The distributed services from different domains, organizations, and regions in the real and virtual world are converged together to form the Internet of Services (IoS). It is required to provide a trusted, orderly and efficient platform environment for service collaboration and delivery. Blockchain is currently recognized as the best practice technique to solve the problem of orderly and trusted execution of system. However, the efficiency issue introduced by it is also a problem that every platform needs to take seriously. Therefore, this paper proposes a blockchain-based IoS architecture, which uses the virtual chain and the embedded EVM(Ethereum Virtual Machine) notary technology to ensure the security and credibility of the service collaboration process in the IoS, and also the efficient operation of the entire system. This architecture has been compared with non-blockchain architecture without credible guarantees and also blockchain-only architecture. This comparative experiment shows that the proposed architecture not only ensures the orderly and trusted execution of the system, but also effectively controls the loss of performance.
Blockchain is a type of distributed ledger technology that is characterized by the five characteristics: Consensus, Decentralization, Immutability, Finality, and Provenance. Blockchain characteristics have been rapidly recognized as a turning point in many use case scenarios beyond the financial sector. Conversely, there is still a significant incongruity regarding how the blockchain’s unique characteristics can be mapped to the elicited non-functional requirements (NFRs) of blockchain-based systems. Motivated by exploring the potential categories of NFRs that dominate the landscape of blockchain-based systems, we conducted an inductive content analysis on a sample of extracted requirements from 7 different blockchain-based projects developed by two startup firms. This paper presents the initial view of the constructed mapping between the blockchain characteristics on one side and the dominating NFRs for the blockchain-based system.
As the core technology behind Bitcoin, Blockchain’s decentralize, tamper-proof, and traceable features make it the preferred platform for organizational innovation. In current Bit-coin, block reward is halved every four years, and transaction fees are expected to become the majority of miner revenues around 2140. When transaction fee dominates mining rewards, strategic deviations such as Selfish Mining, Undercutting, and Mining Gap could threaten the integrity and security of the Blockchain. In this paper, we propose a set of Dynamic Transaction Storage (DTS) strategies for maintaining a sustainable Blockchain under transaction-fee regime. Through the systematic simulation, we demonstrate that block incentive volatility can be reduced by applying DTS strategies, and thus avoid strategic deviations. With DTS, public Blockchains such as Bitcoin become sustainable when the mining reward is solely based on transaction fee.
Rafael Belchior, André Vasconcelos, Miguel Correia, Thomas Hardjono
Enabling blockchain-based digital asset exchanges requires blockchain interoperability capabilities. Although some solutions have been proposed in recent years, asset and crypto-currency transfers across legal jurisdictions are still an unsolved problem. To realize this vision, we propose Hermes, a fault-tolerant middleware that connects blockchain networks, enabling the transfer of data and value across legal jurisdictions. Hermes is based on the Open Digital Asset Protocol (ODAP), an asset transfer protocol. Hermes utilizes a novel mechanism called ODAP-2PC and decentralized logging that can solve disputes regarding asset exchange. We find Hermes to fill an existing gap: the technical infrastructure that can constitute the basis for legislating and regulating cross-chain transfers, enabling the future of finance.
Traditional data collection, storage and processing of Electronic Health Records (EHR) utilize centralized techniques that pose several risks of single point of failure and lean the systems to a number of internal and external data breaches that compromise their reliability and availability. Blockchain is an emerging distributed technology that can solve these issues due to its immutability and architectural nature that prevent records manipulation or alterations. In this paper, we discuss the progress and opportunities of remote patient monitoring using futuristic blockchain technologies and its two primary frameworks: Ethereum and Hyperledger Fabric. We also discuss the possible blockchain use cases in software engineering for systematic, disciplined, and quantifiable application development. The study extends by introducing a system architecture for EHR data management using Ethereum as a model. We discuss the challenges and limitations along with the initial evaluation results of the proposed system and draw future research directions in this promising area.
