Blockchain Papers

Carmen Kreilinger

No abstract is available for this record.

Johannes Hinckeldeyn, Jochen Kreutzfeldt

Blockchain and Internet of Things are supposed to have big impact on logistics. This study presents a prototypical smart contract using smart storage containers in order to investigate the potential and the maturity of Blockchain and Internet of Things for logistical processes. A smart storage container is developed and connected to an Ethereum-based smart contract. The smart contract is based on a multi signature wallet of three parties to process the payment and arbitrate disagreements. Further research implications for the development of smart contracts for supply chains are derived from the experiences of this prototype study.

Univerza v Mariboru, Fakulteta za elektrotehniko, računalništvo in informatiko, Maribor, Slovenija, Marko Hölbl, Blaž Podgorelec, Univerza v Mariboru, Fakulteta za elektrotehniko, računalništvo in informatiko, Maribor, Slovenija

Advanced Information Technology and Services: OTS 2018:  Proceedings of the Twenty-Third Conference, 19th -20th of June, 2018. The papers in the proceedings of the 23rd Professional Conference on Advanced Information Technology and Services address the extremely topical challenges that we (IS/IT experts, software engineers, computer scientists, data scientists, software and solution architects, developers,  IT managers, etc.) encounter in our daily work. The authors present innovative solutions and rich experience gained by conducting real-life projects: using blockchain technologies and platforms, establishing new ecosystems, business models and services contributing to digital transformation, introducing and implementing micro-service architectures, ensuring security, confidentiality and privacy, and related risk-management techniques, providing full virtualization and exploitation of infrastructure, updating and upgrading existing information systems, integrating machine learning algorithms and intelligent services and big data platforms, developing and using web components and technologies, applying agile approaches that enable the rapid and efficient development of both prototypes and production-oriented user-centric solutions via automated processes and continuous integration, delivery & deployment.

Mohammad Ahmad, Abdullah Al-Saleh, Fahad A. Al Masoud

Cryptocurrency subject attracted so many people for the last eight years around the globe. Satoshi’s Nakamoto’s, the founder of the bitcoin cryptocurrency behind this revolutionary change in digital money market. Bitcoin cryptocurrency uses “Power of Work” or simply PoW system as its mining algorithm. But in January of 2016, Ethereum cryptocurrency has launched which adopted a new system called “Power of Stake” or simply PoS that is used in Ethereum as its mining algorithm. This paper explores and compares PoW and PoS systems that is used widely today in cryptocurrencies digital money, concluding the pros and cons for each system with enabling to decide which one is more suitable and stable in digital money market.

Nachiket Tapas, Giovanni Merlino, Francesco Longo

In a Smart City scenario, the authors envisioned an IoT-Cloud framework for the management of boards and resources scattered over a geographic area. It can also become a tool to let device owners contribute freely to the infrastructure. In comparison to datacenter-oriented Cloud middleware, the administrator and the owner of the infrastructure are not one and the same. This translates into the requirement to support delegation-enabled authorization. In this paper, the authors investigate an authorization and delegation model for the IoT-Cloud based on blockchain technology. In particular, the scheme is implemented in the form of smart contracts over the Ethereum platform. Indeed, this approach represents an enhancement, over a function previously designed in a centralized fashion, by enabling the user to audit authorization operations and inspect how access control is actually performed, without blindly trusting the Cloud as a proxy for access to resources.

Univerza v Mariboru, Fakulteta za elektrotehniko, računalništvo in informatiko, Maribor, Slovenija, Blaž Podgorelec, Muhamed Turkanović, Univerza v Mariboru, Fakulteta za elektrotehniko, računalništvo in informatiko, Maribor, Slovenija

Advanced Information Technology and Services: OTS 2018:  Proceedings of the Twenty-Third Conference, 19th -20th of June, 2018. The papers in the proceedings of the 23rd Professional Conference on Advanced Information Technology and Services address the extremely topical challenges that we (IS/IT experts, software engineers, computer scientists, data scientists, software and solution architects, developers,  IT managers, etc.) encounter in our daily work. The authors present innovative solutions and rich experience gained by conducting real-life projects: using blockchain technologies and platforms, establishing new ecosystems, business models and services contributing to digital transformation, introducing and implementing micro-service architectures, ensuring security, confidentiality and privacy, and related risk-management techniques, providing full virtualization and exploitation of infrastructure, updating and upgrading existing information systems, integrating machine learning algorithms and intelligent services and big data platforms, developing and using web components and technologies, applying agile approaches that enable the rapid and efficient development of both prototypes and production-oriented user-centric solutions via automated processes and continuous integration, delivery & deployment.

