Follow blockchain research across journals, conferences, and preprint repositories.
2,085 results · page 41 of 87
Abdullah Lakhan, Mazin Abed Mohammed, Seifedine Kadry, Salman A. AlQahtani · 6 authors
No abstract is available for this record.
Arnaud Laurent, Luce Brotcorne, Bernard Fortz
In blockchains , transaction fees are fixed by the users. The probability for a transaction to be processed quickly increases with the fee level. In this paper, we study the transaction fee optimization problem in the Ethereum blockchain. This problem consists of determining the minimum price a user should pay so that its transaction is processed with a given probability in a given amount of time. To reach this goal, we define a new solution method based on a Monte Carlo approach to predict the probability that a transaction will be mined within a given time limit. Numerical results on real data highlight the quality of the results.
Carlos Melo, Felipe Oliveira, Jamilson Dantas, Jean AraĂșjo · 7 authors
No abstract is available for this record.
Konstantinos Iliakis, Konstantina Koliogeorgi, ÎÎœÏÏÎœÎčÎżÏ ÎÎŻÏÎșΔ, Theodora Varvarigou · 5 authors
Abstract Blockchain is a distributed ledger based on peerâtoâpeer networks, originally used for cryptoâcurrency systems. Blockchains are being used as an enabling technology for decentralised applications in the areas of InternetâofâThings, finance, supplyâchain and others. Consistency, data privacy, performance, and energy efficiency are of paramount importance in such applications. The full nodes of public, permissionless blockchains undertake the task of verifying the transactions generated by the network. Full nodes perform operations such as confirming balances, transactions, and history, i.e. mostly database search queries. Consequently, their throughput is crucial for the performance of blockchain systems. In this work, the benefits of accelerating the blockchain search and insert queries by leveraging GPU platforms are studied. An extensive comparison between the most dominant utilized database is provided, i.e. LevelDB, and MegaKV, a highâperformance GPUâaccelerated database. Realistic operations that take place in blockchain systems are emulated and evaluated over representative scenarios, showing three orders of magnitude gains in throughput and energy efficiency without compromising the security aspect. The extensive comparison between LevelDB and MegaKV indicates that GPU acceleration is an effective solution for runtime and energy efficiency enhancement of blockchain systems, and the integration of the two technologies is a promising field of research.
Vaidas Giedrimas
In the blockchain context, the information system (IS) is considered a part of its infrastructure. However, blockchain itself can be used for IS development using software components and services. As the trust for binary components or services is still a problem, we propose to use the blockchain of components to solve this problem. In this paper, the part of such solution, namely consensus algorithms, is discussed. We focus on Proof-of-Stake algorithms and present their feasibility to be used in the blockchain of software components. It was found that the use of probabilistic algorithms (RRR, CloudPoS, WV, DDPoS, Panda) allow the partial solution of the problem in the blockchain of reliable software components.
Milton Chang, Santanu Das, Dale Montrone, Tapan Chakraborty
This paper proposes an energy efficient approach for securing inter-connecting IOT devices with servers. A scheme using blockchain and a second network for security management was previously described [1]. To overcome the drawbacks and shortcomings of using traditional smart contract with Ethereum, a new approach is proposed. The proposed approach ensures that the overall IoT network is âhardenedâ against attack using a framework which is environmentally sustainable and meets the stringent requirements of mission critical applications. This new approach also results in shorter latency, higher throughput and consuming less power, thus suitable for edge computing environment in mobile.
Abdullah Yousafzai, Priyan Malarvizhi Kumar, Choong Seon Hong
No abstract is available for this record.
Songlin He, Eric Ficke, Mir Mehedi Ahsan Pritom, Huashan Chen · 9 authors
No abstract is available for this record.
Jingang Yu, Yongkang Hou, Li Shu, Zhifeng Wen
Blockchain is also known as distributed ledger. All full nodes connected to the blockchain network participate in the maintenance of the data in the ledger. It is a technology in many fields such as computer science, cryptography, distributed storage, and finance. Industrial and academic research on blockchain technology has achieved great results, including research on blockchain networks, consensus mechanisms, and smart contracts. However, limited by the data storage mode and the characteristics of distributed storage at the bottom of the blockchain, there are still problems that need to be solved urgently, such as the single retrieval function and the low retrieval rate of the data retrieval on the blockchain. We focused on this problem, and based on the built-in index and external data warehouse method, we proposed a high-speed data retrieval model on blockchain. The model consists of three parts: a blockchain network with improved index storage, a data processing cluster, and application layer services. The new blockchain network improves the organization of transaction data in the traditional blockchain system, and designs a data structure suitable for high-speed retrieval to organize transaction data; the data processing cluster is responsible for ensuring data consistency and in accordance with high efficiency The synchronization strategy is to synchronize the data on the chain to the relational data warehouse under the chain; the application layer service encapsulates the rich query functions supported by the relational database, and finally provides services to the outside in the form of HTTP, RPC, etc. Experimental results show that the model can effectively expand the blockchain system in terms of query efficiency and query functions, improve the query rate of data on the blockchain, and meet people's needs for blockchain query functions.
