Eder J. Scheid, Manuel Keller, Muriel Figueredo Franco, Burkhard Stiller
Current projects applying blockchain technology to enhance the trust of NFV environments do not consider the VNF repository. However, the blockchain’s properties can enhance trust by allowing to verify a VNF package’s integrity without relying (a) on a Trusted Third Party (TTP) for remote attestation or (b) a secure database. This paper presents BUNKER , a Blockchain-based trUsted VNF packagE Repository, intended to be integrated with traditional database-based package verification environments, acting as a trusted repository containing VNF package information. Moreover, BUNKER allows users to acquire VNFs without the need of a TTP using an Ethereum Smart Contract (SC). The SC automatically transfers license fees to the vendor once a VNF is acquired, and sends the VNF package’s link to the buyer before verifying its integrity.
Today more and more enterprises and individuals are outsourcing their data to cloud storage system. Data deduplication is one of the important technologies to reduce the storage cost of cloud storage system. In a cloud storage system with deduplication technology, the client can outsource the data files to the cloud storage server and pay for them. Fair payment is one of key issues in the cloud deduplication storage system. At present, a variety of secure deduplication encryption schemes have been designed to protect the privacy of client data. However, most existing fair payment solutions use traditional electronic cash systems to generate payment tokens, which requires a trusted authority to prevent double-spending. Trusted authorities will become bottlenecks in the payment system. Faced with this problem, in this paper, we propose a new decentralized fair payment protocol for cloud deduplication storage system by utilizing ethereum blockchain technology. The new protocol takes advantage of the decentralization of blockchain technology, allowing direct transactions without the participation of trusted third parties. In the new protocol, if a malicious situation occurs, the system can guarantee fair payment by pre-storing penalty money in the smart contract. Safety analysis and experimental analysis show that our new protocol is feasible.
K. Rajeswari Amrita B. Chavan Amrita B. Chavan, TJPRC
a showcase of ethereum Dapps, where the encryption keys are prolonged and open just to the end client. The client can also share the reports safely with various clients that they pick. Also the ID document will be stored in the hash format. The solidity smart contracts help to make tamper-proof records. It provides animmutability.
Distributed ledger technology especially in the form of publicly coordinated validation networks such as Ethereum and Bitcoin with their own monetary circles provide for a revealing litmus test for current financial regulatory schemes.The article highlights the interrelation between distributed coordination and the emission of virtual currency to make sense of the function of the new monetary phenomenon.It then argues for the regulation of financial services on the ground of the technology to ensure integrity standards.In this respect, it is useful to gear the development of a regulatory scheme towards the existing financial regulatory principles.However, future measures of the regulators must take the distributed nature of the platforms into account by relying on a "regulated self-regulation" of the community.Finally, the article focuses on the shortcomings of the current EU regulatory regimes, especially the regulation frameworks regarding financial services, payment services and electronic money. I.
This research is an attempt at deepening the understanding of hyped cryptocurrencies. A deductive nature is used where we attempt to estimate the linear dependencies of cryptocurrencies with four different time series models. Investigating linear dependencies of univariate time series offers the reader an understanding on how previous prices of cryptocurrencies affect future prices. The linear interdepencies for a multivariate scenario will provide an apprehension on how, and if, the cryptocurrency market is correlated. The dataset used consists of the prices between January 1, 2016 to March 31, 2019 of the four cryptocurrency rivals: Bitcoin, Ethereum, Ripple and Litecoin. The modeling is performed by using autoregression and fitting on 80% of the data. Thereafter, the models are forecasted on the last 20% of the data in order to test the accuracy of the model. The four types of model are used in this thesis and are named by the abbreviations AR(p), MSAR(p), VAR(p) and MSVAR(p) where AR(p) represents an autoregressive model of order p; MSAR(p) represents a Markov-Switching autoregressive model of order p; VAR(p) represents a multivariate model for of the AR(p) also known as the vector autoregressive model of order p; finally MSVAR(p) stands for a Markov-Switching vector autoregressive model of order p. As cryptocurrencies are said to be very volatile, we hope that the Markov-Switching approach would help to classify the level of volatility into different regimes. Further, we anticipate that the fitted time series for each regime will offer a greater accuracy than the regular AR(p) and VAR(p) models. By using scale-dependent error estimators, the thesis concludes that the Markov-Switching approach does in fact improve the efficiency of chosen time series models for our cryptocurrencies.
