Blockchain Papers

Umesh Kumar Chopra, Ayush Kumar Rathore, Rajiv Pandey

No abstract is available for this record.

Dodo Khan, Low Tang Jung, Manzoor Ahmed Hashmani, Ahmad Waqas

The state-of-art Blockchain technology has been receiving enormous attention from researchers and industry practitioners in recent years. Basically Blockchain is a distributed immutable ledgerutilized by user mainly to perform transactions across various nodes in a blockchain network after a mutual consensus of all the associated nodes in the network. Noticeably, Blockchain is made famous by the Bitcoin cryptocurrency. As of 2017 Blockchain has seen to disrupt many applications to a global worth of 150B. The consensus models are responsible for the process of reaching an agreement between all nodes in blockchain to accept a new block. The consensus model plays a vital role in sustaining Blockchain efficiency. Using the right consensus model can significantly increase the performance of blockchain operation. The consensus models can be divided into two categories. The first category is the proof-based consensus model whereby a node in the Blockchain performs enough proof over other nodes to gain a chance to append the next block to the chain. The second category is the voting-based model in which nodes need to share their results in verifying a transaction of a new block before a final decision is reached. In this paper we discuss the characteristics of some major existing consensus models and provide some critical reviews on their performances. The reviewis mainly concerning these aspects: transaction throughput, latency, network bandwidth, and storage.

Yang Qin, Tiantian Zhang, Mengya Li

No abstract is available for this record.

Ragini Krishna, Chandrasekhar Tekur, Ravi Mukkamala, Pallav Kumar Baruah

No abstract is available for this record.

Naoya Okanami, Ryuya Nakamura, Takashi Nishide

Sharding is an approach to designing a highly scalable blockchain. A sharded blockchain achieves parallelism by dividing consensus nodes (validators) into groups called shards and making them process different transactions in each shard. In this paper, we economically analyze users’ behavior on sharded blockchains and identify a phenomenon that users’ accounts 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 the above problem, we propose a load balancing ramework in sharded blockchains in which accounts and contracts are frequently reassigned into shards to reduce the difference of loads between shards. We formulate the contract reassignment as an optimization problem and present the algorithm to solve it. Further, we apply the framework to an existing sharding design (Ethereum 2.0) and modify the protocol to do load balancing. Finally, we simulate the protocol and observe smaller transaction delays and fees.

Rudrashish Pal

Today's state of the art blockchains suffer from two major setbacks. The first among these, bootstrapping, is the introduction of new nodes into the peer-to-peer (P2P) network in the presence of adversarial nodes. It is crucial that new nodes are prevented from joining adversarial nodes to protect the integrity of the network. The second challenge that today's blockchains face is that of storage efficiency. Blockchains use replication to store the data (or ledger) among users. Users acting as full nodes need to store the entire ledger. As opposed to replication, coding techniques such as fountain codes can be utilised to create an efficient distributed storage system.

M. Francisca Hinarejos, Josep Lluís Ferrer Gomila

In this article, we present the first solution for multi-party certified email that achieves fairness and confidentiality without the intervention of a TTP but with blockchain support when problems arise. Our solution preserves the confidentiality of the mail exchanged between the sender and the recipients even when the blockchain is involved. We provide a proof of concept implementation based on Ethereum smart contracts that shows it is feasible from a practical point of view. Because the functions of a smart contract are only executed on the blockchain in the case of conflict, costs are minimised compared to solutions that execute the functions on the blockchain in all cases (on-chain solutions). Moreover, the solution can be integrated into the existing email infrastructure.

Weilong Lv, Songjie Wei, Shasha Li, YU Ming-hui

No abstract is available for this record.

Sandeep Kadam, Shajimon K. John

No abstract is available for this record.

Xuan Chen, Kien Nguyen, Hiroo Sekiya

No abstract is available for this record.

Simon Krejci, Marten Sigwart, Stefan Schulte

No abstract is available for this record.