Emanuel Palm, Olov Schelén, Ulf Bodin

Distributed ledger technologies, such as blockchain systems, have in recent years emerged as promising platforms for machine-to-machine commerce and other forms of multi-stakeholder applications. However, despite the potential demonstrated by projects such as Bitcoin, Ethereum, and Hyperledger Fabric, the disk space typically required to host a copy of a ledger may be prohibitively large for many categories of devices. In this paper, we introduce an approach for reducing ledger size in blockchain systems, based on arbitrary pruning predicate functions, allowing each network participant to independently select and remove any already applied transactions. We also show that if only pruning certain ledger transactions, the ability to derive an unmodified state data structure from the remaining transactions is maintained. The approach is validated through a supply chain use case utilizing a modified version of Hyperledger Fabric, in which ledger size is reduced by about 84.49% via selective transaction pruning.

Kazım Rıfat Özyılmaz, Mehmet Ug̃ur Dog̃an, Arda Yurdakul

Today, Internet of Things (IoT) devices are the powerhouse of data generation with their ever-increasing numbers and widespread penetration. Similarly, artificial intelligence (AI) and machine learning (ML) solutions are getting integrated to all kinds of services, making products significantly more "smarter". The centerpiece of these technologies is "data". IoT device vendors should be able keep up with the increased throughput and come up with new business models. On the other hand, AI/ML solutions will produce better results if training data is diverse and plentiful. In this paper, we propose a blockchain-based, decentralized and trustless data marketplace where IoT device vendors and AI/ML solution providers may interact and collaborate. By facilitating a transparent data exchange platform, access to consented data will be democratized and the variety of services targeting end-users will increase. Proposed data marketplace is implemented as a smart contract on Ethereum blockchain and Swarm is used as the distributed storage platform.

Rodelio Arenas, Proceso Fernandez

Blockchain, the underlying technology that powers cryptocurrencies such as Bitcoin and Ethereum, is gaining so much attention from different industry stakeholders, governments and research communities. Its application is extending beyond cryptocurrencies and has been exploited in different domains such as finance, E-commerce, Internet of Things (IoT), healthcare, and governance. Some key attributes of the technology are decentralization, immutability, security and transparency. This paper aims to describe how permissioned Blockchain can be applied to a specific educational use case - decentralized verification of academic credentials. The proposed Blockchain-based solution, named `CredenceLedger', is a system that stores compact data proofs of digital academic credentials in Blockchain ledger that are easily verifiable for education stakeholders and interested third party organizations.

Seong Seok Choi, Jin Wook Burm, Wonjin Sung, Ju Wook Jang · 5 authors

We implement a scheme to securely control IoT devices using smart contracts which resides on blockchain. Our implementation provides guaranteed authentication, nonrepudiation and integrity without any central administration. We illustrate how a smart contract works in conjunction with a blockchain to prevent any tempering from possible intruders. We implement ethereum nodes on Raspberry Pi using node.js and web3 library.

Ahsan Manzoor, Yining Hu, Madhusanka Liyanage, Parinya Ekparinya · 9 authors

Cash-less payment via a variety of credit, debit or prepaid cards is pervasive in our interconnected society, but not so ubiquitous in remote rural regions where network connectivity is intermittent. We proposed a cash-less payment scheme for remote villages based on blockchains that allow maintaining a record of verifiable transactions in a distributed manner. We overcome the limitations of intermittent network connectivity by solely relying on blockchain mining nodes in the village for transaction processing and verification. The bank joins as a peer and monitors node behaviors, rewards miners and processes currency exchanges whenever the connectivity is available. We take advantage of the Ethereum network to develop our solution and demonstrate the feasibility of the proposed system on off-the-shelf computing devices. We emulate a remote village scenario with intermittent network connectivity and show the robustness and reliability of the proposed system.

Yue Hao, Yi Li, Xinghua Dong, Li Fang · 5 authors

Blockchain technology has the characteristics of decentralization, security and non-modifiable. The consensus algorithm is the core of blockchain framework, which solves the problem of mutual trust among nodes in the distributed network. Selecting the appropriate consensus algorithm or not directly affects the performance of blockchain. However, existing private blockchain platform lacks theory and data support for the performance analysis of the consensus algorithm. This paper proposes a method to evaluate the performance of consensus algorithm in private blockchain platforms of Ethereum and Hyperledger Fabric. Through quantitative analysis of latency and throughput, we obtain the performance evaluation results of consensus algorithms with different numbers of transactions. The results show that the consensus mechanism induces performance bottleneck. Besides, Practical Byzantine Fault Tolerance (PBFT) consistently outperforms Proof-of-Work (PoW) in terms of latency and throughput under varying workloads. This paper contributes to providing not only the quantitative data support for the further research of consensus algorithm, but also the guidance to the blockchain practitioners in the selection of consensus mechanism.

