Evidence-based applications of resources remain one of the greatest challenges faced by governments, businesses, and policymakers. The United States Government Accountability Office (GAO) evaluated ten large programs, which together cost more than $10 billion/year, through randomised control trials – the highest standard of evidence-based practice (EBP). The evaluation found that nine of them had ‘weak or no positive effects’ on their participants. Many programs were not evaluated at all. In January 2019, U.S. President signed the ‘Foundations for Evidence-based Policy Making Act’ into law. A USAID (US Agency for International Development) study looked at 43 blockchain projects and companies claiming to have solved various problems using distributed ledgers. The study found that almost no company was willing to share their results and MERL (monitoring, evaluation, research and learning) processes. Other observational data revealed that 80–90% of blockchain-based token offering projects failed to deliver on their promises, a prediction also made by Vitalik Buterin, the founder of Ethereum blockchain, in 2017. The concept of evidence-based blockchain (EBB) was first introduced by Naqvi in 2018. We conducted an evaluation of 517 blockchain firms against PCIO framework of evidence-based practice: Problem – Comparison – Intervention and Outcomes. We define the fundamentals of EBB (Ask, Acquire, Appraise, Apply, Assess), provide a review of the literature on EBB, report findings of our study and propose an Assessment Framework of Evidence Based Blockchain.
In general, Cloud storage is considered as a distributed model. Here, the data is usually stored on remote servers to properly maintain, back up and make it accessible to clients over a network, whenever required. Cloud storage providers keep the data and processes to oversee it on capacity servers based on secure virtualization methods. A security framework is proposed for auditing the cloud data, which makes use of the proposed blockchain technology. This ensures to efficiently maintain the data integrity. The blockchain structure inspects the mutation of operational information and thereby ensures the data security. Usually, the data auditing scheme is widely used in a Third Party Auditor (TPA), which is a centralized entity that the client is forced to trust, even if the credibility is not guaranteed. To avoid the participation of TPA, a decentralised scheme is suggested, where it uses a smart contract for auditing the cloud data. The working of smart contracts is based on blockchain. Ethereum is used to deploy a smart contract thereby eliminating the need of a foreign source in the data auditing process.
Financial stability is the problem that correlated with many aspects. In this digital era, virtual currency has emerged as one of financial assets. Fluctuation from cryptocurrencies price made an impact into financial stability indirectly. It has been proved by the market capitalization of publicly traded cryptocurrencies in 2019 reach USD 240 billion. The percentages reach 66% for the market capitalization. Three highest cryptocurrencies uphold are Bitcoin, Ethereum and XRP. This condition made these three cryptocurrencies become the important investment products. However, cryptocurrency is the product with high volatility. Because of that, this study aims to monitor financial stability from cryptocurrencies prediction using artificial intelligent algorithm. This research copes the problem by predicting bitcoin, Ethereum and XRP using three different intelligent algorithms, which are K-Nearest Neighbours (KNN), Support Vector Machine (SVM) and Long Short-Term Memory (LSTM). By this prediction had been figured out about up and down value of cryptocurrencies using Root Mean Square Error (RMSE) to evaluate stabilization of finance. Accuration system with LSTM shown that the price of cryptocurrency will fit with the data actual using LSTM, in which the accuracy around 80%. This condition meant that LSTM had been succeeded to proposed as algorithm that could fit the cryptocurrencies value. It could strengthen usability to indicate financial stability refer into cryptocurrencies price.
Compiling technology is an important technology in computer science. It is of great practical significance to create a language and implement its compiler. At the same time, with the rise of blockchain technology in recent years, smart contracts reappear in people's vision, and the combination of the two has great potential. The typical smart Contract languages, such as Solidity and LLL, have complex syntax and are not easy for beginners to learn and use. This paper introduces the process of making a simple smart contract language that is easy for beginners to learn. The whole process includes from language design to intermediate code execution. The compiler uses Python as the programming language, and the target running platform is Ethereum virtual machine. At the end of this paper, a demonstration example is shown.
