Blockchain Papers

Caciano dos Santos Machado, Carla Merkle Westphall

No abstract is available for this record.

Juntao Zhao, Yuanfang Chi, Zehua Wang, Victor C. M. Leung · 5 authors

By rendering game scenes on the remote cloud and delivering real-time video to end devices via the Internet, cloud gaming enables players to access game services anytime anywhere despite the hardware capacity of their terminals. However, as a commercial service, the state-of-the-art payment models for cloud gaming are still in their preliminary stages. In this paper, we reveal the shortages of existing cloud gaming pricing models and propose CloudArcade, a token-based cloud gaming system that employs blockchain-empowered cryptocurrency as a payment method for the players using the cloud gaming services. By using cryptocurrency, CloudArcade provides a transparent and resource-aware pricing method, it also enables a time irrelevant silent payment on the floating price to protects users' payment. These features eliminate the quality of experience degradation caused by the spot price in the traditional dynamic pricing model on the QoE-aware service pricing. We also employ the payment channel in CloudArcade to improve the system performance. Discussions on service pricing criteria are put forward, open issues about token issuing and malicious resource speculation are also reviewed. We believe the design of CloudArcade can show a good generality on other QoE-aware and human-centered applications.

Zi Hau Chin, Timothy Tzen Vun Yap, Ian K. T. Tan

A blockchain is a gradually increasing list of "blocks" containing information that are linked together using cryptographic hashes. It is a distributed, decentralized, and public digital ledger technology. Blockchains have caught not only the attention of researchers but also industries that are interested in implementing blockchains into existing products and services. However, performing studies on actual blockchain networks remain challenging as they may involve many nodes or these nodes could be placed in different geographical regions. Simulators for Proof-of-Work blockchain exists to facilitate this, but features such as difficulty adjustment or dynamic hash rate are not available. Using SimBlock, a blockchain network simulator as a base, difficulty adjustment algorithm and the capacity to increase or decrease hash rate dynamically were added to the simulator and the efficacy of the implementation was investigated for two scenarios; fixed hash rate and increasing hash rate periodically, over the length of the simulations. Based on the experiments, higher precision in terms of the average of actual time taken to mine a block were obtained, with a deviation of 0.68% compared to 5.73% in original SimBlock, and a deviation of 7.10% compared to 10.91% in original SimBlock, for fixed hash rate and dynamic hash rate adjustment respectively. Further studies were conducted for data from 2019 where the proposed implementation resulted in less than half the deviation achieved by the original implementation of SimBlock.

Wei‐Ting Lin, Shun-Wen Hsiao, Fang Yu

Using hard-fork mechanism on the blockchain to recover the losses caused by attacks contradicts the immutable characteristic of a blockchain system. To prevent malicious transactions from getting into blockchains in advance, we propose a runtime hook technique to synchronize and analyze the ongoing transactions exposed to the Ethereum transaction pool. Having a complete view of the past and the ongoing transactions, we can identify and enforce abortion of malicious transactions and prevent losses due to attacks being executed and recorded in the blockchain. Specifically, we modify the Ethereum source code to instrument the entry point of a node to synchronize data received from the Ethereum P2P network and systematically scan suspicious patterns in transactions to identify potential attacks. As a proof-of-the-concept, we show how to deploy the proposed runtime hook system on a private blockchain system, such that we can detect and prevent transactions of double spending on the 51% attack and reentrancy attack of smart contracts.

Taotao Wang, Chonghe Zhao, Qing Yang, Shengli Zhang · 5 authors

The peer-to-peer (P2P) network of blockchain used to transport its transactions and blocks has a high impact on the efficiency and security of the system. The P2P network topologies of popular blockchains such as Bitcoin and Ethereum, therefore, deserve our highest attention. The current Ethereum blockchain explorers (e.g., Etherscan) focus on the tracking of block and transaction records but omit the characterization of the underlying P2P network. This work presents the Ethereum Network Analyzer (Ethna), a tool that probes and analyzes the P2P network of the Ethereum blockchain. Unlike Bitcoin that adopts an unstructured P2P network, Ethereum relies on the Kademlia DHT to manage its P2P network. Therefore, the existing analytical methods for Bitcoin-like P2P networks are not applicable to Ethereum. Ethna implements a novel method that accurately measures the degrees of Ethereum nodes. Furthermore, it incorporates an algorithm that derives the latency metrics of message propagation in the Ethereum P2P network. We ran Ethna on the Ethereum Mainnet and conducted extensive experiments to analyze the topological features of its P2P network. Our analysis shows that the Ethereum P2P network possesses a certain effect of small-world networks, and the degrees of nodes follow a power-law distribution that characterizes scale-free networks.

