With increasingly complex activities, scientific workflows are becoming more data-intensive. In this context, may require a collaborative, distributed or high performance (HPC) environment such as grids or clouds for their execution. Considering its extensibility feature, resources pool and pay-to-use, cloud computing environments have been increasingly adopted. Scientists are formulating their scientific experiments in a collaborative way, provisioning resources (software, hardware) and managing large volumes of data, based on cloud infrastructures. In data-driven collaborative scientific experiments, aspects such interoperability, privacy and trust in shared provenance data should be considered to allow the reproducibility of the results. In this paper, we present the BlockFlow architecture, which aims to bring trust to scientists of a scientific ecosystem platform (E-SECO) in the execution of their collaborative scientific experiments on cloud platforms.
Cloud ERP systems are the ultimate aspiration of the business community as they provide collaboration with partners, external applications and information systems. However, Cloud ERP solutions still have issue on the data security, data transparency, and trust. Due to these problems, a radical change is required within Cloud ERP framework to enhance Cloud ERP infrastructural and functionality. The goal of this research is to merge cloud ERP and Blockchain benefits together to improve the Data Security, Transaction Traceability, Transparency, Data Ownership, Encryption and Trust through a proposed framework. For this purpose, we firstly analyze the prominent issues in current ERP systems through a comprehensive comparison between cloud ERP before and after moving to blockchain environment. Secondly, we propose a generic framework for Cloud ERP systems based on Blockchain. The proposed framework follows the Distributed Ledger Techniques in blockchain. Finally, the feasibility and efficiency of the proposed framework is tested through the study of the Supply Chain Management Module.
Microservices architecture has become one of the most prominent software architectures in the software development processes due to its features such as scalability, maintainability, resilience, and composability. It allows developing business applications in a decentralized manner by dividing the important business logic into separate independent services. Digital certificates are used to verify the identity of microservices in most cases. However, the certificate authorities (CA) who issue the certificates to microservices cannot be trusted always since they can issue certificates without the consent of the relevant microservice. Nevertheless, existing implementations of certificate transparency are mostly centralized and has the vulnerability of the single point of failure. The distributed ledger technologies such as blockchain can be used to achieve decentralized nature in certificate transparency implementations. A blockchain-based decentralized certificate transparency system specified for microservices architecture is proposed in this paper to ensure secure communication among services. After the implementation and deployment in a cloud service, the system expressed average certificate querying time of 643 milliseconds along with the highly secured service provided.
In Bitcoin and Ethereum, nodes require large storage capacity to maintain all the blockchain data, such as transactions, UTXOs, and account states. As of May 2020, the storage size of the Bitcoin blockchain has expanded to 270 GB, and it will continue to increase. This storage requirement is a major hurdle to becoming a block proposer or validator. Although many studies have attempted to reduce the storage size, in the proposed methods, a node cannot keep all blocks or cannot generate a block. We propose an architecture called Trail that allows nodes to hold all blocks in a small storage and to generate and validate blocks and transactions. Trail does not depend on a consensus algorithm or fork choice rule. In this architecture, a client who issues transactions has the data to prove its own balances and can generate a transaction containing the proof of balances. The nodes in Trail do not store transactions, UTXOs and account balances: they keep only blocks. The blocksize is approximately 8 KB, which is 100 times smaller than that of Bitcoin. Further, the block size is constant regardless of the number of accounts and the number of transactions. Compared to traditional blockchains, clients who issue transactions must store additional data. However, we show that proper data archiving can keep the account device storage size small. Trail allows more users to be block proposers and validators and improves the decentralization of the blockchain.
Modern blockchains use smart contracts to implement automatic and decentralized programs, which are the foundations of Decentralized Applications (DApp). The poor performance on general purpose computers has become the bottleneck that limits the blockchain and smart contracts from being widely used. In this paper, we present BPU, a high-performance modularized blockchain processing unit. BPU aims at bringing performance and flexibility to the blockchain and DApp processing. Our design achieves significant speedup compared against the software implementation on an Intel CPU.
Abstract Blockchain-based cloud application (BCP) is an emerging cloud application architecture. By moving trust-critical functions onto blockchain, BCP offers unprecedented function transparency and data integrity. Ethereum is by far the most popular blockchain platform chosen for BCP. In Ethereum, special programs named smart contracts are often used to implement key components for BCP. By design, users can send transactions to smart contracts, which will automatically lead to code execution and state modification. However, unlike regular programs, smart contracts are restricted in execution by gas limit, i.e., a form of runtime resource. If a transaction uses up all available gas, an out of gas exception () will trigger, reverting state until right before that transaction.In this work, we study the out of gas exceptions (or gas exceptions in short) on Ethereum empirically for the very first time. In particular, we collect exception transactions using an instrumented Ethereum client. By investigation, we found gas exceptions stand out in terms of both occurrences and losses. Moreover, we focused on individual contracts and transactions, aiming at discovering and identifying common causing factors triggering these exceptions. At last, we also investigate existing tools in preventing gas exceptions. Our results suggest further research and study in this direction.