Cryptocurrency market has a potential growth since Bitcoin emerged as one of the commodity investment in Indonesia. Besides Bitcoin, there is another altcoin which rapidly developing and dominating the cryptocurrency market, Ethereum. Therefore, this study aims to analyze the factors that affect Ethereum prices through macroeconomic aspects, such as EUR/USD exchange rate and the price of gold, as well as Bitcoin and other altcoins prices in the cryptocurrency market. The time series data consists of weekly data of all variables will be utilized during the 2016-2018 period. This study will conduct an empirical analysis by using the Autoregressive Distributed Lag (ARDL) test model. The result found that only in the short term, EUR/USD affects the Ethereum prices, while the price of gold do not show any effect on Ethereum prices. Moreover, Bitcoin and 2 alt-coins (Litecoin, and Monero) affect significantly the Ethereum prices. Nevertheless, Ripple and Stellar do not show significant effect on Ethereum prices.
Juliana Zanelatto Gavião Mascarenhas, Artur Ziviani, Klaus Wehmuth, Alex Borges Vieira
Abstract Distributed blockchain-based consensus platforms have witnessed steady growth in recent years. In special, cryptocurrency is one of the main applications of the blockchain technology. Despite the recent interest in blockchain, we still lack in-depth analysis of systems that use such a technology. In fact, most of the existing works focus on Bitcoin. Moreover, blockchain-based cryptocurrency systems are highly dynamic. Their internal mechanisms and consensus algorithms evolve over time. Users also change their interests in a given platform, which in turn, reflect their behaviour. In this article, we model the Ethereum-based cryptocurrency transaction network, a more recent blockchain platform that is gaining a significant share in the cryptocurrency market. We model the transactions of Ethereum as a complex system, representing this complex system as a time-varying graph. Our model and the analysis we conduct rely on a 3-year dataset of Ethereum-based cryptocurrency transactions, comprising more than 38 million users (i.e. unique wallet addresses) and almost 300 million transactions. We analyse the evolution of users and transactions over time. Our study also highlights the centralization tendency of the transaction network on both user and time aspects. Finally, we also analyse the formation of communities and the evolution of connected components considering the dynamics of the Ethereum-based cryptocurrency transaction network.
As Ethereum's smart contracts have boomed, it has become an integral part of the blockchain ecosystem. Unfortunately, some malicious users also find the opportunity to use fraudulent means to profit. A new reported approach is to lure new users or other attackers into the contract in an attempt to make a profit by exposing seemingly obvious flaws in the contract. But in fact, the contract contains a hidden trap that ultimately benefits the creator of the contract. Such contracts are known as honeypot contracts in the blockchain ecosystem. Previous studies proposed two methods to identify such smart contracts by using symbolic execution and contract behaviors. However, these methods either make it difficult to discover new categories or fail to warn users before they lose money. To solve this problem, we propose a machine learning model to detect honeypot contracts based on N-gram features and LightGBM. Extensive experiments show that our proposed model performs well in different conditions.