Steven Cao, Swanand Kadhe, Kannan Ramchandran

Validating a blockchain incurs heavy computation, communication, and storage costs. As a result, clients with limited resources, called light nodes, cannot verify transactions independently and must trust full nodes, making them vulnerable to security attacks. Motivated by this problem, we ask a fundamental question: can light nodes securely validate without any full nodes? We answer affirmatively by proposing CoVer, a decentralized protocol that allows a group of light nodes to collaboratively verify blocks even under a dishonest majority, achieving the same level of security for block validation as full nodes while only requiring a fraction of the work. In particular, work per node scales down proportionally with the number of participants (up to a log factor), resulting in computation, communication, and storage requirements that are sublinear in block size. Our main contributions are light-node-only protocols for fraud proofs and data availability.

Yuhui Li, Jianlong Xu, Wei Liang

Blockchain-as-a-service (BaaS) experienced a dramatical growth in recent years, making it a hot research topic. With the expanding scale of distributed services deployed on the blockchain system, it is increasingly urgent to evaluate quality of service (QoS) attributes of blockchain services and in-blockchain peers-clients connections. The complicated association of service invocation and network environment naturally form a graph, making it possible to extract features through graph neural networks (GNN). To incorporate graph-structured information in QoS prediction, we proposed a graph matrix factorization (GraphMF) take advantages of both GNNs and collaborative filtering to estimate missing QoS values in the data matrix. Experiment conducted on a real-world dataset demonstrated the effectiveness of our model.

Faiez Altamimi, Waqar Asif, Muttukrishnan Rajarajan

This paper proposes a comprehensive framework using blockchain architecture to create a decentralized applications store, in order to reduce the approval time for apps that are to be deployed on deployment systems i.e. applications stores, and specially for mobile platforms e.g. Apple and Google play stores. This work potentially can solve some of the existing challenges with the current centralized application approval process by Apple and Google. These companies currently charge a flat commission rate of 30% [1] of the total applications revenues from the applications owners. This commission is considered to be very high, especially for applications with revenues in the order of few million dollars. In addition, the length of the review period prior to deployment for any new or revised apps delays the release to the marketplace hence costing economic losses to the app owners. Currently, Apple and Google stores takes around two days and two hours respectively to review and approve the apps on their stores. However, by using decentralized technologies such as the blockchain, the time to review and publish a new or a revised app can be significantly reduced from few days to few minutesIn this paper a novel framework is proposed based on the blockchain architecture incorporating the Ethereum network, Interplanetary Files System (IPFS), VueJS, and a backend database. The framework is experimentally validated, and the results show the reduction in terms of the number of minutes to approve apps by the app stores.

Lara Mauri, Ernesto Damiani, Stelvio Cimato

Distributed Ledgers (DLs) like Blockchain have become a popular technique to build collective trust in digital records. The rationale is that any agent wishing to append a block to a DL needs to provide proof of holding some property/asset or having performed some costly activity. Thus, “poisoning” a DL with spurious content requires much more effort than poisoning a conventional shared data structure. Based on this idea, DLs are now being deployed as community stores of trusted transaction records, reputation values and even of trustworthy training data for Machine Learning (ML) models. Certainly, when injecting spurious or hostile content in a DL, a rational attacker has to consider whether the damage δ caused by a spurious block B is worth the effort ε needed to append B to the DL; but practical experience has shown that being certain to disrupt a DL-supported application may be a powerful motivator for digital vandalism even when it is costly. In this paper, we put out an alternative idea: Reciprocally Useful Work (RUW), a novel DL update mechanism where any agent wishing to add a block B to the ledger must first perform an activity that will improve the utility for the DL-supported application of some other agent's block B'. We discuss in detail how to apply RUW to DLs storing training data for Machine Learning (ML) models, in order to show that reciprocity can play the role of a direct compensation of the potential disruption, which is measurable in term of the performance of the ML model trained on the DL content.

