distance measure, the bottleneck distance, for generative models used to compare adversarial samples in the context of credit card transactions. [less ▲]

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See detailMint Centrality: A Centrality Measure for the Bitcoin Transaction Graph
Fiz Pontiveros, Beltran UL; Steichen, Mathis UL; State, Radu UL

Poster (2019, May 17)

In this work, we consider the graph of confirmed transactions in Bitcoin. Understanding this graph is essential to discern the different economic activities conducted by the pseudonymous actors. In ... [more ▼]

In this work, we consider the graph of confirmed transactions in Bitcoin. Understanding this graph is essential to discern the different economic activities conducted by the pseudonymous actors. In addition to traditional graph analysis methods, new metrics need to be engineered specifically for the bitcoin transaction graph. Hence, we propose a new centrality measure named mint centrality. The measure uses the inherent tree structure of transactions in bitcoin and their relation to the corresponding set of coinbase transactions, and can be evaluated with linear complexity. We evaluate the mint centrality on the first 200,000 blocks of the public bitcoin blockchain. [less ▲]

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See detailDemo: Blockchain for the Simplification and Automation of KYC Result Sharing
Norvill, Robert UL; Steichen, Mathis UL; Shbair, Wazen UL et al

in IEEE International Conference on Blockchain and Cryptocurrency (ICBC 2019) (2019, May 14)

Know Your Customer (KYC) processes performed by banks on their customers are redundant, cumbersome and costly. Therefore, a system is proposed to automate menial tasks and allow sharing of data related to ... [more ▼]

Know Your Customer (KYC) processes performed by banks on their customers are redundant, cumbersome and costly. Therefore, a system is proposed to automate menial tasks and allow sharing of data related to KYC. A blockchain dictates the collaboration between different participants and several services are built around it to support the functionality of the system as a whole. An access control system is used to share data legitimately. [less ▲]

Detailed reference viewed: 117 (7 UL)