Blockchain technology introduces a new approach to storing information, implementing tasks and functions, and building trust between participating nodes. Although blockchain technology has received extensive attention in various application contexts in recent years, the issue of privacy and security remains the primary focus of discussions of the blockchain. The use of hash algorithms can provide secure blockchain integration, and many hash algorithms offer solutions to data integrity and security problems within the context of blockchain technology. However, they are also subject to problems related to time, lack of resources, and memory usage. In this research, an algorithm is proposed to generate a hash based on chaos theory (1D and 2D) logistic maps and the new Merkle-Damgård construction. Hash outputs are tested in terms of time, complexity, and collision. The proposed algorithm is evaluated according to Jaccard similarity and various coefficient measurements, and it was found that the similarity between the inputs and the outputs does not exceed 0.1932 percent. All outcomes indicated successful performance. The proposed algorithm was implemented on a blockchain-based transaction flow system, consumed fewer resources than other hash algorithms (such as SHA1, SHA2, and MD5), and requires mere milliseconds to implement.
Service fulfillment for clients increasingly involves cooperation between information technology (IT) systems. Designing such solutions requires an architectural approach that ensures symmetry between the communicating parties. For the design of such systems, the author introduces the 1+5 architectural views model. The model contains three new architectural views. For business process modeling, it ensures the integrated processes view. Integration aspects cover two additional views: integrated services, and contracts. Moreover, new stereotypes and tagged values have been added to the unified modeling language (UML). The author has introduced two profiles: UML profile for integration flows, and UML profile for distributed ledger deployment. Communication between systems requires flows that arrange mediation mechanisms. The paper describes an integration flow diagram that extends a UML activity diagram. In the case of blockchain, the author has proposed the smart contract design pattern. The paper describes three case studies that have employed the model to design various solutions. The 1+5 model has proven to be well suited for designing both centralized integration environments with enterprise service bus (ESB) and distributed blockchain solutions with peer-to-peer (P2P) connections.
Viraaji Mothukuri, Sai S. Cheerla, Reza M. Parizi, Qi Zhang · 5 authors
Hadoop Distributed File System (HDFS) is one of the widely used distributed file systems in big data analysis for frameworks such as Hadoop. HDFS allows one to manage large volumes of data using low-cost commodity hardware. However, vulnerabilities in HDFS can be exploited for nefarious activities. This reinforces the importance of ensuring robust security to facilitate file sharing in Hadoop as well as having a trusted mechanism to check the authenticity of shared files. This is the focus of this paper, where we aim to improve the security of HDFS using a blockchain-enabled approach (hereafter referred to as BlockHDFS). Specifically, the proposed BlockHDFS uses the enterprise-level Hyperledger Fabric platform to capitalize on files' metadata for building trusted data security and traceability in HDFS.
Oct 10, 2021·Proceedings of the ... Annual Hawaii International Conference on System Sciences/Proceedings of the Annual Hawaii International Conference on System Sciences
Johannes Sedlmeir, Tim Wagner, Emil Djerekarov, Ryan Green · 6 authors
Enterprises have been attracted by the capability of blockchains to provide a single source of truth for workloads that span companies, geographies, and clouds while retaining the independence of each party's IT operations. However, so far production applications have remained rare, stymied by technical limitations of existing blockchain technologies and challenges with their integration into enterprises' IT systems. In this paper, we collect enterprises' requirements on distributed ledgers for data sharing and integration from a technical perspective, argue that they are not sufficiently addressed by available blockchain frameworks, and propose a novel distributed ledger design that is "serverless", i.e., built on cloud-native resources. We evaluate its qualitative and quantitative properties and give evidence that enterprises already heavily reliant on cloud service providers would consider such an approach acceptable, particularly if it offers ease of deployment, low transactional cost structure, and a combination of latency and scalability aligned with real-time IT application needs.
Kashif Mehboob Khan, Junaid Arshad, Waheed Iqbal, Sidrah Abdullah · 5 authors
Abstract Cloud computing is an important technology for businesses and individual users to obtain computing resources over the Internet on-demand and flexibly. Although cloud computing has been adopted across diverse applications, the owners of time-and-performance critical applications require cloud service providers’ guarantees about their services, such as availability and response times. Service Level Agreements (SLAs) are a mechanism to communicate and enforce such guarantees typically represented as service level objectives (SLOs), and financial penalties are imposed on SLO violations. Due to delays and inaccuracies caused by manual processing, an automatic method to periodically verify SLA terms in a transparent and trustworthy manner is fundamental to effective SLA monitoring, leading to the acceptance and credibility of such service to the customers of cloud services. This paper presents a blockchain-based distributed infrastructure that leverages fundamental blockchain properties to achieve immutable and trustworthy SLA monitoring within cloud services. The paper carries out an in-depth empirical investigation for the scalability of the proposed system in order to address the challenge of transparently enforcing real-time monitoring of cloud-hosted services leveraging blockchain technology. This will enable all the stakeholders to enforce accurate execution of SLA without any imprecisions and delays by maintaining an immutable ledger publicly across blockchain network. The experimentation takes into consideration several attributes of blockchain which are critical in achieving optimum performance. The paper also investigates key characteristics of these factors and their impact to the behaviour of the system for further scaling it up under various cases for increased service utilization.