Umut Uyar, Göksal Selahatdin Kelten, Tuncay MORALI
Bireysel ve kurumsal yatırımcıların finansal piyasalarda yatırım kararları alırken sıklıkla kullandıkları analizler temel analiz ve teknik analiz şeklinde ikiye ayrılmaktadır. Temel analiz; makroekonomik gidişatı, sektörel gelişmeleri ve spesifik olarak yatırım yapılacak varlığın finansal göstergelerini dikkate alırken, teknik analiz; finansal varlıkların geçmiş fiyat hareketlerinden yola çıkarak bu finansal varlığın gelecekteki fiyat hareketlerini tahminlemeye çalışmaktadır. Teorik altyapısı Dow Teorisine dayanan ve “finansal varlığın geçmiş fiyat hareketleri zamanla tekrarlanacaktır” gibi bir takım varsayımlar barındıran teknik analiz yöntemine göre yatırım kararı alınırken çeşitli indikatörler, osilatörler ve formasyonlar kullanılmaktadır. Bu göstergelerden Hareketli Ortalamaların Yakınsaması/Uzaklaşması (MACD), Bollinger Band (BBand), Göreceli Güç Endeksi (RSI) yatırımcıların sıklıkla kullandıkları göstergeler arasındadır. Bu çalışmada 2014-2018 Bitcoin (BTC) ve Ethereum (ETH) günlük fiyat verileri kullanılarak MACD, BBand ve RSI test edilmiş, BTC ve ETH Al/Sat kararları tahmin edilmeye çalışılmıştır. Çıkan sonuçlar neticesinde kripto paraların yatırımcılara sağlayacağı getiriler hesaplanmıştır. Finansal piyasalarda en fazla işlem gören kripto paraların analiz edildiği çalışmada, yatırım kararlarında teknik analizin ne derece etkili olduğu ve bu yatırımlardan teknik analiz kullanılarak herhangi bir getiri sağlanıp sağlanamayacağı irdelenmiştir. Elde edilen bulgulara göre BBand, RSI ve MACD yöntemleri birbirleri ile çelişkili sinyaller verebilmektedir. Bu nedenle yatırımcıların kullanacakları analiz yöntemine göre kazanç ve kayıplarının farklılaşabileceğini söylemek mümkündür
Evidence is a tangible demonstrative artifact that proves a fact and shapes the investigation of various misconduct cases involving for instance corruption, misbehavior, or violation. It is imperative to maintain proper evidence management to guarantee the admissibility of an evidence in a court of law. Chain of custody forms the forensic link of evidence sequence of control, transfer, and analysis to preserve evidence's integrity and to prevent its contamination. Blockchain, a distributed tamper-resistant ledger can be leveraged to offer a decentralized secure digital evidence system. In this paper, we propose a secure chain of custody framework by utilizing the blockchain technology to store evidence metadata while the evidence is stored in a reliable storage medium. The framework is built on top of a private Ethereum blockchain to document every transmission from the moment the evidence is seized, thus ensuring that evidence can only be accessed or possessed by authorized parties. The framework is integrated with the digital evidence system where evidence is physically stored and locked using smart locks. To secure the sequence of evidence submission and retrieval, only an authorized party can possess the key to unlock the evidence. Our proposed framework offers a secure solution that maintains evidence integrity and admissibility among multiple stakeholders such as law enforcement agencies, lawyers, and forensic professionals. The research findings shed light on hidden opportunities for the efficient usage of blockchain in other realms beyond finance and cryptocurrencies.
Many popular blockchain platforms are supporting smart contracts for building decentralized applications. However, the vulnerabilities within smart contracts have led to serious financial loss to their end users. For the EOSIO blockchain platform, effective vulnerability detectors are still limited. Furthermore, existing vulnerability detection tools can only support one blockchain platform. In this work, we present WANA, a cross-platform smart contract vulnerability detection tool based on the symbolic execution of WebAssembly bytecode. Furthermore, WANA proposes a set of test oracles to detect the vulnerabilities in EOSIO and Ethereum smart contracts based on WebAssembly bytecode analysis. Our experimental analysis shows that WANA can effectively detect vulnerabilities in both EOSIO and Ethereum smart contracts with high efficiency.