Yassin M. Thibodeau Hafid, Dimitrios Makrakis, Etienne Elie

Nowadays, the proportion of the global supply of green energy sources (e.g., solar and wind) is increasing dramatically. Integrating these sources into the current smart grid is very challenging, given that the smart grid has centralized topology which is costly and inefficient. In particular, the current procedures used in the wholesale energy market are slow, time-consuming and thus expensive for small-scale energy sources (e.g., small-scale solar energy farms). Indeed, these sources are excluded in practice from the energy market. Thus, to integrate the increasing number of small-scale energy sources, there is a need to transform the smart grid into a decentralized system. A promising technology to realize this decentralization is Blockchain. With its characteristics like immutability, security, and decentralization, we believe that Blockchain will be the core technology for the future decentralized smart grid. In this paper, we propose a peer-to-peer (P2P) energy trading system based on Ethereum. The objective is to allow any participant (e.g., big/small producers and consumers) to securely trade energy with minimum cost. The proposed approach moves most of the processing and storage off-chain, with the objective to minimize the cost of on-chain (i.e., smart contract) processing and storage while guaranteeing the security of the trading process. Stable coins are used to pay for the trade so as to overcome the problem of the instability regarding cryptocurrency exchange rates. Our proposal has been implemented, tested and deployed on the Ethereum official test network Ropsten. The results show that the proposed approach implements the P2P trading process with very small cost, making it an affordable solution for all participants, including small-scale sources.

D. Praveena Anjelin, S. Ganesh Kumar

No abstract is available for this record.

Qing Yang, Hao Wang

Transactive energy plays a key role in the operation and energy management of future power systems. However, the conventional operational mechanism, which follows a centralized design, is often less secure, vulnerable to malicious behaviors, and suffers from privacy leakage. In this work, we introduce blockchain technology in transactive energy to address these challenges. Specifically, we develop a novel blockchain-based transactive energy framework for prosumers and design a decentralized energy trading algorithm that matches the operation of the underlying blockchain system. We prove that the trading algorithm improves the individual benefit and guarantees the socially optimal performance, and thus incentivizes prosumers to join the transactive energy platform. Moreover, we evaluate the feasibility of the transactive energy platform throughout the implementation of a small-scale network of Internet of Things (IoT) devices and extensive simulations using real-world data. Our results show that this blockchain-based transactive energy platform is feasible in practice, and the decentralized trading algorithm reduces the user's individual cost by up to 77% and lowers the overall cost by 24%.

B. Sriman, S. Ganesh Kumar, P. Shamili

No abstract is available for this record.

Nguyen Khoi Tran, Muhammad Ali Babar, Jonathan Boan

No abstract is available for this record.

Piyumika Peiris, Chathura Rajapakse, Bimali Jayawardena

Mobile ad-hoc networks also known as MANETs have been in global use for numerous applications which are not possible with fixed network topologies. The distributed operation and dynamic topology have encouraged MANETs to be applied for establishing communication in unstable environments. MANET's dynamic topology and mobility have been very advantageous in the fields of military and disaster management. These dynamic characteristics of a MANET also create a major challenge in managing trust between the mobile nodes. Managing the trustworthiness of information that a node provides to the rest of the MANET is very crucial as misinformation spread can lead to erroneous decision making. Although previous studies have been carried out on trust management in MANETs using price-based and reputation systems, the potential of a globally distributed system has not been utilized practically. Therefore, these systems address the trust management issue within a boundary of a single MANET. Above mentioned systems should be re-evaluated when a node from another MANET joins a new MANET as the reputations of the node in the previous MANET cannot be imported to the new MANET. Lack of a possible solution for this gap may result in misinformation spreading by a malicious node before other nodes determine its reputation, which could be very dangerous in sensitive environments. Therefore, a globally distributed reputation model is a timely need in mobile ad-hoc networking. Blockchain technology is one of the most suitable technologies in present for its immutable and distributed properties to build robust systems. Blockchain is a distributed ledger, that has the ability to store feedback from mobile nodes about the accuracy of information provided by other nodes. A trust factor for each node can be calculated using these feedbacks. A mobile node can then decide whether to trust information, based on nodes’ trust factors. Adopting a development-oriented research methodology, a blockchain based reputation model prototype has been implemented and validated within the study.

Matthieu Stephant, Kahina Hassam-Ouari, Dhaker Abbes, Antoine Labrunie · 5 authors

This paper presents a private blockchain environment designed to optimize energy exchanges and reach consensus between different users on a university grid. The objectives of this work are to present a fully distributed energy sharing framework that takes into account the individual preferences of the users, and to give guidelines for development of blockchain applications relative to energy sharing. A private Ethereum blockchain with a Proof-of-Authority mechanism is deployed on a local energy community. A smart contract written in Solidity is used to perform distributed optimization under a global power constraint. Python client are used to enable direct interactions between users and the smart contract. The simulations performed on real data show that consensus is obtained after a few iterations, and thus prove that our framework has the potential to be practically used in real situations.