Péter Garamvölgyi, Imre Kocsis, Benjamin Gehl, Attila Klenik

Applications of Distributed Ledger Technologies (DLTs) in IoT and Cyber-Physical Systems (CPS) are rapidly emerging. However, developing correct and resilient smart contracts for these use cases is even less understood than it is for cryptocurrency-based contracts. This paper presents an initial approach for generating smart contracts for coordinating the usage of cyber-physical system elements from UML statecharts. While the current target platform is Ethereum, our approach can easily be extended to other blockchain platforms.

Shuai Wang, Yong Yuan, Xiao Wang, Juanjuan Li · 6 authors

With the rapid development of cryptocurrency and its underlying blockchain technologies, platforms such as Ethereum and Hyperledger began to support various types of smart contracts. Smart contracts are computer protocols intended to digitally facilitate, verify, or enforce the negotiation or performance of a contract. Smart contracts have broad range of applications, such as financial services, prediction markets and Internet of Things (IoT), etc. However, there are still many challenges such as security issues and privacy disclosure that await future research. In this paper, we present a comprehensive overview on blockchain powered smart contracts. First, we give a systematic introduction for smart contracts, including the basic framework, operating mechanisms, platforms and programming languages. Second, application scenarios and existing challenges are discussed. Finally, we describe the recent advances of smart contract and present its future development trends, e.g., parallel blockchain. This paper is aimed at providing helpful guidance and reference for future research efforts.

Merija Jirgensons, Jānis Kapenieks

Abstract Blockchain educational technology has created assessment and management tools for learner credentials that are permanent, transparent and sustainable while giving users direct access. Personal encrypted credentials enable users to shape lifelong learning pathways and personalizes education according to individual values and needs. They allow for the permanent documentation of both formal and informal learning based on transversal competencies, adjustable across the economic sector and responsive to situational needs. Badging was the initial response to online credentialing. Mozilla’s open digital badges have become the unofficial global standard and the specifications remain free. They may be viewed in e-portfolios and social networks. Yet, if issuers cease hosting badges, they become invalid even when authentic. Some experiments with blockchain technology remedy this situation by creating a permanent, secure and sustainable infrastructure for learning records. The MIT Media Lab has produced the bitcoin based Blockcerts; whereas the Knowledge Institute, Open University, UK has developed Ethereum’s Smart Contracts to document Microcredentials (Badges). Both are Open Source products. Most EU nations are experimenting with educational blockchain. The technology creates an infrastructure to document, store and manage credentials and provides learners with a sustainable record of achievements they can control. It also benefits universities by reducing administrative costs and bureaucracy.

Jae-Hwan Jin, Wookun Lee, Myung-Joon Lee

Distributed applications based on the Ethereum blockchain have a great advantage in the analysis of the history of group work and the contribution factor to a group project of each group member. In these applications, multiple users share resources and their histories together in a robust way thanks to the characteristics of the blockchain that is practically impossible to be forged or modified. However, there has not yet been developed a scheme for providing a systematic management scheme of a group of users or authentication of the members of the group to allow the members to use shared resources through various access rights.

Lingjun Fan, J. Ramón Gil-García, Derek Werthmuller, Geraldine Burke · 5 authors

This poster describes an ongoing research project that builds an IoT data management experimental environment based on Ethereum Blockchain and smart contracts. The goal of the project is to simulate the application of IoT devices in smart city initiatives, and explore how IoT data management could benefit from Blockchain technology. In this project, there are three basic questions we are attempting to answer. 1) How do you link various kinds of IoT devices to the Blockchain, as they have different computing capabilities? 2) How do you store data on Blockchain from different IoT devices, and retrieve data for further utilization? 3) To what extent, smart contracts can be designed to implement automated data access management?

Shahar Somin, Goren Gordon, Yaniv Altshuler

Blockchain technology, which has been known by mostly small technological circles up until recently, is bursting throughout the globe, with a potential economic and social impact that could fundamentally alter traditional financial and social structures. Issuing cryptocurrencies on top of the Blockchain system by startups and private sector companies is becoming a ubiquitous phenomenon, inducing the trading of these crypto-coins among their holders using dedicated exchanges. Apart from being a trading ledger for tokens, Blockchain can also be observed as a social network. Analyzing and modeling the dynamics of the "social signals" of this network can contribute to our understanding of this ecosystem and the forces acting within in. This work is the first analysis of the network properties of the ERC20 protocol compliant crypto-coins' trading data. Considering all trading wallets as a network's nodes, and constructing its edges using buy--sell trades, we can analyze the network properties of the ERC20 network. Examining several periods of time, and several data aggregation variants, we demonstrate that the network displays strong power-law properties. These results coincide with current network theory expectations, however nonetheless, are the first scientific validation of it, for the ERC20 trading data. The data we examined is composed of over 30 million ERC20 tokens trades, performed by over 6.8 million unique wallets, lapsing over a two years period between February 2016 and February 2018.

