Blockchain Papers

Abdullah Al-Noman Patwary, Anmin Fu, Sudheer Kumar Battula, Ranesh Kumar Naha · 6 authors

No abstract is available for this record.

Claudia Pop, Mirela Prata, Marcel Antal, Tudor Cioara · 6 authors

This paper addresses the problem of the traditional online auctions by proposing an Ethereum based implementation for three of the most popular auctions: English, Dutch, First-price sealed-bid (FPSB). Such centralized systems are subjects to malicious attacks, unreliable third-party for payment module or repudiation of bids. We present a set of properties that advantages a blockchain auction, which tackles the drawbacks of a traditional one. Furthermore, we define smart contracts for expressing the auctions based on strict rules regarding the role of the participants and stage delimitation. While English and Dutch auction have a public character, the sealed bids from a FPSB can be questioned. The proposed solution incorporates the Merkle proof algorithm for honest verification of these offers. The experimental results show that a Dutch auction is more suitable for sellers, while an English auction for bidders in terms of transaction fees. Based on the behavior of each type of auction, the solution is exemplified by an English auction in the real-estate field, including a protocol for storing data off-chain.

M S Bhargavi, Sushmitha M Katti, M Shilpa, Vaishnavi P Kulkarni · 5 authors

Ethereum is a blockchain based development platform for users to build and deploy decentralized applications and smart contracts. Transactions substituting money over Ethereum space are carried out using Ethereum's cryptocurrency `Ether'. Though the decentralization and public ledger recording of the transactions proves its limpidity, the anonymity of the users, hiding their true identity behind the addresses echoes the need for discerning the behavioural traits in transactions. The appalling nature of Ethereum transactions to have both, security and threat at a comparable level, demands analytics for inferring traits for better perspectives and insights. This research work focuses on characteristic analysis of Ethereum transaction space for inferring behavioural traits in supervised and unsupervised context. In an unsupervised environment, raw transaction data is extradited to a tabular transaction structure by selecting appropriate features. The data is further clustered and validated to form coherent groupings of similar patterns. The clusters are characteristically analyzed based on the features through Radar plots for inferring behavioural traits. In supervised context, labelled transactions are represented using histograms and feature-based characteristic analysis is performed to infer traits. Such analytics lay foundations for future deeper analysis that can be used to discover trends and patterns to understand the transaction network, enhancement of trading strategies, identification of bot activities, anomaly detection and several others.

Mohd Azeem Faizi Noor, Saba Khanum, Taushif Anwar, Manzoor Ansari

Blockchain, the technology behind most popular cryptocurrency Bitcoin and Ethereum, has attracted wide attention recently. It is the most emerging technology that has changed the financial and non-financial transaction system. It is omnipresent. Currently, this technology is enforcing banks, industries, and countries to adopt it in their financial, industrial, and government section. Earlier, it solved the centralize and double-spending problems successfully. In this chapter, the authors present a study of blockchain security issues and its challenges as well. They divided the whole chapter into two parts. The primer part covers a holistic overview of blockchain followed by the later section that argues about basic operations, 51% attack, scalability issue, Fork, Sharding, Lightening, etc. Finally, they mention an intro about its adaptation (financial or non-financial) in our 24/7 life and collaboration with fields like IoT.

U. Padmavathi, Narendran Rajagopalan

Blockchain refers to a distributed ledger technology that helps people to regulate and manage their information without any intermediaries. This technology emerges as a promising panacea for authentication and authorization with potential for use in every possible domain including financial, manufacturing, educational institutions, etc. Blockchain has its birth through the concept of Bitcoin, a digital cryptocurrency by Satoshi Nakamoto, called as Blockchain 1.0. Blockchain 2.0 came into existence in 2014 with Ethereum and smart contracts. The challenges such as scalability, interoperability, sustainability, and governance led to the next generation of Blockchain also called as IOTA, a blockchainless cryptocurrency for the internet of things runs on the top of their own ledger called Tangle, which is immune towards quantum computers. This disruptive technology evolved to provide cross chain support and more security through Blockchain 4.0. Finally, the chapter concludes by discussing the various applications of this technology and its advantages and security issues.

