Blockchain Papers

Ching-Hu Lu, Chi-Hsien Liu, Zhi Hong Chen

No abstract is available for this record.

Kolja Heck, Esther Mengelkamp, Christof Weinhardt

No abstract is available for this record.

Wei Tong, Xuewen Dong, Yulong Shen, Jiawei Zheng

No abstract is available for this record.

N. Deepa, Quoc‐Viet Pham, Dinh C. Nguyen, Sweta Bhattacharya · 9 authors

Big data has generated strong interest in various scientific and engineering domains over the last few years. Despite many advantages and applications, there are many challenges in big data to be tackled for better quality of service, e.g., big data analytics, big data management, and big data privacy and security. Blockchain with its decentralization and security nature has the great potential to improve big data services and applications. In this article, we provide a comprehensive survey on blockchain for big data, focusing on up-to-date approaches, opportunities, and future directions. First, we present a brief overview of blockchain and big data as well as the motivation behind their integration. Next, we survey various blockchain services for big data, including blockchain for secure big data acquisition, data storage, data analytics, and data privacy preservation. Then, we review the state-of-the-art studies on the use of blockchain for big data applications in different vertical domains such as smart city, smart healthcare, smart transportation, and smart grid. For a better understanding, some representative blockchain-big data projects are also presented and analyzed. Finally, challenges and future directions are discussed to further drive research in this promising area.

Hongman Wang, Yingxue Li, Xiaoqi Zhao, Fangchun Yang

Reasonable allocation of storage and computing resources is the basis of building big data system. With the development of IoT (Internet of Things), more data will be brought. A three-layer architecture includes smart devices layer, edge cloud layer and blockchain-based distributed cloud layer. Blockchain is used in IoT for building a distributed decentralize P2P architecture to deal with the secure issue while edge computing deals with increasing volume of data. Edge caching is one of the important application scenarios. In order to allocate edge cache resources reasonably, to improve the quality of service and to reduce the waste of bandwidth resources, this paper proposes a content selection algorithm of edge cache nodes. The algorithm adopts markov chain model, improves the utilization of cache space and reduces the content transmission delay. The hierarchical caching strategy is adopted and the secondary cache stores slides of contents to expand the coverage of cached content and to reduce user waiting time. Regional node cooperation is adopted to expand the cache space and to support the regional preference of cache content. Compared with the classical substitution algorithm, simulation results show that the algorithm in this paper has higher cache hit ratio and higher space utilization.

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.

Qingqi Pei, Enyuan Zhou, Yang Xiao, Deyu Zhang · 5 authors

As a decentralized trusted database, the blockchain is finding applications in a growing number of fields such as finance, supply chain and medicine traceability, where large volumes of valuable data are stored on the blockchain. Currently, the mainstream blockchains employ a hybrid data storage architecture combining on-chain and off-chain storage. Real-time distributed search of mass data stored in this hybrid system is now a major need. However, previous fast retrieval schemes for the blockchain system are aimed only at on-chain data without considering their relevance to off-chain data, and thus fail to meet the requirement. In this paper, we propose an efficient blockchain data query scheme by introducing a novel Merkle Semantic Trie-based indexing technique without modifying the underlying database. A consensus on-chain index structure is constructed using the extracted semantic information of the off-chain data to create a mapping between the on-chain and off-chain data, thus enabling real-time data query both on and off the chain. Our scheme also provides multiple complex analytical query primitives to support semantic query, range query, and even fuzzy query. Experiments on three open data sets show that the proposed scheme has good query performance with shorter query latency for four different search types and offers better retrieval performance and verification efficiency than those available.

Togoe Nicolae-Bogdan-Cristian, Spataru Alexe Luca, Ciprian Pungilă

Due to increasing popularity in distributed ledger systems and the increasing demand of a stable model of a blockchain, fitting both for the development of IoT (Internet of Things) and DApps(Decentralized Applications), the current generation of blockchain needs to solve its main problems ranging from scalability to security and to bring improvements, in order to fit the real-world needs of society nowadays. One of many solutions brought by current prospective blockchains is a form of governance through different types of nodes, usually equipped with more computational resources, that have a more important significance in the network. In this paper, we tried to showcase the applicability of democratic governance in the blockchain ecosystem through the use of supernodes, in order to solve some of the current dilemmas. Despite the multitude of the use-cases, we will focus on four that show great potential in improving the blockchain technology, by outlining both their positive and negative points. Besides that, current blockchains that have a form of governance will be analyzed by examining the use-cases of the supernodes as well as the benefits and negative aspects they give to the ecosystem.

