Wei Cai, Zehua Wang, Jason B. Ernst, Zhen Hong · 6 authors
Blockchain technology has attracted tremendous attention in both academia and capital market. However, overwhelming speculations on thousands of available cryptocurrencies and numerous initial coin offering (ICO) scams have also brought notorious debates on this emerging technology. This paper traces the development of blockchain systems to reveal the importance of decentralized applications (dApps) and the future value of blockchain. We survey the state-of-the-art dApps and discuss the direction of blockchain development to fulfill the desirable characteristics of dApps. The readers will gain an overview of dApp research and get familiar with recent developments in the blockchain.
Blockchain ledgers and the Cloud are a perfect match. On the one hand, there is an inherent requirement for multiple separate authentication nodes to validate every Blockchain transaction with each node requiring substantial encryption calculation capability. On the other hand, massive economies of scale can bring down the cost per transaction, and provide service continuity. Additionally, the Cloud provides a perfect incubator for proof-of-concept projects. This paper considers the future implications of Blockchain, as the concept of disintermediated trustless ledgers stimulates the imagination of computer scientists and innovators. The Cloud’s role in implementing this new paradigm is also highlighted, as a new decentralized P2P-Cloud model. Finally, this paper discusses how Blockchain may be integrated into the university level computer science and information technology curriculum.
Government information resource (GIR) sharing, an important means for efficient government working, requires new technology to enhance its reliability and security. Blockchain, as an emerging technology for building decentralized applications, is gradually penetrating various fields. In this paper, we present a technical combination that consists of Blockchain structure, network sharing model and consensus algorithms. With these techniques, we design and implement a Blockchain-based GIR sharing system (BGIRSS), which is decentralized, to make the sharing procedure more efficient. The results of a series of emulational experiments show that our system is securer and more reliable than conventional sharing schemes, and can effectively promote the sharing efficiency of GIRs with lower implementation cost.
Blockchain uses the idea of storing transaction data in the form of a distributed ledger wherein each node in the network stores a current copy of the sequence of transactions in the form of a hash chain. This requirement of storing the entire ledger incurs a high storage cost that grows undesirably large for high transaction rates and large networks. In this work we use the ideas of secret key sharing, private key encryption, and distributed storage to design a coding scheme such that each node stores only a part of the entire transaction thereby reducing the storage cost to a fraction of its original cost. When further using dynamic zone allocation, we show the coding scheme can also improve the integrity of the transaction data in the network over current schemes. Further, block validation (bitcoin mining) consumes a significant amount of energy as it is necessary to determine a hash value satisfying a specific set of constraints; we show that using dynamic distributed storage reduces these energy costs.
Zehui Xiong, Yang Zhang, Dusit Niyato, Ping Wang · 5 authors
Blockchain, as the backbone technology of the current popular Bitcoin digital currency, has become a promising decentralized approach for resource and transaction management. Although blockchain has been widely adopted in many applications, e.g., finance, healthcare, and logistics, its application in mobile environments is still limited. This is due to the fact that blockchain users need to solve preset proof-of-work puzzles to add new transactions to the blockchain. Solving the proof-of-work, however, consumes substantial resources in terms of CPU time and energy, which is not suitable for resource-limited mobile devices. To facilitate blockchain applications in future mobile Internet of Things systems, multiple access mobile edge computing appears to be an auspicious option to solve the proof-of-work puzzles for mobile users. We first introduce a novel concept of edge computing for mobile blockchain. Then, we introduce an economic approach for edge computing resource management. Moreover, a demonstrative prototype of mobile edge computing enabled blockchain systems is presented with experimental results to justify the proposed concept.
Nelson Bore, Samuel Karumba, Juliet Mutahi, Shelby S. Darnell · 6 authors
Several initiatives have been proposed to collect, report, and analyze data about school systems for supporting decision-making. These initiatives rely mostly on self-reported and summarized data collected irregularly and rarely. They also lack a single independent and systematic process to validate the collected data during its entire lifecycle. Furthermore, schools in developing countries still do not maintain complete and up-to-date school records. Due to these and other factors addressing the education challenges in those countries remains a high priority for local and international governments, donor and non-governmental agencies across the world. In this paper, we discuss our initial design, implementation, and evaluation of a blockchain-enabled School Information Hub (SIH) using Kenya's school system as a case study.