Leili Soltanisehat, Reza Alizadeh, Haijing Hao, Kim‐Kwang Raymond Choo

Blockchain can be used to build a peer-to-peer, secure, and smart transaction system. As a horizontal technology that has changed several fields of industry, blockchain has tremendous potential to transform healthcare systems as well. In this article, a systematic review is conducted to critically evaluate 64 articles on blockchain-based healthcare systems, published between 2016 and January 2020 in 21 conferences, 33 journals, and ten online sources. The aim of this article is to answer three main questions. First, what are the applications of blockchain in the healthcare systems, and what are the structures and challenges of applying blockchain to a specific healthcare domain? Second, what are the technical, temporal, and spatial aspects of the currently developed blockchain applications for different healthcare domain? Third, what are the future research directions in designing and implementing blockchain-based healthcare systems? Statistical facts about the technical aspects of these 64 articles show that most of the proposed blockchain-based healthcare systems use private blockchain and Ethereum platforms; furthermore, the majority of the authors are affiliated with research institutions in the USA and China. We also discuss potential future research directions, e.g., integrating the blockchain in artificial intelligence based solutions, cloud-computing-based solutions, and parallel blockchain architecture.

Tao Chen, Wei Tian, Jingying Wu, Lin Ye · 6 authors

In this paper, we study a local P2P energy trading with help of Blockchain technologies and consideration for customers’ risk preference. The local energy transactions are based on double-side auction mechanism, meanwhile enabling immediate seller-buyer pairing process via iterative price adjustment. Additionally, the quantitative description of risk preference guarantees the optimal decision-making according to customers’ subjective gain reference. The Blockchain platform is also used to support the proposed P2P energy trading mechanism, strengthening the decentralized implementation and smart contract deployment. The demonstration is provided using Ethereum and Remix development environment.

Martin Westerkamp, Jacob Eberhardt

We facilitate trusted cross-blockchain state proofs by implementing a chain-relay that validates block headers from proof-of-work blockchains. While current approaches require proof sizes linear to the amount of blocks the state was built on, trusted intermediaries, or economic assumptions, we propose the utilization of off-chain computations through zkSNARKs to provide a cryptographically secure and highly scalable sidechain mechanism. Multiple block headers are included in batches and verified off-chain, while preserving light client support. Only the validity of the off-chain computation is verified on-chain, creating a sidechain mechanism that requires constant verification costs and releases the target ledger from processing and storing every single block header of the source blockchain. Efficient Merkle proofs enable including intermediary blocks for any batch that was submitted. We provide a prototypical implementation that facilitates the verification of 504 Bitcoin headers in a single proof on Ethereum using the ZoKrates framework. Hereby, the verification costs are reduced by a factor of 187 compared to current approaches such as BTC Relay.

Swapnil Anil Surdi

No abstract is available for this record.

A. Melki

This paper investigates volatility spillovers among six competitor Cryptocurrencies from August 8, 2015 to September 01, 2019. A Generalized VAR framework is used to measure time varying spillovers index. Results provide evidence of (i) a rise in volatility spillovers transmitted among monitored Cryptocurrencies since the second quarter of 2017. (ii) Ethereum acts as the major contributor on spillovers index, contrary to Ripple that presents the main recipient of spillovers. (iii) the pairwise (Monero-Ripple) and (Bitcoin-Ethereum) present a low connectedness level driving consequently beneficial diversification opportunities for cryptocurrency investors.

Kei Leo Brousmiche, Pascal Ménégazzi, Olivier Boudeville, Eric Fantino

The concept of peer-to-peer energy trading became popular with the increase of local energy production and use of renewable energies. Based on a sharing economy, this framework allows energy trading between households, bringing flexibility and decreasing the dependency on energy providers. In parallel, the increasing adoption of electric vehicles and the development of vehicle-to-grid (V2G) technology open new ways to store, transport and deliver renewable energy. V2G-enabled cars could contribute to the flexibility of peer-to-peer energy marketplaces. Our physical demonstrator illustrates the benefits of V2G-enabled vehicles in the context of local energy marketplaces in terms of economical gain, overall power balancing and consumed renewable energy rate. The demonstrator is composed of smart contracts implementing such marketplace running on a local Ethereum blockchain deployed on Raspberry Pis, autonomous agents simulating the energy consumption and production behavior of 4 households as well as their buying/selling behavior, and finally a V2G car whose behavior is controlled by a user through a tablet.