Soo Hoon Maeng, Meryam Essaid, Hong Taek Ju

Ethereum is arguably the second most popular cryptocurrency-based network after Bitcoin, both make use of the distributed ledger technology known as blockchain. The blockchain-based networks are considered to be secure, but the level of provided security is proportional to the number of connected nodes, the number of influential nodes and the supported amount of hash power. Thus, the knowledge of the network properties and nodes behavior is useful to protect the network from the possible attacks such as double spending attacks, DDoS attacks, 51% attacks, and Sybil attacks. In this paper, we propose nodes discovery mechanism, which performs a P2P links discovery on Ethereum main-network. For that, we developed the Search-node, a modified version of Ethereum Client that search for all participating nodes in the network, store the nodes identification in the Bucket, and then process the peer discovery method. We analyze the collected data to discover the relationship between nodes, heavily-connected nodes, nodes geo-distribution and provide network snapshots, as well as some data related to security issues and possible attacks over the influential nodes. Our results show that approximately 300,000 nodes are connected over Ethereum network, and among these roughly 139 nodes show a high-degree.

Usama Mir

Recent years have shown a great interest of public in buying and selling of crypto/digital currency. With hundreds of digital currencies in financial market, bitcoin remains the most widely used, adapted, and accepted currency around the world. However, the critics of bitcoin still consider it a threat to modern day power usage. This paper discusses the important pitfalls, pros, and cons related to bitcoin's energy consumption. The paper begins by highlighting the flexibilities cryptocurrency can bring to online money transfers compared to traditional 'fiat' architecture. Then, the focus of the paper entirely remains on listing various facts related to bitcoin's energy utilization including a brief description of several emerging approaches for energy optimization. This paper is concluded by revealing key current challenges associated to bitcoin's energy usage.

Kai Lei, Junjie Fang, Qichao Zhang, Junjun Lou · 8 authors

No abstract is available for this record.

Hussein Hellani, Layth Sliman, Motaz Ben Hassine, Abed Ellatif Samhat · 6 authors

No abstract is available for this record.

Yao Yu, Shumei Liu, Phee Lep Yeoh, Branka Vucetic · 5 authors

The combination of pervasive edge computing and blockchain technologies opens up significant possibilities for industrial Internet of Things (IIoT) applications, but there are several critical limitations regarding efficient storage and rapid response for large-scale low-delay IIoT scenarios. To address these limitations, in this article we propose a hierarchical edge-cloud blockchain called LayerChain. Specifically, to promote scalability, we design a layered structure to hierarchically store the blockchain data in multiple distributed clouds and edge nodes. Next, we propose a node classification method to accommodate differences between the edge nodes when deploying the blockchain. Moreover, to mitigate lengthy delays during block propagation, we propose a tree-based clustering algorithm where blocks are propagated through different clusters with a compressed tree depth. Simulation results show that our LayerChain efficiently reduces the system's resource requirements and block propagation time, making it well-suited for large-scale low-delay IIoT applications.

Nikolaos Kapsoulis, Alexandros Psychas, Georgios Palaiokrassas, Achilleas Marinakis · 10 authors

Private and permissioned blockchains are conceptualized and mostly assembled for fulfilling corporations’ demands and needs in the context of their own premises. This paper presents a complete and sophisticated end-to-end permissioned blockchain application for governance and management of musical rights endorsed by smart contract development. In a music industry use case, this disclosed solution monitors and regulates conflicting musical rights of diverse entities under a popular permissioned distributed ledger technology network. The proposed implementation couples various and distinct business domains across the music industry organizations and non-profit blockchain associations.

Jelle Hellings, Daniel P. Hughes, Joshua Primero, Mohammad Sadoghi

To enable high-performance and scalable blockchains, we need to step away from traditional consensus-based fully-replicated designs. One direction is to explore the usage of sharding in which we partition the managed dataset over many shards that independently operate as blockchains. Sharding requires an efficient fault-tolerant primitive for the ordering and execution of multi-shard transactions, however. In this work, we seek to design such a primitive suitable for distributed ledger networks with high transaction throughput. To do so, we propose Cerberus, a set of minimalistic primitives for processing single-shard and multi-shard UTXO-like transactions. Cerberus aims at maximizing parallel processing at shards while minimizing coordination within and between shards. First, we propose Core-Cerberus, that uses strict environmental requirements to enable simple yet powerful multi-shard transaction processing. In our intended UTXO-environment, Core-Cerberus will operate perfectly with respect to all transactions proposed and approved by well-behaved clients, but does not provide any guarantees for other transactions. To also support more general-purpose environments, we propose two generalizations of Core-Cerberus: we propose Optimistic-Cerberus, a protocol that does not require any additional coordination phases in the well-behaved optimistic case, while requiring intricate coordination when recovering from attacks; and we propose Pessimistic-Cerberus, a protocol that adds sufficient coordination to the well-behaved case of Core-Cerberus, allowing it to operate in a general-purpose fault-tolerant environments without significant costs to recover from attacks. Finally, we compare the three protocols, showing their potential scalability and high transaction throughput in practical environments.

