Abdullah Ayub Khan, Zaffar Ahmed Shaikh, Лаура Байтенова, Lyailya Mutaliyeva · 9 authors
Quality-of-service (QoS) is the term used to evaluate the overall performance of a service. In healthcare applications, efficient computation of QoS is one of the mandatory requirements during the processing of medical records through smart measurement methods. Medical services often involve the transmission of demanding information. Thus, there are stringent requirements for secure, intelligent, public-network quality-of-service. This paper contributes to three different aspects. First, we propose a novel metaheuristic approach for medical cost-efficient task schedules, where an intelligent scheduler manages the tasks, such as the rate of service schedule, and lists items utilized by users during the data processing and computation through the fog node. Second, the QoS efficient-computation algorithm, which effectively monitors performance according to the indicator (parameter) with the analysis mechanism of quality-of-experience (QoE), has been developed. Third, a framework of blockchain-distributed technology-enabled QoS (QoS-ledger) computation in healthcare applications is proposed in a permissionless public peer-to-peer (P2P) network, which stores medical processed information in a distributed ledger. We have designed and deployed smart contracts for secure medical-data transmission and processing in serverless peering networks and handled overall node-protected interactions and preserved logs in a blockchain distributed ledger. The simulation result shows that QoS is computed on the blockchain public network with transmission power = average of −10 to −17 dBm, jitter = 34 ms, delay = average of 87 to 95 ms, throughput = 185 bytes, duty cycle = 8%, route of delivery and response back variable. Thus, the proposed QoS-ledger is a potential candidate for the computation of quality-of-service that is not limited to e-healthcare distributed applications.
Andrés Heredia, Maria-Jose Barros, Gabriel Barros-Gavilanes
When the monetary or financial value is not take into account in blockchain, there is still room for a digital ledger system for universities. As in any institution, universities have processes defined in a unique way, involving many verification steps. Issuance of end-of-course certificates requires fulfillment of multiple requirements, i.e. signatures from authorities, instructors and in some cases administrative staff. This work presents an initial work for certificates issuance using blockchain for education purposes. We generate a prototype including no signature but registered nodes to record transactions over the infrastructure generated for the Smart Ecosystem for Learning and Inclusion or SELI project. This prototype records certificates in a private non-monetary blockchain network, and is provided as an open source project. Countries like Ecuador, Turkey, Uruguay, and Finland can share certificates from the SELI platform through local nodes. This article provides relevant details about the implementation of the system, always with the aim of reusing existing software to reduce implementation time. The main result is that the project has generated a simple international university network with three countries for the exchange of certificates.
The energy sector is facing increasing risks, mainly concerning fraudulent activities and cyberattacks. This paradigm shift in risks would require innovative solutions. This paper proposes an innovative architecture based on Distributed Ledger Technologies (Blockchain) and Triple Entry Accounting (X-Accounting). The proposed architecture focusing on new applications of payment and billing would improve accountability and compliance as well as security and reliability. Future research can extend this architecture to other energy technologies and systems like EMS/SCADA and associated applications.
Runkai Yang, Xiaolin Chang, Jelena Mišić, Vojislav B. Mišić
Bitcoin and Ethereum are the top two blockchain-based cryptocurrencies whether from cryptocurrency market cap or popularity. However, they are vulnerable to selfish mining and stubborn mining due to that both of them adopt Proof-of-Work consensus mechanism. In this paper, we develop a novel Markov model, which can study selfish mining and seven kinds of stubborn mining in both Bitcoin and Ethereum. The formulas are derived to calculate several key metrics, including relative revenue of miners, blockchain performance in terms of stale block ratio and transactions per second, and blockchain security in terms of resistance against double-spending attacks. Numerical analysis is conducted to investigate the quantitative relationship between the relative-revenue-optimal mining strategy for malicious miners and two miner features in Bitcoin and Ethereum, respectively. The quantitative analysis results can assist honest miners in detecting whether there is any malicious miner in the system and setting the threshold of mining node's hash power in order to prevent malicious miners from making profit through selfish and stubborn mining.
