Blockchain Papers

Nerenda N. Atako

No abstract is available for this record.

Cătălina Goanță

No abstract is available for this record.

Fahad Ahmed Al-Zahrani

In modern times, many individuals, businesses and the Internet of Things (IoT) integrated industries collect huge amounts of meaningful data daily, which may be beneficial for other individuals and businesses as well. By utilizing this data, future trends to make the right decisions on the bases of facts and figures are analyzed efficiently. In addition to that, many new ways are paved for researchers to utilize this data in their upcoming research. However, due to some major issues like security, privacy and access control of data, data owners avoid sharing data among themselves. Another main problem is the selfish behavior of data owners. Businesses also act selfishly and invest huge amounts of money to collect and maintain the data for their benefits. Therefore, data owners are hesitant to share their data with others without the availability of a fair profit and secure data-sharing platform. Moreover, consumers are not much motivated to buy data from Data Providers (DPs) due to its bad quality and inconsistency. The data provided by data owners is mostly incomplete, outdated, heterogeneous and costly. In this paper, a subscription-based data-sharing model is proposed by leveraging the blockchain technology and Data as a Service (DaaS) concept. In this model, users subscribe to a DP for a specific period to get access to the data and pay according to the subscription plan. The DP keeps receiving revenue recurrently for a long-time, which has a huge profit margin in comparison with selling data at once. Furthermore, two major pricing models, Flat Rate Pricing (FRP) and Usage-Based Pricing (UBP), are discussed to set standards for data owners to monetize their data, and a new hybrid pricing model is also proposed. Blockchain technology is utilized in the proposed model to make it secure, transparent and immutable. To investigate the performance of the proposed model, a private blockchain network is deployed using a web interface provided by MultiChain blockchain. The simulation results demonstrate that the proposed model is feasible and efficient. The theoretical discussion proves that the proposed model is beneficial for both data owners and data consumers and has a good scope in the future for data management and trading processes.

Abylay Satybaldy, Mariusz Nowostawski, Jørgen Ellingsen

No abstract is available for this record.

Joseph Lee, Florian L’heureux

The paper examines cryptocurrency in the crypto-finance ecosystem and identifies areas in which regulatory intervention is required. Part I focuses on the system and processes of cryptocurrency and identifies the features of this ‘decentralised’ system and the legal and regulatory implications. Part II discusses the perceived benefits and the rise of cryptocurrency to determine whether those benefits fit with regulatory objectives and contribute to the rise of cryptocurrency. Part III discusses the fall of cryptocurrency and some associated factors, particularly a lack of governance. Part IV discusses the need for regulation and governance. Cryptocurrency, blockchain, DLT, tokenization, cryptoasset, exchanges, investor protection

Dan Wang, Jindong Zhao, Yingjie Wang

As a kind of point-to-point distributed public ledger technology, blockchain has been widely concerned in recent years. The privacy protection of blockchain technology has always been the core issue of people's attention. In this paper, some existing solutions to the current problems of user identity and transaction privacy protection are surveyed, including coin mixing mechanism, zero knowledge proof, ring signature and other technologies. Secondly, five typical applications of privacy protection technology based on blockchain are proposed and analyzed, which are mainly divided into technology applications based on coin mixing protocol, encryption protocol, secure channel protocol and so on. Finally, in view of the shortages of the existing blockchain privacy protection technology, we explore future research challenges that need to be studied in order to preserve privacy in blockchain system, and looks forward to the future development direction.