Naoya Okanami, Ryuya Nakamura, Takashi Nishide
Sharding is a solution to the blockchain scalability problem. A sharded blockchain divides consensus nodes (validators) into groups called shards and processes transactions separately to improve throughput and latency. In this paper, we analyze the rational behavior of users in account/balance model-based sharded blockchains and identify a phenomenon in which accounts (users' wallets and smart contracts) eventually get concentrated in a few shards, making shard loads unfair. This phenomenon leads to bad user experiences, such as delays in transaction inclusions and increased transaction fees. To solve this problem, we propose two load balancing methods in account/balance model-based sharded blockchains. Both methods perform load balancing by periodically reassigning accounts: in the first method, the blockchain protocol itself performs load balancing and in the second method, wallets perform load balancing. We discuss the pros and cons of the two protocols, and apply the protocols to the execution sharding in Ethereum 2.0, an existing sharding design. Further, we analyze by simulation how the protocols behave to confirm that we can observe smaller transaction delays and fees. As a result, we released the simulation program as âShargri-La,â a simulator designed for general-purpose user behavior analysis on the execution sharding in Ethereum 2.0.
Marco Schletz, Angel Hsu, Brendan R. Mapes, Martin Wainstein
The Paris Agreementâs decentralized and bottom-up approach to climate action poses an enormous accounting challenge by substantially increasing the number of heterogeneous national, sub-national, and non-state actors. Current legacy climate accounting systems and mechanisms are insufficient to avoid information asymmetry and double-counting due to actor heterogeneity and fragmentation. This paper presents a nested climate accounting architecture that integrates several innovative digital technologies, such as Distributed Ledger Technology, Internet of Things, Machine Learning, and concepts such as nested accounting and decentralized identifiers to improve interoperability across accounting systems. Such an architecture can enhance capacity building and technology transfer to the Global South by creating innovation groups, increasing scalability of accounting solutions that can lead to leapfrogging into innovative systems designs, and improving inclusiveness.
Queping Kong, Ziyan Wang, Yuan Huang, Xiangping Chen · 7 authors
No abstract is available for this record.
Patrick Ocheja, Brendan Flanagan, Hiroaki Ogata, Solomon Sunday Oyelere
The use of blockchain in education has become one of the trending topics in education technology research. However, only a handful of education blockchain solutions have provided a measure of the impact on students' learning outcomes, teaching, or administrative processes. This work reviews how academic data stored on the blockchain is being visualized across various education blockchain solutions. We argue that education's uniqueness requires a different visualization approach that supports students' learning activities, advances teaching methods, and facilitates administrative procedures. We identify a consistent trend where most of the proposed education blockchain solutions focus on credentials collection and do not provide a way to make sense of the blockchain's data. Thus, we conducted a needs analysis by interviewing four teachers to understand essential features when accessing distributed academic data, report these results and use them to inform the features of our proposed visualizations. Our unique contributions include: presenting typical use cases of distributed learning records from multiple education institutes and demonstrating how past learning records of students stored on the blockchain can be visualized to support current learning. We also propose a method of visualization to increase the data awareness of information owners through the blockchain.
QuanâLin Li, Yan-Xia Chang, Chi Zhang
It is interesting but difficult and challenging to study Ethereum with multiple mining pools. One of the main difficulties comes from not only how to represent such a general tree with multiple block branches (or sub-chains) related to the multiple mining pools, but also how to analyze a multi-dimensional stochastic system due to the mining competition among the multiple mining pools. In this paper, we first set up a mathematical representation for the tree with multiple block branches. Then we provide a block classification of Ethereum: Regular blocks (in the main chain), orphan blocks, uncle blocks, stale blocks, and nephew blocks, and give some key ratios and probabilities of generating the different types of blocks by applying the law of large numbers. Based on this, we further discuss the growth rate of blockchain and the reward allocation among the multiple mining pools through applying the renewal reward theorem. Finally, we use some simulation experiments to verify our theoretical results, and show that the approximate computation approaches developed, such as the key ratios and probabilities, the long-term growth rate of blockchain, and the long-term reward allocation (rate) among the multiple mining pools, can have a faster convergence. Therefore, we provide a powerful tool for observing and understanding the influence of the selfish mining attacks on the performance of Ethereum with multiple mining pools. We believe that the methodology and results developed in this paper will shed light on the study of Ethereum with multiple mining pools, such that a series of promising research can be inspired potentially.
