As the number of Web APIs is rapidly increasing, it is an urgent issue to discover qualified Web APIs and provide value-added services by orchestrating them. However, most of the interface descriptions of Web APIs are informal, and the Web API SLA contracts, which are a key to quality of services orchestration, require manual operations at the consumers. Meanwhile, applying the blockchain, the distributed ledger technology, to various domains beyond Fintech is attracting attention because of its fault-tolerant and anti-tampering. However, it isn't applied to Web API SLA contracts, yet. In this article, the authors propose a formal specification description of Web APIs together with its associated SLA specifications based on RDF, and an SLA contract method based on the common SLA contract platform built on the blockchain. We implemented the prototype of the SLA contract platform, and applied it to the examples for demonstrating its feasibility. Those experiences prove the feasibility of the proposed Web API SLA contract method and its supporting platform.
Xiang Fu, Wang Huaimin, Shi Peichang, Yingwei Fu · 5 authors
With the development of Economic Globalization, traditional single-cloud providers can not meet the needs of the explosive, global, diverse cloud services. JointCloud aims at empowering the cooperation among multiple Cloud Service Providers (CSP) to provide cross-cloud services. Our work in this paper is mainly focused on the accounting technology for JointCloud computing and we propose the JCLedger - a blockchain based distributed ledger. A new participant CCP (Cryptocurrency Provider) is introduced into the JointCloud collaboration environment to provide the cryptocurrency transferred. We have a detailed description of JCLedger model. We further analyze the four most important mechanisms for JCLedger and provide basic perspectives for in-depth analysis. Finally, we discuss the innovations of JCLedger and our future work in this field.
ABSTRACT Since 2009, blockchain has served as a potentially transformative information technology expected to be as revolutionary as the Internet. Originally developed as a methodology to record cryptocurrency transactions, blockchain's functionality has evolved into a large number of applications, such as banking, financial markets, insurance, voting systems, leasing contracts, and government service. Despite such advancements, the application of blockchain to accounting and assurance remains under-explored. This paper aims to provide an initial discussion on how blockchain could enable a real-time, verifiable, and transparent accounting ecosystem. Additionally, blockchain has the potential to transform current auditing practices, resulting in a more precise and timely automatic assurance system.
Tien Tuan Anh Dinh, Ji Wang, Gang Chen, Rui Liu · 6 authors
Blockchain technologies are taking the world by storm. Public blockchains, such as Bitcoin and Ethereum, enable secure peer-to-peer applications like crypto-currency or smart contracts. Their security and performance are well studied. This paper concerns recent private blockchain systems designed with stronger security (trust) assumption and performance requirement. These systems target and aim to disrupt applications which have so far been implemented on top of database systems, for example banking, finance and trading applications. Multiple platforms for private blockchains are being actively developed and fine tuned. However, there is a clear lack of a systematic framework with which different systems can be analyzed and compared against each other. Such a framework can be used to assess blockchains' viability as another distributed data processing platform, while helping developers to identify bottlenecks and accordingly improve their platforms.
Until now, most systems for Internet of Things (IoT) management, have been designed in a Cloud-centric manner, getting benefits from the unified platform that the Cloud offers. However, a Cloud-centric infrastructure mainly achieves static sensor and data streaming systems, which do not support the direct configuration management of IoT components. To address this issue, a virtualization of IoT components (Virtual Resources) is introduced at the edge of the IoT network. This research also introduces permission-based Blockchain protocols to handle the provisioning of Virtual Resources directly onto edge devices. The architecture presented by this research focuses on the use of Virtual Resources and Blockchain protocols as management tools to distribute configuration tasks towards the edge of the IoT network. Results from lab experiments demonstrate the successful deployment and communication performance (response time in milliseconds) of Virtual Resources on two edge platforms, Raspberry Pi and Edison board. This work also provides performance evaluations of two permission-based blockchain protocol approaches. The first blockchain approach is a Blockchain as a Service (BaaS) in the Cloud, Bluemix. The second blockchain approach is a private cluster hosted in a Fog network, Multichain
May 1, 2017·2017 IEEE 3rd International Conference on Big Data Security on Cloud (BigDataSecurity), IEEE International Conference on High Performance and Smart Computing, (HPSC) and IEEE International Conference on Intelligent Data and Security (IDS)
The increasing popularity of blockchain-based cryptocurrencies has made scalability a primary and urgent concern. Compared with the completely open, uncontrolled public blockchain system, private blockchain can provide better access control management. This paper proposes an architecture for distributed private blockchain. At the same time, we propose three strategies to improve the scalability of private blockchain: optimization of block construction, block size and time control optimization, and transaction security mechanism optimization. This system also redesigns the format of the trading, block structure and the way how system constructs blocks, makes it more suitable for the requirements of the private blockchain. From experiment results, we show that our system achieves better performance and scalability without compromising security guarantees.