Diego Fernandes Gonçalves Martins, Marco Aurélio Amaral Henriques
Este artigo apresenta um novo método de consenso para blockchains públicas baseado em Proof-of-Stake que não precisa de comitês de validação para aceitar novos blocos. Primeiramente, o texto mostra os princípios do mecanismo e como um nó é selecionado para criar um bloco na cadeia. Logo depois, é apresentado o processo de confirmação probabilística como forma de tornar definitiva a aceitação de um bloco sem comitês de validação, além de resultados práticos que avaliam o desempenho e a segurança do mecanismo. A segurança do método é demonstrada por um estudo teórico da probabilidade de reversão de blocos.
Xiaogang Xing, Yuling Chen, Tao Li, Yang Xin · 5 authors
Abstract Blockchain technology has the characteristics of decentralization and tamper resistance, which can store data safely and reduce the cost of trust effectively. However, the existing blockchain system has weak performance in data management, and only supports traversal queries with transaction hashes as keywords. The query method based on the account transaction trace chain (ATTC) improves the query efficiency of historical transactions of the account. However, the efficiency of querying accounts with longer transaction chains has not been effectively improved. Given the inefficiency and single method of the ATTC index in the query, we propose a subchain-based account transaction chain (SCATC) index structure. First, the account transaction chain is divided into subchains, and the last block of each subchain is connected by a hash pointer. The block-by-block query mode in ATTC is converted to the subchain-by-subchain query mode, which shortens the query path. Multiple transactions of the same account in the same block are merged and stored, which simplifies the construction cost of the index and saves storage resources. then, the construction algorithm and query algorithm is given for the SCATC index structure. Simulation analysis shows that the SCATC index structure significantly improves query efficiency.
As the number of blockchain (BC) platforms providing specific features increases, selecting a platform that fits all requirements needed for a specific case becomes a cumbersome task. For example, not only are BCs' technical details relevant, but also their intrinsic characteristics (e.g., cryptocurrency price) must be considered in selecting a BC for a given case. Hence, the management of data stored in multiple BCs and the selection process are not straightforward due to the myriad platforms and both technical and economic details (e.g., BC throughput and the underlying price fluctuation). This article defines a novel refinement flow (based on the policy continuum) of high-level BC selection policies to low-level BC transactions. Experiments with the BC selection framework developed applying policy-based management (PBM) in the BC context do show that such synergy simplifies data management in multiple BCs driven by user requirements (e.g., based on costs or performance policies). The performance analysis of the framework demonstrates the successful employment of PBM for BC selections with minimal overhead.
Bitcoin Edge Exact exchanging and simple payouts are a certain something, yet client care can frequently represent the moment of truth any business. The client care and client security gave by Bitcoin Edge is ironclad. You don't host to stress over a third gathering getting to your private data on the stage which is basic for any monetary program. In the event that you do require help, the client support entrance of Bitcoin Edge offers speedy reaction times and exact help.\n\n \n\nhttps://www.bitcoinedge.app/\nhttps://www.facebook.com/bitcoinedge/\nhttps://twitter.com/bitcoinedge_app\nhttps://www.pinterest.co.uk/bitcoinedge/\nhttps://www.instagram.com/bitcoinedge/\n\n \n\n
Blockchain-based smart contracts provide transparent automation in a broad range of services, including finance, the Internet of Things, and autonomous systems. However, the implementation of such services may easily involve security risks and functional errors, especially for complex services composed of different blockchains. To help developers focus on their business model instead of diving into the blockchain architecture heterogeneity, we propose a framework to enable analysis and comparison of composed services before deployment. This is achieved through the intensive use of model-based engineering allowing reasoning on the model before generating concrete deployment artifacts, especially for the safe orchestration of contract calling transactions.