Chencheng Zhou, Liudong Xing, Jun Guo, Qisi Liu
Blockchain technology has gained prominence over the last decade. Numerous achievements have been made regarding how this technology can be utilized in different aspects of the industry, market, and governmental departments. Due to the safety-critical and security-critical nature of their uses, it is pivotal to model the dependability of blockchain-based systems. In this study, we focus on Bitcoin, a blockchain-based peer-to-peer cryptocurrency system. A continuous-time Markov chain-based analytical method is put forward to model and quantify the dependability of the Bitcoin system under selfish mining attacks. Numerical results are provided to examine the influences of several key parameters related to selfish minersâ computing power, attack triggering, and honest minersâ recovery capability. The conclusion made based on this research may contribute to the design of resilience algorithms to enhance the self-defense and robustness of cryptocurrency systems.
B. Sriman, Ganesh Kumar S.
Blockchain is the distributed decentralized application for developing many of the use cases. In blockchain, the applications are transparent to all the nodes in the decentralized network and the application may be private or public depends upon the use cases. The nodes in the distributed network shares all the data to the other nodes without any modification in the blockchain technology. The transaction by the node is secured through the digital signatures. In this paper, we implemented the application by confirming the transaction without paying the gas fee by deploying the smart contract. The solidity is a JavaScript programming language for writing our smart contract. We explained the gas optimization technique used by the users and the gas station network in a decentralized application and also explained about the parameters in the Ethereum transactions. We used the open zeppelin library, which allows us to run our đ·đđđ to implement the gasless transaction.
Claudio Di Ciccio, Giovanni Meroni, Pierluigi Plebani
Abstract Being the blockchain and distributed ledger technologies particularly suitable to create trusted environments where participants do not trust each other, business process management represents a proper setting in which these technologies can be adopted. In this direction, current research work primarily focuses on blockchain-oriented business process design, or on execution engines able to enact processes through smart contracts. Conversely, less attention has been paid to study if and how blockchains can be beneficial to business process monitoring. This work aims to fill this gap by (1) providing a reference architecture for enabling the adoption of blockchain technologies in business process monitoring solutions, (2) defining a set of relevant research challenges derived from this adoption, and (3) discussing the current approaches to address the aforementioned challenges.
Nianqi Jiang, Fenhua Bai, Lin Huang, Zhengyuan An · 5 authors
The Internet of Things that links the cyber and physical worlds brings revolutionary changes to society, however, its security and efficiency problems have not been solved. The Consortium Blockchain + IoT is considered to be an effective solution. The IoT blockchain networkâs demand for transaction processing speed is gradually increasing. The throughput problem of the blockchain needs to be solved urgently and the security problem of transaction processing that comes with it. To solve the above problems, this paper proposes a reputation-driven dynamic node security sharding consensus model (RDSCM) in the blockchain, which consists of two parts: a reputation-driven node to eliminate PBFT (RE-PBFT) and a reputation-driven node cross reconfiguration sharding scheme (NCRS). The RE-PBFT eliminates abnormal nodes in the consensus network and reduces the probability of abnormal nodes becoming master nodes. NCRS improves the blockchain throughput while ensuring sharding reliability. Finally, the experiment proves that RE-PBFT can identify abnormal nodes and remove them in a short time. NCRS can effectively guarantee the reliability of sharding, and the transaction processing efficiency has been greatly improved after sharding.
M. Srikanth, R. N. V. Jagan Mohan
Blockchain is the core of computer technology. It is cryptographically endangered distributed and parallelized database (DB) knowledge for storing and transmitting facts. Each tuple in the DB broadly called a block and covers such as the query timestamp and a link to the previous block. Blockchain and Big data are two expertises in full swing then again they are also two complementary expertise. We can study the how the Blockchain executes big query analysis. Many pursuits query only require the traditional approach of ranking a set of matching results. However, some queries require a more complex approach, either because they are broad or ambiguous. It is important for a DB search engine to identify such queries along with to differentiate broad queries from ambiguous ones. In this chapter, we propose that there is a diversity of indications that the Hadoop-based DB search engine is used. This allows the Hadoop DB search engine to explore and improve the query as correct relevant. The experiment result is measured by the query response time (RT) for optimized queries and broad queries.