Blockchain platforms, such as Ethereum, promise to facilitate transactions on a decentralized computing platform among parties that have not established trust. Recognition of the unique challenges of blockchain programming has inspired developers to create domain-specific languages, such as Solidity, for programming blockchain systems. Unfortunately, bugs in Solidity programs have recently been exploited to steal money. We propose a new programming language, Obsidian, to make it easier for programmers to write correct programs.
Xueping Liang, Sachin Shetty, Deepak K. Tosh, Charles Kamhoua · 6 authors
Cloud data provenance is metadata that records the history of the creation and operations performed on a cloud data object. Secure data provenance is crucial for data accountability, forensics and privacy. In this paper, we propose a decentralized and trusted cloud data provenance architecture using blockchain technology. Blockchain-based data provenance can provide tamper-proof records, enable the transparency of data accountability in the cloud, and help to enhance the privacy and availability of the provenance data. We make use of the cloud storage scenario and choose the cloud file as a data unit to detect user operations for collecting provenance data. We design and implement ProvChain, an architecture to collect and verify cloud data provenance, by embedding the provenance data into blockchain transactions. ProvChain operates mainly in three phases: (1) provenance data collection, (2) provenance data storage, and (3) provenance data validation. Results from performance evaluation demonstrate that ProvChain provides security features including tamper-proof provenance, user privacy and reliability with low overhead for the cloud storage applications.
Lijun Wu, Kun Meng, Shuo Xu, Shuqin Li · 6 authors
Blockchain is attracting more and more attentions from many kinds of fields, such as finance, industry, and theory researchers. Rather than viewing blockchain as a novel technology, we should think it as an innovation for managing digital society, which provides fundamental principles to support democratically distributed applications. Based on the design and application of the Energy Internet, this paper analyzes the core architecture of the initial blockchain technology, and combines the security of the public chain with the efficiency of the private chain, solving the poor efficiency problem of the initial blockchain by using the high efficiency of private chain. At the same time, it inherits the security and non-tampering of initial blockchain. This paper designs a new hybrid blockchain storaging mode that is Block Static Storage(BSS, internal structure is N+X hybrid blockchain, following can be referred to as N+X HBC),for purpose that improving the overall efficiency of the Internet running, achieving decentralized supervision, and provoding a credible, safe and efficient performance of the Energy Internet in the storage of its massive data, as well as a huge business system.
Rajitha Yasaweerasinghelage, Mark Staples, Ingo Weber
Blockchain is an emerging technology for sharing transactional data and computation without using a central trusted third party. It is an architectural choice to use a blockchain instead of traditional databases or protocols, and this creates trade-offs between non-functional requirements such as performance, cost, and security. However, little is known about predicting the behaviour of blockchain-based systems. This paper shows the feasibility of using architectural performance modelling and simulation tools to predict the latency of blockchain-based systems. We use established tools and techniques, but explore new blockchain-specific issues such as the configuration of the number of confirmation blocks and inter-block times. We report on a lab-based experimental study using an incident management system, showing predictions of median system level response time with a relative error mostly under 10%. We discuss how the approach can be used to support architectural decision-making, during the design of blockchain-based systems.
Paul Rimba, An Binh Tran, Ingo Weber, Mark Staples · 6 authors
Blockchain is of rising importance as a technology for engineering applications in cross-organizational settings, avoiding reliance on central trusted third-parties. The use of blockchain, instead of traditional databases or services, is an architectural choice in the development of a software system. The costs of execution and storage are important non-functional qualities, but as yet very little has been done to study them for blockchain-based systems. We investigate the cost of using blockchain using business process execution as a lens. Specifically, we compare the cost for computation and storage of business process execution on blockchain vs. a popular cloud service. First, we capture the cost models for both alternatives. Second, we implemented and measured the cost of business process execution on blockchain and cloud services for an example business process model from the literature. We observe two orders of magnitude difference in this cost.
Blockchain is an emerging technology for decentralised 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. A major difficulty for architects designing applications based on blockchain is that the technology has many configurations and variants. Since blockchains are at an early stage, there is little product data or reliable technology evaluation available to compare different blockchains. In this paper, we propose how to classify and compare blockchains and blockchain-based systems to assist with the design and assessment of their impact on software architectures. Our taxonomy captures major architectural characteristics of blockchains and the impact of their principal design decisions. This taxonomy is intended to help with important architectural considerations about the performance and quality attributes of blockchain-based systems.
The Internet of Things (IoT) technology has a potential to bring the benefits of intelligently interconnecting not just computers and humans, but most of everyday things. IoT has a promise of opening significant business process improvement opportunities leading to economic growth and cost reductions. However, there are many challenges facing IoT, including significant scalability and security challenges due to the integration of potentially huge number of things into the network. Many of scalability and security issues stem from a centralized, primarily client/server, architecture of IoT systems and frameworks. Blockchain technology, as a relativelly new approach to decentralized computation and assets management and transfer, has a potential to help solve a number of scalability and security issues that IoT is facing, primarilly through the removal of centralized points of failure for such systems. As such, blockchain technology and IoT integration provides a promising direction and it has recently generated significant research interest, e.g., [4].