Alejandro Ranchal Pedrosa, Giovanni Pau

This paper makes the case for the use of blockchains in emerging intelligent transportation systems applications. Specifically, we argue for the use of blockchains to settle contracts and transactions in a variety of intelligent transportation scenarios. We argue that mainstream blockchains such as Ethereum have the foundations to sustain transactions with fine tunable granularity at large scale and in a near-realtime manner. The paper analyzes the refueling scenario for autonomous electric vehicles and proposes an algorithm to guarantee the execution of energy recharges.

Uzair Javaid, Ang Kiang Siang, Muhammad Naveed Aman, Biplab Sikdar

Many IoT devices lack memory and computational complexities of modern computing devices, making them vulnerable to a wide range of cyber attacks. Among these, DDoS attacks are a growing concern in IoT. Such attacks are executed through the introduction of rogue devices and then using them and/or other compromised devices to facilitate DDoS attacks by generating relentless traffic. This paper aims to address DDoS security issues in IoT by proposing an integration of IoT devices with blockchain. This paper uses Ethereum, a blockchain variant, with smart contracts to replace the traditional centralized IoT infrastructure with a decentralized one. IoT devices are then required to access the network using smart contracts. The integration of IoT with Ethereum not only prevents rogue devices from gaining access to the server but also addresses DDoS attacks by using static resource allocation for devices.

Liam Bell, William J. Buchanan, Jonathan Cameron, Owen Lo

There are several areas of healthcare and well-being that could be enhanced using blockchain technologies. These include device tracking, clinical trials, pharmaceutical tracing, and health insurance. Within device tracking, hospitals can trace their asset within a blockchain infrastructure, including through the complete lifecycle of a device. The information gathered can then be used to improve patient safety and provide after-market analysis to improve efficiency savings. This paper outlines recent work within the areas of pharmaceutical traceability, data sharing, clinical trials, and device tracking. Keywords: Asset Tracking, Blockchain, Drug tracking, Ethereum, Healthcare, Internet of Things, IoT

Yao‐Chieh Hu, Ting‐Ting Lee, Dimitris Chatzopoulos, Pan Hui

Although the primary role of decentralized ledgers, such as blockchains in cryptocurrencies, is to store data related to interactions between users to establish trust within incognizant parties, their capabilities allow them to offer more sophisticated functionalities. Smart contracts are decentralized rules that are stored on the blockchain and are executed on demand. Furthermore, smart contracts can interact with each other via message exchange to access data that are stored on them and to call each others' methods. In this paper, we propose a two-level hierarchical architecture that is composed of two types of smart contracts: custodian and client. A custodian contract can deploy on-demand client contract, access their data and call their methods to perform specific updates. Moreover, we develop a framework to allow client contracts to share common variables among all or partial group of the contracts, which may only be mutated by its creator, custodian contracts. We measure the performance of our proposal by developing the proposed contracts and deploying them on three popular testnets.

Susanne Boshuis, Tim B. Braam, Alejandra Pedroza Marchena, Slinger Jansen

Thus far, no research has been done into the effect of business strategies on software ecosystem health. This research aims to fill that gap by combining the Open Source Ecosystem Health Operationalization (OSEHO) and generic strategies. These models are combined and tested on five cases of cryptocurrency ecosystems: Ripple, Ethereum, Litecoin, IOTA and zCash. Findings suggest that the generic strategy Focused Differentiation has the biggest positive impact on ecosystem health. Further research is necessary to see if this is also true for more mature and more stable ecosystems.

Daniel Martens, Walid Maalej

Online portals include an increasing amount of user feedback in form of ratings and reviews. Recent research highlighted the importance of this feedback and confirmed that positive feedback improves product sales figures and thus its success. Online portals' operators act as central authorities throughout the overall review process. In the worst case, operators can exclude users from submitting reviews, modify existing reviews, and introduce fake reviews by fictional users. This paper presents ReviewChain, a decentralized review approach. Our approach avoids central authorities by using blockchain technologies, decentralized apps and storage. It enables users to submit and retrieve untampered reviews. We highlight the implementation challenges encountered when realizing our approach on the public Ethereum blockchain. Then, we discuss possible design alternatives and their trade-offs regarding costs, security, and trustworthiness. Finally, we analyze which design decision should be chosen to support specific trade-offs and present resulting combinations of decentralized blockchain technologies, also with conventional centralized technologies.