State sharding is a common solution to the scalability problem in blockchain systems, allowing nodes to hold a partial view of the system state. With sharding, the processing of a transaction might not be completed locally within a node and potentially requires involvement of multiple shards. Such cross-shards transactions have a negative impact on system performance and are frequent with traditional state partition solutions which are often based on a simple mapping of data into shards. By locating together parts of the system state accessed by frequent transactions, the amount of cross-shard transactions can be reduced. On the other hand, the representation of such particular mappings can be memory intensive. In this article, we study traffic-aware sharding that can be described in memory-efficient mappings. We first survey existing mapping schemes in common blockchains. We indicate the tradeoff between the size of the mapping of data to shards and the required transaction processing time and suggest algorithms for finding memory-light sharding of low cross-shard rate. We generalize the approach towards an efficient incremental computation of shards and probabilistic representation of the mapping to shards. We examine the efficiency of the solutions and the required frequency of sharding computation based on real information of the Ethereum network.
Smart contract is an event-driven code contract with state attributes, which has been widely concerned and studied with the deep development of blockchain technology. This article proposes a new smart contract architecture, and discusses the main functions implemented at each layer and some of the key technologies and their operation mechanism in the blockchain. On this basis, it is attempted to establish a core description of commitment, and use a finite state machine to implement a formal description of smart contracts with the support of actions and finite periods. Finally, a commercial contract is implemented on the blockchain as an example to verify the feasibility of this standardized definition of smart contracts.
In recent times, Blockchain has become one of the most influential technology. Numerous industry projects are developed and are under the development phase for enhancing blockchain technology in every way possible and making it applicable to various application-domains. Since the inception of Ethereum, many blockchain platforms have been developed using different types of technologies. Blockchain platforms, from its security perspective, don't interact with the outside world and acts as an independent and standalone ledger. But blockchain technology can not meet the needs of today's world if different ledgers don't interact with each other and with the legacy systems. Hence, Blockchain platforms should be able to communicate with each other and provide services to each other. Researchers and developers around the world are already working to achieve blockchain interoperability. In this paper, we survey interoperability solutions provided for blockchain platforms, both by industry people and the research community.
ABSTRACT Blockchain and distributed ledger technologies are changing the way financial and business records are created and stored. New approaches to collaboration within and across industries enabled by this technology will increasingly result in new opportunities for data analysis and enable fundamental changes in accounting and auditing. The importance of this technology is increasing and “CPAs will need to learn, adjust, and adapt to emerging uses of blockchain” (AICPA 2020). This paper presents a pencil-and-paper activity that can help students unfamiliar with blockchain-related technologies understand these systems, the inter-organizational databases that result from their use, and their potential impacts for the accounting profession. We include optional reference materials that can be used as background reading for faculty members unfamiliar with blockchain or that can be integrated into a course.
This paper proposes a novel embedded Markovian queueing model of the M(1,n)/Mn/1 type in order to establish a theoretical foundation to design a blockchain-based system with specific interest in Ethereum. The model assumes variable bulk arrivals of transactions in Poisson distribution, i.e., M(1,n), where n the number of slots across all the mined transactions and static bulk service of transactions in exponential time, i.e., Mn, for posting in the current block, namely, VBASBP. The primary performance measurements to be taken are the average number of slots no matter how many transactions are mined under the assumption of the maximum number of slots per block as specified by n; the average waiting time per slot; and the throughput in terms of the average number of slots to be processed per time. The variable bulk arrival rate is assumed to vary linearly proportional to the size of the transactions in a multiple of per slot, and the static bulk service is assumed to take place when the number of slots in the mined transactions reaches at n, i.e., a bulk processing of multiple transactions in multiple slots for posting in a block. Numerical simulations are conducted on Matlab to demonstrate the efficacy of the model.
Distributed Ledger Technology (DLT) currently stands in the limelight. In many people's eyes, DLT has great potential to accelerate the digitalization process and substantially change the roles and services of central banks. On the other hands, as many new applications for DLT spring up, there isn't an assessment framework to evaluate DLT applied in the financial industry, leaving those systems to be easily under attack. This paper presents an initial DLT assessment framework for financial application. Through a suite of benchmarks, we show the evaluation results and explore the factors which affect the performance and security of DLT application.