Vikas Jaiman, Visara Urovi

In modern healthcare systems, the ability to share electronic health records is crucial for providing quality care and for enabling a larger spectrum of health services. Health data sharing is dependent on obtaining individual consent which, in turn, is hindered by a lack of resources. To this extent, blockchain-based platforms facilitate data sharing by creating a trusted distributed network of users. These users are enabled to share their data without depending on the time and resources of specific actors (such as the health services). In blockchain-based platforms, data governance mechanisms become very important due to the need to specify and monitor data sharing and data use conditions. In this article, we present a blockchain-based data-sharing consent model for access control over individual health data. We use smart contracts to dynamically represent the individual’s consent over health data and to enable data requesters to search and access those data. The dynamic consent model extends to two ontologies: the Data Use Ontology (DUO) which models the individual consent of users and the Automatable Discovery and Access Matrix (ADA-M), which describes queries from data requesters. We deploy the model on Ethereum blockchain and evaluate different data sharing scenarios. The contribution of this article consists of the creation of an individual consent model for health data sharing platforms. Such a model guarantees that individual consent is respected and that all the participants in the data sharing platform are accountable. The evaluation of our solution indicates that such a data sharing model provides a flexible decision-making approach over data usage by data requesters. Our experimental evaluation shows that the proposed model is efficient and adapts to personalized access control policies in different data-sharing scenarios.

Emerson B. Tomaz, José Cláudio do Nascimento, Abdelhakim Hafid, José Neuman de Souza

The advent of miniaturized mobile devices with wireless communication capability and integrated with biosensors has revolutionized healthcare systems. The devices can be used by individuals as wearable accessories to collect health data regularly. This type of medical assistance supported by mobile devices to monitor patients and offer health services remotely is known as mobile health (mHealth). Although mHealth provides many benefits and has become popular, it can pose severe privacy risks. Many features in mHealth are managed through a smartphone. Thus, one of the most worrying issues involves communication between the monitoring devices and the smartphone. When communication uses Bluetooth, it is standard for a device to be paired with the smartphone; but generally, it is not exclusively associated with a specific mHealth app. This characteristic can allow a data theft attack by a malicious app or fake data injection by an illegitimate device. To address this issue, we present an authentication scheme based on Non-Interactive Zero-Knowledge Proof that is lightweight enough to run on mHealth devices with minimal resources. Our scheme ensures that legitimate devices interact exclusively with the official mHealth application. To ensure the patient's privacy-preserving throughout the system, we address the issues of storing, managing, and sharing data using blockchain. Since there is no privacy in the standard blockchain, we present a scheme in which the health data transmitted, stored, or shared are protected by Attribute-Based Encryption. The outcome is a system with fine-grained access control, entirely managed by the patient, and an end-to-end privacy guarantee.

Mirko Zichichi, Michele Contu, Stefano Ferretti, Victor Rodrı́guez-Doncel

Personal data has undoubtedly assumed a great value with the advancements on technologies able to gather it and infer from it. The businesses that operate in a data-driven economy offer services that rely on data collected about their users and usually they store this personal information in “silos” that impede transparency on their use and possibilities of easy interactions. The introduction in EU of the General Data Protection Regulation (GDPR) moves this economy towards a user-centered vision, in which individuals have rights for their data sovereignty and the free portability of it. However, more efforts are needed to reach both transparency and balance between privacy and data sharing. In this paper, we present a solution to promote the development of personal data marketplaces, exploiting the use of Distributed Ledger Technologies (DLTs) and a Sensing-as-a-Service (SaaS) model, in order to enhance the privacy of individuals, following the principles of personal data sovereignty and interoperability. Moreover, we provide experimental results of an implementation based on IOTA, a promising DLT for managing and transacting IoT data

Samer Shorman, Mohammad Allaymoun

Social networking pages authenticate by blockchain technology, through authenticating personal information and profile pages in the form of block and then distributing them with Blockchain to become a trusted reference point. To identified and verified social network accounts. This research proposed an effective and easy technical mechanism to authenticate the personal pages on social networks. Using this mechanism, anyone can authenticate any account on social networks, as well as increasing the possibility of making sure of the real individual behind social networking accounts. Moreover, this technique will show the fake accounts in order to reach a more confident and secure social network environment. Blockchain technique requires only a simple update to the characteristics of its platforms by developers, which is only a participatory mechanism between Blockchain and personal information. It is then combined with personal pages, to indicate that these pages contain the real personal information of the account holder, which is stored in an encrypted block that is difficult to modify, copy, or steal.