Zehui Xiong, Yang Zhang, Dusit Niyato, Ping Wang · 5 authors
Blockchain, as the backbone technology of the current popular Bitcoin digital currency, has become a promising decentralized data management framework. Although blockchain has been widely adopted in many applications (e.g., finance, healthcare, and logistics), its application in mobile services is still limited. This is due to the fact that blockchain users need to solve preset proof-of-work puzzles to add new data (i.e., a block) to the blockchain. Solving the proof of work, however, consumes substantial resources in terms of CPU time and energy, which is not suitable for resource-limited mobile devices. To facilitate blockchain applications in future mobile Internet of Things systems, multiple access mobile edge computing appears to be an auspicious solution to solve the proof-of-work puzzles for mobile users. We first introduce a novel concept of edge computing for mobile blockchain. Then we introduce an economic approach for edge computing resource management. Moreover, a prototype of mobile edge computing enabled blockchain systems is presented with experimental results to justify the proposed concept.
A blockchain is a distributed transaction ledger, a disruptive technology that creates new possibilities for digital ecosystems. The blockchain ecosystem maintains an immutable transaction record to support many types of digital services. This paper compares the performance and scalability of a web-based groupware communication application using both non-blockchain and blockchain technologies. Scalability is measured where message load is synthesized over two typical communication topologies. The first is 1 to n network -- a typical client-server or star-topology with a central vertex (server) receiving all messages from the remaining n - 1 vertices (clients). The second is a more naturally occurring scale-free network topology, where multiple communication hubs are distributed throughout the network. System performance is tested with both blockchain and non-blockchain solutions using multiple cloud computing configurations. We analyze the empirical results from each configuration to identify the costs and overhead of blockchain technology.
Antonio Fernández Anta, Chryssis Georgiou, Nicolas Nicolaou
In his PODC’2017 keynote address, Maurice Herlihy pointed out that despite the hype about blockchains and distributed ledgers, no formal abstraction of these objects has been proposed. To face this issue, in this paper we provide a proper formulation of a distributed ledger object. In brief, we define a ledger object as a sequence of records, and we provide the operations and the properties that such an object should support. We then provide a variation of the ledger – the validated ledger – which requires that each record in the ledger satisfies a particular validation rule. A (validated) ledger is distributed if it is implemented on top of multiple (possibly geographically dispersed) computing devices.
Raja Sakti Arief Daulay, Surya Michrandi Nasution, Marisa W. Paryasto
The implementation research and analyze address blockchain on this bitcoin will have the results that refers to making address bitcoin a safe and boost security of address the bitcoin. The working mechanism of blockchain in making address bitcoin which is already in the blockchain system.
Chun-Feng Liao, Ching-Ju Cheng, Kung Chen, Chen-Ho Lai · 6 authors
In recent years, Blockchain technology has been highly valued, and the related applications have begun to be developed in large numbers. A smart contract is a software component encompass business logics and transactions that run on a blockchain. Thus, verifying whether the contract logics fully reflect the business requirements are one of the most important software engineering issues in blockchain application development. Currently, developing smart contracts is still a challenging task even for experienced programmers due to the lacking of an integrated tool for developing and testing. In response to this challenge, this paper presents a service platform that supports BDD-style (Behavior-Driven Development) smart contract development, testing, and deployment for the Ethereum-based blockchains. This platform focuses on providing and resolving the cross-cutting concerns across the life-cycle of smart contract development. The feasibility of this platform is shown by demonstrating how an application scenario, namely, loyalty points exchange, can be implemented using the proposed platform. Our experiences indicate that the burdens of developers when developing smart contracts can be effectively reduced and thus increases the quality of contracts.
Nowadays, more and more companies migrate business from their own servers to the cloud. With the influx of computational requests, datacenters consume tremendous energy every day, attracting great attention in the energy efficiency dilemma. In this paper, we investigate the energy-aware resource management problem in cloud datacenters, where green energy with unpredictable capacity is connected. Via proposing a robust blockchain-based decentralized resource management framework, we save the energy consumed by the request scheduler. Moreover, we propose a reinforcement learning method embedded in a smart contract to further minimize the energy cost. Because the reinforcement learning method is informed from the historical knowledge, it relies on no request arrival and energy supply. Experimental results on Google cluster traces and real-world electricity price show that our approach is able to reduce the datacenters cost significantly compared with other benchmark algorithms.