Ruxiang Ma, Hongyi Zhou, Weihang Qian, Chengzhi Zhang · 6 authors

Blockchain technology is a decentralized data storage method. The application of blockchain technology to virtual power plants will have an important impact on its operation mode. This paper first expounds the blockchain technology and analyzes the applicability of its combination with virtual power plants. On this basis, it designs the virtual power plant transaction and management framework based on blockchain technology, and establishes the power transaction mode of virtual power plants based on blockchain technology. Finally, on the Ethereum platform, the simulation test is carried out. The results show that the virtual power plant transaction mode based on blockchain technology, combined with the continuous double auction mechanism, can realize the peer-to-peer transaction of distributed resources and loads within the virtual power plant, promote the local elimination of distributed energy source, and reduce the cost of power transaction and energy loss.

Panagiotis Anastasiadis, Katsaros Efthymios, Koutsioukis Anastasios-Taxiarchis, Pandazis Athanasios

Abstract This study investigates how twelve cryptocurrencies with large capitalization get influenced by the three cryptocurrencies with the largest market capitalization (Bitcoin, Ethereum, and Ripple). Twenty alternative specifications of ARCH, GARCH as well as DCC-GARCH are employed. Daily data covers the period from 1 January 1 2018 to 16 September 2018, representing the intense bearish cryptocurrency market. Empirical outcomes reveal that volatility among digital currencies is not best described by the same specification but varies according to the currency. It is evident that most cryptocurrencies have a positive relationship with Bitcoin, Ethereum and Ripple, therefore, there is no great possibility of hedging for crypto-currency portfolio managers and investors in distressed times.

Lanxiang Chen, Wutong Bai, Zhiqiang Yao

The patients' medical image data are one of the most important data in e-health. Medical image data usually play a crucial role in disease diagnosis and implicate unpredictable potential values for improving diagnostic methods and adjusting diagnostic results. To exploit their incredible potential values, medical images need to be shared among different hospitals, medical institutions and insurance companies and others. But how to securely and effectively share these medical image data becomes a challenging problem. In this paper, we proposed to combine encryption and digital watermark technology to achieve a secure and privacy-preserving medical image sharing method. The QR code image of the concatenation of authoritative diagnosis results and the hash of the original medical image is generated as the watermark image. The Discrete cosine transform (DCT) and Inverse DCT (IDCT) algorithms are utilized to embed the watermark image. As the watermarked medical images are desensitized, they are stored to a smart contract based blockchain, such as Ethereum, to achieve secure and fair sharing between data owners and users. The experimental results show that the proposed method can resist several attacks meanwhile it is efficient in medical image sharing.

Nur Endah Dwijayanto

The U.S. Navy seeks to leverage emerging technologies to manage massive amounts of data from multiple geographically separated systems. It is aware of the importance of data usage and data transfer in supporting its operations. Data management requires a data transfer system that is safe, fast, and scalable. Autonomous Navy Unclassified Software Distribution (ANUSD) is an application for delivering software to all nodes on the Navy's enterprise network based on blockchain technology. Blockchain is the right candidate and emerging solution to ensure the triad of confidentiality, integrity, and availability. In this thesis, we perform a comparison of public blockchain and private blockchain with the aim of determining which one would perform better in conjunction with ANUSD. We used an IBM Hyperledger (private blockchain) network and an Ethereum blockchain (public blockchain) network as the basis of the comparative analysis of their latency and scalability. We compared the transactions per second (TPS) achieved with Ethereum against that of Hyperledger with the ANUSD application installed. The results showed that as we scaled up the Ethereum network, there was a significant increase in TPS. In contrast, increasing scalability did not have a significant impact on TPS for the Hyperledger network.

