Lei Zeng, Weiwei Qiu, Xiaoyi Wang, Hongkai Wang · 6 authors
In the context of advocating the reduction of greenhouse gases, green energy trade has become the focus of attention. At this stage, green energy is relatively dispersed (such as wind power, hydropower, solar power, etc.), and energy generation is real-time. At present, green energy trading based on blockchain has become a better solution. In the transaction itself, the blockchain has better security and traceability, but in terms of statistical information and interval query, because the basic data structure of the blockchain is a key-value data structure, performance problems are prone to occur. A transaction-based static indexing method is proposed, which can effectively improve the efficiency of statistical information and interval query on the chain.
Software-defined wide-area network (SD-WAN) is an emerging and advanced networking platform extending software-defined networking (SDN) across multiple networking domains. Because SD-WAN manages the data plane in the networking domains separated by the public Internet, SDWAN provides a distinct environment and challenges from SDN, including greater risks for the security threats injecting control plane communications from attackers residing outside of the SDN domain. We design and build blockchain-coordinating controllers (BCC) to secure control communications of the SD-WAN controller network formed by the distributed controllers spread across multiple domains. BCC provides resiliency against the security threats in the control plane where an attacker compromises controller communications to manipulate the coordination and the operations of the other controllers. More specifically, BCC provides secure control communications even when up to n controllers’ networking credentials are compromised. BCC is also designed for modularity so that it applies generally across the controller implementations. We prototype BCC using Ethereum and smart contract on CloudLab to validate its effectiveness and efficiency. We experiment on geographically separate nodes on CloudLab and show that BCC achieves the distributed consensus at sub-second level for certificate/key distribution and for network-wide control communication synchronization.
Xu Wang, Wei Ni, Xuan F. Zha, Guangsheng Yu · 7 authors
As distributed ledgers, blockchains run consensus protocols which trade capacity for consistency, especially in non-ideal networks with incomplete connectivity and erroneous links. Existing studies on the tradeoff between capacity and consistency are only qualitative or rely on specific assumptions. This paper presents discrete-time Markov chain models to quantify the capacity of Proof-of-Work based public blockchains in non-ideal networks. The comprehensive model is collapsed to be ergodic under the eventual consistency of blockchains, achieving tractability and efficient evaluations of blockchain capacity. A closed-form expression for the capacity is derived in the case of two miners. Another important aspect is that we extend the ergodic model to analyze the capacity under strong consistency, evaluating the robustness of blockchains against double-spending attacks. Validated by simulations, the proposed models are accurate and reveal the effect of link quality and the distribution of mining rates on blockchain capacity and the ratio of stale blocks.
To support new and more complex software systems, tools, and applications, the IT Infrastructures have evolved to be more flexible and grow both in size and complexity. To manage those Infrastructures, several tools are used. For large datacenters and public cloud infrastructures, complex managements systems have been developed in-house, according to specific implementations and philosophies. However, for the small, business owned, infrastructures, such tools are usually used independently. In this paper, we present the architecture of a new Orchestrator tool that aims to provide a single point of management, while also maintaining a resource inventory, by means of a Distributed Ledger, in order to maintain records of all the changes in the infrastructure, ensuring traceability over past changes, and even allowing for rollback of certain actions.
In recent years, China's charity exposed a variety of problems, which caused a trust crisis towards China's charity among public, and further led to China's charity once deadlocked. This paper designs a charity donation system by using blockchain distributed ledger and software engineering method, aiming to use blockchain to get through the related links of charity donation, so as to improve the transparency and credibility of donation behavior.
Flavio Corradini, Alessandro Marcelletti, Andrea Morichetta, Andrea Polini · 7 authors
As a disruptive technology, the blockchain is continuously finding novel application contexts, bringing new opportunities and radical changes. In this paper, we use blockchain as a communication infrastructure to support multi-party business processes. In particular, through smart contracts specifically generated by the mentioned business process, it is possible to derive a trustable infrastructure enabling the interaction among parties. Moreover, the emergence of different blockchain technologies, satisfying different characteristics, gives the possibility to support the same business process dealing with different non-functional needs. In this paper, we propose a novel engineering methodology supported by a practical framework called Multi-Chain. It permits to derive, using a model-driven strategy, a blockchain-based infrastructure, that can be deployed over a specific blockchain technology (e.g., Ethereum or Hyperledger Fabric). The objective is to permit the single definition and multiple deployments of the business process, to deliver the same functionalities, but satisfying different non-functional needs. In such a way, organisations willing to cooperate can select the multi-party business process and the blockchain technology they would like to use to satisfy their needs. Using Multi-Chain, they will be able to automatically derive from a Business Process Modelling Notation (BPMN) choreography diagram a blockchain infrastructure ready to be used. This overcomes the need to get acquainted with many details of the specific technology.