Yongjun Ren, Yan Leng, Jian Qi, Pradip Kumar Sharma · 7 authors

No abstract is available for this record.

Randhir Kumar, Rakesh Tripathi

There are many critical applications working with blockchain-based technology including the financial sector, healthcare, and supply chain management. The fundamental application of blockchain is Bitcoin, which was primarily designed for the financial value transfer. Owing to the feature of decentralized storage structure, immutability, integrity, availability, and reliability of transactions, the blockchain has become the need of the current industry like VANET. However, presently, not much work has been done in order to mitigate the redundancy in the distributed ledger. Hence, the authors arrive at the intelligible conclusion to detect a similar transaction that can mitigate the redundancy of transaction in a distributed ledger. In this chapter, they are addressing two main challenges in blockchain technology: firstly, how to minimize the storage size of blockchain distributed ledger and, secondly, detecting the similar transaction in the distributed ledger to mitigate the redundancy. To detect similar transaction from the distributed ledger they have applied the average hash technique.

Fei Chen, Zhe Xiao, Laizhong Cui, Qiuzhen Lin · 6 authors

No abstract is available for this record.

Khizra Asaf, Rana Asif Rehman, Byung-Seo Kim

No abstract is available for this record.

Steven Platt, Luis Sanabria-Russo, Miquel Oliver

Virtual Network Functions allow the effective separation between hardware and network functionality, a strong paradigm shift from previously tightly integrated monolithic, vendor, and technology dependent deployments. In this virtualized paradigm, all aspects of network operations can be made to deploy on demand, dynamically scale, as well as be shared and interworked in ways that mirror behaviors of general cloud computing. To date, although seeing rising demand, distributed ledger technology remains largely incompatible in such elastic deployments, by its nature as functioning as an immutable record store. This work focuses on the structural incompatibility of current blockchain designs and proposes a novel, temporal blockchain design built atop federated byzantine agreement, which has the ability to dynamically scale and be packaged as a Virtual Network Function (VNF) for the 5G Core.

Saqib Hakak, Wazir Zada Khan, Gulshan Amin Gilkar, Basem Assiri · 7 authors

The rise of blockchain technology within a few years has attracted researchers across the world. The prime reason for worldwide attention is undoubtedly due to its feature of immutability along with the decentralized approach of data protection. As this technology is progressing, lots of developments in terms of identifying new applications, blockchain-based platforms, consensus mechanisms, etc are taking place. Hence, in this article, an attempt has been made to review the recent advancements in blockchain technology. Furthermore, we have also explored the available blockchain platforms, highlighted and explored future research directions and challenges.

Samuel Karumba, Salil S. Kanhere, Raja Jurdak, Subbu Sethuvenkatraman

The emergence of the Internet of Things (IoT) and distributed energy resources (DERs), has given rise to collaborative communities that manage their energy production and consumption load through peer-to-peer decentralized energy trading (P2P DET). To address the issue of distributed trust in these communities, blockchain technology is widely considered as a promising solution due to its ability to provide records provenance and visibility. However, the current blockchain-based platforms are known to compromise on scalability and privacy in favor of trustless interactions and often do not support interoperability. In this work, we propose a hypergraph-based adaptive consortium blockchain (HARB) framework, which coordinates DERs through high-order relationships rather than P2P pairwise relationships. HARB is presented in a three-layered network architecture to address the aforementioned challenges. The bottom layer (Underlay) addresses the issue of scalability, by exploiting the rich representation ability of hypergraphs to describe complex relationships among DERs and end users. We use the described complex relations to form scalable network clusters with intra- and inter-community energy trading relationships. The middle layer (Overlay) presents a blockchain service model to describe adaptive blockchain modules that support interoperability between the network clusters. To preserve privacy, we present a data tagging and anonymization model in the top layer (Contract), which attributes transactions to specific network clusters. To evaluate our framework, we modeled various IoT devices with different computing resource profiles to simulate a distributed energy trading (DET) environment. The analyzed results have shown that our proposed framework can effectively improve the performance of blockchain-based DET systems.

Zhitao Guan, Xin Lu, Wenti Yang, Longfei Wu · 6 authors

No abstract is available for this record.