Nathaniel Aldred, Luke Baal, Graeham Broda, Steven Trumble · 5 authors

A blockchain is a distributed ledger forming a distributed consensus on a\nhistory of transactions. It is the underlying technology for the Bitcoin\ncryptocurrency, but there are many applications beyond the financial sector.\nWith built-in security and removal of the need for third party trust,\nblockchain has started to see some use within contract applications among other\nthings. In this paper, we present the design and implementation of a\npermissioned-based blockchain third party consent management system, whose\npolicy can be decided by a government agency. We have constructed a proof of\nconcept implementation using Hyperledger Fabric to provide a service that\nallows end-users to control and consent to who manages their private\ninformation. We believe our solution meets the guiding principles of EU General\nData Protection Regulation or GDPR. While our performance and usability\nevaluation are limited, our solution design and its implementation meet the 7\nfoundational principles of privacy by design.\n

Liudmila Zavolokina, Gianluca Miscione, Gerhard Schwabe

The second-hand automotive market is one with the least trust from consumers. Customers on the second-hand car market suffer from such problems as the car being in worse condition than initially indicated, accident damage that is not disclosed, fraud, etc. Akerlof, described the market for used cars as an example of the problem of information asymmetries and resulting quality uncertainty. In order to cope with quality uncertainties, used car buyers actively engage themselves in information seeking. Blockchain technology promises to automatize the tracking of cars through their lifecycles and provide reliable information at any point in time it is needed. In our study, we investigate the problems car buyers face during information seeking and propose requirements for the design of a blockchain-based system to address these.

Temidayo Abayomi-Zannu, Isaac Odun-Ayo, T. F. Barka

Abstract Voting is fundamental to any consensus-based society and is one of the most critical functions of democracy. Mobile voting (m-voting) was utilized as a means for voters to easily and conveniently cast their votes using their mobile devices which have been the most adopted means of communication but has a major problem which is safely securing the casted votes and avoiding any form of tampering. In this paper, we propose an m-voting framework that utilizes blockchain technology to securely store the casted votes and multi-factor authentication to authenticate the voters before they cast their votes while also providing an easily accessible, secure and transparent m-voting system.

Magnus Westerlund, Martin Gilje Jaatun

If the cloud is just someone else's computer, securing forensic evidence in case of a breach can be tricky. A blockchain-based distributed ledger could contribute to solve this problem, provided the required forensic information finds its way onto the blockchain. In this paper we sketch how blockchain technology and smart contracts apply to various processing models and their respective forensic challenges, and highlight how an accountability-based approach will be instrumental to the overall acceptability of the solution.

Iñigo Querejeta-Azurmendi, Panagiotis Papadopoulos, Matteo Varvello, Antonio Nappa · 6 authors

Abstract Recent studies show that 20.4% of the internet traffic originates from automated agents. To identify and block such ill-intentioned traffic, mechanisms that verify the humanness of the user are widely deployed, with CAPTCHAs being the most popular. Traditional CAPTCHAs require extra user effort (e.g., solving mathematical puzzles), which can severely downgrade the end-user’s experience, especially on mobile, and provide sporadic humanness verification of questionable accuracy. More recent solutions like Google’s reCAPTCHA v3, leverage user data, thus raising significant privacy concerns. To address these issues, we present zkSENSE: the first zero-knowledge proof-based humanness attestation system for mobile devices. zkSENSE moves the human attestation to the edge: onto the user’s very own device, where humanness of the user is assessed in a privacy-preserving and seamless manner. zkSENSE achieves this by classifying motion sensor outputs of the mobile device, based on a model trained by using both publicly available sensor data and data collected from a small group of volunteers. To ensure the integrity of the process, the classification result is enclosed in a zero-knowledge proof of humanness that can be safely shared with a remote server. We implement zkSENSE as an Android service to demonstrate its effectiveness and practicality. In our evaluation, we show that zkSENSE successfully verifies the humanness of a user across a variety of attacking scenarios and demonstrate 92% accuracy. On a two years old Samsung S9, zkSENSE’s attestation takes around 3 seconds (when visual CAPTCHAs need 9.8 seconds) and consumes a negligible amount of battery.

