Blockchain Papers

Han-Min Kim

No abstract is available for this record.

Mazin Debe, Khaled Salah, Raja Jayaraman, Junaid Arshad

An enormous amount of drug supply is regularly wasted due to several reasons related to incorrect prescription, purchase of unnecessary quantities, drug intolerance, allergy, or interactions. On the other hand, these medicines may be needed by patients who cannot afford to purchase them. To address this challenge, we propose a fully decentralized solution that governs the return and redistribution of unused drugs that are fit for usage. Our approach exploits the decentralized blockchain technology, smart contracts, and decentralized storage systems such as the Interplanetary File Systems (IPFS). We develop a system that provides the ability for customers as well as pharmacies to return re-usable, resellable drugs for donation or resale at a lower price. The proposed scheme tracks the production of drugs from manufacturers to traders that subsequently sell them to customers. Unused drugs can be returned after approval by specialized entities and then redistributed. In particular, we present the decentralized system architecture and implement a prototype on a test Ethereum blockchain platform to present the suggested workflow. Further, we provide system evaluation focused on assessing system functionality, performance, execution cost, and security of smart contracts and their robustness. We have also made our smart contracts code publicly available on Github.

Xiyue Zhang, Yi Li, Meng Sun

No abstract is available for this record.

Jorge Eterovic, Jonatan Uran Acevedo, Alejandro Rusticcini, Nora Gigante

Blockchain Federal Argentina (BFA) es la primera plataforma multiservicios abierta y participativa de Argentina pensada para integrar servicios y aplicaciones sobre la Blockchain de Ethereum. Las organizaciones, tanto públicas como privadas, pueden formar parte de Blockchain Federal Argentina, ejerciendo distintos roles de control dentro de la organización. También pueden desplegar aplicaciones sobre la plataforma. El proyecto de investigación consiste en implementar un nodo Minero (en adelante nodo Sellador) en la Universidad Nacional de La Matanza, dentro de la red Blockchain Federal Argentina, para lo cual se celebrará un contrato de colaboración público-privada entre la UNLaM, representada por el Departamento de Ingeniería e Investigaciones Tecnológicas (DIIT) y el consorcio Blockchain Federal Argentina. Este contrato hará a la UNLaM parte del mencionado consorcio y permitirá montar un nodo Sellador dentro de la infraestructura Blockchain-BFA. En el marco de este proyecto, se desarrollará e implementará una dApp (Aplicación Distribuida) que quedará disponible para su uso libre para toda la comunidad académica. La relevancia de este trabajo radica en la importancia que tiene para una institución formar parte de una red con las características de BFA. Hasta el momento, la UNLaM, no forma parte de BFA ni de otras plataformas similares.

Jun Yang

No abstract is available for this record.

Miaolei Deng, Pan Feng

The frequent occurrence of food safety accidents at the global level has triggered consumer sensitivity. Establishing a food traceability system can effectively guarantee food safety and increase consumer confidence and satisfaction. Existing food traceability systems often ignore environmental factors that affect food quality at all stages of the supply chain, and the authenticity of the information obtained through traceability is difficult to guarantee. In this study, a food supply chain traceability model was established based on blockchain and radio frequency identification (RFID) technologies. The model focused on the traceability of environmental data during the various stages of the food supply chain and combined a centralized database and blockchain for data storage. The lot identification data of the various supply chain stages were stored in a centralized database, while the environmental data were stored in a blockchain. Thereby, the authenticity and accuracy of the traceability data were ensured. The blockchain part of the model has been simulated in the Ethereum test environment, and the experiment has achieved traceability of temperature data.

Xinxin Fan, Qi Chai, Zhi Zhong

No abstract is available for this record.

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.

S. Santhosh Kumar

Bitcoin, Ethereum and Ripple are the three major cryptocurrencies with market capitalisation exceeding 70% of all the cryptos. The covid-19 threats since the beginning of the 2020 are disturbing the financial markets all around the world. This study is an enquiry to model the fluctuations among the three cryptocurrencies with the hypothesis that whether a combination of two coins could explain the changes in the other coin. The study found that Bitcoin and Ripple are better explaining the Ethereum returns in the short-run. The negative error correction coefficient found in the regression indicates that if the daily log returns of ETH is above that of the daily log return of BTC by one point, the daily log return of ETH fall by 1.11 point. On the other hand, the positive error correction coefficient indicates that if the daily log return of ETH is above that of the daily log return of XRP by one point, the daily log return of ETH increases by 0.14 point.