The current micro-teaching process is readily online, and it is functional anywhere and anytime ubiquitously. All or most teaching and learning activities are accessible in centralized storage. However, centralized storage has inherent problems, such as a single point of failure with many possible data breaches, much duplication of data stored repeatedly in one location, and the lack of trust in third parties for data stored in centralized storage. Further issues include the high cost and low performance of the online systems that hinder the quality of the education process. In this paper, we propose a new framework Education Exchange Storage Protocol (EESP). EESP aims to improve the efficiency of the decentralized storage ecosystem in micro-teaching, coupled with blockchain technology acting as a control layer. Blockchain empowers the decentralized system by bringing together the most incompatible unstructured entities and integrate them. The decentralized storage system is armed with a blockchain smart contract that acts as a control layer, featuring impregnable security, immutability, trace-ability, and transparency. The EESP framework aims to elevate teaching and learning through blockchain decentralized storage systems in a transformational way, including but not limited to things like micro-credential, massive open online courses, and gamification, all in a single immersive learning platform. Finally, we tested and evaluated this framework using the truffle simulator, and the results demonstrate that the EESP model significantly improves performance.
This paper conducts a performance analysis of popular blockchain platforms, RISC-V, to assess the performance and limitations of these state-of-the-art platforms. This paper performs a performance analysis of popular blockchain platforms, RISC-V, to evaluate the performance and limitations of these state-of-the-art platforms. Blockchain, a decentralized transaction and data management technology, is the technology that will have similar impacts as the Internet had on people's lives. Many industries have become interested in adopting blockchain in their IT systems, but scalability is an often-cited concern of current blockchain technology. Therefore, the goal of this article, to analyze and compare the performances of var-ious hardware platforms available for blockchain. The plat-forms preferred for conducting this research works are X86, ARM, and RISC-V. The computational capabilities have been showcased and elaborated in detail. First, the compatibility of the blockchain has been checked with Ethereum. Second, critical parameters like time and space complexity are considered to find the best suitable platform.
Blockchain is a popular topic of research in recent years. For worthwhile research into the use Blockchains, they often must be deployed into environments that are as close to real-world scenarios as possible. Real-world networks are large and complex and therefore the Blockchains used to research them should be large and complex. Creating large Blockchains like this may seem out-of-reach for the humble researcher. The tool introduced in this paper - Containerchain - seeks to make it much easier to spin up a large Blockchain system with little-or-no setup. The ultimate goal being to allow researchers to spend more time on actual research, rather than on setting up the network. Containerchain allows the user to deploy a real Blockchain system (not simulated) with several configurable parameters at their disposal. The user can control the number of nodes in the system, the consensus mechanism used and can observe and analyze the network traffic in the Blockchain - which is recorded out-of-the-box.
Blockchain has attracted wide attention in both industry and academia due to its decentralized and anti-tamper characteristics. To query the blockchain data, all the transactions in the blockchain must be iterated one by one, which is quite inefficient. Existing solutions improve the query efficiency by exporting transactions to external databases, and yet they incur the incompleteness and incorrectness of query results. To avoid above weaknesses, we propose an efficient query method based on the internal blockchain database and apply it to the construction engineering management to solve the problems of information management. In our design, we construct a dual-index based on the B+ tree and the key-value pair through smart contracts, and it supports multiple query operations, such as range query and file-type query. We implement the designed method by simulating the blockchain testbed and the experimental results demonstrate the efficiency of our design.
Sukrutha L. T. Vangipuram, Saraju P. Mohanty, Elias Kougianos
This is a demo abstract based on our previously published article [1]. Some of the significant challenges of central cloud systems and the blockchain include lack of scalability, security risks and higher energy consumption. As a solution, an application with an off-chain Interplanetary File System (IPFS) distributed storage system is presented as CoviChain. The IPFS is used for storing and hashing different data formats of various sizes into immutable links. The links are passed through smart contracts of the Ethereum blockchain to provide a double hash guarantee, along with user access permissions.