Panagiotis Papadopoulos, Iñigo Querejeta Azurmendi, Jiexin Zhang, Matteo Varvello · 6 authors

Recent studies show that 20.4% of the internet traffic originates from automated agents. To identify and block such ill-intentioned traffic, mechanisms that verify the humanness of the user are widely deployed across the internet. CAPTCHA is the most popular among such mechanisms. Original CAPTCHAs require extra user effort (e.g., solving mathematical or image-based puzzles), which severely harms user's experience, especially on mobile, and provide only sporadic verification of their humanness. More recent solutions like Google's reCAPTCHA v3 leverage attestation data (e.g., user behavioral data, device fingerprints) shared with a remote server, thus raising significant privacy concerns. To address all of the above, we present ZKSENSE: the first zero knowledge proof-based humanness attestation system designed for mobile devices. Contrary to state-of-the-art systems, ZKSENSE assesses humanness continuously on the background in a privacy preserving way. ZKSENSE achieves that by classifying the motion sensor outputs of the mobile device based on a model trained by using both publicly available sensor data and data collected from a small group of volunteers. The classification result is enclosed in a zero knowledge proof of humanness that can be safely shared with an attestation service such as Privacy Pass. We implement ZKSENSE as an Android service to demonstrate its effectiveness and practicability. In our evaluation, we show that ZKSENSE verifies the humanness of the users asynchronously, on the background, without degrading their experience or jeopardizing user privacy, while it achieves 91% accuracy across a variety of attack scenarios. On a two years old Samsung S9, each attestation takes around 3 seconds in total (when visual CAPTCHAs need 9.8 seconds) and consumes a negligible amount of battery.

David Allessie, Martijn Janssen, Jolien Ubacht, Scott W. Cunningham · 5 authors

Blockchain technology has the potential to provide public services directly to the public. This challenges the need for public organizations, who traditionally provided these services. Much of the current work is focused on the technology, whereas the influence on public administration structure has gained less attention. The goal of this paper is to investigate the impact of blockchain technology on the governance of public service provision. For this, we performed a case study of an EU-wide system that monitors the movement of excise goods under duty suspension. We developed two scenarios for blockchain technology’s use based on a permissionless blockchain architecture on the one hand and a permissioned one on the other. The scenarios were evaluated based on their impact on transaction validation, data quality and governance. The findings show that blockchain technology alone cannot be an alternative for the current data quality controls, equal access assurances and adaptations to legislation conducted by public administrations. As such, governments will remain playing a key role in registration of documents and assets, however, the governance will likely change depending on the type of blockchain architecture.

Megan Knittel, Shelby Pitts, Rick Wash

Bitcoin is an innovative technological network, a new, non-governmental currency, and a worldwide group of users. In other words, Bitcoin is a complex sociotechnical system with a complex set of risks and challenges for anyone using it. We investigated how everyday users of Bitcoin develop trust in Bitcoin on one of the largest online communities devoted to Bitcoin: the Reddit.com r/bitcoin forum. Using qualitative content analysis, we examined how trust in Bitcoin develops based on contributions to this community. On r/bitcoin, trust in Bitcoin is driven by a pervasive ideology we call the "True Bitcoiner" ideology. This ideological viewpoint in centered on the interpretation of Bitcoin as functionally "trustless" and risk-free. Despite widespread evidence of emerging individual and system-level risks with using Bitcoin, participants continue to maintain this ideological perspective. This ideology consists of three primary beliefs: viewing Bitcoin's technology as more trustworthy than its people; rejecting 'corrupt' social hierarchies related to money; and the importance of accumulating or 'HODLing' quantities of Bitcoin as a strategy to create an ideal future. We conclude that this "True Bitcoiner" ideology is maintained despite contradictory evidence in the world because it allows participants to more easily interpret Bitcoin and make decisions by reducing perceived risk and uncertainty in the system. The role of this ideology on r/bitcoin demonstrates an expanded conceptualization of how trust is created and socially-mediated in socio-technical contexts.

Mohammad Reza Nosouhi, Shui Yu, Wanlei Zhou, Marthie Grobler · 5 authors

No abstract is available for this record.