Xuan Chen, Kien Nguyen, Hiroo Sekiya

No abstract is available for this record.

Xixi Yan, Xiaohan Yuan, Qing Ye, Yongli Tang

In order to solve the problem that most of the existing blockchain-based searchable encryption schemes only support exact keyword search and mutual distrust between the cloud server and the user, a searchable encryption scheme based on blockchain, that has functions such as file update dynamically, search results verification, fuzzy keyword search, and fair payment, is proposed. We use edit distance to generate the fuzzy keywords set. According to the un-modification characteristic of Ethereum blockchain and the security of the RSA accumulator, our scheme can verify the search results by the smart contract and realize the service-payment fairness between the user and the cloud server. The security analysis shows that the proposed scheme achieves non-adaptive semantic security. Performance analysis and experiment show that our scheme is efficient and meets the demand of search application in the cloud environment.

Qing Han, Jiajing Wu, Zibin Zheng

In spite of the increasing popularity of Ethereum, market analysis of the corresponding cryptocurrencies Ether is relatively unexplored until now. This paper is devoted to filling in the research gap of Ether market analysis, the purpose being to provide useful insights on Ether investment. In particular, we first employ the detrended fluctuation analysis and the asymmetric multifractal detrended fluctuation analysis to investigate the properties of long-range dependence, multifractality, and its asymmetry. After that, we study the causality between returns and volume of Ether to find how the activity of investors influences returns based on a nonparametric causality-in-quantiles test. Besides, by making a comparison with the Bitcoin market, we further uncover some unique properties of the Ether market.

Simon Krejci, Marten Sigwart, Stefan Schulte

No abstract is available for this record.

Dongxiang Song, Mingju Yuan

No abstract is available for this record.

Vera Barberán, José María

The main thrust of time-series forecasting models in recent years has gone in the direction of pattern-based learning, in which the input variable for the models is a vector of past observations of the variable itself to predict. The most used models based on this traditional pattern-based approach are the autoregressive integrated moving average model (ARIMA) and long short-term memory neural networks (LSTM). The main drawback of the mentioned approaches is their inability to react when the underlying relationships in the data change resulting in a degrading predictive performance of the models. In order to solve this problem, various studies seek to incorporate external factors into the models treating the system as a black box using a machine learning approach which generates complex models that require a large amount of data for their training and have little interpretability. In this thesis, three different algorithms have been proposed to incorporate additional external factors into these pattern-based models, obtaining a good balance between forecast accuracy and model interpretability. After applying these algorithms in a study case of Ethereum price time-series forecasting, it is shown that the prediction error can be efficiently reduced by taking into account these influential external factors compared to traditional approaches while maintaining full interpretability of the model.

杰 杨

No abstract is available for this record.

Robin Westerlund

Background: Due to the rising popularity of autonomous unmanned vehicles, and the lack of well-defined rules to follow, a solution is needed when the physical space is crowded to a point where it becomes a hazard. Partitioning space discretely is currently done in some cases, allowing vehicles to reserve partitions to operate within. This idea is expanded upon to ultimately propose a blockchain-based solution to the inefficiency of safety margins. Objectives: The main objective was to explore whether a blockchain-based system can be used by vehicles to automatically reserve the volumes of space they need for a limited time. The solution to congestion becomes a method for vehicles to communicate between each other to exchange the remainder of their reservations once they are no longer needed, even while disconnected from the main blockchain network, in exchange for the same currency used to reserve the volumes. Methods: An Ethereum private blockchain network is set up, and a smart contract is developed and deployed onto this blockchain. An emulation program used the smart contract functions to reserve and exchange volumes to evaluate the functionality, several isolated tests evaluated the network performance, and aspects that could not be tested were theoretically analyzed. Results: The system functions as intended, although a level of trust is required during exchanges. There is no risk of two vehicles reserving the same volume at the same time. The results indicate that some performance aspects will be affected by an increasing number of users, although the entire effect can be placed on synchronization time if the network parameters are adjusted. This likely affects the overall efficiency but not as much as it would with the original parameters. Conclusions: The proposed solution is viable to use, although further development is necessary before it is ready for release. The necessity currently is not evident, although projections suggest that this solution, or a similar one, will be necessary in the future.