Eranga Bandara, Deepak K. Tosh, Sachin Shetty, Bheshaj Krishnappa
For operational efficiency, enterprise-level Energy Delivery Systems (EDS) rely on a number of software or hardware providers. Overseas suppliers generally manufacture and integrate critical EDS components, increasing the attack surface for adversaries looking to enter EDS (e.g., the recent SolarWinds supply chain attack). The EDS supply chain requires cyber risk management that can track cyber vulnerabilities, establish quantifiable mechanisms to understand the severity and exploitability of EDS applications while providing a remediation plan to effectively mitigate such risks. In this work, we propose a Cyber Supply Chain Provenance platform for EDS by leveraging distributed ledger technology for enabling cyber risk management capability to defend and respond to cyber supply-chain attacks (e.g., SolarWinds) and establish data provenance in a cyber supply chain ecosystem.
Ali Shahaab, Imtiaz Khan, Ross Maude, Chaminda Hewage
Public service organisations (PSOs) have a need to collaborate with each other in order to provide a seamless user experience, mitigate fraud and increase operational efficiency at a reduced tax payer's cost. However, legacy systems built over decades using different technology stacks, make collaboration challenging and hinder efficiency. Distributed ledger technologies (DLTs) have been proposed as a trust and efficiency mechanism for several inter organisation collaborative tasks. They can reduce friction in operations and help achieve a more streamlined and unified public service infrastructure. However, most of the work are either based on theory or purely conceptual and lack implementation. In this paper, we elaborate on the design and implementation of a proof of concept (POC) of a blockchain based interoperability and data sharing system that allows PSOs to seamlessly collaborate and share information in real time. The POC is based on the Registration of Overseas Entities and Beneficial Owners (ROEBO) legislation in the UK and demonstrates interactions between Companies House UK and other PSOs in a hybrid blockchain setting.
Since version 0.11 of Bitcoin Core, a user can run a full node in pruning mode, i.e. a pruned node, in resource-limited devices. The pruned node is a lightweight full node as it can independently verify new transactions and blocks received from other peers in the Bitcoin network by only maintaining some recently verified blocks (not the complete blockchain) and the complete Unspent Transaction Output (UTXO) set. However, the rapid increase in the size of the UTXO set has caused the main part of the UTXO set to be stored in the low-speed disk, and thus slows down the verification speed of new blocks in lightweight full nodes. Existing verification schemes for pruned nodes do not take advantage of the fact that different UTXO-related transactions are included in a new block with different probabilities, resulting in poor verification performance. In this paper, we propose a prediction-based UTXO cache optimization mechanism to increase the verification speed of new blocks. In order to achieve higher prediction accuracy and reduce the memory requirements of UTXO set, we first design a method to synchronize unconfirmed transactions for lightweight full nodes to ensure that the local and miners' unconfirmed transaction sets are highly consistent. Then, a lightweight full node predicts which unconfirmed transactions will have a greater probability of appearing in the new block by utilizing the fact that most miners will prioritize unconfirmed transactions to maximize the total transaction fee when mining a new block. Based on this mechanism, we can pre-load the UTXOs required for new block verification into the memory, thereby greatly improving the verification performance. Experimental results show that the proposed mechanism can accelerate the block verification of lightweight full nodes with small memory requirements.
Due to the high interest in the past few years, blockchain technology benefited from a fast increase in adoption rate as well as fast evolution. One of the crucial points in the blockchain space, the consensus mechanism, generally still suffers from lack of development, thus decreasing the adoption of the technology in big scale projects and daily use. Older-established consensus algorithms, such as Proof of Work (PoW) and Proof of Stake (PoS), suffer from various flaws, ranging from the high costs of maintaining a node in the network and generating new blocks, to the risk of being affected by a series of attacks, as well potential of network monopoly by various entities. This paper proposes a model of a democratically-governed consensus algorithm that is focused on a fair distribution of assets, with a fast and secure way of validating and distributing the blocks, while being impervious to a sizeable range of attacks.