Yongbin Zhao, Meng Cui, Lijuan Zheng, Rui Zhang · 7 authors

For the medical industry, there are problems such as poor sharing of medical data, tampering, and leakage of private data. In view of these problems, a blockchain-based electronic medical record access control research scheme based on the role-based access control model is proposed in this article. First, the appropriate access control strategy is adopted to solve the leakage problem of the user’s medical privacy information during the access process. Then, the information entropy technology is used to quantify the medical data, so that the medical data can be effectively and maximally utilized. Using the distributed general ledger characteristics of blockchain and its inherent security attributes, data islands can be eliminated, data sharing among medical systems can be promoted, access records can be prevented from being tampered with, and medical research and precise medical treatment can be better supported. Through this research, not only can user’s medical privacy information protection be realized during the service process but also patients can manage their own medical data autonomously, which is beneficial to privacy protection under the medical data sharing.

Bhuman Vyas

Protecting sensitive medical data, including prescription and pill data, during its handling and storage is critical in the digital era. Data vaults that protect privacy provide a strong way to protect this information, guaranteeing that patient information is kept private but yet available for authorised uses. Focussing on the safe preservation of pharmaceutical data, this project investigates the creation of sophisticated algorithms for privacy-preserving data vaults. We start by contrasting the suggested innovative technique, which combines elements of Zero-Knowledge Proofs with Enhanced Homomorphic Encryption, with other known cryptographic and data masking algorithms, such as Differential Privacy, Secure Multi-Party Computation, and Homomorphic Encryption. Data integrity, computational efficiency, and resistance to different attack vectors are some of the characteristics used in the comparison.As the results show, the suggested method offers aimproved performance against confidentiality compromises, especially in real-time data retrieval scenarios, while existing techniques offer varied degrees of efficiency and security. But this comes with more implementation complexity and processing overhead. Improved security characteristics, like less data leakage and strong user authentication systems, are benefits of the suggested approach. Large-scale applications may experience latency problems and require more powerful hardware, which are drawbacks.The trade-offs between various data privacy strategies are highlighted in this study, and it also highlights the necessity for on-going innovation in privacy-preserving technology, which makes a contribution to the region.

Bong-Gyeol Choi, EuiSeob Jeong, Sangwoo Kim

As the number of Internet of Things (IoT) devices increases, services expand and illegal hacking and infringement methods become more sophisticated, an effective solution for blockchain technology is required as a fundamental solution to security threats. In this paper, we develop the security module of an IoT device based on blockchain technology that blocks hacking and information infringement and forms a multi-security blockchain system between the IoT device and the user device and we develop a user application. We contribute to addressing the security threats faced by IoT application services by developing a new method. In particular, we present some schemes for the development of a multi-security certification system based on blockchain for IoT security.

Konstantinos Rantos, George Drosatos, Antonios Kritsas, Christos Ilioudis · 6 authors

In the Internet of Things (IoT) ecosystem, the volume of data generated by devices in the user’s environment is continually increasing and becoming of particular value. In such an environment the average user is bound to face considerable difficulties in understanding the size and scope of his/her collected data. However, the provisions of the European General Data Protection Regulation (GDPR) require data subjects to be able to control their personal data, be informed, and consent to its processing in an intelligible manner. This paper proposes ADVOCATE platform, a user-centric solution that allows data subjects to easily manage consents regarding access to their personal data in the IoT ecosystem. The proposed platform also assists data controllers to meet GDPR requirements, such as informing data subjects in a transparent and unambiguous manner about the data they will manage, the processing purposes, and periods. The integrity of personal data processing consents and the immutable versioning control of them are protected by a blockchain infrastructure. Finally, the paper provides a prototype implementation of the proposed platform that supports the main consents management functionality.

Sofia Terzi, Konstantinos Votis, Dimitrios Tzovaras, Ioannis Stamelos · 5 authors

The adoption of Information Communication Technologies (ICT) and Web 3.0 contributes to the e-government sector by transforming how public administrations provide advanced and innovative services to interact with citizens. Blockchain (BC) and Artificial Intelligence (AI) disruptive technologies will reshape how we live, work, and interact with government sectors and industries. This paper presents how Blockchain 3.0 and Artificial Intelligence enhance robust, secure, scalable, and authenticity provenance solutions. Two validation scenarios are analyzed to present how blockchain smart contracts and AI agents support energy and health-oriented e-government services.