Samuel H. Christie, Amit K. Chopra, Munindar P. Singh
A decentralized application involves multiple autonomous principals, e.g., humans and organizations. Autonomy motivates (i) specifying a decentralized application via a protocol that captures the interactions between the principals, and (ii) a programming model that enables each principal to independently (from other principals) construct its own protocol-compliant agent. An agent encodes its principal's decision making and represents it in the application. We contribute Deserv, the first protocol-based programming model for decentralized applications that is suited to the cloud. Specifically, Deserv demonstrates how to leverage function-as-a-service (FaaS), a popular serverless programming model, to implement agents. A notable feature of Deserv is the use declarative protocols to specify interactions. Declarative protocols support implementing stateful agents in a manner that naturally exploits the concurrency and autoscaling benefits offered by serverless computing.
Yuqian Zhang, Saeid Pourroostaei Ardakani, Wenqi Han
Abstract Blockchain technology has the potential to reduce transaction errors and enhance the quality of reporting significantly. This article proposes a conceptual blockchain‐based protocol, labelled Smart Ledger, as a replacement for the traditional accounting information recording system. A smart ledger is a computerized algorithm that utilizes blockchain technology to perform accounting ledger functions. Its validity is based on two mechanisms within the blockchain architecture: Fractional Accounting Transactions (FAT) and Hierarchical Accounting Transaction Execution (HATE). As such, the smart ledger is a hybrid protocol that combines accounting information recording principles with the immutability of blockchain technology. If widely implemented, it could have a significant impact on accounting practices and the accounting profession.
This paper presents a blockchain cloud deployment for an industrial vehicle use case. Hyperledger Sawtooth is used as distributed ledger with Rancher and Kubernetes as container-orchestration. This paper aims to explore the feasibility and scalability of the use case in a real-world scenario cloud deployment. Also, the blockchain performances is analyzed by stressing the implementation with virtual IoT clients, changing the blockchain settings, number of peer members and editing the core software default parameters. Benchmarks will reveal that Hyperledger Sawtooth performance can be as high as 25 transaction per seconds for a network of 4 nodes with PBFT consensus. Results lead us to discuss the possible components reducing throughput and blockchain commit rate.
Kemal Turksonmez, Marcin Furtak, Mike P. Wittie, David L. Millman
Blockchain transactions compete for limited space in blockchain blocks. Miners prefer to include transactions with higher fees into new blocks. In the context of Ethereum, gas price price oracles predict fees such that transactions submitted at those fees make it into a block within a target delay. In practice, however, oracles are not accurate, which makes it difficult for distributed applications to operate predictable services in terms of price and performance.To understand oracle performance we define a new gas prediction accuracy metric. We demonstrate that oracles underprice transactions, causing them to miss the delay target, as well as overprice transactions, causing them to meet the delay target, but at a higher than necessary cost. We provide comparative analysis of five gas price oracles showing their relative accuracy, transaction accept rates, price stability, and discuss factors that influence oracle accuracy. We observe that the ETHGasStation oracle produces the most accurate and stable price predictions. For users that prefer to run their own oracle Web3.py provides comparable performance.
Marco Mazzoni, Antonio Corradi, Vincenzo Di Nicola
Given the availability of several blockchain technologies in permissioned contexts, blockchain application designers have to cope with the increasing complexity of choosing which technology and consensus algorithm best fit a specific use case. However, the lack of a standard framework allowing to assess the scalability of permissioned blockchain platforms and to compare performances and features of consensus algorithms makes the development of a sensible evaluation a costly and difficult time-consuming problem. Throughout this article, we propose a practical scalability and applicability evaluation of the Quorum blockchain and its consensus algorithms. Although we apply our evaluation workflow to a financial use case, we define a methodology that can be generalized to any permissioned blockchain technology. We leverage Hyperledger Caliper as a benchmarking tool, and Docker as a deployment tool, making our analysis easy to be repeated, cross-platform, and cost-effective.
