Danilo Bizarria de Oliveira, Geraldo Lucas Fernandes do Amaral, Markel Pedrosa Duarte de Macedo, Matheus Ferreira Mesquita · 5 authors
Sistemas de processamento de transações são parte essencial de negócios online, e exigem tanto confiança quanto desempenho para entregar o serviço esperado. Uma ferramenta de blockchain é capaz de oferecer escalabilidade e confiança na validação de transações. A abordagem proposta neste trabalho é da avaliação do potencial de escalabilidade da rede Ethereum, e seu comportamento em cenários progressivamente mais distribuídos. Com destaque para um aumento observado de cerca de 10× o número de transações por segundo, quando comparados um nó isolado e uma rede de 16 nós, esta que também proporcionou uma queda de mais da metade da latência com relação ao cenário centralizado.
Xinyu Ye, Meng Li, Pengbo Si, Ruizhe Yang · 6 authors
Recently, the rise of the Internet of Vehicles (IoV) has driven the broad development of intelligent transportation and smart cities. In order to promote the computing power of mobile vehicles and decrease the content delivery latency of suppliers, mobile edge computing (MEC) is recognized as a promising computational paradigm and used in vehicular networks. However, there are some essential issues to be considered: 1) privacy and authenticity of data transmission in IoV, and 2) reasonable resource allocation for collaborative computing and caching. In this paper, to solve above issues, blockchain technology is introduced and adopted to ensure the accuracy and reliability of data transmission and interaction. Meanwhile, we develop an intelligent framework of resource allocation about computing and caching for blockchain-enabled MEC systems in IoV. Through jointly considering and optimizing offloading decision of computation task carried by vehicle, caching decision, the number of offloaded consensus nodes, block interval and block size, the weighted consumption costs of energy consumption and computation overheads can be decreased, and the transactional throughput of the blockchain can be increased. Moreover, due to the continuity and dynamic of the available resources of mobile vehicles and computing servers, the optimization problem is modeled as a Markov decision process (MDP). Facing the large-scale and dynamic characteristics of the system, the asynchronous advantage actor-critic (A3C) approach is introduced to deal with the optimization problem. Simulation results show that our proposed scheme achieves significant advantages over other comparison schemes, such as the total reward of the proposed scheme is about 14% higher than that of the deep$Q$-network based scheme.
Dewi Immaniar, Anna Ayu Aryani, Shinta Zahrotul Ula
Globally, interest in renewable energy has grown recently. The microgrid integrates traditional dispersed energy resources utilizing technological tools and information technology, making it more effective and flexible to enhance the economic and environmental situations (IT). One of these technologies that has drawn interest in microgrid applications to create a sustainable society is blockchain. The blockchain idea can offer immutability for microgrid transactions such as recording power generation levels and confirming transactions between generators and end consumers. By eliminating the need to connect with third parties, blockchain-based smart contracts can be utilized for auditing or resolving a transaction dispute between the producers and the users. In this paper, we highlight many recent research projects on blockchain applications in microgrids and the use of smart contracts to enhance the transactive resilience in microgrids.
Junhyeong Ryu, Aeri Kim, Meryam Essaid, Hongtaek Ju
This paper presents the development results for the Wireshark dissector of the Ethereum Node Discovery Protocol for monitoring and analyzing Ethereum P2P networks. The new version v5 of the Ethereum Node Discovery Protocol applied encryption to the traffic. Therefore, the Wireshark Node Discovery Protocol based on previous versions, such as the v4 dissector, can no longer be used to analyze the network. This paper develops a dissector that interprets encrypted packets of the Node Discovery Protocol based on Ethereum Node Discovery Protocol v5. Node Discovery Protocol analysis can be used to research network properties and improve network performance.
Bitcoin is a decentralized cryptocurrency. It is open-source; its design is public, nobody owns or controls it and everyone can take part. And Bitcoin, just like any other open-source projects, has been subject to forks.In this paper, we will consider some popular Bitcoin forks and we will examine if we can find a link between the value of the fork (i.e. its price) and the overall sentiment of the fork based on Twitter data. The forks we consider here are: Litecoin (LTC), Bitcoin Cash (BCH), Bitcoin Gold (BTG), Bitcoin Diamond (BCD), Bitcoin Private (BTCP), Bitcoin Atom (BCA), and Bitcoin SV (BSV). From the results, we can state that, for most cryptocurrencies studied here, the number of tweets follows the price trend more closely than the sentiment evolution does.The findings can have practical implications for both researchers and practitioners, indeed the results: (i) can be a stepping stone for future research on hard forks, (ii) can help practitioners identify the relevant indicators for hard forks price evolution.