Kimberly Swanson Church, Sean Stein Smith, Ethan Kinory
ABSTRACT Blockchain technology, commonly associated with bitcoin cryptocurrency, attracted large amounts of investment, attention, and analysis. In addition to attracting the attention of investors, speculators, and regulators, implications for financial practitioners and organizations are increasingly apparent. Financial transactions, property transfers, audit and attestation services, supply chains, and numerous other areas of industry are continuing to integrate blockchains into operations. This paper bridges the gap between the technical concept of blockchain and relevance to the accounting field. By distilling technical components of blockchain into understandable components, practitioners and other users of this research are poised to better understand, explain, and apply salient concepts. This paper proposes a Hyperledger Composer use case method through which practitioners and researchers can familiarize themselves with blockchain concepts using an interactive demonstration of an accounting integration for intangible assets. Addressing the growing need for increased awareness, this paper builds a necessary skillset with blockchain technology and applications.
The shift towards cloud marketplaces and API-centric services is enabling enterprises to rapidly develop and deliver their IT solutions and services. Enterprises are increasingly adopting a multicloud approach to leverage the latest innovations and unique capabilities of different cloud providers. This is resulting in multicloud systems that utilize independent services, which in turn may be dependent on other services. Clients rely on Service Level Agreements (SLAs) to ensure a minimum quality of service. However, monitoring service quality becomes difficult in a multi-level and multi-provider system due to decentralized control and lack of visibility in the entire system hierarchy. SLA violations often go undetected as multicloud systems lack automated means to monitor SLAs and conduct root cause analysis of violations. We propose SLAM, an autonomous and trusted framework for continuous SLA monitoring in a multicloud ecosystem. It is based on blockchain and leverages smart contracts to detect SLA violations and determine their root cause across the hierarchical system structure.
This paper proposes a comprehensive framework using blockchain architecture to create a decentralized applications store, in order to reduce the approval time for apps that are to be deployed on deployment systems i.e. applications stores, and specially for mobile platforms e.g. Apple and Google play stores. This work potentially can solve some of the existing challenges with the current centralized application approval process by Apple and Google. These companies currently charge a flat commission rate of 30% [1] of the total applications revenues from the applications owners. This commission is considered to be very high, especially for applications with revenues in the order of few million dollars. In addition, the length of the review period prior to deployment for any new or revised apps delays the release to the marketplace hence costing economic losses to the app owners. Currently, Apple and Google stores takes around two days and two hours respectively to review and approve the apps on their stores. However, by using decentralized technologies such as the blockchain, the time to review and publish a new or a revised app can be significantly reduced from few days to few minutesIn this paper a novel framework is proposed based on the blockchain architecture incorporating the Ethereum network, Interplanetary Files System (IPFS), VueJS, and a backend database. The framework is experimentally validated, and the results show the reduction in terms of the number of minutes to approve apps by the app stores.
The development of the Internet has increased the amount of data exponentially, and the reliable transmission, sharing, and storage of data have become the primary problems of data sharing. This article combines the decentralized and irreversible characteristics of the Ethereum blockchain, integrates IPFS distributed storage technology, and proposes a data sharing platform under a new technology environment to ensure data security, user rights protection, and high-speed data processing. Provide a new technology application environment for current data sharing.
Laizhong Cui, Ziteng Chen, Shu Yang, Zhongxing Ming · 8 authors
Edge computing is promising to solve the latency issue in the Internet of Vehicles (IoV). However, due to decentralization, traditional edge computing suffers in management, deployment, and security. Containerization relaxes resource deployment and migration problems, but current container scheduling policies are inefficient to process complicated tasks based on directed acyclic graph or DAG structures. In this article, we design a containerized edge computing platform CUTE, which provides low-latency computation services for the Internet of Vehicles. The centralized controller is empowered with resource management and orchestration, and containers are scheduled to appropriate edge servers to optimize the computation delay. CUTE is also integrated with blockchain to improve network security. We formulate the vehicle task offloading and container scheduling problems and develop a heuristic container scheduling algorithm for DAG-based computation tasks submitted by vehicles remotely. We implement and deploy CUTE into the China Mobile Network, and conduct comprehensive experiments and a case study. The experiment results show that CUTE can provide low-latency computation services for vehicular applications and that the heuristic algorithm outperforms traditional container scheduling policies.
Smart cities will depend on reliable Internet of things to effectively provide residential and commercial services. Smart city applications generate vast amount of data and will need the infrastructure to support high transaction throughput. The data associated with smart cities can include sensitive information and there is a need to guarantee the security and privacy through a blockchain-based decentralized infrastructure. Current blockchain environments face several challenges, such as, lack of high transaction throughput, high scalability, real-time transaction processing, and back-end stress operations, etc. In this paper, we propose “Bassa”, a blockchain platform that will meet the aforementioned challenges. Bassa employs a Apache Kafka based consensus and `validate-execute-group” blockchain architecture to realize real-time transaction. Bassa's smart contract platform realizes concurrent transaction by leveraging actor-based concurrency.