At an era of new emerging technologies, and spotting lights to blockchain technology specifically; many promises take place. Blockchain has attracted many researchers and practitioners from various professions and disciplines, due to the powerful characteristics behind adopting such technology. And in order to formulate a better understanding of it, many researchers are interested in classifying the Blockchain-Based Software Systems (BBSSs). Unfortunately, none of the available taxonomies in the literature considers the various Software Engineering (SWE) aspects for building a BBSS. A blockchain subject matter expert (SME) may absorb a specific aspect understanding from each of the related taxonomies, and in order to have a complete understanding of the various options available for building a BBSS, they will have to flip from a resource to another in order to collect the scattered information they need. So, this paper aims to assist the blockchain SMEs to articulate a comprehensive understanding of the various and most recent concepts and design decisions available, in order to implement or propose a BBSS solution. The taxonomy is derived from the fundamental knowledge and the major SWE aspects which a BBSS implementer or researcher has to consider, and thus is not biased to a specific SWE aspect.
With the evolution and proliferation of blockchain, the technology is becoming more prevalent in enterprise software development. Using the already proven DevOps approach in this setting makes sense, as it can accelerate the general pace of software development and delivery, improve software quality, and increase overall productivity. However, there is currently a lack of guidance on a structured DevOps approach and a breakdown of the specifics in the context of blockchain-based software development. Therefore, we combined gray literature and DevOps application studies from pertinent GitHub projects to systematically investigate current practices and solution approaches for an efficient blockchain-oriented DevOps procedure. In this process, we elaborated procedural steps and related activities according to the main stages of Continuous Integration and Continuous Delivery. Our research shows that core DevOps concepts and activities are similar to other areas and are entirely possible with already established CI/CD solutions that orchestrate the right tools, with the difference that more rigorous testing and differentiated deployment practices are required due to the inherent immutability of blockchain.
Abstract Cloud federations offer numerous advantages such as improved resilience, improved performance, and the prevention of vendor lock‐in. In order to function efficiently, however, they must be supported by automated solutions to deploy cloud resources securely and efficiently. In particular, a system which allows virtual machine (VM) migration from one cloud to another while recording this for charging and security purposes is particularly useful. This paper presents a lightweight framework called BlockchainBus which offers secure VM migration in cloud federations using blockchain. This framework is a VM migration Blockchain ledger which can be used to record these migrations. BlockchainBus framework is implemented using the HyperLedger solution and deployed on the Microsoft Azure cloud platform. The overhead of this system is then evaluated. The performance of the BlockchainBus framework was compared with the overall VM migration time and was determined as 2.36 seconds. This result is shorter than the overall VM migration time of 5 seconds and indicates that the BlockchainBus gives better performance.
The Ethereum ecosystem was maintained by a distributed global network of computers that required massive amounts of computational power. Previous work on estimating the energy use and emissions of the Ethereum network has relied on top-down economic analysis and rough estimates of hardware efficiency and emissions factors. In this work we provide a bottom-up analysis that works from hashrate to an energy usage estimate, and from mining locations to an emissions factor estimate, and combines these for an overall emissions estimate. We analyze the entire history of PoW Ethereum, from creation to the merge.
Cloud computing has become an important technology for the processing of large computationally expensive programs and data from real-world. IT organizations are en-trusting the cloud vendors for the security of their computational infrastructures including the data. Thus, there is a need for better provenance assurance for the data present in the cloud for better security and to establish trust between the cloud vendors and customers. Blockchain technology operates in a decentralized way for building trust between the entities in the system using immutable ledger. In this work, we propose the decentralized and trusted cloud data provenance mechanism using Ethereum blockchain platform, IPFS and scalable consensus mechanism. PoW is the consensus algorithm currently used in Ethereum Blockchain. PoW consensus mechanism needs lot of computational power for the processing of data in the Blockchain. Thus, we implement Proof of Stake (POS) consensus algorithm in Ethereum to improve the efficiency of the proposed data provenance mechanism. We demonstrate the performance of PoS-enabled provenance framework in a multi-node testbed. The results reveal that POS performs better than PoW for cloud data provenance.