Cryptocurrencies are digital assets desig ned to work as a medium of exchange that uses cryptography to secure its transactions, to control the creation of additional units, and to verify the transfer of assets. In the past few years there is a growing number of cryptocurrencies like Bitcoin, Ethereum, Ripple, etc. In my paper and presentation I would like to present the difficulties of the legal classification of cryptocurrencies. Countries all over the world have different solutions to this question. It is not written in stone whether cryptocurrencies should be considered a currency, a commodity, or an investment. In my study I examine each of these possibilities.
I. H. Yano, A. de Castro, Francisco Carlos da Silva, Geraldo Magela de Almeida Cançado
O objetivo deste trabalho é apresentar a implementação de um contrato inteligente em uma rede privada Ethereum Blockchain, de forma a tornar possível o uso desta rede nos mais diversos tipos de aplicação, principalmente nos casos de rastreabilidade; neste caso, foi escolhido como exemplo a possibilidade de rastreamento de caixas de manga.
This paper aims to gain and improve understanding of the three most common cryptocurrencies (Bitcoin, Ethereum and Ripple) by applying standard econometric tools upon their time-series data.Cryptocurrencies' returns are compared to six major stock indices: two American (S&P500 and Russell 2000), one European (Stoxx 600), one Japanese (Nikkei 225), one Chinese (Hong Kong Hang Seng) and a global index (S&P Global 1200).The findings indicate that observed cryptocurrencies could be regarded as a new asset class, a fully digital, sui-generis financial instruments, as they are not coherently connected to the stock market.However, allocating capital into cryptocurrencies remains in the domain of pure speculation due to their strong volatility.
Mikael Beyene, Kannengießer, Niclas, Pandl, Konstantin D, Thiebes, Scott · 5 authors
A concept for distributed gene-drug interaction data sharing based on Ethereum Smart Contracts. The data is stored in a map with, both, keys and values utilizing a mixed-radix integer encoding that relies on the finiteness of the domains of given genes, drugs, and interactions. Thus, we get random access and, further, data queries are reduced to cheap bit comparisons.
Open access
Innovative Microfluidic and Catalytic Techniques Innovation
In recent years, there is growing interest in the ways the European aviation industry can leverage the multi-source data fusion towards augmented domain intelligence. However, privacy, legal and organisational policies together with technical limitations, hinder data sharing and, thus, its benefits. The current paper presents the ICARUS data policy and assets brokerage framework, which aims to (a) formalise the data attributes and qualities that affect how aviation data assets can be shared and handled subsequently to their acquisition, including licenses, IPR, characterisation of sensitivity and privacy risks, and (b) enable the creation of machine-processable data contracts for the aviation industry. This involves expressing contractual terms pertaining to data trading agreements into a machine-processable language and supporting the diverse interactions among stakeholders in aviation data sharing scenarios through a trusted and robust system based on the Ethereum platform.
Applications of blockchain technologies got a lot of attention in recent years. They exceed beyond exchanging value and being a substitute for fiat money and traditional banking system. Nevertheless, being able to exchange value on a blockchain is at the core of the entire system and has to be reliable. Blockchains have built-in mechanisms that guarantee whole system's consistency and reliability. However, malicious actors can still try to steal money by applying well known techniques like malware software or fake emails. In this paper we apply supervised learning techniques to detect fraudulent accounts on Ethereum blockchain. We compare capabilities of Random Forests, Support Vector Machines and XGBoost classifiers to identify such accounts basing on a dataset of more than 300 thousands accounts. Results show that we are able to achieve recall and precision values allowing for the designed system to be applicable as an anti-fraud rule for digital wallets or currency exchanges. We also present sensitivity analysis to show how presented models depend on particular feature and how lack of some of them will affect the overall system performance.
The Ethereum platform supports the decentralized execution of smart contracts, i.e. computer programs that transfer digital assets between users. The most common language used to develop these contracts is Solidity, a Javascript-like language which compiles into EVM bytecode, the language actually executed by Ethereum nodes. While much research has addressed the formalisation of the semantics of EVM bytecode, relatively little attention has been devoted to that of Solidity. In this paper we propose a minimal calculus for Solidity contracts, which extends an imperative core with a single primitive to transfer currency and invoke contract procedures. We build upon this formalisation to give semantics to the Ethereum blockchain. We show our calculus expressive enough to reason about some typical quirks of Solidity, like e.g. re-entrancy.