Mohammad Dabbagh, Mohsen Kakavand, Mohammad Tahir, Angela Amphawan
Recent years have witnessed a sizeable growth of Blockchain applications in enterprises. Blockchain is transforming the traditional approach of storing and managing data in a single location into a decentralized ledger. Although many industries are keen on adopting Blockchain technology for enhanced transaction transparency, the performance of the current Blockchain platforms is still perplexing to stakeholders. Therefore, this research aims to conduct an empirical study to evaluate the performance of two prominent Blockchain platforms, Hyperledger Fabric and Ethereum. The performance evaluation is based on measuring four metrics including success rate, average latency, throughput, and resource consumption. The experimental results of executing 100 transactions show that Hyperledger Fabric generally surpasses Ethereum against the four performance metrics. The presented results in this research would assist practitioners in their decision-making process of adopting the ideal Blockchain platform into their IT systems based on application requirements.
William Pourmajidi, Lei Zhang, John Steinbacher, Tony Erwin · 5 authors
Service Level Agreements (SLA) are employed to ensure the performance of Cloud solutions. When a component fails, the importance of logs increases significantly. All departments may turn to logs to determine the cause of the issue and find the party at fault. The party at fault may be motivated to tamper with the logs to hide their role. We argue that the critical nature of Cloud logs calls for immutability and verification mechanism without the presence of a single trusted party. This article proposes such a mechanism by describing a blockchain-based log storage system, called Logchain, which can be integrated with existing private and public blockchain solutions. Logchain uses the immutability feature of blockchain to provide a tamper-resistance platform for log storage. Additionally, we propose a hierarchical structure to address blockchains’ scalability issues. To validate the mechanism, we integrate Logchain into Ethereum and IBM Blockchain. We show that the solution is scalable and perform the analysis of the cost of ownership to help a reader select an implementation that would address their needs. The Logchain's scalability improvement on a blockchain is achieved without any alteration of blockchains’ fundamental architecture. As shown in this work, it can function on private and public blockchains and, therefore, can be a suitable alternative for organizations that need a secure, immutable log storage platform.
Pingcheng Ruan, Tien Tuan Anh Dinh, Qian Lin, Meihui Zhang · 6 authors
The success of Bitcoin and other cryptocurrencies bring enormous interest to blockchains. A blockchain system implements a tamper-evident ledger for recording transactions that modify some global states. The system captures the entire evolution history of the states. The management of that history, also known as data provenance or lineage, has been studied extensively in database systems. However, querying data history in existing blockchains can only be done by replaying all transactions. This approach is feasible for large-scale, offline analysis, but is not suitable for online transaction processing. We present LineageChain, a fine-grained, secure, and efficient provenance system for blockchains. LineageChain exposes provenance information to smart contracts via simple interfaces, thereby enabling a new class of blockchain applications whose execution logics depend on provenance information at runtime. LineageChain captures provenance during contract execution and stores it in a Merkle tree. LineageChain provides a novel skip list index that supports efficient provenance queries. We have implemented LineageChain on top of Hyperledger Fabric and a blockchainoptimized storage system called ForkBase. We conduct extensive evaluation, demonstrating benefits of LineageChain, its efficient querying, and its small storage overhead.
João Henrique Faes Battisti, Maurício A. Pillon, Guilherme Koslovski, Charles C. Miers
A considerable number of electronic transaction systems employ classicapproaches based on centralized trust mechanisms, not exploitingthe latest technological advances. Alternatively, the concept ofblockchain stands out, elaborated without the need for this centralizedtrust, but rather dependent on securely chained technologies in whichthe elements involved can conduct secure negotiations. Blockchain isdesigned to address security and distributed system issues through theuse of encryption, algorithms, P2P networks, and consensus mechanisms.This paper presents a Denial of Service (DoS) security analysisof the more traditional Practical Byzantine Fault Tolerance (PBFT)and Proof of Work (PoW) consensus mechanisms available onMultichain and Ethereum solutions based on a private / consortiumblockchain scenario. We present our results of a controlled DoSattack, revealing the importance and need for security-relatedanalysis of blockchain implementations of private / consortiumblockchains.
Blockchain is also used for bitcoin transactions as a technology for accumulating data files in the cloud for key distribution and file manipulation in distributed fashion. It is a service of cloud that manages elasticity of compute cloud, storage, and technology of network security (i.e., secure solution to store and share information by offering a distributed ledger service). In distributed systems, abandoned events are much more frequent than centralized system. This concept causes a number of issues including data reliability, high economical cost, and information system security. In this chapter, the authors present a new framework in blockchain to supervise the cloud server for administration of blockchain, which is verified the transaction reliability in peer-to-peer networks for sharing of data files in centralized manner. Each transaction can be generated keys for server authentication to verify all the connected members for monitoring the web server.