Aimen Djari, Emmanuelle Anceaume, Sara Tucci-Piergiovanni
The arrival of Bitcoin [1] drove the shift to decentralized ecosystems through the exchange of transactions without intermediary. However, one of the main challenges that need to face permissionless blockchains are scalability and security. In this paper, we present a performance evaluation of Sycomore++, a permissionless graph-based distributed ledger whose main feature is to dynamically self-adapt the number of created blocks to the current number of submitted transactions, and compare them with the ones of Bitcoin and Sycomore, a graph-based distributed ledger. Our evaluation relies on agent-based simulations to evaluate the capability of these distributed ledgers to address the aforementioned challenges, within different execution contexts.
Meroua Moussaoui, Nischal Aryal, E. Bertin, Noël Crespi
Cellular networks have played a critical role in building today’s Internet. However, they are facing more and more challenges such as softwarization and programmability, decentralization, as well as opening to new business models, while keeping a very high level of trust and reliability. DLT (Distributed Ledger Technology) is a promising field to address these challenges in an innovative way. In this paper, we present a comprehensive analysis of DLT applications for cellular networks, covering the Radio Access Network (RAN), Core Network (CN), Applications & services, as well as Inter-actor communication & cooperation.
Purpose As the core technology of blockchain, various consensus mechanisms have emerged to satisfy the demands of different application scenarios. Since determining the security, scalability and other related performance of the blockchain, how to reach consensus efficiently of consensus mechanism is a critical issue in the blockchain. Design/methodology/approach The paper opted for a research overview on the blockchain consensus mechanism, including the consensus mechanisms' consensus progress, classification and comparison, which are complemented by documentary analysis. Findings This survey analyzes solutions for the improvement of consensus mechanisms in blockchain that have been proposed during the last few years and suggests future research directions around consensus mechanisms. First, the authors outline the consensus processes, the advantages and disadvantages of the mainstream consensus mechanisms. Additionally, the consensus mechanisms are subdivided into four types according to their characteristics. Then, the consensus mechanisms are compared and analyzed based on four evaluation criteria. Finally, the authors summarize the representative progress of consensus mechanisms and provide some suggestions on the design of consensus mechanisms to make further advances in this field. Originality/value This paper summarizes the future research development of the consensus mechanisms.
Eventual consistency is a consistency model that favors liveness over safety. It is often used in large-scale distributed systems where models ensuring a stronger safety incur performance that are too low to be deemed practical. Eventual consistency tends to be uniformly applied within a system, but we argue a demand exists for differentiated eventual consistency, e.g. in blockchain systems. We propose update-query consistency with primaries and secondaries (UPS) to address this demand. UPS is a novel consistency mechanism that works in pair with our novel two-phase epidemic broadcast protocol gossip primary-secondary (GPS) to offer differentiated eventual consistency and delivery speed. We propose two complementary analyses of the broadcast protocol: a continuous analysis and a discrete analysis based on compartmental models used in epidemiology. Additionally, we propose the formal definition of a scalable consistency metric to measure the consistency trade-off at runtime. We evaluate UPS in two simulated worldwide settings: a one-million-node network and a network emulating that of the Ethereum blockchain. In both settings, UPS reduces inconsistencies experienced by a majority of the nodes and reduces the average message latency for the remaining nodes.