Smart contracts are programs, which are stored in a decentralized network i.e. Block chain. These are written by users to develop decentralized applications using different platform like Ethereum and bitcoin. In current scenario, even though blockchain support features like security and transparency. Because of solidity language vulnerability, there is a possibility of attacks on smart contracts in blockchain. So, to avoid those attacks like i.e. Locked Ether, Transaction order dependency and Time stamp dependency. We discussed, analyzed and tested these attacks in this paper. Further, in our project supply chain management for textile industry using block chain technology, we have developed smart contract using solidity language on Ethereum Platform. With the aim of protecting our project from these attacks, we are thoroughly and experimentally analyzed. And based on the experimental observations, we are going to protect our project from these attacks. All the above mentioned attacks are thoroughly studied and experimentally tested on Ganache, Ropston test network, Rinkeby test network using Remix IDE in JVM, injectedweb3and web3 provider environments. Finally, we have suggested security measures to protect from these attacks
Blockchain has been proclaimed as one of the fastest growing technologies that have the potential to penetrate almost any industry available. In contrast to centralized systems of operations which have been mostly used till date, blockchain is based on a decentralized system. Through the use of decentralized database architecture, the procurement, authentication and maintenance of various operations are dependent upon the agreement of several parties instead of a single central authority. Blockchain not only makes operations transparent, but safer and faster also. Blockchain became popular with the emergence of the cryptocurrency Bitcoin. Since blockchain was first successfully applied for Bitcoin, people assumed these two to be synonyms of each other. Bitcoin transactions are managed using a distributed ledger on a peer-to-peer network that has anonymous, open and public access. Blockchain is the underlying technology which maintains the Bitcoin transaction ledger. Although blockchain technology emerged in financial sector with cryptocurrencies like Bitcoin, Litecoins and Ethereum, later it was realized that the blockchain technology can be adapted to be used in other domains also. Many years ago, the Internet changed the world by connecting digital devices worldwide, to have greater access to information. Similarly, blockchain is changing the way of doing business by proving more trust. The decentralized database architecture of blockchain provides more reliability for the maintenance of records and transactions. Any transaction, once recorded on a blockchain, cannot be altered. While the participants in a business network may not be able to trust each other, they can trust the blockchain. Businesses are benefited by blockchain in numerous ways, including quick access to information, immediate verification of transactions, reduced cost due to intermediaries, lowered risk due to fraud and tempering and reduced time for settling of disputes. Blockchain has attracted lot of researchers, in order to incorporate it into other emerging areas of technology like big data, the Internet of things and artificial intelligence. Artificial intelligence (AI) refers to the technological advancements that enable machines to act more intelligently. From drones to chatbots, AI enables machines to learn from a huge amount of data and apply that knowledge for efficient decision making. The focus of blockchain is to keep records accurate and to authenticate access, while AI is concerned with identifying patterns in the data stream for efficient decision making. Both these technologies are evolving and have prospects to be used in most of the industries. So, the merger of AI and blockchain would bring a revolutionary change worldwide. We could think of developing a decentralized system of database, where the machines could use these data to behave like humans. In this chapter, different aspects of AI are explored which can be improved by the use of robust blockchain architecture and is studied in the healthcare domain.
This paper describes the Distributed Ledger Network Analyzer (DiLeNA), a new software tool for the analysis of the transactions network recorded in Distributed Ledger Technologies (DLTs). The set of transactions in a DLT forms a complex network. Studying its characteristics and peculiarities is of paramount importance, in order to understand how users interact in the distributed ledger system. The tool design and implementation is introduced and some results are provided. In particular, the Bitcoin and Ethereum blockchains, i.e. the most famous and used DLTs at the time of writing, have been analyzed and compared.
The increasing of digital technology today has helped many people to fulfill their needs. But the election system, still conventionally using paper in its implementation. Elections in general still use a centralized system, where there is an organization that manages it. Some of the problems that may occur in traditional electoral systems are that there are organizations that have full control over the database and system, so the possibility of hacking the database is quite a big opportunity.Blockchain innovation is one arrangement that can be utilized in light of the fact that it has a decentralized framework and the whole database is duplicated by all clients. Blockchain itself has been used by Bitcoin and Ethereum cryptocurrency which is known as a decentralized system. By using the blockchain in database recording on an e-voting system can reduce one source of fraud that is database manipulation. This study discusses the recording of voting data using blockchain technology. The implementation of Smart Contracts contained in the Ethereum Blockchain will be implemented to create this voting system
India is the largest democracy in the world, and in spite of that, it faces various challenges on a daily basis that hinder its growth like corruption and human rights violations. One of the ugliest phases of corruption and political mayhem is visible during the election process where no stone is kept unturned in order to gain power. However, it is the common citizen who suffers most in terms of clarity as well as security when it comes to his/her vote. Blockchain can play a very important role in ensuring that the voters registering their votes are legit and the counting of votes is not manipulated in any way. It is also needed in today's times where the world is available to people in their smart phones to also give them the opportunity to register their votes hassle free via their smart phones without having to worry about the system getting hacked. Therefore, in this chapter, the proposed layout will be based on a smart contract, using Ethereum software to create an e-voting app. In this chapter, the authors have proposed a secure e-voting framework through blockchain mechanism.
Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
Taking the unique advantage of the cryptocurrency market setting, this paper examines the relationships between blockchain participation and returns, trading volume and realized volatility of main cryptocurrencies (i.e., Bitcoin, Ethereum and Litecoin). Dissimilar to previous theoretical studies that model the influencing factors on participation, we employ the number of unique from addresses 1 as the proxy for cryptocurrency investors’ blockchain participation and further explore the impact of such participation. By using vector autoregressive (VAR) model, we find that the blockchain participation has a significant and positive impact on the next day’s trading volume and realized volatility for the main cryptocurrencies. Our results are robust to the Granger causality test and alternative measure for blockchain participation.
Sharding is a promising blockchain scaling solution. But it currently suffers from high latency and low throughput when it comes to cross-shard transactions, i.e., transactions that require coordination from multiple shards. The root cause of these limitations arise from the use of the classic two-phase commit protocol, which involves locking assets for extended periods of time. This paper presents Rivet, a new paradigm for blockchain sharding that achieves lower latency and higher throughput for cross-shard transactions. Rivet has a single reference shard running consensus, and multiple worker shards maintaining disjoint states and processing a subset of transactions in the system. Rivet obviates the need for consensus within each worker shard, and as a result, tolerates more failures within a shard and lowers communication overhead. We prove the correctness and security of Rivet. We also propose a more realistic framework for evaluating sharded blockchains by creating a benchmark based on real Ethereum transactions. An evaluation of our prototype implementation of Rivet and the baseline two-phase commit, atop 50+ AWS EC2 instances, using our evaluation framework demonstrates the latency and throughput improvements for cross-shard transactions.
T. Rama Reddy, P. V. G. D. Prasad Reddy, Rayudu Srinivas, Ch. V. Raghavendran · 6 authors
Abstract Education acts as a soul in the overall societal development, in one way or the other. Aspirants, who gain their degrees genuinely, will help society with their knowledge and skills. But, on the other side of the coin, the problem of fake certificates is alarming and worrying. It has been prevalent in different forms from paper-based dummy certificates to replicas backed with database tampering and has increased to astronomic levels in this digital era. In this regard, an overlay mechanism using blockchain technology is proposed to store the genuine certificates in digital form and verify them firmly whenever needed without delay. The proposed system makes sure that the certificates, once verified, can be present online in an immutable form for further reference and provides a tamper-proof concealment to the existing certification system. To confirm the credibility of the proposed method, a prototype of blockchain-based credential securing and verification system is developed in ethereum test network. The implementation and test results show that it is a secure and feasible solution to online credential management system.
Open access
2 source records
Blockchain Technology Applications and Security
Retinal Imaging and Analysis
Advanced Steganography and Watermarking Techniques
Vulnerabilities of smart contract are certainly one of the limiting factors for wider adoption of blockchain technology. Smart contracts written in Solidity language are considered due to common adoption of the Ethereum blockchain platform. Despite its popularity, the semantics of the language is not completely documented and relies on implicit mechanisms not publicly available and as such vulnerable to possible attacks. In addition, creating formal semantics for the higher-level language provides support to verification mechanisms. In this paper, a novel approach to smart contact verification is presented that uses ontologies in order to leverage semantic annotations of the smart contract source code combined with semantic representation of domain-specific aspects. The following aspects of smart contracts, apart from source code are taken into consideration for verification: business logic, domain knowledge, run-time state changes and expert knowledge about vulnerabilities. Main advantages of the proposed verification approach are platform independence and extendability.