Ali Alzubaidi, Karan Mitra, Pankesh Patel, Ellis Solaiman
Within cloud-based internet of things (IoT) applications, typically cloud providers employ Service Level Agreements (SLAs) to ensure the quality of their provisioned services. Similar to any other contractual method, an SLA is not immune to breaches. Ideally, an SLA stipulates consequences (e.g. penalties) imposed on cloud providers when they fail to conform to SLA terms. The current practice assumes trust in service providers to acknowledge SLA breach incidents and executing associated consequences. Recently, the Blockchain paradigm has introduced compelling capabilities that may enable us to address SLA enforcement more elegantly. This paper proposes and implements a blockchain-based approach for assessing SLA compliance and enforcing consequences. It employs a diagnostic accuracy method for validating the dependability of the proposed solution. The paper also benchmarks Hyperledger Fabric to investigate its feasibility as an underlying blockchain infrastructure concerning latency and transaction success/fail rates.
Due to the unique characteristics of decentralization and security, blockchain is believed to have considerable potential to provide a wide range of benefits for ed-ucation development. Its application in education is relatively new but increasing very quickly. This paper introduced the typical blockchain techniques and charac-teristics briefly. Then, recent applications of blockchain in education were sum-marized comprehensively, especially those regarding learning record keeper, cer-tificate issue and management, and decentralized education ecosystem. Finally, technical and non-technical challenges were discussed. It is hoped to provide an in-depth look at the perspectives of blockchain in evolving education and help to the development of new application systems.
This paper recommends a blockchain framework that secures the e-learning platform. The proposed framework was used to build a widely manageable and safe data delivery facility that will connect to existing educational data. Institutions can simply have amassed their data history without demanding a copy from central servers. The proposed blockchain framework enhances data security and removes trust concerns amongst users or between third-party institutions accessing applications and services. Data distribution can be used with smart contracts to warranty that institutions will continue to be in control of their data entrance, are alert of the source of collected data sources, and are up-to-date when their data is log on by others. Immutable audit logs are generated through data source and contact history to keep institutions informed of the time their data are retrieved. Blockchain has the potential that could provide a system with massive openness, online secure database that e-learning platforms needed. The blockchain can be implemented on different learning platforms based on the information security policies of the institutions.
ABSTRACT Blockchain brought about the potential for improved data reliability, but only when those data are the result of transactions that happen completely within a blockchain. The reliability of blockchain data is threatened when information is introduced from the outside world, such as when oracles are used to observe occurrences and provide this information to smart contracts. This specific threat to the reliability of blockchain data is known as the oracle problem. This study offers a working definition of blockchain oracles and argues that they should be viewed as service organizations under the auditing standards from the AICPA and PCAOB. The study then discusses risks associated with the oracle's function of collecting, storing, transforming, and transmitting information, and proposes control objectives for auditors to consider when evaluating the information provided by oracles. Finally, the study closes by discussing open questions the audit profession still needs to address with the oracle problem.
Bitcoin is a distributed online payment system that facilitates anonymous transactions using a peer-to-peer network without a central trusted authority. Every peer in the Bitcoin network keeps the collection of all transactions which is referred to as a ledger. This public ledger will work effectively for honest peers, however, one well-known attack is the fifty-one percent or majority attack. This paper provides an Uppaal model of the Bitcoin protocol focusing on its three important components namely transactions, blocks and the blockchain. It presents a probability analysis for two scenarios of the fifty-one percent attacks. Two Phase Proof-of-Work (2PPoW) is a proposed solution to address attacks of this type, and we will extend the model to include 2PPoWand calculate the probability of a successful attack. The analysis shows that a traditional fifty-one percent attacks can be successful even if the attacker has less than a majority of the processing pool.
Increasing presence of distributed energy resources (DERs) is evolving electricity distribution system to decentralized and active networks. Utilising the data emerging from such networks is an essential step for developing sustainable future energy systems, as such systems must be closely monitored and managed to avoid blackouts and failures. The datasets within energy systems are very large, must be immutable, are often interrelated, yet owned by competing organisations. How then should these datasets be stored and shared? This is the main focus of my research. To provide a reliable way of collecting, storing, sharing, and analysing energy systems data, I propose to use the newly emerging distributed ledger technology. I will work towards developing a middleware-like platform over distributed ledgers, which would aim to provide a reliable data storage solution for immutable energy datasets, while also maintaining relationships between the datasets and addressing the read and write latency and scalability problems of the present distributed ledgers.