Ethereum smart contracts are executable programs, deployed on a peer-to-peer network and executed in a consensus-based fashion. Their bytecode is public, immutable and once deployed to the blockchain, cannot be patched anymore. As smart contracts may hold Ether worth of several million dollars, they are attractive targets for attackers and indeed some contracts have successfully been exploited in the recent past, resulting in tremendous financial losses. The correctness of smart contracts is thus of utmost importance. While first approaches on formal verification exist, they demand users to be well-versed in formal methods which are alien to many developers and are only able to analyze individual contracts, without considering their execution environment, i.e., calls to external contracts, sequences of transaction, and values from the actual blockchain storage. In this paper, we present Annotary, a concolic execution framework to analyze smart contracts for vulnerabilities, supported by annotations which developers write directly in the Solidity source code. In contrast to existing work, Annotary supports analysis of inter-transactional, inter-contract control flows and combines symbolic execution of EVM bytecode with a resolution of concrete values from the public Ethereum blockchain. While the analysis of Annotary tends to weight precision higher than soundness, we analyze inter-transactional call chains to eliminate false positives from unreachable states that traditional symbolic execution would not be able to handle. We present the annotation and analysis concepts of Annotary, explain its implementation on top of the Laser symbolic virtual machine, and demonstrate its usage as a plugin for the Sublime Text editor.
Micro and decentralized generation of electrical power is an emerging trend in the power industry. Blockchain technology allows decentralized and instant monetary and contractual transactions to occur over peer to peer private and public networks by satisfying cyber security concerns. Both changes have the potential to enable paradigm shift in the field of energy in the coming years. Decentralization in the energy business makes this sector a good playground for blockchain technology. As of now, energy applications of blockchain technology are in conceptual and early stage prototyping levels. This paper aims to present a comprehensive review of P2P energy trading related blockchain technology applications and proposes a comprehensive multi-layer energy model architecture for the peer to peer (P2P) energy trading implementations where the use of blockchain technology is integrated. P2P energy trading allows consumers to become prosumers of electricity in a more efficient, trustable, and profitable way. Furthermore, this study demonstrates an Ethereum based blockchain testbed exhibiting blockchain concepts and how they can be used in the field of P2P energy trading within a commodity microgrid using a sample use-case scenario.
Decentralized applications (DApps) – digital applications that operate on blockchain and smart contract technologies – have proliferated across diverse industrial sectors. With the recent surge in DApp adoption, we have yet to understand the impetus behind this rapid expansion. Our research aims to bridge this gap by examining the role and extent of peer influence on individual decisions to adopt DApps. Given the inherently peer-to-peer nature of blockchain and the robust sense of community amongst users, this influence is expected to be significant. To identify evidence, we empirically study Ethereum, the world's largest DApp platform. We utilize an unprecedented dataset encompassing the entire lifetime of Ethereum, from inception to the present day. Our findings reveal a positive correlation between DApp adoption and the decisions of proximate peers. We further uncover that the magnitude of peer influence varies depending on network structure characteristics, including network size, density, and the degree of decentralization. These results substantiate the powerful role of peer influence in driving the diffusion of DApps, operating through a variety of mechanisms. Such insights could offer valuable guidance for industry practitioners to devise targeted marketing strategies that capitalize on this peer influence to optimize DApp adoption rates.
Centralized network solution have been around for a long time, despite having a considerable issue of trust, in which users need to rely on the implementation of the system. During unfortunate incidents such as centralized server hacking attacks, users' data can be stolen and distorted, as well as not available while requested. Blockchain is discovered and believed to be a distributed network solution which can mitigate the above issue. \n \nThis bachelor's thesis studies how blockchain network can be integrated into a social financial mobile application. The research is completed by developing a smart contract and connect it with the mobile application. The smart contract is written in the Solidity programming language and run on the Ethereum network.