The advent of Ethereum opened up a pandora box of decentralized possibilities. While allowing for the replicated, decentralized computation of Turing-complete instructions, platforms such as Ethereum do not offer the possibility of direct, interactive, real-time processing of users’ inputs that could later affect the decentralized state machine. They cannot directly observe, replicate and authenticate users’ actions performed in real-time while presenting the results of these. They lack mechanics that would incentivize full-nodes to provide low-latency-constrained services to users in-between epochs of a decentralized state machine, thus pushing dApps’ developers towards hybrid architectures—ones employing centralized servers while not even considering certain applications, due to the aforementioned limitations. In this research paper, we explore our results of an attempt to create a ‘decentralized operating system’ user experience a reality. We propose an architecture which solves the problems of the responsiveness and finalization of multiple actions performed by users in real-time—without the need for users to pre-authenticate but after having presented a single, unitary consent to commit—through the hereby proposed Deferred Authentication mechanism. To allow for this, we employ an in-house developed #GridScript programming language, used by our decentralized state machine, along with a computer-vision-enabled and AI-aided mobile app (available for both iOS and Android). We introduce the concept of Decentralized Processing Threads (DPTs) and see how these enable fascinating possibilities. In addition, we look into how Access-Control-Lists (ACLs)-enabled, incentivized storage, incentivized Sybil-proof communication, embedded firewall apparatus, integrated off-the-chain payments, and crypto-incentivized off-the-chain storage aid such a system and thus render it as feasible. We highlight various interesting troubles we have encountered, such as state recovery after disconnects of the UI and the replication of its state across both nodes maintaining the network and web browsers. We depict ‘off-the-chain’ mechanics, which we use to reward for real-time services provided to users by nodes maintaining the network. We tackle crypto-incentivized WebRTC swarms not needing centralized servers for signaling. We look into a user-friendly approach to Non-Fungible Tokens (NFTs). The test-bed is readily available with multiple functional UI dApps already in place. Indeed, the paper presents UI and UX design decisions we have undertaken based on conclusions from statistical research results on a group of 50,341 volunteers over 4 years, which we have used to formulate what we codenamed as the Venice UI/UX design paradigm. We extend upon the notion of Token Pools to allow for the Sybil-proof incentivization of multiple-peers from a single data structure stored on the decentralized state machine.
Abstract This study proposes a primary node election method based on probabilistic linguistic term set (PLTS) for the practical Byzantine fault tolerance (PBFT) consensus mechanism to effectively enhance the efficiency of reaching consensus. Specifically, a novel concept of the probabilistic linguistic term set with a confidence interval (PLTS-CI) is presented to express the uncertain complex voting information of nodes during primary node election. Then, a novel score function based on the exponential semantic value and confidence approximation value for the PLTS-CI, called Score-ESCA, is used to solve the problems of comparing different nodes with various voting attitudes. This method helps select the node with the highest score by utilizing complex decision attitudes, making it an accurate primary node election solution. Furthermore, the feasibility of our proposed method is proved by both theoretical analysis and experimental evaluations.
Sharding is a promising approach to scale permissionless blockchains. In a sharded blockchain, participants are split into groups, called shards, and each shard only executes part of the workloads. Despite its wide adoption in permissioned systems, transferring such success to permissionless blockchains is still an open problem. In permissionless networks, participants may join and leave the system at any time, making load balancing challenging. In addition, the adversary in such networks can launch the single-shard takeover attack by compromising a single shard's consensus. To address these issues, participants should be securely and dynamically allocated into different shards. However, the protocol capturing such functionality - which we call shard allocation - is overlooked.
Michael Sober, Marten Sigwart, Philipp Frauenthaler, Christof Spanring · 6 authors
Abstract Today, several solutions for cross-blockchain asset transfers exist. However, these solutions are either tailored to specific assets or neglect finality guarantees that prevent assets from getting lost in transit. In this paper, we present a cross-blockchain asset transfer protocol that supports arbitrary assets, is adaptable to different means of cross-blockchain communication, and adheres to requirements such as finality. The ability to freely transfer assets between blockchains may increase transaction throughput and provide developers with more flexibility by allowing them to design digital assets that leverage the capacities and capabilities of multiple blockchains. We define the general requirements and specifications for a cross-blockchain asset transfer protocol and provide a proof-of-concept implementation for EVM-based blockchains. Further, we evaluate the protocol concerning costs, transfer duration, and security.
In the era of the digital economy, blockchain has developed well in various fields, such as finance and digital copyright, due to its unique decentralization and traceability characteristics. However, blockchain gradually exposes the storage problem, and the current blockchain stores the block data in third-party storage systems to reduce the node storage pressure. The new blockchain storage method brings the blockchain transaction retrieval problem. The problem is that when unable to locate the block containing this transaction, the user must fetch the entire blockchain ledger data from the third-party storage system, resulting in huge communication overhead. For this problem, we exploit the semi-structured data in the blockchain and extract the universal blockchain transaction characteristics, such as account address and time. Then we establish a blockchain transaction retrieval system. Responding to the lacking efficient retrieval data structure, we propose a scalable secondary search data structure BB+ tree for account address and introduce the I2B+ tree for time. Finally, we analyze the proposed scheme’s performance through experiments. The experiment results prove that our system is superior to the existing methods in single-feature retrieval, concurrent retrieval, and multi-feature hybrid retrieval. The retrieval time under single feature retrieval is reduced by 40.54%, and the retrieval time is decreased by 43.16% under the multi-feature hybrid retrieval. It has better stability in different block sizes and concurrent retrieval scales.