Ethereum, the well-known blockchain platform, does not have any limit for block size, unlike Bitcoin. However, there are other obstacles in processing unlimited transactions per second. Ethereum blockchain code runs by different clients, and they run on different speed and present the different level of performance. This paper studies Ethereum transactions and it analyzes two most popular Ethereum clients, Geth and Parity, on a private blockchain to obtain the better understanding of the effect of different clients on Ethereum performance. The results show that the transactions are 89.8 percent on average faster in Parity client in comparison with Geth client, using the same system configuration.
Blockchain is an emerging technology for decentralized and transactional data sharing across a large network of untrusted participants. It enables new forms of distributed software architectures, where agreement on shared states can be established without trusting a central integration point. As a database and computational platform, blockchain has both advantages and disadvantages compared with conventional techniques. Blockchain may be an appropriate choice for some use cases while conventional technologies will be more appropriate for other use cases. A major difficulty for practitioners to decide whether or not to use blockchain is that limited product data or reliable technology evaluation available to assess the suitability of blockchains. In this paper, we propose an evaluation framework that comprises a list of criteria and a typical process for practitioners to assess the suitability of applying blockchain using these criteria based on the characteristics of the use cases. We then use several existing industrial trails to evaluate the feasibility of our framework.
Bert-Jan Butijn, Damian A. Tamburri, Willem‐Jan van den Heuvel
In recent years, the UK railway industry has struggled with the effects of poor integration of data across ICT systems, particularly when that data is being used across organizational boundaries. Technical progress is being made by the industry towards enabling data sharing, but an open issue remains around how the costs of gathering and maintaining pooled information can be fairly attributed across the stakeholders who draw on that shared resource. This issue is particularly significant in areas such as Remote Condition Monitoring, where the ability to analyse the network at a whole-systems level is being blocked by the business cases around the purchase of systems as silos. Blockchains are an emerging technology that have the potential to revolutionize the management of transactions in a number of industrial sectors. This chapter will address the outstanding issues around the fair attribution of costs and benefits of data sharing in the rail industry by proposing blockchains as a forth enabler of the rail data revolution, alongside ESB, ontology, and open data.
Paolo Missier, Shaimaa Bajoudah, Angelo Capossele, Andrea Gaglione · 5 authors
Internet of Things (IoT) data are increasingly viewed as a new form of massively distributed and large scale digital assets, which are continuously generated by millions of connected devices. The real value of such assets can only be realized by allowing IoT data trading to occur on a marketplace that rewards every single producer and consumer, at a very granular level. Crucially, we believe that such a marketplace should not be owned by anybody, and should instead fairly and transparently self-enforce a well defined set of governance rules. In this paper we address some of the technical challenges involved in realizing such a marketplace. We leverage emerging blockchain technologies to build a decentralized, trusted, transparent and open architecture for IoT traffic metering and contract compliance, on top of the largely adopted IoT brokered data infrastructure. We discuss an Ethereum-based prototype implementation and experimentally evaluate the overhead cost associated with Smart Contract transactions, concluding that a viable business model can indeed be associated with our technical approach.
Adam Brinckman, Donal Luc, Jarek Nabrzyski, Gary L. Neidig · 8 authors
The Cloud computing paradigm is built on the concept of virtualization, allowing multiple virtual machines to cohabit on one physical device to enable the scaling up and down of applications through elastic on-demand provisioning. More recently containers e.g. Docker, have been shown to enable a more lightweight mechanism than hypervisors and proved to be a viable alternative for virtualization, based on shared operating systems. The advent of such lightweight environments has brought a multitude of application uses in research, science and industry, enabling pre-configured operating environments to be shared, reused and instantiated on demand. The sharing of containers has currently been exposed using centralized repositories (e.g. Dockerhub), which allows containers to be shared and to form the building blocks for further development. In this paper, we take a look at the next evolution of this lifecycle and consider whether it is viable to securely share container-based applications within a decentralized group of individuals and to provide an audit trail recording exactly who has shared what, and with whom. For this purpose we consider the use of Blockchain technologies, and consequently perform a comparative analysis of Blockchain technologies for this use case. The paper provides mostly a review and taxonomy of different ledger systems, which we believe may be of interest to the SafeData Workshop participants.
Blockchain technology is a kind of distributed database network, which provides the P2P (Peer-to-Peer) digital currency transaction mode through the encryption algorithm and the decentralized mechanism. This paper is to study the application of blockchain technology related to industry 4.0, and put forward blockchain technology in the cooperative development of power electronic devices. The above application scenario includes a producer and a number of engineers, and they are trading on the blockchain. The producer publishes the special requirement of power electronic device which has a preference considering the conflicts between different parameters to apply to his certain industrial scenario. The participants are to design the power supply topology in accordance with the parameters required by the producer. When all parameters are satisfied the order of the producer, it is about to complete the transaction. All participants are required to provide true data of their topology design models.