Since it takes time and effort to put a new product or service on the market, one would like to predict whether it will be a success. In general this is not possible, but it is possible to follow best practices in order to maximize the chance of success. A smart contract is intended to encode business logic and is therefore at the heart of every new business on the Ethereum blockchain. We have investigated how to measure the success of smart contracts, and whether successful smart contracts have characteristics that less successful smart contracts lack. The appearance of a smart contract on a listing website such as Etherscan or StateoftheDapps is such a characteristic. In this paper, we present a three-pronged analysis of the relative success of listed smart contracts. First, we have used statistical analysis on the publicly visible transaction history of the Ethereum blockchain to determine that listed contracts are significantly more successful than their unlisted counterparts. Next, we have conducted a survey among more than 200 developers via an anonymous online survey about their experience with the listing process. A significant majority of respondents do not believe that listing a contract itself contributes to its success, but they believe that the extra attention that is typically paid in tandem with the listing process does contribute. Finally, based on the respondents' answers, we have drafted 10 recommendations for developers and validated them by submitting them to an international panel of experts.
In traditional cloud computing system, searchable encryption is deemed as a core technology to realize data confidentiality protection and information retrieval functions. However, the online payment problem and mutual distrust between cloud platforms and users may hinder the wide adoption of cloud service. In this paper, we construct a blockchain based multi-keyword ranked search with fair payment (BMFP) system, which leverages smart contracts to verify the correctness and completeness of the search result, and automatically execute the fair payment operations. The system realizes public verifiability on a multi-keyword ranked search result. The data owner manages the search authority, and a concrete fair payment smart contract is designed. The BMFP is compatible with Ethereum, and the verification algorithm executed by the smart contract is cost-efficient.
2008 yılında yayınlanan "Bitcoin: A Peer-to-Peer Electronic Cash System" adlı makale sayesinde bilgi sahibi olduğumuz Bitcoin, bilimsel litaratüre yeni terimler kazandırarak popülerliğini arttırmaktadır. Alternatif sanal para olarak geliştirilen Ethereum, merkezi bir sunucu veya bir kontrol noktaya ihtiyaç duymadan, karşılıklı uçlar arası anonim ve ucuz şekilde varlık transferine olanak sağlayan bir sistemdir. Blokzincir yapısının en yaygın kullanımı olan Bitcoin ve altcoinlerdir. Kripto paralar madencilik olarak adlandırılan ve zorlu bir algoritmanın çözümü ile gerçekleşmektedir. Sistemde yer alan herhangi bir madenci bu çözümü elde etmek için elinde bulunan ekran kartı ve işlemci gücünü kullanmaktadır. Bu çalışmada GPU'ların barındırdığı işlemcilerin, kayan noktalı işlem hesaplamalarında daha verimli olmaları sebebiyle Ethereum madenciliğinde kullanılan çeşitli ekran kartlarının performansları 4 kademeli bir iyileştirme paketi ile artırılarak karşılaştırılmıştır. Önerilen iyileştirme metotları için kullanılan ekran kartlarının model ve bellek miktarları şu şekildedir: 4 GB AMD R9 290, 4 GB AMD R9 380, 8 GB AMD R9 390, 4 GB AMD RX 560, 4 GB AMD RX 470, 4 GB AMD RX 480, 4 GB AMD RX 570, 4 GB AMD RX 580, 6 GB NVIDIA GTX1060, 8 GB NVIDIA GTX1070, 8 GB NVIDIA GTX1080. Bu çalışmanın en önemli amacı, Ethereum madenciliğine özgü Ethash özet algoritmasında iyileştirme yöntemleri uygulamaktır. Bu amaçla, AMD ve NVIDIA yonga seti grafik kartlarının daha düşük güç tüketimi ile daha hızlı algoritmalar çözmelerini sağlamak için iyileştirmeler yapılmıştır. Grafik kartları fabrika ayarlarıyla çalıştırıldığında, hiçbiri geçerli döviz kurlarından dolayı fayda getiremeyecek durumdadır. Algoritmanın hızını arttırmanın yanı sıra güç tüketimini azaltmak kar bölgesine geçiş için önemli bir faktör olmuştur. Yapılan çalışmalar sonucunda elde edilen değerlere bakıldığında yaklaşık % 30 performans artışı görülmüştür. Ayrıca iyileştirme paketi ile ekran kartlarının tükettiği elektrik enerjisi yüzde 20 ile yüzde 30 arası azaltılmıştır. Anahtar Kelimeler: Ethereum, Blokzincir, Kripto para madenciliği, GPU madenciliği
Open access
Blockchain Technology Applications and Security
Currency Recognition and Detection
Advanced Steganography and Watermarking Techniques