Cloud computing has been exploited in managing large-scale IoT systems. IoT cloud servers usually handle a large number of requests from various IoT devices. Due to the fluctuant and heavy workload, the servers require the cloud to provide high scalability, stable performance, low price and necessary functionalities. However, traditional clouds usually offer computing service with the abstraction of virtual machine (VM), which can hardly meet these requirements. Meanwhile, different cloud vendors provide different performance stabilities and price models, which fluctuate according to the dynamic workload. A single cloud cannot satisfy all the requirements of the IoT scenario well. The JointCloud computing model empowers the cooperation among multiple public clouds. However, it is still difficult to dynamically schedule the workload on different clouds based on the VM abstraction. This paper introduces HCloud, a trusted JointCloud platform for IoT systems using serverless computing model. HCloud allows an IoT server to be implemented with multiple serverless functions and schedules these functions on different clouds based on a schedule policy. The policy is specified by the client and includes the required functionalities, execution resources, latency, price and so on. HCloud collects the status of each cloud and dispatches serverless functions to the most suitable cloud based on the schedule policy. By leveraging the blockchain technology, we further enforce that our system can neither fake the cloud status nor wrongly dispatch the target functions. We have implemented a prototype of HCloud and evaluated it by simulating multiple cloud providers. The evaluation results show that HCloud can greatly improve the performance of serverless workloads with negligible costs.
The U.S. Navy seeks to leverage emerging technologies to manage massive amounts of data from multiple geographically separated systems. It is aware of the importance of data usage and data transfer in supporting its operations. Data management requires a data transfer system that is safe, fast, and scalable. Autonomous Navy Unclassified Software Distribution (ANUSD) is an application for delivering software to all nodes on the Navy's enterprise network based on blockchain technology. Blockchain is the right candidate and emerging solution to ensure the triad of confidentiality, integrity, and availability. In this thesis, we perform a comparison of public blockchain and private blockchain with the aim of determining which one would perform better in conjunction with ANUSD. We used an IBM Hyperledger (private blockchain) network and an Ethereum blockchain (public blockchain) network as the basis of the comparative analysis of their latency and scalability. We compared the transactions per second (TPS) achieved with Ethereum against that of Hyperledger with the ANUSD application installed. The results showed that as we scaled up the Ethereum network, there was a significant increase in TPS. In contrast, increasing scalability did not have a significant impact on TPS for the Hyperledger network.
Pol Alemany, Ricard Vilalta, Raül Muñoz, Ramon Casellas · 5 authors
This paper presents a non-hierarchical architecture to deploy End-to-End Network Slices in a multi-domain network using an Ethereum-based Blockchain to manage the Network Slicing requests across domains. The use of Blockchain aims to look towards a collaboration vision to deploy Networks Slices using the resources to deploy them as if they would be placed under the domain of the Network Slice requester. The authors describe a possible instantiation procedure and they present results showing how much the use of Blockchain might increase the deployment time of an End-to-End Network Slice.
This paper is to improve the performance of Hy-perledger Fabric that is one of the private blockchain open-source projects. The decentralization of data management, which has recently become important, is realized as a blockchain. Blockchain is a technology used in various fields such as data verification, storage, and banking, but performance is one of the important problems and is always mentioned. This is because a transaction must be agreed quickly and recorded in the ledger so that it can be used smoothly in systems that generate tens of thousands of transactions per second, such as banking and card use. Hyperledger fabric sends transactions generated by clients to peer nodes on the network. The transactions are hashed with the previous block in the distributed ledger. Peer nodes collect transactions received from multiple clients and execute chain code for verification, which is then sent to the orderer node and made into blocks. The block created at this time compares hash values to several peer nodes to verify the integrity of the data after verifying the block. Orderer node collects the transactions and is ordering them into the block. In this paper, we proposed to improve the performance of the hyperledger fabric by reducing network latency and the number of transfers by batch processing the process of sending and receiving chain code messages in the process of delivering transactions generated by clients for verification. The results of the performance are expressed in transactions per second(TPS), with the experiment showing that send rate(TPS) nearly doubling to 2302→4244, and throughput(TPS) increasing by about 1.5 times to 1677→2244. As a result of the experiment, send rate and throughput increased by a large margin, the batch processing of chain code messages can perform much higher performance.