Jianting Zhang, Zicong Hong, Xiaoyu Qiu, Yufeng Zhan · 6 authors

To overcome the limitations on the scalability of current blockchain systems, sharding is widely considered as a promising solution that divides the network into multiple disjoint groups processing transactions in parallel to improve throughput while decreasing the overhead of communication, computation, and storage. However, most existing blockchain sharding systems adopt a static sharding policy that cannot efficiently deal with the dynamic environment in the blockchain system, i.e., joining and leaving of nodes, and malicious attack. This paper presents SkyChain, a novel dynamic sharding-based blockchain framework to achieve a good balance between performance and security without compromising scalability under the dynamic environment. We first propose an adaptive ledger protocol to guarantee that the ledgers can merge or split efficiently based on the dynamic sharding policy. Then, to optimize the sharding policy under dynamic environment with high dimensional system states, a deep reinforcement learning-based sharding approach has been proposed, the goals of which include: 1) building a framework to evaluate the blockchain sharding systems from the aspects of performance and security; 2) adjusting the re-sharding interval, shard number and block size to maintain a long-term balance of the system’s performance and security. Experimental results show that SkyChain can effectively improve the performance and security of the sharding system without compromising scalability under the dynamic environment in the blockchain system.

Yonggang Xiao, Yanbing Liu, Tun Li

The dissemination of false messages in Internet of Vehicles (IoV) has a negative impact on road safety and traffic efficiency. Therefore, it is critical to quickly detect fake news considering news timeliness in IoV. We propose a network computing framework Quick Fake News Detection (QcFND) in this paper, which exploits the technologies from Software-Defined Networking (SDN), edge computing, blockchain, and Bayesian networks. QcFND consists of two tiers: edge and vehicles. The edge is composed of Software-Defined Road Side Units (SDRSUs), which is extended from traditional Road Side Units (RSUs) and hosts virtual machines such as SDN controllers and blockchain servers. The SDN controllers help to implement the load balancing on IoV. The blockchain servers accommodate the reports submitted by vehicles and calculate the probability of the presence of a traffic event, providing time-sensitive services to the passing vehicles. Specifically, we exploit Bayesian Network to infer whether to trust the received traffic reports. We test the performance of QcFND with three platforms, i.e., Veins, Hyperledger Fabric, and Netica. Extensive simulations and experiments show that QcFND achieves good performance compared with other solutions.

Laizhong Cui, Xiaoxin Su, Zhongxing Ming, Ziteng Chen · 7 authors

Edge computing architectures can help us quickly process the data collected by Internet of Things (IoT) and caching files to edge nodes can speed up the response speed of IoT devices requesting files. Blockchain architectures can help us ensure the security of data transmitted by IoT. Therefore, we have proposed a system that combines IoT devices, edge nodes, remote cloud, and blockchain. In the system, we designed a new algorithm in which blockchain-assisted compressed algorithm of federated learning is applied for content caching, called CREAT to predict cached files. In the CREAT algorithm, each edge node uses local data to train a model and then uses the model to learn the features of users and files, so as to predict popular files to improve the cache hit rate. In order to ensure the security of edge nodes’ data, we use federated learning (FL) to enable multiple edge nodes to cooperate in training without sharing data. In addition, for the purpose of reducing communication load in FL, we will compress gradients uploaded by edge nodes to reduce the time required for communication. What is more, in order to ensure the security of the data transmitted in the CREAT algorithm, we have incorporated blockchain technology in the algorithm. We design four smart contracts for decentralized entities to record and verify the transactions to ensure the security of data. We used MovieLens data sets for experiments and we can see that CREAT greatly improves the cache hit rate and reduces the time required to upload data.