Blockchain-based smart contract platforms have traditionally employed the transaction-driven execution model. This paper presents an alternate framework for blockchain-based smart contract execution called EDSC. Our platform design presents a novel approach to tackle the scalability and performance challenges facing the smart contract ecosystem. We base EDSC's design on the Ethereum template, and it can be readily implemented for other existing smart contract platforms. To evaluate our design, we perform an experimental implementation using the Ethereum client. Our experiments with performance modeling show, on average, a 2.2 to 4.6 times reduced total latency of event-triggered smart contracts, demonstrating the effectiveness of the design in supporting time-sensitive applications. Additionally, we comment on the design's potential security aspects and demonstrate its utility by discussing potential use cases.
Summary With the problems of data sharing and information diddling in the field of education, we construct a highly available education consortium blockchain platform to ensure trusted sharing and privacy protection of education data. We employ erasure codes to process blockchain ledger files and optimize the data storage model according to the characteristics of education data, which can reduce the storage volume effectively. A HotStuff consensus algorithm is designed to access the ordering service of Hyperledger Fabric. A suitable educational blockchain network architecture based on the node complexity of education scenarios is proposed to achieve the high availability of the platform. To manage the education blockchain network, we implement the Fabric deployment based on Kubernetes and achieve the goal of including chaincode into Kubernetes environmental management. To improve the resource utilization of chaincode, we explore the new way of chaincode management by the functional computing service. Finally, on the premise of ensuring a 1/2 fault tolerance rate, the total ledger has decreased by 53.56%. Our platform enhanced the Byzantine fault tolerance while ensuring higher efficiency. Experimental results show that our platform is quite suitable for education scenario with many nodes.
ABSTRACT The purpose of this article is to study the potential impact of blockchain technology on accounting systems and businesses. Blockchain technology characteristics and operating modes have the potential to bring about innovations to the fields of accounting and auditing. After describing the function of blockchain technology, we examine potential accounting transformations and identify how the deployment of this technology might impact accountants and external auditors. To that end, we review the literature and take a prospective approach to the use of blockchain in accounting and auditing. Three major issues regarding the future of blockchain in accounting and auditing emerge: (i) the transformation of accounting techniques; (ii) main evolutions in accounting and auditing; and (iii) main evolutions in the work, skills, and education of auditors.
Permissioned blockchain systems promise to provide both decentralized trust and privacy. Hyperledger Fabric is currently one of the most wide-spread permissioned blockchain systems and is heavily promoted both in industry and academia. Due to its optimistic concurrency model, the transaction failure rates in Fabric can become a bottleneck. While there is active research to reduce failures, there is a lack of understanding on their root cause and, consequently, a lack of guidelines on how to configure Fabric optimally for different scenarios. To close this gap, in this paper, we first introduce a formal definition of the different types of transaction failures in Fabric. Then, we develop a comprehensive testbed and benchmarking system, HyperLedgerLab, along with four different chaincodes that represent realistic use cases and a chaincode/workload generator. Using HyperLedgerLab, we conduct exhaustive experiments to analyze the impact of different parameters of Fabric such as block size, endorsement policies, and others, on transaction failures. We further analyze three recently proposed optimizations from the literature, Fabric++, Streamchain and FabricSharp, and evaluate under which conditions they reduce the failure rates. Finally, based on our results, we provide recommendations for Fabric practitioners on how to configure the system and also propose new research directions.
For the future large-scale IoT ecosystem, the number and frequency of micro-payments will increase dramatically. However, the mainstream of cryptocurrencies such as Bitcoin and Ethereum fail to meet the need for a large-scale IoT ecosystem due to limit transaction throughput and high transaction fee. Although Layer-2 solutions such as Lightning Network (LN) increases the throughput of cryptocurrencies by allowing participants to conduct off-chain transactions, LN still suffers from two main limitations: participants need to access the Blockchain within a short bounded time, and a payment channel can only accommodate two participants. To overcome these limitations, we propose HyperChannel, a novel distributed layer-2 payment network designed specifically for the IoT ecosystem which outsources the transaction processing task safely to a group of Intel Software Guard Extensions (SGXs) run by for-profit selfish third parties. Clients such as IoT devices and IoT service providers who often trade with each other will be assigned to a channel to conduct high-frequency in-channel transactions while being allowed to conduct crosschannel transactions in a fee-saving fashion. Compared with existing SGX-based layer-2 payment framework, HyperChannel achieves maximum throughput, addresses both limitations of LN, and further lightens the burden of participants so that IoT devices can conduct layer-2 transactions without running an SGX by themselves.