Cristina Argelich Comelles

El presente trabajo ofrece soluciones a los problemas juridicos que plantean los smart contracts, por tratarse de clausulas contractuales autoimplementadas en un codigo informatico que autoejecuta su contenido. Estos versan sobre su discutida naturaleza juridica, la adhesion del consumidor 2.0 mediante Blockchain, su personalizacion con Ethereum, los errores de programacion y la responsabilidad civil, la proteccion y encriptacion de datos de caracter personal, y la formacion y ejecucion del contrato. Las dificultades que plantean los smart contracts requieren de una regulacion europea, inspirada en las legislaciones existentes en algunos territorios de los Estados Unidos y Francia, asi como en los estudios formulados en el ambito de UNIDROIT y la CNUDMI.

Ahmad H. Juma’h, Ranjan Karri

In this study, we examine how the performance of companies using cryptocurrencies is affected by the major external events about cryptocurrencies. The subject of our study is the reactions of the stock market on the firm’s disclosure of events related to digital currencies. We identified firms that included the four major cryptocurrencies (Bitcoin, Ripple, Litecoin, and Ethereum) in their financial reports from the Edgar database. We identified major events related to cryptocurrencies and conducted an event study analysis to determine the effects of the events on stock market prices of the companies. Preliminary results indicate a significant effect of external events on firm performance. The extent of effects from regulatory and government-related events and external security breach events as well as industry-related events helps us understand the significance of the investors’ attention to any disclosures of cryptocurrency-related events.

Xiangping Chen, Queping Kong, Haonan Zhu, Yixin Zhang · 6 authors

No abstract is available for this record.

EBELOGU Christopher U, ORIAKHI Joseph E, OJO Samuel D, AGU Edward O

Cryptocurrency is generally known to be a digital record of ownership of nominal balance which can be used to pay for transactions. Thus, for any transaction, the buyer gives instructions to transfer ownership of a certain amount of his balances tothe seller. The use of cryptocurrencies such as Bitcoin and Ethereum in performing online transactions has been on the rise andalmost accepted generally in the world. Africa as a continent is not left out in the adoption of blockchain and cryptocurrencies.Today, in 2019, the question of whether or not digital money can actually become a useful and secure part of the Nigerianeconomy is being seriously debated. This paper explores how cryptocurrency technology can be a means of leveraging theNigeria economy and its extremely large population.

Pan Chun-Ting, Meng-Ju Lee, Nen‐Fu Huang, Jhong-Ting Luo · 5 authors

The traceability of agricultural products has always been one of the most important things that customers care about. For the past decades, the trend of applying Internet of Things (IoT) technology to agriculture has been on an exponential rise and has also shown great success in different aspects. Not only crops can be irrigated and taken care of more precisely, but more reliable production history can be created based on the environmental data collected by IoT sensors. To achieve a trustable traceability for agricultural production process, data security becomes a major factor after the collection of massive data via IoT. By using blockchain technology for data storing, integrity and reliability can be ensured due to its immutability. Furthermore, when dealing with several components (producer, processor, distributor…etc.) on a food production chain, blockchain also has the ability to connect untrusted nodes and restrict them in following certain protocols. This study designs and implements an agriculture blockchain service platform for farm-to-fork traceability with IoT sensors. The Ethereum blockchain technology is employed and smart contracts are also designed to support tampering-proof data storing and provide reliable financial transactions which may happen throughout the entire food production chain.

Affaf Shahid, Umair Sarfraz, Muhammad Waseem Malik, Muhammad Sohaib Iftikhar · 6 authors

Supply chains are evolving into automated and highly complex networks and are becoming an important source of potential benefits in the modern world. However, it is challenging to track the provenance of data and maintain traceability throughout the network. The traditional supply chains are centralized and dependent on third party for trading. Centralized systems lack transparency, accountability and auditability. In our proposed solution, we have presented a blockchain-based reputation system in Agriculture and Food (Agri-Food) supply chain. It leverages the key features of blockchain and smart contract deployed over ethereum blockchain network. Although blockchain provides an immutable network for supply chain events, it still fails to solve the problem of trust among entities. Therefore, a reputation system is required that logs reviews of sellers and maintains the trust between trading entities.

Jianxi Peng, Guijiao Xiao

No abstract is available for this record.