Directed acyclic graph (DAG) blockchain is a new paradigm of blockchain that solves the poor scalability and low throughput caused by a single-chain structure for IoT applications in the blockchain. However, for DAG-structured blockchains, it is difficult to determine the order of blocks. Additionally, there is also lack of secure and efficient ways to generate blocks in parallel. To address these problems, we propose an efficient DAG blockchain architecture. First, a novel heaviest chain rule based on the block weight is proposed to guide the selection of the parent and uncle blocks for a new block, which realize that appending is ordering. Second, a tree-based gossip protocol (TBGP) is proposed to improve consensus efficiency by reducing message redundancy. Furthermore, federated learning is used to select nodes constructing the tree-based gossip network (TBGN). Finally, compared to the random gossip protocol (RGP), the simulation results indicate TBGP can effectively reduce communication redundancy and improve consensus efficiency.
Atualmente, existem diversos dispositivos que coletam dados e prestam serviços na Internet. Alguns desses dispositivos colaboram para trocar informacões e usá-las para tomar decisões mais inteligentes em um ambiente chamado Internet das Coisas (IoT). Recentemente, a tecnologia blockchain surgiu como uma possível solução para superar problemas de segurança em IoT. Apesar disso, blockchains tradicionais (como Bitcoin ou Ethereum) nao são adequados para a natureza de capacidade/recursos limitados dos dispositivos IoT. Alem disso, as propostas atuais carecem de uma discussão sobre o comportamento do usuario em diferentes contextos e como ele pode ser adaptado para diferentes algoritmos de consenso. Para superar esses problemas, apresentamos na tese um conjunto de etapas para criar um mecanismo de consenso multinível para diferentes contextos usando uma estrutura blockchain leve chamada appendable-block blockchain. Essa abordagem fornece uma solução que permite usar diferentes configurações ou consensos, de acordo com os requisitos de cada contexto no ambiente IoT. Por fim, a tese mostra que um consenso multinível pode produzir uma alta taxa de transferencia e baixa latência para inserir novas transações em appendable-block blockchains.
Sep 12, 2022·2022 IEEE Intl Conf on Dependable, Autonomic and Secure Computing, Intl Conf on Pervasive Intelligence and Computing, Intl Conf on Cloud and Big Data Computing, Intl Conf on Cyber Science and Technology Congress (DASC/PiCom/CBDCom/CyberSciTech)
Agostino Forestiero, Antonio Francesco Gentile, Davide Macrì
Fog computing solutions provide a consolidated way to quickly process the huge amount of data generated by IoT devices connected to the Internet. Different to cloud computing, Fog infrastructure achieve efficient data processing without excessive latency on data transfers. The blockchain technology supports distributed and reliable information storage mechanisms and, when combined with smart contracts, it can provide a distributed system where all the nodes independently contribute to a common global state. This provides inherent desirable features, such as immutability and transparency. In this work a blockchain based approach to address fault-tolerance and load balancing in smart environments at Fog level, is proposed. A Non-fungible Tokens based methodology, exploiting tailored smart contracts, is designed and implemented to manage load balancing and failover activities on container-oriented infrastructure. Preliminary results have show the effectiveness of the approach.
Peiyun Zhang, MengChu Zhou, Chenxi Li, Abdullah Abusorrah
The recent development of channel technology has promised to reduce the transaction verification time in blockchain operations. When transactions are transmitted through the channels created by nodes, the nodes need to cooperate with each other. If one party refuses to do so, the channel is unstable. A stable channel is thus required. Because nodes may show uncooperative behavior, they may have a negative impact on the stability of such channels. In order to address this issue, this work proposes a dynamic evolutionary game model based on node behavior. This model considers various defense strategies' cost and attack success ratio under them. Nodes can dynamically adjust their strategies according to the behavior of attackers to achieve their effective defense. The equilibrium stability of the proposed model can be achieved. The proposed model can be applied to general channel networks. It is compared with two state-of-the-art blockchain channels: Lightning network and Spirit channels. The experimental results show that the proposed model can be used to improve a channel's stability and keep it in a good cooperative stable state. Thus its use enables a blockchain to enjoy higher transaction success ratio and lower transaction transmission delay than the use of its two peers.