Pol Alemany, Ricard Vilalta, RaĂŒl Muñoz, Ramon Casellas · 5 authors
Data center (DC) interconnection allows us to have optical transmissions between DCs directly connected to optical networks, avoiding the use of a packet-based infrastructure. Thanks to the use of next-generation pluggable coherent optics, it is possible to create connectivity services (CSs) across multiple optical transport domains. In this multi-domain CS scenario, cloud operators and transport operators have to work together in the most dynamic way possible. To do so, they need a common place (i.e., a market) where the transport operators may expose their available optical resources and the cloud operators request (e.g., rent) them to be used in order to create end-to-end (E2E) CSs between DCs. Having multiple transport operators exposing their resource information in a common place requires a set of common rules (i.e., how much of the topology to show) to create E2E CSs requested between cloud operators. This paper makes use of the blockchain technology to present a blockchain-based extension for the software-defined network (SDN) architecture to allow each optical transport operator domain to become a peer in a blockchain network. In there, each peer follows the same rules and shares the same exact level of topology information by using a specific abstraction model to map the optical domain resources. This paper uses a set of three different abstraction models to validate their behavior on a blockchain system when managing multiple domain resources and the deployment of CSs across these domains. To do so, an experimental comparison on how the different abstraction models affect the performance of the blockchain system is presented.
Jelena MiĆĄiÄ, Vojislav B. MiĆĄiÄ, Xiaolin Chang
In this work we describe and analyze a novel multi-tier architecture for recording Internet of Things (IoT) data. Each tier in the architecture consists of vertically interconnected node clusters that may be operated by different service providers. Blocks of IoT data are accepted by a cluster tier by tier, until they reach the top tier which adds them to the global blockchain and makes them available to client applications. To allow for large geographical coverage and reduce the dependency on any individual node in the cluster, clusters run a multiple entry version of the Practical Byzantine Fault Tolerance (PBFT) consensus algorithm. We describe an analytical model of the system and find the optimal allocation of clusters and nodes within clusters for a given number of tiers and system coverage area. Our results show that the total number of orderers for given system coverage and total load are main predictors of the block linking time, and indicate that minimizing block linking time is easier to achieve with a smaller number of tiers and large number of clusters with a smaller number of orderers per cluster. These observations can be used as guidelines for planning and dimensioning of multi-tier cluster architectures that create and maintain blockchain structures in a given coverage area.
Huawei Huang, Zheng-Yu Yue, Xiaowen Peng, Liuding He · 8 authors
This article studies the PBFT-based sharded permissioned blockchain, which executes in either a local datacenter or a rented cloud platform. In such permissioned blockchain, the transaction (TX) assignment strategy could be malicious such that the network shards may possibly receive imbalanced transactions or even bursty-TX injection attacks. An imbalanced transaction assignment brings serious threats to the stability of the sharded blockchain. A stable sharded blockchain can ensure that each shard processes the arrived transactions timely. Since the system stability is closely related to the blockchain throughput, how to maintain a stable sharded blockchain becomes a challenge. To depict the transaction processing in each network shard, we adopt the Lyapunov Optimization framework. Exploitingdrift-plus-penalty(DPP) technique, we then propose an adaptive resource-allocation algorithm, which can yield the near-optimal solution for each network shard while the shard queues can also be stably maintained. We also rigorously analyze the theoretical boundaries of both the system objective and the queue length of shards. The numerical results show that the proposed algorithm can achieve a better balance between resource consumption and queue stability than other baselines. We particularly evaluate two representative cases of bursty-TX injection attacks, i.e., the continued attacks against all network shards and the drastic attacks against a single network shard. The evaluation results show that the DPP-based algorithm can well alleviate the imbalanced TX assignment, and simultaneously maintain high throughput while consuming fewer resources than other baselines.
Samer Y. Al-Imamy, Sotiris Zygiaris
No abstract is available for this record.
Jiangyao Wu, Ye Liu, Jiefei Cai, ShuâHui Su
In order to reduce the cost of grid dispatching and increase the transparency of energy transactions, the distributed energy transaction model based on blockchain is constructed. At the same time, in order to improve the high communication overhead and low throughput of the traditional PBFT algorithm in the consortium blockchain, an efficient Byzantine faultâtolerant consensus mechanism (DEâBFT) for the energy blockchain is designed. The algorithm improves from two aspect: node election and main chain consensus. In the stage of node election, the model uses a health score evaluation and a verifiable random function to improve the security and randomness of node selection. In the stage of main chain consensus, the efficient data consistency interaction protocol decreases the complexity of the communications between nodes, down to a constant term level from exponential one. The result shows that, compared with other consensus algorithm, the DEâBFT algorithm performs better in terms of consensus delay, communication overhead, throughput, and consensus node reliability.