In this paper we describe LUNES-Blockchain, an agent-based simulator of\nblockchains that relies on Parallel and Distributed Simulation (PADS)\ntechniques to obtain high scalability. The software is organized as a\nmulti-level simulator that permits to simulate a virtual environment, made of\nmany nodes running the protocol of a specific Distributed Ledger Technology\n(DLT), such as the Bitcoin or the Ethereum blockchains. This virtual\nenvironment is executed on top of a lower-level Peer-to-Peer (P2P) network\noverlay, which can be structured based on different topologies and with a given\nnumber of nodes and edges. Functionalities at different levels of abstraction\nare managed separately, by different software modules and with different time\ngranularity. This allows for accurate simulations, where (and when) it is\nneeded, and enhances the simulation performance. Using LUNES-Blockchain, it is\npossible to simulate different types of attacks on the DLT. In this paper, we\nspecifically focus on the P2P layer, considering the selfish mining, the 51%\nattack and the Sybil attack. For which concerns selfish mining and the 51%\nattack, our aim is to understand how much the hash-rate (i.e. a general measure\nof the processing power in the blockchain network) of the attacker can\ninfluence the outcome of the misbehaviour. On the other hand, in the filtering\ndenial of service (i.e. Sybil Attack), we investigate which dissemination\nprotocol in the underlying P2P network makes the system more resilient to a\nvarying number of nodes that drop the messages. The results confirm the\nviability of the simulation-based techniques for the investigation of security\naspects of DLTs.\n
Enterprise Resource Planning (ERP) software is extensively used for the management of business processes. ERP offers a system of integrated applications with a shared central database. Storing all business-critical informatio... | Find, read and cite all the research you need on Tech Science Press
Selma Steinhoff, Chrysoula Stathakopoulou, Matej Pavlovič, Marko Vukolić
Reconfiguration of long-lived blockchain and Byzantine fault-tolerant (BFT) systems poses fundamental security challenges. In case of state-of-the-art Proof-of-Stake (PoS) blockchains, stake reconfiguration enables so-called long-range attacks, which can lead to forks. Similarly, permissioned blockchain systems, typically based on BFT, reconfigure internally, which makes them susceptible to a similar "I still work here" attack. In this work, we propose BMS (Blockchain/BFT Membership Service) offering a secure and dynamic reconfiguration service for BFT and blockchain systems, preventing long-range and similar attacks. In particular: (1) we propose a root BMS for permissioned blockchains, implemented as an Ethereum smart contract and evaluate it reconfiguring the recently proposed Mir-BFT protocol, (2) we discuss how our BMS extends to PoS blockchains and how it can reduce PoS stake unbonding time from weeks/months to the order of minutes, and (3) we discuss possible extensions of BMS to hierarchical deployments as well as to multiple root BMSs.
Smart contracts, scripts at the heart of blockchain-based applications, are meant to be available forever once deployed. However, this property has a price. The amount of space required to store new contracts keeps increasing. This increase impacts each participating node's performance and makes it inconvenient for low-end devices to participate in the network. Among all contracts deployed in the blockchain, a vast majority will lead to little if any usage. We demonstrate that, in the course of one year, 70 % of deployed contracts lead to no use. Unfortunately, unused contracts keep occupying space on the blockchain. To tackle this issue, we propose a new protocol to identify and delete unused contracts. Through simulation, based on Ethereum historical data, we show that deletion of smart contracts after an inactivity period of 90 days could lead to a 66 % reduction in the number of contracts stored over a year.
Blockchain is not widely applied in various fields due to the critical issue of scalability as part of the blockchain trilemma. This issue arises during consensus among the nodes in a public blockchain. To address the issue of low scalability with proof-of-work (PoW) consensus, various methods have been proposed for transaction per second (TPS) improvement. However, no such methods include an improvement in the consensus step. Therefore, to improve PoW public blockchain scalability, it is important to shorten the time required for PoW consensus. This paper proposes a method for minimizing the block intervals that occur during consensus over a PoW blockchain network. A shortened block interval leads to an increase in the probability of three different attacks: selfish mining, double-spending, and eclipse attacks. According to an experiment using Ethereum, with a typical PoW blockchain, it is inevitable to provide rewards for stable block mining in competition between mining pools. To find an optimal block interval in the PoW consensus algorithm, we conducted a four-step experiment. The purpose of this experiment was to verify the difficulty level and issues with Mainnet security. Therefore, considering stale block mining rewards, an optimal block interval is proposed. The Ethereum TPS was improved by at least 200%. Given this finding, it is considered possible to achieve a similar improvement in a different PoW blockchain. On balance, even if the block interval is shorter than that of the PoW Mainnet, network security falls by only 1.21% in Testnet, even with a rise in the stale block rate, while performance is increased at up to 120 TPS, which is three times higher than that in Mainnet.
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.
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.
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.
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.