Arun Prasad Mohan, Mohamed Asfak R., Angelin Gladston
Cloud computing is the fastest growing and most promising field in the service provisioning segment. It has become a challenging task to provide security in the cloud. The purpose of this article is to suggest a better and efficient integrity verification technique for data referred to as cloud audit. The deployment of cloud storage services has significant benefits in the management of data for users. However, this raises many security concerns, and one of them is data integrity. Though public verification techniques serve the purpose they are vulnerable to procrastinating auditors who may not perform verifications on time. In this article, a cloud data auditing system is proposed. The proposed cloud data auditing system integrates Merkle Tree-based Cloud audit and the blockchain-based audit recording system, thus the core idea is to record each verification result into a blockchain as a transaction. Utilizing the time-sensitive nature of blockchain, the verifications are time-stamped after the corresponding transaction is recorded into the blockchain, which enables users to check whether auditors have performed the verifications at the prescribed time. The proposed cloud data auditing system is experimentally validated. The investigations with varied dataset size revealed less time taken, on an average of 0.25 milliseconds with the use of Merkle Tree. Further results reveal consistency of the data integrity checking.
In this paper, we report the benchmarking results of Hyperledger, a Distributed Ledger, which is the derivation Blockchain Technology. Method to evaluate Hyperledger in a limited infrastructure is developed. The measured infrastructure consists of 8 nodes with a load of up to 20000 transactions/second.. The benchmarking of Hyperledger shows better than a database system in a high workload scenario. We found that the maximum size data volume in one transaction on the Hyperledger network is around ten (10) times of MySQL. Also, the time spent on processing a single transaction in the blockchain network is 80-200 times faster than MySQL. This initial analysis can provide an overview for practitioners in making decisions about the adoption of blockchain technology in their IT systems.
In isolated network domains, global trustworthiness (e.g., consistent network view) is critical to the multiple-domain business partners who aim to perform the trusted corporations depending on each isolated network view. However, to achieve such global trustworthiness across distributed network domains is a challenge. This is because when multiple-domain partners are required to exchange their local domain views with each other, it is difficult to ensure the data trustworthiness among them. In addition, the isolated domain view in each partner is prone to be destroyed by malicious falsification attacks. To this end, we propose a blockchain-based approach that can ensure the trustworthiness among multiple-party domains. In this paper, we mainly present the design and implementation of the proposed trustworthiness-protection system. A cloud-based prototype and a local testbed are developed based on Ethereum. Finally, experimental results demonstrate the effectiveness of the proposed prototype and testbed.
Seyed Mehdi Fattahi, Adetokunbo Makanju, Amin Milani Fard
Predicting the performance of a blockchain application during the design phase is difficult and evaluation after it is built could be expensive. The ability to simulate a blockchain network during the design stage in order to evaluate it is therefore a necessity. In this paper, we present a simulator for blockchain applications, called SIMBA (SIMulator for Blockchain Applications). SIMBA extends an existing simulator by adding the Merkle tree feature to blockchain nodes to improve efficiency and allowing more realistic evaluations not possible with the base tool to be performed. Results of our experiments show that the inclusion of Merkle trees has a high impact of up to 30 times reduction in the verification time of block transactions without an impact on block propagation delay. Since block verification is a critical part of the computational load of nodes on the network, this performance improvement significantly affects the overall performance of each node and consequently the entire network.
This column delves into privacy risks of the IoT using risk concepts that are more native to the security domain in order to conceptually bridge our collective understanding, articulation, and management of privacy concerns in the IoT which otherwise might not be sufficiently considered or foreseen by existing legal and technical controls. Trustworthiness and privacy are of primary concern as companies connect their manufacturing and logistic infrastructures to the Internet of Things (IoT). They want to reap the benefit of automated asset management, process control and predictive maintenance. However, to do so effectively, companies need to facilitate information sharing among trustworthy partners while complying with data protection and privacy preserving regulations. In this respect, Distributed Ledgers (a.k.a. Blockchains) offer a viable solution by enabling their participants to discover one another and establish peer-to-peer trust relations without a centralized intermediary.