Abdeljalil Beniiche, Amin Ebrahimzadeh, Martin Maier
Today’s Internet powered by decentralised blockchain technology is bringing us a true peer-to-peer platform that has the potential to go far beyond digital currencies. A blockchain technology of particular interest is Ethereum, which provides capabilities that Bitcoin lacked, to enable new models of distributed ownership and help realise future techno-social systems such as the Tactile Internet, the next evolutionary leap of the Internet of Things (IoT), by adding a new dimension to human-to-machine interaction. After explaining the commonalities and specific differences between Ethereum and Bitcoin blockchains, we first provide an up-to-date survey on how Ethereum can be used for realising the emerging blockchain IoT (B-IoT), briefly reviewing recent progress and open challenges. We then elaborate on how specific Ethereum blockchain technologies may be leveraged to realise future techno-social systems, notably the Tactile Internet, which at present is yet unclear in many ways how it would work. Towards this end, we explore the salient features that set Ethereum apart from other blockchains, including its symbiosis with other emerging key technologies such as artificial intelligence and robots as well as decentralised edge computing solutions, to let new hybrid forms of collaboration emerge among individuals benefitting from automation at the centre and humans at the edges.
Santiago Figueroa-Lorenzo, Jon Goya, Javier Añorga, Iñigo Adín · 6 authors
The European Union is moving toward the “smart” era having as one of the key topics the smart mobility. What is more, the European union (EU) is moving toward Mobility as a Service (MaaS). The key concept behind MaaS is the capability to offer both the traveler's mobility and goods' transport solutions based on travel needs. For example, unique payment methods, intermodal tickets, passenger services, freight transport services, etc. The introduction of new services implies the integration of many Internet-of-Things (IoT) sensors. At this point, security gains a key role in the railway sector. Considering an environment where sensor data are monitored from sensor events, and alarms are detected and emitted when events contain an anomaly, this document proposes the development of an alarms collection system, which ensures both traceability and privacy of these alarms. This system is based on Ethereum blockchain events-log, as an efficient storage mechanism, which guarantees that any railway entity can participate in the network, ensuring both entity security and information privacy.
Tim K. Mackey, Ken Miyachi, Danny Fung, Samson Qian · 5 authors
BACKGROUND: An estimated US $2.6 billion loss is attributed to health care fraud and abuse. With traditional health care claims verification and reimbursement, the health care provider submits a claim after rendering services to a patient, which is then verified and reimbursed by the payer. However, this process leaves out a critical stakeholder: the patient for whom the services are actually rendered. This lack of patient participation introduces a risk of fraud and abuse. Blockchain technology enables secure data management with transparency, which could mitigate this risk of health care fraud and abuse. OBJECTIVE: The aim of this study is to develop a framework using blockchain to record claims data and transactions in an immutable format and to enable the patient to act as a validating node to help detect and prevent health care fraud and abuse. METHODS: We developed a health care fraud and abuse blockchain technical framework and prototype using key blockchain tools and application layers including consensus algorithms, smart contracts, tokens, and governance based on digital identity on the Ethereum platform (Ethereum Foundation). RESULTS: Our technical framework maps to the claims adjudication process and focuses on Medicare claims, with the US Centers for Medicare and Medicaid Services (CMS) as the central authority. A prototype of the framework system was developed using the blockchain platform Ethereum (Ethereum Foundation), with its design features, workflow, smart contract functions, system architecture, and software implementation outlined. The software stack used to build the system consisted of a front-end user interface framework, a back-end processing server, and a blockchain network. React was used for the user interface framework, and NodeJS and an Express server were used for the back-end processing server; Solidity was the smart contract language used to interact with a local Ethereum blockchain network. CONCLUSIONS: The proposed framework and the initial prototype have the potential to improve the health care claims process by using blockchain technology for secure data storage and consensus mechanisms, which make the claims adjudication process more patient-centric for the purposes of identifying and preventing health care fraud and abuse. Future work will focus on the use of synthetic or historic CMS claims data to assess the real-world viability of the framework.