Sudip Misra, Anandarup Mukherjee, Arijit Roy, Nishant Saurabh · 6 authors

The proliferation of IoT in various technological realms has resulted in the massive spurt of unsecured data. The use of complex security mechanisms for securing these data is highly restricted owing to the low-power and low-resource nature of most of the IoT devices, especially at the Edge. In this article, we propose to use blockchains for extending security to such IoT implementations. We deploy a Ethereum blockchain consisting of both regular and constrained devices connecting to the blockchain through wired and wireless heterogeneous networks. We additionally implement a secure and encrypted networked clock mechanism to synchronize the non-real-time IoT Edge nodes within the blockchain. Further, we experimentally study the feasibility of such a deployment and the bottlenecks associated with it by running necessary cryptographic operations for blockchains in IoT devices. We study the effects of network latency, increase in constrained blockchain nodes, data size, Ether, and blockchain node mobility during transaction and mining of data within our deployed blockchain. This study serves as a guideline for designing secured solutions for IoT implementations under various operating conditions such as those encountered for static IoT nodes and mobile IoT devices.

K. Toda, Naomi Kuze, Toshimitsu Ushio

Blockchain is a distributed ledger technology for recording transactions. To guarantee the immutability of the blocks, miners need a lot of computational resources for generating blocks (mining). Since mining is conducted distributedly by many miners, chain forks can occur in the blockchain. In this paper, we investigate the effects of miners’ locations, the size of the mining pool (MP), and the network structure on the selection rate of blocks generated by the MP when chain forks occur through simulations.

Shi-Syun Kuo, Wei-Tsung Su

In this paper, we propose the blockchain-indexed storage (BIS) to provide scalable and secure IoT-enabled supply chain traceability. Although blockchain can prevent data from being maliciously tampered with, scalability is the challenge to directly store supply chain data into blockchain. A massive IoT devices can generate enormous transactions and data which can significantly increase latency and cost. Instead of directly storing supply chain data into blockchain, BIS stores data and data fingerprint into off-chain storages and blockchain, respectively. In addition, BIS supports adaptive transaction arrival rate to control latency and cost according to demand. Our preliminary implementation and analysis show the feasibility of applying BIS to provide scalable and secure supply chain traceability.

Mohammad Amiri-Zarandi, Rozita Dara

Social Internet of Things (social IoT) is a paradigm that integrates the social network concepts with IoT in which objects in the network are able to establish social relationships with each other. In these networks, to preserve privacy and security, the access to IoT resources can be handled based on social trust evaluation of the devices. This paper examines a blockchain-based trust management system for edge-enhanced IoT that uses social information of the system to strengthen the trust evaluation. Moreover, this system leverages information entropy to enhance security. We also developed a proof of concept system to show that the proposed solution can effectively assess trust factors in social IoT.

Suyash Gupta, Jelle Hellings, Sajjad Rahnama, Mohammad Sadoghi

Since the introduction of Bitcoin---the first widespread application driven by blockchains---the interest in the design of blockchain-based applications has increased tremendously. At the core of these applications are consensus protocols that securely replicate client requests among all replicas, even if some replicas are Byzantine faulty. Unfortunately, these consensus protocols typically have low throughput, and this lack of performance is often cited as the reason for the slow wider adoption of blockchain technology. Consequently, many works focus on designing more efficient consensus protocols to increase throughput of consensus. We believe that this focus on consensus protocols only explains part of the story. To investigate this belief, we raise a simple question: Can a well-crafted system using a classical consensus protocol outperform systems using modern protocols? In this tutorial, we answer this question by diving deep into the design of blockchain systems. Further, we take an in-depth look at the theory behind consensus, which can help users select the protocol that best-fits their requirements. Finally, we share our vision of high-throughput blockchain systems that operate at large scales.

Wenjun Fan, Sang‐Yoon Chang, Shawn Emery, Xiaobo Zhou

Distributed banking platforms and services forgo centralized banks to process financial transactions. For example, M-Pesa provides distributed banking service in the developing regions so that the people without a bank account can deposit, withdraw, or transfer money. The current distributed banking systems lack the transparency in monitoring and tracking of distributed banking transactions and thus do not support auditing of distributed banking transactions for accountability. To address this issue, this paper proposes a blockchain-based distributed banking (BDB) scheme, which uses blockchain technology to leverage its built-in properties to record and track immutable transactions. BDB supports distributed financial transaction processing but is significantly different from cryptocurrencies in its design properties, simplicity, and computational efficiency. We implement a prototype of BDB using smart contract and conduct experiments to show BDB’s effectiveness and performance. We further compare our prototype with the Ethereum cryptocurrency to highlight the fundamental differences and demonstrate the BDB’s superior computational efficiency.