Molud Esmaili, Reza Javidan

Today's video-sharing systems are platforms that have been developed to be a hub for the introduction and sharing of videos created by video creators from all over the world. These systems generate significant revenue through advertising or copyright transferring they receive from video viewers, which share only certain percentage with video creators. However, To make more profit for video creators, in this paper we proposed a distributed video sharing architecture with the possibility of performing financial transactions that works on the Ethereum. In this new architecture, the Blockchain network separated from storage; because video storage in Blockchain results to be costly for mining in the nodes in the network. Ethereum's smart contract is responsible for monitoring the validity, transparency, immutability, integrity, and security of transactions as well as controlling video access. On the other side of the architecture, there is an Ethereum-compatible distributed file storage called Swarm for video storage. Due to the lack of video storage in the Blockchain network, the integrity of the videos is questionable. To solve this problem in the proposed scheme, a Merkel tree of video hashes in the swarm is created and stored in the Blockchain to ensure the immutability and integrity of the videos and, to be transparent and valid to everyone. Finally, the performance of the proposed architecture in terms of security, structure distribution, downtime probability, fault tolerance, transparency, content integrity, immutability, and sustainability has been compared with similar systems and its performance has been proven.

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.

Swaraj Kumar, Sandipan Dutta, Shaurya Chatturvedi, M. P. S. Bhatia

Several recent advances in Federated Learning have made it possible for researchers to train their models on private data present on contributing devices without compromising their privacy. In this paradigm, each contributor’s local updates are aggregated and averaged to update the global model. In this paper, we introduce a secure and decentralized training for distributed data. In order to develop an efficient decentralized system, blockchain technology is introduced via Ethereum, which enables us to create a value-driven incentive mechanism. This is done to encourage the contributors to positively affect the learning of the global model. We provide an enhanced security mechanism by implementing differential privacy and homomorphic encryption. The performance of the global model has been significantly boosted by implementing Elastic Weight Consolidation, which prevents Catastrophic forgetting, a scenario where the model learns only on new data and forgets its previous learnings. It proves essential in distributed training since the model is being trained on a spectrum of data, often present in clusters on each contributor’s device. We introduce an innovative way of using hyperparameter optimization in federated learning with the help of Hyperopt and deposit based reward mechanism. Experiments verify the capability of the novel strategies incorporated in our system.

Daniel Rincon Silva

It is widely accepted that Ethereum mining is highly centralized. Nonetheless, centralization has been mostly characterized by exclusively looking at the influence that independent miners or mining pools can have over the network. Moreover, models of mining behavior assume that miners are either unrelated or only relate via mining pools under highly structured and transparent agreements. If these assumptions and the predictions they entail were to be completely accurate, there would not be any evidence of on-chain transactions between miners, other than the ones expected from mining pool payouts. By looking at on-chain transactions between miners in the Ethereum Network we find that aside from the payouts from mining pools to small miners, there are also transactions that define relationships between mining pools, independent miners and between independent miners and mining pools. Furthermore, by characterizing the topology of the network of miner transactions, we find the emergence of highly connected clusters that control significant amounts of hashing power and exhibit relationships in the opposite direction of what theoretical models predict. This more nuanced characterization of mining centralization can help identify network vulnerabilities and inform protocol redesigns.

Віктор Миколайович Чешун, Ihor Muliar, Vasyl Yatskiv, Ruslan Shevchuk · 6 authors

Decentralized applications, architectures and Blockchain are very popular and progressive technologies that are definitely ahead of its time. Nowadays world has a lot of decentralized applications and proposals, however the approaches and concepts decentralized software development based on the Blockchain technology is only emerging. This process is a common thing for new technologies as far as its adaptation takes time and often requires to change a usual approach to it. This article suggests a new way of safe decentralized applications development using Blockchain technologies and Ethereum platform. Ethereum platform-it's a project that is undoubtedly second best after bitcoin for a quite long period of time. Ethereum is presented as a platform for various tasks, such as maintaining a stable application performance in case of any threats. The main object of the research are the decentralized applications, build on a Ethereum platform basis using the smart-contracts algorithm. The study helped to improve an existing crypto-token allocating model which goal is acquiring more stable performance. On the basis of improved model a new method of allocating cryptotokens in decentralized Ethereum applications was developed, defined a main stage of apps elaboration, offered an allocating crypto-token algorithm which is able to use associative tables and dictionaries.