In order to have transactions executed and recorded on blockchains such as the Ethereum Mainnet, fees expressed in crypto-currency units of the blockchain must be paid. One can buy crypto-currency called Ether of the Ethereum blockchain from exchanges and pay for the transaction fees. In the case of test networks (such as Rinkeby) or scientific research blockchains (such as Bloxberg), free crypto-currency, Ether, is distributed to users via faucets. Since transaction slots on the blocks, storage and smart contract executions are consuming blockchain resources, Ethers are distributed by fixed small amounts to users. Users may have different amount of Ether requirements; some small amounts and some large amounts during different times. As a result, rather than allowing the user to get a fixed small amount of Ether, a more general distribution mechanism that allows a user to demand and claim arbitrary amounts of Ether, while satisfying fairness among users, is needed. For this end, Max-min Fairness based schemes have been used in centralized settings. Our work contributes a Max-min Fairness based algorithm and its Solidity smart contract implementation that requires low transaction costs independent of the number of users. This is important on the Ethereum blockchain, since a smart contract execution with transaction costs depending on the number of users would mean block gas limit exhaustion problem will eventually be met, making the smart contract ineffective. We report tests which confirm that the low transaction cost aims have been achieved by our algorithm.
The cutting-edge technology, namely Cloud of Things (CoT) has shaped the existing business process into a new orientation in terms of performance, usability, and reliability. Among different business processes, online education is one of the prime areas where CoT can be used to make it more agile in the context of performance and usability. In this endeavor, a novel methodology has been proposed for an online higher education framework based on CoT. The proposed framework is made agile using Service Oriented Architecture (SOA). Furthermore, in order to make the proposed framework more reliable, a Zero Knowledge Proof (ZKPF) system has been introduced here. The proposed ZKPF algorithm is based on the Hadamard matrix. Experimental results have shown to lay bare the effectiveness of the proposed algorithms.
Multiplayer computer games can be divided into two architectural groups: client-server and Peer-to-Peer (P2P). While the peer-to-peer approach is very promising due to its independence of expensive game servers, a number of issues, such as state synchronization in an un-trusted environment, arise. Blockchain networks are a special case of a P2P network, and they have the potential to efficiently tackle some issues with P2P-based multiplayer games. However, blockchain development is a vast and complicated area, foreign to most game developers. In this paper, we present a framework to connect an existing game client to a blockchain network, friendly towards game developers. More precisely, we develop a middleware solution and a data model therein, to store the game state on a chain and communicate it to the game client.
Aiming at the problem that learners' personal information, courses and relevant certificates can not provide detailed information about learning depth and learning or teaching methods, this paper takes learners' learning information, learning record smart contract and Ethereum Blockchain related technology as the research object, aiming to use Ethereum Blockchain and smart contract to connect learners' learning records. On the one hand, it can use the block data stored in the Blockchain to easily verify the authenticity of the data and ensure the privacy and security of the data. On the other hand, it can provide personalized learning path for learners and be used to evaluate a person's educational achievement, employment suitability and intelligence evaluation.
Emerson de Brito Souza, Elisângela Carneiro, Antonio Coutinho
Este artigo propõe um sistema para a geração e validação de diplomas e certificados onde os documentos sejam confiáveis e facilmente verificáveis. Para isso foi utilizada a rede blockchain pública da Ethereum aliada com uma rede de arquivos distribuída usando o protocolo InterPlanetary File System e ferramentas de código aberto. O modelo mostra que a realização do sistema é viável, englobando propriedades de sistemas off-chain e on-chain para a arquitetura proposta.
An Internet of Things (IoT) scenario is a heterogeneous and complex environment, where large volumes of data are constantly generated, manipulated, and transferred between different devices. In this context, some difficulties may arise, such as the correct identification of the devices generating the data, the trustworthiness of these devices and their generated data, detecting abnormal behavior, and controlling access to the data. Data provenance allows maintaining information about the origin of the data, the operations through which this data has undergone, and its processing history, from its creation to its current state. Aiming to provide means to mitigate the mentioned problems, we propose an architecture for data provenance management in IoT environments, enabling different levels of granularity, using a distributed ledger architecture.