Subhasish Goswami, Syed Muhammad Danish, Kaiwen Zhang
Blockchain smart contracts can only operate on data available on-chain, and face a major challenge of not being able to communicate with the world outside their own network. Blockchain oracles solve this problem by bridging the gap between on-chain and off-chain data. Chainlink is one of the most widely used decentralized oracle network with competing independent data providers with distinct characteristics in terms of price, performance, security, trust, etc. As a Chainlink service purchaser with unique a service level agreement (SLA) proposal for each job, a random selection of oracles to execute a certain job can result in sub-optimal solution, that could be alleviated by another oracle data provider. Therefore, in this work, we propose a middleware design to select the best data providers available in Chainlink oracle network based on individual job's service requirements. We model the oracle selection problem as a decision optimization problem and prove it to be NP-hard. We also propose two heuristic algorithms to approximate a solution to the modelled problem. We experimentally evaluate and compare the proposed design, and conclude that the proposed middleware architecture efficiently selects the oracles in terms of performance parameters.
Bhaskar B. Gardas, Arash Heidari, Nima Jafari Navimipour, Mehmet Ünal
The broad availability of connected and intelligent devices has increased the demand for Internet of Things (IoT) applications that require more intense data storage and processing. However, cloud-based IoT systems are typically located far from end-users and face several issues, including high cloud server load, slow response times, and a lack of global mobility. Some of these flaws can be addressed with edge computing. In addition, node selection helps avoid common difficulties related to IoT, including network lifespan, allocation of resources, and trust in the acquired data by selecting the correct nodes at a suitable period. On the other hand, the IoT’s interconnection of edge and blockchain technologies gives a fresh perspective on access control framework design. This article provides a novel node selection approach for blockchain-enabled edge IoT that provides a quick and dependable node selection. Moreover, fuzzy logic to approximation logic was used to manage numerical and linguistic data simultaneously. In addition, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), a powerful tool for examining Multi-Criteria Decision-Making (MCDM) problems, is used. The suggested fuzzy-based technique employs three input criteria to select the correct IoT node for a given mission in IoT-edge situations. The outcomes of the experiments indicate that the proposed framework enhances the parameters under consideration.
Bitcoin is one of the popular cryptocurrencies but it has many pitfalls due to its slow payment nature. The average confirmation time of a Bitcoin transaction is ten minutes. Block propagation, validation, and mining are time-consuming tasks in the Bitcoin network. They increase confirmation delay, which becomes a large overhead, especially for micropayment transactions. In a micropayment transaction, the buyer expects quick service and the seller expects fast payment. Another downside of excess delay is that attackers get better chances to perform successful double-spending attacks. In this paper, we propose a protocol named ZCC that not only provides quick service to users but also guarantees payment to sellers. In ZCC, a group of full nodes acts as an approval committee that commits the user's ZCC transactions based on majority approvals obtained from group members. In the ZCC scheme, mining time is much less compared to the mining time of Bitcoin transactions because of lower difficulty targets. We analyze total acceptance time and the probability of a double-spending attack in the ZCC scheme. Also, we evaluate the performance of ZCC using the BlockSim simulator for the different transaction and block-related parameters, and observe substantially improved performance for the ZCC scheme.
Andrew Howell, Takfarinas Saber, Malika Bendechache
New blockchain platforms are launching at a high cadence, each fighting for attention, adoption, and infrastructure resources. Several studies have measured the peer-to-peer (P2P) network decentralisation of Bitcoin and Ethereum (i.e., two of the largest used platforms). However, with the increasing demand for blockchain infrastructure, it is important to study node decentralisation across multiple blockchain networks, especially those containing a small number of nodes. In this paper, we propose NodeMaps, a data processing framework to capture, analyse, and visualise data from several popular P2P blockchain platforms, such as Cosmos, Stellar, Bitcoin, and Lightning Network. We compare and contrast the geographic distribution, the hosting provider diversity, and the software client variance in each of these platforms. Through our comparative analysis of node data, we found that Bitcoin and its Lightning Network Layer 2 protocol are widely decentralised P2P blockchain platforms, with the largest geographical reach and a high proportion of nodes operating on The Onion Router (TOR) privacy-focused network. Cosmos and Stellar blockchains have reduced node participation, with nodes predominantly operating in large cloud providers or well-known data centres.