Martin Onyeka Okoye, Junyou Yang, Jia Cui, Zhenjiang Lei · 9 authors

In the power sector, microgrids play a supportive role in bridging the adequacy gap in the conventional electricity supply. Trading of the generated energy has recently been improved by blockchain technology which offers a new cheap, secure, and decentralized transaction approach. Its operation is however associated with an undesired inherent delay during energy transactions initiated by the prosumers, thus, failure to timely attend to incidences of urgent demand could end up in catastrophe at the consumer's side. This article thus proposes a cyber-enhanced transactive microgrid model using blockchain technology with optimized participants' permission protocol to ameliorate this challenge. It is demonstrated that the optimized blockchain participants' permission model leads to improved transaction speed and greater convenience. The transaction speed simulation is thereafter performed and it was also demonstrated that the node population has a greater effect than the transaction block size on the transaction speed improvement.

Yonghyun Kim, Ki‐Hyung Kim, Jai-Hoon Kim

Various technologies are mentioned in the 4th Industrial Revolution. One of the emerging issues in the power market is the blockchain-based smart grid network. We propose the architecture of the network by incorporating blockchain technology into the existing smart grid system. The Ethereum and Hyperledger Fabrics are widely used in the blockchain technology as public blockchains and private blockchains, respectively. We describe the network architecture in the smart grid blockchain and compare the performance of transactions processing. The performance analysis shows that Hyperledger Fabric is viable approach by providing pipelined concurrent transaction among peers processing and MVCC(multi-version concurrency control).

Xingtang Xiao, Zhuo Yu, Ke Xie, Shaoyong Guo · 6 authors

No abstract is available for this record.

Ronald Doku, Danda B. Rawat, Moses Garuba, Laurent Njilla

Named Data Network's (NDN) data-centric approach makes it a suitable solution in a networking scenario where there are connectivity issues as a result of the dynamism of the network. Coupling of this ability with the blockchain's well-documented immutable trustworthy-distributed ledger feature, the union of blockchain and NDN in an Internet-of-Battlefield-Things (IoBT) setting could prove to be the ideal alliance that would guarantee data exchanged in an IoBT environment is trusted and less susceptible to cyber-attacks and packet losses. Various blockchain technologies, however, require that each node has a ledger that stores information or transactions in a chain of blocks. This poses an issue as nodes in an IoBT setting have varying computing and storage resources. Moreover, most of the nodes in the IoT/IoBT network are plagued with limited resources. As such, there needs to be an approach that ensures that the limited resources of these nodes are efficiently utilized. In this paper, we investigate an approach that merges blockchain and NDN to efficiently utilize the resources of these resource-constrained nodes by only storing relevant information on each node's ledger. Furthermore, we propose a sharding technique called an Interest Group and introduce a novel consensus mechanism called Proof of Common Interest. Performance of the proposed approach is evaluated using numerical results.

Blaž Podgorelec, Muhamed Turkanović, Martina Šestak

No abstract is available for this record.

Nikolaos Papadis, Leandros Tassiulas

Blockchain technology has been developed with the vision to enable trusted collaboration between untrusted parties, without the need for a central authority. Despite its many promising applications, the technology suffers from a scalability problem. In order to increase transaction throughput and decrease transaction confirmation latency, payment channel networks have been proposed. Payment channel networks introduce a layer on top of the main chain, in which transactions can happen in a safe manner between only the transacting parties without burdening the entire network. In this article, we present and highlight the many interesting research aspects this new type of network introduces. We first provide background on the mechanics of the operation of payment channel networks, and then proceed to present a plethora of research problems of networking and/or economics flavor arising in this context, including routing, scheduling, rebalancing, network design and topology analysis, and fee optimization. This work is within the scope of both the networking and network economics communities.