Distributed ledger technology, a method of storing and maintaining the integrity of multiple copies of critical data using a massively redundant network of participating machines, has found a “killer application” in blockchain, a type of distributed ledger. A blockchain consists of sequential blocks that may never be modified or reordered, leaving a public, auditable record that is consistent and highly resistant to tampering and deletion. These qualities make blockchain eminently suitable for its most common use, cryptocurrency, and its occasional variants in the form of cryptocurrency tokens, used to represent ownership or some other right to virtual or physical goods and capabilities. Blockchain also enables smart contracts, discrete bodies of software written to serve both as the memorial and the means of execution of an agreement between parties. Smart contracts can have all the elements of a traditional contract, and as jurisdictions legislate or jurists rule on the fine points of enforceability and the acceptability of smart contracts as traditional contracts, applications in nearly every area of commerce have emerged. Digital lawyers may not need to become software developers, but deepening their understanding of the capabilities and limitations of the technology, developing a keen awareness of the issues at the intersection between code and the law, as well as the law’s readiness in this area, will be of great advantage to them and their clients in this rapidly evolving area at the intersection of technology, commerce and law.
Tien Tuan Anh Dinh, Ji Wang, Gang Chen, Rui Liu · 6 authors
Blockchain technologies are taking the world by storm. Public blockchains, such as Bitcoin and Ethereum, enable secure peer-to-peer applications like crypto-currency or smart contracts. Their security and performance are well studied. This paper concerns recent private blockchain systems designed with stronger security (trust) assumption and performance requirement. These systems target and aim to disrupt applications which have so far been implemented on top of database systems, for example banking, finance applications. Multiple platforms for private blockchains are being actively developed and fine tuned. However, there is a clear lack of a systematic framework with which different systems can be analyzed and compared against each other. Such a framework can be used to assess blockchains' viability as another distributed data processing platform, while helping developers to identify bottlenecks and accordingly improve their platforms. In this paper, we first describe BlockBench, the first evaluation framework for analyzing private blockchains. It serves as a fair means of comparison for different platforms and enables deeper understanding of different system design choices. Any private blockchain can be integrated to BlockBench via simple APIs and benchmarked against workloads that are based on real and synthetic smart contracts. BlockBench measures overall and component-wise performance in terms of throughput, latency, scalability and fault-tolerance. Next, we use BlockBench to conduct comprehensive evaluation of three major private blockchains: Ethereum, Parity and Hyperledger Fabric. The results demonstrate that these systems are still far from displacing current database systems in traditional data processing workloads. Furthermore, there are gaps in performance among the three systems which are attributed to the design choices at different layers of the software stack.
The Hyperledger Project is a Linux Foundation initiative to develop an open source ecosystem of blockchain development. The Linux Foundation aims to create an environment in which communities of software developers and companies meet and coordinate to build blockchain frameworks. Hyperledger itself is not another cryptocurrency, but rather an open hub for enterprise-grade blockchain projects to incubate and mature through all stages of development and commercialization. In this chapter, we talk about the current state of the Hyperledger Project, with a focus on the currently incubating projects, a summary of the project scope being implemented, and a review of the comprehensive set of technologies involved in creating an open source enterprise-grade blockchain.
Marco Baldi, Franco Chiaraluce, Emanuele Frontoni, Giuseppe Gottardi · 6 authors
Public key infrastructures (PKIs) are of crucial importance for the life of online services relying on certificate-based authentication, like e-commerce, e-government, online banking, as well as e-mail, social networking, cloud services and many others. One of the main points of failure (POFs) of modern PKIs concerns reliability and security of certificate revocation lists (CRLs), that must be available and authentic any time a certificate is used. Classically, the CRL for a set of certificates is maintained by the same (and sole) certification authority (CA) that issued the certificates, and this introduces a single POF in the system. We address this issue by proposing a solution in which multiple CAs share a public, decentralized and robust ledger where CRLs are collected. For this purpose, we consider the model of public ledgers based on blockchains, introduced for the use in cryptocurrencies, that is becoming a widespread solution for many online applications with stringent security and reliability requirements.
Abstract This chapter gives an introduction to blockchain technology which was proposed by the pseudonymous Nakamoto (2008) with his well-known Bitcoin paper to enable online payments in a decentralized digital cash system, solving the double-spending problem where someone can make two payments with the same coin. The chapter starts with an informal outline of the application of a blockchain and a brief explanation of how a blockchain network is able to reach consensus about the common state of a transaction history. Furthermore, it introduces the Proof-of-Work (PoW) algorithmwhich needs to be donein order to extend the blockchain with new blocks. Since the PoW is a very costly computational algorithm, the transaction data is stored in previous blocks resistant to modification, and thus the PoW safeguards the order of blocks, forming a tamper-proof history of transactions. As a last step, it examines the double-spending attack, which is a fundamental attack to the integrity of a blockchain based system.