Igor Gonçalves Silva, Pedro Henrique González, Diogo Mendonça
Blockchain technology is increasingly being used by several companies in the most varied sectors of the economy. The possibility of having decentralized applications (DApps) allows for the emergence of technological innovations such as cryptocurrencies and decentralized asset tracking applications. Many of these DApps are deployed in the cloud with Infrastructure as a Service (IaaS) payment model, in which the payment is made according to the use of the service. However, it is not simple to estimate the cloud infrastructure costs that a DApp will consume. Furthermore, correctly estimating infrastructure costs is essential to analyze the viability and develop business models for enterprise DApps. This work presents an experience report on estimating the cloud infrastructure cost for an enterprise DApp. To do that, we deployed a private Ethereum DApp, using Proof-of-Authority consensus algorithm, with several different configurations of Amazon Web Services (AWS) EC2 instances and blockchain parameters. We benchmark the transaction processing capacity, CPU and disk usage in each configuration, estimating their maximum capacity and costs. We shared our methodology to measure and estimate those costs and our insights on best configuration practices for reducing costs of deploying enterprise DApps in the cloud.
The application opportunities of distributed ledger technologies (DLT) for replicated, shared and synchronized data, across multiple nodes in a network, may create new possibilities in computing. There are notable differences between applications designed from scratch for being DLT-enabled and established IT applications that assume fundamentally a centralized computing architecture. This short paper reflects on the challenges in transforming established, conventional IT applications to be DLT-enabled. If such a transformation can be implemented successfully, repeatedly, and with acceptable effort, this means that today’s currently deployed IT applications may subsequently take advantage of beneficial properties of DLT. However, there are still a variety of aspects that need to be considered—this short paper contributes to that discussion.
Through the Bitcoin application, the innovative technology was miraculously launched in the markets, influencing numerous industries. Bitcoin is nothing but a form of digital currency (cryptocurrency) that can be used for trading in place of fiat money, where the underlying infrastructure is called Blockchain. The Blockchain is an open ledger that provides decentralization, transparency, immutability, and confidentiality. Blockchain can be used in massive, beneficial applications such as healthcare, logistics, supply chain management, the Internet of Things (IoT), etc. Most of the industrial applications rely on the permissioned Blockchain. However, the permissioned Blockchain fails in some aspects, such as scalability and throughput. This paper suggests a system to solve the scalability issue of permissioned Blockchain by incorporating data science techniques. The scalability analysis of the proposed solution is done in the hyperledger fabric framework with a variable number of transactions and results in scalability improvement.
Abstract The progression of Internet of Things (IoT) has resulted in generation of huge amount of data. Effective handling and analysis of such big volumes of data proposes a crucial challenge. Existing cloud-based frameworks of Big Data visualization are rising costs for servers, equipment, and energy consumption. There is a need for a green solution targeting lesser cost and energy consumption with tamper-proof record-keeping, storage, and interactive visualization with only demanded data. We have proposed a Blockchain-based Green big data Visualization (BGbV) solution using Hyperledger Sawtooth for optimum utilization of organization resources. BGbV will support current distributed data visualization platforms and guarantee benefits like security and data availability with lesser storage costs. It helps reduce costs by utilizing small resources that are already available and consume less energy, making it an environmentally friendly solution.
In 2008, the world was introduced to Blockchain. In 2009, the first open-source Blockchainbased cyber currency was introduced as Bitcoin. By 2025, studies indicate that Blockchain-based enterprise-wide application revenue will reach nearly $20 billion. Therefore, this study proposes to build on the success of Thailand's National Single Window (THAINSW) gateway document interchange architecture (DIA) and further expand its availability to a much larger network of e-Government participants using Blockchain architecture. Therefore, the authors set how to investigate how and where Blockchain technology could be implemented in order to support of Thailand's 4.0 and digital economy visions. In addition to the qualitative analysis of the literature, the authors used input from a panel of 25 Thai experts to develop a foundation for the analysis based on Sathosi Nakamoto’s seven Blockchain disciplines. This analysis was enhanced from the authors’ own experiences in real-world Blockchain implementations. Results revealed that Blockchain is a highly innovative approach to secure transaction execution, information storage, performing functions, and establishing trust in an open architectural environment.Blockchain has the potential to increase good governance, increase transparency and privacy, and reduce the chance of corruption.