Zhuoli Zhao, Juntao Guo, Xi Luo, Jizhong Xue · 7 authors

With the decreasing reserves of fossil energy and the increasing capacity of renewable energy generation, the scale of microgrid based on distributed generations is expanding. However, more operation data and transaction information of microgrids will also bring several problems: the sufficient capacity of the server in the central management needed, the crises of trust among members, the transparency of transaction information and the confidentiality of data storage. In this paper, blockchain technology is used to deal with these problems as distributed data storage technology. A double-layer framework of energy transactions based on blockchain in multi-microgrids is proposed to provide decentralized trading, information transparency and mutual trust system of each node in the trading market. The central node within the microgrid collects the demand information of the trading market in lower layer and sends them to the trading market of multi-microgrids in higher layer to seek the energy transaction. The continuous double auction mechanism is used in the trading market to guarantee free and fair transactions among nodes. The proposed transaction framework effectively reduces the transaction volume with the main grid which improves energy utilization. Comprehensive simulation results are presented to prove the feasibility of the proposed transaction framework.

Chinazaekpere Emmanuel Ngubo, Mischa Döhler

Consensus mechanisms are at the core of any Distributed Ledger Technology. They define how transactions are validated and verified, how the network resolves conflicts and protects against malicious intent, and how multiple devices on a distributed network with no central authority arrive at the same global view of the ledger. Experience with the consensus mechanisms employed in popular blockchain platforms have warranted years of research into more scalable and energy-efficient consensus mechanisms for a green society using constrained devices. Most of the “high-security” consensus mechanisms require the use of computational resources which are simply not available to devices with a constrained nature. Hence, the presence and activity of these devices do not contribute to the security of the ledger, irrespective of how numerous they are on the network. In this paper, we propose a novel consensus scheme, fully dependent on WiFi technology, suitable for constrained devices. Whilst in traditional Blockchain consensus mechanisms, constrained devices do not add to the security of the ledger, the security of our consensus mechanism increases with the number of connected devices.

Amritraj Singh, Reza M. Parizi, Meng Han, Ali Dehghantanha · 6 authors

No abstract is available for this record.

Gianmaria Del Monte, Diego Pennino, Maurizio Pizzonia

Public blockchains should be able to scale with respect to the number of nodes and to the transactions workload. The blockchain scalability trilemma has been informally conjectured. This is related to scalability, security and decentralization, stating that any improvement in one of these aspects should negatively impact on at least one of the other two. In fact, despite the large research and experimental effort, all known approaches turn out to be tradeoffs. We theoretically describe a new blockchain architecture that scales to arbitrarily high workload provided that a corresponding proportional increment of nodes is provisioned. We show that, under reasonable assumptions, our approach does not require tradeoffs on security or decentralization. To the best of our knowledge, this is the first result that disprove the trilemma considering the scalability of all architectural elements of a blockchain and not only the consensus protocol. While our result is currently only theoretic, we believe that our approach may stimulate significant practical contributions.

Huawei Huang, Jianru Lin, Baichuan Zheng, Zibin Zheng · 5 authors

Constructing globally distributed file systems (DFS) has received great attention. Traditional Peer-to-Peer (P2P) distributed file systems have inevitable drawbacks such as instability, lacking auditing and incentive mechanisms. Thus, Inter-Planetary File System (IPFS) and Swarm, as the representative DFSs which integrate with blockchain technologies, are proposed and becoming a new generation of distributed file systems. Although the blockchain-based DFSs successfully provide adequate incentives and security guarantees by exploiting the advantages of blockchain, a series of challenges, such as scalability and privacy issues, are also constraining the development of the new generation of DFSs. Mainly focusing on IPFS and Swarm, this paper conducts an overview of the rationale, layered structure and cutting-edge studies of the blockchain-based DFSs. Furthermore, we also identify their challenges, open issues and future directions. We anticipate that this survey can shed new light on the subsequent studies related to blockchain-based distributed file systems.

Nikolay Ivanov, Jianzhi Lou, Qiben Yan

No abstract is available for this record.

Marco Zecchini, Andrea Bracciali, Ioannis Chatzigiannakis, Andrea Vitaletti

No abstract is available for this record.