Recently the blockchain technology has been actively studied due to its great potentiality. The smart contract is a key mechanism of the blockchain system. Due to the short history of the smart contract, many issues have not been solved yet. One main issue is vulnerability and another main issue is cost optimization. While the vulnerability of smart contract has been actively studied, the cost optimization has been rarely studied. In this paper, we propose two cost optimization methods for smart contracts running on the blockchain system. Triggering a function in a smart contract program code may require costs and it is repeated continuously. So the minimization of costs required to trigger a function of smart contract while maintaining the performance equally is very important. The proposed two methods minimize the usage of expensive permanent variables deployed on the blockchain system. We apply the proposed two methods to three prevalent blockchain platforms: Ethereum, Klaytn and Tron. Evaluation experiments verify that the proposed scheme significantly reduces the costs of functions in the smart contract written with Solidity.
Jelena Mišić, Vojislav B. Mišić, Xiaolin Chang
Compact blocks and compact block protocol are a recent addition to the Bitcoin (BTC) data propagation protocol that aims to reduce bandwidth requirements and, possibly, reduce latency as well. In this work we have evaluated improvement of operation of BTC network under a mix of regular and compact block traffic in low-bandwidth mode. We have performed queuing analysis of the BTC network and obtained performance descriptors of block and transaction delivery times as well as forking probability. Although compact block size is more than an order of magnitude smaller than regular block size, improvement of delivery times is within bounds of 0% to 20%. Forking probability shows highest improvement of 25%. However, further analysis shows that compact block protocol requires high transaction traffic in order to prevent transaction pool deficit which causes further interaction among the peers.
In this paper, we study the business ecosystem around 5G network slice brokering, where a dynamic mechanism conducts multiple trades among resource providers and the network operators, to dynamically provision slices (e.g., in the order of minutes). Then we address a significant and realistic scenario, where there is a lack of trust between market players. This typically occurs when the central slice broker has conflicting interests (e.g., being simultaneously infrastructure provider and virtual operator). We propose a distributed market design, lever-aging smart contracts technology, where the brokering mechanism is operated and validated by all of the parties involved. In addition, we use blockchain technology to enable a manipulation-proof record-keeping system, where a record is accepted into the ledger only when all the parties have reached a consensus to do so. We deploy a realistic blockchain application/network hosted on the cloud-based Hyperledger Fabric framework. Finally, we investigate the performance of the blockchain-based slice brokering market in terms of transaction latency, throughput and computing intensity. Our results show that the proposed market could support 100 auction transactions per second with a latency below one second, which would add no considerable delay even to a highly dynamic slicing market mechanism.
Luca Foschini, Andrea Gavagna, Giuseppe Martuscelli, Rebecca Montanari
Hyperledger Fabric, created and supported by the Linux Foundation and IBM, is one of the most popular open-source blockchain permissioned platforms that has been already used in many industrial scenarios. One of the main characteristics of this platform is that it provides a smart contract system that relies on general-purpose languages instead of an ad hoc one. In fact, a chaincode in the Fabric platform (the equivalent of the Ethereum smart contract) is a software program which encapsulates the business logic for the creation and modification of logical assets in the ledger that can be written in different general-purpose programming languages (currently Java, Go, and Node.js). This paper analyses the transaction performance of the Fabric platform by identifying at a fine-grained degree level the factors that most contribute to the overall overhead. In particular, we focus on how the transaction latency is affected by the programming language adopted for implementing the chaincode and by varying the number of participating endorser peers. Finally, the paper shows a thorough test assessment aimed at evaluating the impact of the different chaincode implementation on performance overhead. As it emerges from our experimental results, Go is the most performing programming language.
With the gradual development of blockchain technology and the decentralized demand of the Internet market, the programmable financial system with blockchain technology has been proposed. However, the uncertainty of smart contract in Ethereum application layer leads to fatal problems on Ethereum network, which affects the efficiency and usages. Moreover, most schools or enterprises have not mastered blockchain technology, so it is difficult to carry out experiments of Ethereum, such as the simple account transfer transaction and deployment of smart contract. The paper is to research the Ethereum private blockchain network locally, and provide an experimental platform, which can conduct operations of Ethereum account and block information among multiple nodes. Through the research on private blockchain multi-nodes platform, a test environment for some school lessons or enterprise projects is provided. Then we implement and test of smart contract applications on Ethereum to ensure the overall security of Ethereum network.
A distributed ledger is a decentralized database spread across many participants. Various models describe software architecture and represent different architectural views. The paper concentrates on the deployment view. Model-Driven Development (MDD) is a software engineering approach that leverages models and transformations. The paper describes the UML2Deployment transformation of the distributed ledger’s deployment model into its deployment script. The deployment model, expressed in Unified Modeling Language (UML), is augmented with stereotypes and tagged values from UML Profile for Distributed Ledger Deployment. The target of the transformation is Gradle Groovy Domain Specific Language (DSL) deployment script for DLT network configuration. The transformation has been designed for R3 Corda framework. The authors propose the complete solution. The transformation has been incorporated into Visual Paradigm modeling tool.