Decentralized systems and protocols are becoming more popular every year. The main limitations of public permissionless blockchains are low bandwidth and high fees. There are various ways to reduce the load on the network to address these drawbacks, the majority of them were developed for Ethereum but stay valid for many other chains. The paper considers the following options for scaling decentralized systems: consensus modification and sharding that are embedded in the core of a blockchain, second layer solutions and sidechains that can be built on top of a network.
Amazon Elastic Kubernetes Service (EKS) high availability demands architectural, operational, and security considerations. Results show that Kubernetes cluster durability and performance under different workloads need multi-region failover, intelligent auto-scaling, and adequate networking. Cluster auto-scaler updates and vertical and horizontal autoscaling rules improve resource efficiency and computational overhead. High Kubernetes availability requires security. Least privilege enforcement, automatic certificate rotation, RBAC, and encryption reduce data breaches, compliance violations, and illegal access. AWS KMS, Secrets Manager, and service mesh-based mutual TLS authentication safeguarded cluster communication. Observability and performance benchmarking are critical for proactive system monitoring and resilience engineering. Companies use Prometheus and Grafana for metric collecting, Fluentd and OpenTelemetry for distributed tracing, and chaos engineering frameworks for fault injection to foresee and correct issues. These methods improve enterprise MTTR, downtime, and predictability. Industry case studies prove EKS installation works. Kubemetes' scalability, dependability, and affordability aid financial institutions, healthcare, e-commerce, and telecoms. Plenty of choice Best Kubernetes practices decrease latency, infrastructure costs, and downtime. Many themes are developing for Kubemetes' high availability. Rethinking workload orchestration with serverless Kubernetes solutions like AWS Fargate for EKS simplifies infrastructure administration and resource utilization. Without node provisioning, organizations can develop quickly and inexpensively. Kubernetes-based edge computing for latency-sensitive applications including real-time analytics, 10T device orchestration, and 5G network optimization is another trend. K3s and MicroK8s at the network edge and centralized multi-cluster control planes enable regionally distributed high availability with minimal latency. Istio, Linkerd, and Consul enhance interservice communication, traffic routing, and security. Massive Kubernetes systems benefit from progressive traffic shifting, zero-downtime rolling deployments, and autonomous circuit breaking. Another achievement is Kubernetes monitoring system machine learning-driven anomaly detection and predictive maintenance. Al-powered observability frameworks can identify infrastructure deterioration, forecast resource congestion, and automate preemptive scaling to avert failures and enhance workload allocation. Kubernetes high availability optimization has improved, however Al-driven auto-scaling and self-healing clusters need research. Traditional auto-scaling ümresholds disregard non-linear workloads, traffic surges, and unexpected failures. Analysis of reinforcement learning-based scaling algorithms that dynamically adjust cluster capacity in real time utilizing historical data, prediction analytics, and workload demand predictions. Kubernetes clusters that self-heal are another autonomous infrastructure management frontier. Complexities may prevent human intervention or failover. Al-driven failure detection, automatic node repair, and intelligent fault recovery can identify abnormalities, problematic nodes, shift workloads, and take real-time remedial action in Kubernetes clusters. Studying genetic algorithms and evolutionary computing for Kubemetes scheduler development is intriguing. Least-loaded node selection schedulers and computationally efficient bin packing are not adaptive. Al-driven evolutionary scheduling models may improve Kubernetes pod placement, inter-node communication cost, and workload allocation. Cross-cluster federation and Al-augmented multi-cluster load balancing are promising research areas. Dynamic workloads need real-time adaptive load balancing in Kubernetes Federation v2. Future Al-powered predictive load distribution models may improve federated cluster job allocation by factoring network latency, computational cost, and failure likelihood. Finally, blockchain-based decentralized cloud orchestration and Kubernetes high availability intrigue. Distributed ledger technology for secure state synchronization, federated identity management, and decentralized resource scheduling may make Kubernetes more resilient to cloud provider outages, security breaches, and infrastructure failures. Blockchain-based Kubernetes topologies may increase fault tolerance, frustless multi-cloud deployments, and data integrity across geographically distant clusters. High availability computing will be defined by Al-driven automation, self-healing infrastructure, and decentralized cloud-native designs as Kubernetes use grows. These improvements may improve Kubernetes workload orchestration, system resilience, and cloud-native application scalability.
Abhilash Kancharla, Jongho Seol, Hye-Young Kim, Nohpill Park
This paper proposes a quantitative model for a new blockchain technology that distributes public ledger in a decentralized manner, referred to as Distributed Decentralized chain (DDC). A clique of k nodes in the P2P network participates in storing a complete copy of blockchain instead of having every node carry an entire copy. The proposed model is k-Queue Variable Bulk Arrival and Static Bulk Service queueing model (k-VBASBS), in which the state is defined by (i,k), where i is the number of slots from 0 upto n in a block on the current node, and k is the number of distributed nodes to store a complete copy of a chain of blocks. Without loss of generality and practicality, it is assumed that there are two different transaction posting rates assumed to take into account the overhead of inter-node (i.e., μ(inter-node)) control-hopping versus the one of the original intra-node posting rate (i.e., μ(intra-node)), and μ(inter-node)μ<<(intra-node). Based on the proposed k-VBASBS model, the average waiting time, space requirement, and throughput of the transactions will be simulated for the performance, and the dependability will be also modeled and simulated by the vulnerability to 51% attack.