Yue Li, Han Liu, Zhiqiang Yang, Bin Wang · 7 authors

While smart contracts have enabled a wide range of applications in many public blockchains, e.g., Ethereum, their security issues have been raising an increasing number of threats on the stability of blockchain ecosystem. In practice, many external attacks on smart contracts result from broken payments with digital assets, e.g., cryptocurrencies. While an increasing number of research works have been focusing on such problems, many of them adopted pattern-based heuristics (e.g., reentrancy) to find payment-related attacks thus can incur a considerably large portion of both false positives and negatives. To overcome these limitations and achieve better payment security on blockchain, we introduced a new class of payment attacks in this paper, i.e., unfair payment (UP). Compared to existing heuristics, UP semantically captures a wider range of payment attacks. Furthermore, we highlighted the general framework SAFEPAY to systematically detect UP. The key insight behind is a novel security invariant, i.e., fair value exchange (FVE), which models the fairness for blockchain payments between multiple parties. More specifically, SAFEPAY systematically explores the transaction space of a given smart contract and generates a bounded set of transaction sequences. For each of the sequence, SAFEPAY reports a UP attack once a violation on FVE is confirmed. We have further instantiated SAFEPAY for Ethereum and applied it in real-world smart contracts. In the empirical evaluation, SAFEPAY managed to identify previously unreported UP attacks and effectively avoid false alarms compared to analyzers in the literature as well.

Maher Alharby, Aad van Moorsel

To simulate blockchain systems as close to reality as possible, we need accurate estimates of the probability distribution of various variables. In this paper we obtain distributions for Ethereum smart contract transactions, with respect to Gas Limit, Used Gas, Gas Price and CPU Time. To determine these distributions we use publicly available Ethereum smart contract information, augmented with experimental data for over 300,000 smart contracts obtained on a test bed. We conclude that Gaussian Mixture Models are appropriate for distributions of smart contracts with respect to Used Gas and Gas Price, and use a uniform distribution for the distribution with respect to the Gas Limit. A correlation analysis shows that the CPU Time is strongly correlated with Used Gas and we therefore apply regression techniques to estimate the CPU Time conditioned on Used Gas. We experiment with three ensemble regression methods, namely Random Forest, Gradient Boosting Machine and Adaptive Boosting and conclude that Random Forest is both fast and accurate.

Chao Li, Balaji Palanisamy, Runhua Xu, Jian Wang · 5 authors

Advancements in distributed ledger technologies are rapidly driving the rise of decentralized crowdsourcing systems on top of open smart contract platforms like Ethereum. While decentralized blockchain-based crowdsourcing provides numerous benefits compared to centralized solutions, current implementations of decentralized crowdsourcing suffer from fundamental scalability limitations by requiring all participants to pay a small transaction fee every time they interact with the blockchain. This increases the cost of using decentralized crowdsourcing solutions, resulting in a total payment that could be even higher than the price charged by centralized crowdsourcing platforms. This paper proposes a novel suite of protocols called NF-Crowd that resolves the scalability issue by reducing the lower bound of the total cost of a decentralized crowdsourcing project to O(1). NF-Crowd is a highly reliable solution for scaling decentralized crowdsourcing. We prove that as long as participants of a project powered by NF-Crowd are rational, the O(1) lower bound of cost could be reached regardless of the scale of the crowd. We also demonstrate that as long as at least one participant of a project powered by NF-Crowd is honest, the project cannot be aborted and the results are guaranteed to be correct. We design NF-Crowd protocols for a representative type of project named crowdsourcing contest with open community review (CC-OCR). We implement the protocols over the Ethereum official test network. Our results demonstrate that NF-Crowd protocols can reduce the cost of running a CC-OCR project to less than $2 regardless of the scale of the crowd, providing a significant cost benefit in adopting decentralized crowdsourcing solutions.

Viktor Manahov

The enormous rise of the cryptocurrencies over the last few years has created one of the largest unregulated markets in the world. In this study, we obtain millisecond data for the five major cryptocurrencies—bitcoin, ethereum, ripple, litecoin and dash—and two cryptocurrency indices—Crypto Index (CRIX) and CCI30 Crypto Currencies Index—to investigate the relationship between cryptocurrency liquidity, herding behaviour and profitability during periods of extreme price movements (EPMs). We demonstrate that cryptocurrency traders (CTs) facilitate EPMs and demand liquidity even during the utmost EPMs. We observe the presence of herding behaviour during up markets across the entire dataset. Our robustness checks indicate that herding behaviour follows a dynamic pattern that varies over time with decreasing magnitude. We also provide novel evidence of CTs’ profitability after transaction costs, and demonstrate their strong profitability-generating record in the future.