Jignesh Karia, Mukundan Sundararajan, G Srinivasa Raghavan
Master Data Management (MDM) in enterprises deal with fixed data/information regarding different aspects of business that are considered single record of truth and form the basis for all business transactions. Enterprises manage their master data by several methods to ensure that it is a unique comprehensive representation of the entity by spending considerable resources in MDM but at the cost of time delays for updating the master data records or structure and with copies of the master data distributed across the enterprise units for operational needs that many times has modifications not reflected back into the master tables. Issues of delays in the master data updates lead to business impacts while the distributed nature of master data across an organization or organizations impacts data quality. Distributed ledger technology (DLT) is one approach that uses blockchain to obtain consensus to cut down the approval cycle time and the distributed nature makes it uniquely suited to manage synchronizing master data updates across the network of required users in the enterprise. Choice of correct business processes to benefit from using DLT for MDM is critical to obtain benefits from improvements. This paper shows a method to select from candidate business processes with coarse or fine process data and the value that can be gained from implementation of DLT for MDM.
N. Sánchez-Gómez, Jesús Torres Valderrama, M. Mejías, Alejandra Garrido
One of the key benefits of blockchain technology is its ability to keep a permanent, unalterable record of transactions. In business environments, where companies interact with each other without a centralized authority to ensure trust between them, this has led to blockchain platforms and smart contracts being proposed as a means of implementing trustworthy collaborative processes. Software engineers must deal with them to ensure the quality of smart contracts in all phases of the smart contract lifecycle, from requirements specifications to design and deployment. This broad scope and criticality of smart contracts in business environments means that they have to be expressed in a language that is intuitive, easy-to-use, independent of the blockchain platform employed, and oriented towards software quality assurance. In this paper we present a key component: a first outline of a UML-based smart contract meta-model that would allow us to achieve these objectives. This meta-model will be enriched in future work to represent blockchain environments and automated testing.
This paper examines the features of blockchain technology from the viewpoint of those responsible for external financial reporting and their auditors. Financial professionals worry about the potential disconnect between digital and real-world transactions that can create potentially misleading illusions-of-truth. The largest objection from financial professionals surrounds the widespread assertion that the consensus verification may replace the financial statements or their required audit. The discussion explains why verified “on chain” data falls considerably short of audited financial statements. In a structured literature review, this work contrasts the treatment of blockchain’s consensus verification feature in IT and accounting literature over a four-year period, showing a dramatic increase in this topic but little convergence between IT and financial communities on the problems with blockchain verification in auditing contexts. Knowing the auditing community’s concerns, as explored in this work, can help direct future developments in blockchain technology and target implementation suited to user needs.
Aleksandr Zavodovski, Lorenzo Corneo, Andreas Johnsson, Nitinder Mohan · 8 authors
Edge computing promises to bring computation close to the end-users to support emergent applications such as virtual reality. However, the computational capacity at the edge of the network is currently limited. To become a pervasive paradigm, edge computing needs highly dispersed decentralized deployments, that, contrary to cloud, cannot benefit from economies of scale. In this situation, crowdsourcing appears attractive - there are plenty of computing devices at the disposal of the general public, and these devices are located exactly where computing power is needed the most - at the edge of the network. Crowdsourcing has been a success maker for scientific computing projects, e.g., [email protected], or distributed ledger systems empowering decentralized finance. However, as of now, there is no crowdsourced system that addresses the needs of edge computing. In this position paper, we aim to identify the causes of this shortcoming, analyze the potential ways to overcome it, and outline future directions.
Guichun Yuan, Liuping Feng, Jing Ning, Xiaoyu Yang
The PBFT (Practical Byzantine Fault Tolerant) is a consensus algorithm widely used in alliance blockchain, but there are some problems of high communication overhead and high latency. Therefore, the original PBFT consensus algorithm is improved in the paper. Firstly, the voting mechanism is introduced for the original PBFT algorithm. The nodes are divided into two classes: consensus node and ordinary node. The primary node is selected from the consensus nodes to lead the consensus process to ensure the reliability of the consensus results. Secondly, the consensus process of PBFT algorithm was optimized. The consensus process is simplified into three phases, which reduces the algorithm complexity and improves the consensus efficiency. The experiment shows that our improved PBFT algorithm has better performance than the original PBFT algorithm in communication overhead and consensus delay.