The emerging blockchain technologies have enabled development of crypto-currencies and autonomous smart contracts that can operate in decentralized and trustless settings. Distributed autonomous organizations can be implemented using smart contracts available on the Ethereum blockchain. In this paper, we propose a distributed autonomous software organization model and its Ethereum smart contract implementation called AutonomousSoftwareOrg for providing a continuously operating virtual organization for software development communities and users. AutonomousSoftwareOrg facilitates a funding mechanism based on crypto-currencies, a decision making mechanism based on voting and record keeping for software usage citations and executions. AutonomousSoftwareOrg is deployed and tested on our local Ethereum based blockchain system (http://ebloc.cmpe.boun.edu.tr). Its Solidity language source code is available at https://github.com/ebloc/AutonomousSoftwareOrg.
Du Mingxiao, Xiaofeng Ma, Zhang Zhe, Xiangwei Wang · 5 authors
Blockchain is the basic technology of bitcoin. With the value appreciation and stable operation of bitcoin, blockchain is attracting more and more attention in many areas. Blockchain has the characteristics of decentralization, stability, security, and non-modifiability. It has the potential to change the network architecture. The consensus algorithm plays a crucial role in maintaining the safety and efficiency of blockchain. Using a right algorithm may bring a significant increase to the performance of blockchain application. In this paper, we reviewed the basic principles and characteristics of the consensus algorithms and analyzed the performance and application scenarios of different consensus mechanisms. We also gave a technical guidance of selecting a suitable consensus algorithm and summarized the limitations and future development of blockchain technology.
A BlockChain is an open record of all digital money exchanges that have ever been executed. It is constantly growing as ‘completed’ blocks are added to it with a new set of recordings. The blocks are added to the blockchain in a linear, chronological order. Each PC associated with the Bitcoin systematize a customer that plays out the task of approving and handing-off exchanges gets a duplicate of the blockchain, which gets downloaded naturally after joining the Bitcoin arrange. The blockchain has finish data about the addresses and their adjusts ideal from the beginning piece to the most as of late finished square. Transactions between individuals have always been a part and parcel of human society for the division of labour made people interdependent. The medium of transaction has also been evolving along with the evolution of society and human consciousness from barter system to commodity money to fiat currency and now to digital currency or cryptocurrency. But as the evolution is a form of error correction, the problem of double spending in digital currency was solved by a distributed ledger system called BlockChain. Since 2008 onwards the blockchain technology has been separated from Bitcoins to be injected to many other problems related especially to banking transactions. Blockchain innovation empowers the production of decentralized monetary forms, savvy contracts and clever resources that can be controlled over the Internet.
Michael A. Walker, Abhishek Dubey, Áron Lászka, Douglas C. Schmidt
With the advent of blockchain-enabled IoT applications, there is an increased\nneed for related software patterns, middleware concepts, and testing practices\nto ensure adequate quality and productivity. IoT and blockchain each provide\ndifferent design goals, concepts, and practices that must be integrated,\nincluding the distributed actor model and fault tolerance from IoT and\ntransactive information integrity over untrustworthy sources from blockchain.\nBoth IoT and blockchain are emerging technologies and both lack codified\npatterns and practices for development of applications when combined. This\npaper describes PlaTIBART, which is a platform for transactive IoT blockchain\napplications with repeatable testing that combines the Actor pattern (which is\na commonly used model of computation in IoT) together with a custom Domain\nSpecific Language (DSL) and test network management tools. We show how\nPlaTIBART has been applied to develop, test, and analyze fault-tolerant IoT\nblockchain applications.\n
Hyperledger Fabric (HLF) is a flexible permissioned blockchain platform designed for business applications beyond the basic digital coin addressed by Bitcoin and other existing networks. A key property of HLF is its extensibility, and in particular the support for multiple ordering services for building the blockchain. Nonetheless, the version 1.0 was launched in early 2017 without an implementation of a Byzantine fault-tolerant (BFT) ordering service. To overcome this limitation, we designed, implemented, and evaluated a BFT ordering service for HLF on top of the BFT-SMaRt state machine replication/consensus library, implementing also optimizations for wide-area deployment. Our results show that HLF with our ordering service can achieve up to ten thousand transactions per second and write a transaction irrevocably in the blockchain in half a second, even with peers spread in different continents.