The revolution with technologies happens very often, here is one such technology called “Blockchain” which will be a game-changer in many functional sectors of the society. Initially, this technology was developed to support cryptocurrencies (such as Bitcoin, Ethereum, and Litecoin etc).Now a days it is gaining the attention of the researchers in almost the entire field. The consensus protocol in the cryptography and peer to peer architecture is one of the essential parts of the blockchain technology. The best consensus protocol in a blockchain system provides the fault tolerance. These censuses in blockchain are broadly classified in to two types. The absolute-finality consensus protocol and probabilistic-finality consensus protocols. In this paper, the different types of censuses protocols are discussed along with their working, strength and weakness. It also gives the overview on the different types of blockchain technology with their advantages and disadvantages. At the last we also presented a comparison of these consensus protocols by considering different qualitative parameters.
Periklis Kostamis, Andreas Sendros, Pavlos S. Efraimidis
The cost of using a blockchain infrastructure as well as the time required to search and retrieve information from it must be considered when designing a decentralized application. In this work, we examine a comprehensive set of data management approaches for Ethereum applications and assess the associated cost in gas as well as the retrieval performance. More precisely, we analyze the storage and retrieval of various-sized data, utilizing smart contract storage. In addition, we study hybrid approaches by using IPFS and Swarm as storage platforms along with Ethereum as a timestamping proof mechanism. Such schemes are especially effective when large chunks of data have to be managed. Moreover, we present methods for low-cost data handling in Ethereum, namely the event-logs, the transaction payload, and the almost surprising exploitation of unused function arguments. Finally, we evaluate these methods on a comprehensive set of experiments.
Blockchain is a novel distributed ledger technology. Through its features and smart contract capabilities, a wide range of application areas opened up for blockchain-based innovation [5]. In order to analyse how concrete blockchain systems as well as blockchain applications are used, data must be extracted from these systems. Due to various complexities inherent in blockchain, the question how to interpret such data is non-trivial. Such interpretation should often be shared among parties, e.g., if they collaborate via a blockchain. To this end, we devised an approach codify the interpretation of blockchain data, to extract data from blockchains accordingly, and to output it in suitable formats [1, 2]. This work will be the main topic of the keynote. In addition, application developers and users of blockchain applications may want to estimate the cost of using or operating a blockchain application. In the keynote, I will also discuss our cost estimation method [3, 4]. This method was designed for the Ethereum blockchain platform, where cost also relates to transaction complexity, and therefore also to system throughput.
IoT industry has come to the fore in this modern techno-frenzy age. This has caused digital data explosion and has kept the data storage industry on its toes. The paper proposes a novel blockchain-based data storage model where users contribute the storage space of their personal electronic devices to meet the growing data storage needs. The paper dives into a decentralized system design, along with an equitable compensation model for all the storage space contributing users. The decentralized framework provides a common platform for interaction between the storage space contributors and buyers. The proposed solution provides an alternative to cloud storage which relies heavily on servers.
Smart contract-based methods are used to implement the blockchain applications. While smart contracts have separate pre-deployed steps, which are suitable for applications that are deployed once and invoked many times. However, there are smart contracts that are used only one time (the disposable smart contract) or few times. Pre-deployment requires an additional step and additional transactions, which bring burdens (such as longer waiting time and more transaction fees) to users. In this paper, we propose a new Lifecycle model of smart contracts, which allows combining the pre-deployment with function invocations. This facilitates the usage of the disposable smart contract, as users are only required to send one transaction to perform both the pre-deployment and the function invocation. Together with the smart contract separation, it also allows participants to customize their special smart contracts at the request time. At last, we verify the proposed model and it shows the potential to save additional burden and to facilitate the usage of the smart contract.
Andrei Vladyko, Anastasia Spirkina, Vasiliy Elagin
Like multiservice networks, blockchain technology is currently experiencing significant development because of its decentralization and ability to organize secure, seamless, reliable data exchange and storage. Due to the significant demand for the technology, there is a need to analyze the impact of these technology processes on network characteristics to predict traffic behavior and ensure required quality indicators, as well as on the stability of public communication network elements when blockchain technology operates. Conducting a full-scale experiment is a time-consuming task that cannot always be accomplished, so in this paper, the authors propose considering approaches to modeling these systems and, as an example, propose to use a simulation system to assess the performance of the network and its elements.