Blockchain Papers

Gao Yu-long, Xiu‐Bo Chen, Gang Xu, Wen Liu · 6 authors

No abstract is available for this record.

Liudmila Zavolokina, Noah Zani, Gerhard Schwabe

Trust is a crucial component for successful transactions regardless of whether they are executed in physical or virtual spaces. Blockchain technology is often discussed in the context of trust and referred to as a trust-free, trustless, or trustworthy technology. However, the question of how the trustworthiness of blockchain platforms should be demonstrated and proven to end users still remains open. While there may be some genuine trust in the blockchain technology itself, on an application level trust in an IT artifact needs to be established. In this article, we examine how trust-supporting design elements may be implemented to foster an end user's trust in a blockchain platform. We follow the design science paradigm and suggest a practically useful set of design elements that can help designers of blockchain platforms to build more trustworthy systems.

Andrey Averin, Alexsandr Samartsev, Nikolay Sachenko

Nowadays a lot of blockchain solutions are presented, in which to some degree implemented methods of anonymization, that allows network participants to hide their operations. Among existing projects, cryptocurrencies stand out: Bytecoin, Monero, Dash, TON (Telegram Open Network), ZCash, Loki, Grin, Beam, Verge, ZCoin, Horizen (ZenCash), BlackCoin, NavCoin, SmartCash, ZeroVert, PIVX, AEON, Fantomcoin and Ring Coin. There are also the privacy enhancing technologies on which they are based: CoinJoin, Mimblewimble, ZK-SNARKs and others. This article studies renowned technologies and methods of de-anonymization and suggests possible directions for further research.

Pierluigi Freni, Enrico Ferro, Gabriele Ceci

In today's social media context, many criticalities have emerged, particularly concerning the security of users' personal data and the unbalanced redistribution of the value generated. This work, analyzing 40 emerging platforms, investigates how Blockchain technology is reshaping the social media scenario through transparency, value redistribution, ownership awareness, decentralization of data, and censorship resistance.

Peter A. Chow-White, Alberto Lusoli, Vu Thuy Anh Phan, Sandy Edward Green

Blockchain is one of the most widely debated technologies in recent years. Pundits and scholars have described it as a disruptive technology that will impact many sectors of society. Skeptics argue blockchain’s popularity is fuelled by the media’s obsession for the ‘next big thing’ rather than the intrinsic potential of the technology. In this paper, we follow a social constructivist approach with the aim of explaining how different discourses are creating new meanings about this technology. As Communication scholars, we focus on the role media play in framing debates about blockchain. Our analysis relies on a human coding of the most popular news about blockchain circulating on Twitter from October 2014 to July 2018. The findings show the general attitude about blockchain is predominantly positive. The discourses developing around crypto technologies are complex and multifaceted and indicate a general transition in the rhetorical definition of blockchain.

Gagangeet Singh Aujla, Masoud Barati, Omer Rana, Schahram Dustdar · 10 authors

The COVID19 Pandemic has highlighted our dependence on online services (from government, e-commerce/retail, and entertainment), often hosted over external cloud computing infrastructure. The users of these services interact with a web interface rather than the larger distributed service provisioning chain that can involve an interlinked group of providers. The data and identity of users are often provided to service provider who may share it (or have automatic sharing agreement) with backend services (such as advertising and analytics). We propose the development of compliance-aware cloud application engineering, which is able to improve transparency of personal data use -- particularly with reference to the European GDPR regulation. Key compliance operations and the perceived implementation challenges for the realization of these operations in current cloud infrastructure are outlined.

Hongyu Wu, Nianle Su, Chunguang Ma, Pengda Liao · 5 authors

Many supply chain finance problems can be fundamentally solved by using blockchain. The current technical challenge of applying blockchain in supply chain finance is the lack of systematic privacy protection architecture. Based on the architecture of Julongchain, through the nonlinear principal component analysis in private data feature extraction, this paper proposed a new type of privacy protection architecture based on specific supply chain financial system. This privacy protection solution split privacy data by decision machine, then mixed data using mixed mechanism, finally determined the characteristic weight of privacy data by applying the decentralized decision institution.

Komal Gilani, E. Bertin, Julien Hatin, Noël Crespi

In the digital revolution, even secure communication between individuals, services and devices through centralized digital entities presents considerable risks. Having service providers continue to offer their centric solutions is inefficient in terms of duplication, has serious security lacunae and is cumbersome to the users. The self-sovereign Identity concept, which includes the individual’s consolidated digital identity and verified attributes, enables the users of data to exert their ownership and gain insights from their data’s usage. The authentication and verification of digital identity is essential to achieve the privacy and security of distributed digital identities. In this paper, we provide a coherent view of the central concepts of self-sovereign Identity, including the components of identity proofing and authentication solutions for different self-sovereign Identity solutions. We discussed an overview of Identity management approaches, introducing an architecture overview as well as the relevant actors in such a system and blockchain technology as solution for distributed user-centric identity. Finally, we discuss the existing solutions and point out the research gaps and elaborate challenges and trade-offs towards building a complete identity management system.

Karoline Busse, Mohammad Tahaei, Katharina Krombholz, Emanuel von Zezschwitz · 7 authors

Payment cultures around the globe are diverse and have significant implications on security, privacy and trust. We study usable security aspects of payment cultures in four culturally distinct societies. Based on a qualitative study in Germany and Iran, we developed an online survey and deployed it in Germany, Iran, China, and the United States. The results reveal significant differences between the studied countries. For example, we found that participants from Iran and China are more comfortable with credential sharing and German participants were most accepting towards cryptocurrencies. We suggest these kinds of differences in payment culture need to be considered in the context of HCI research when evaluating current payment mechanisms or designing new ones.

Gislaine Parra Freund, Priscila Basto Fagundes, Douglas Dyllon Jerônimo de Macedo

No abstract is available for this record.

Robin Renwick, Rob Gleasure

Blockchain systems afford new privacy capabilities. This threatens to create conflict, as different social groups involved in blockchain development often disagree on which capabilities specific systems should enact. This article adopts a boundary object perspective to make sense of disagreements between collaborating social worlds. We perform a case study of privacy attitudes among collaborating actors in Monero, a cryptocurrency community that emphasises privacy and decentralisation alongside a set of values sometimes described as anti-establishment, crypto-anarchist, and/or cypherpunk. The case study performs a series of interviews with users, developers, cryptographic researchers, corporate architects, and government regulators. Three novel and important findings emerge. The first is that none of the social worlds express a desire to monitor routine transactions, despite the obvious business and tax-collection value of such data. The second is that regulators are happy to postpone active involvement, based on the flawed assumption they can impose privacy-related regulation later, once risks have become clear. Such regulation may not be possible as protocols and rulesets currently being coded into the system may be impossible to amend in the future (unless they can obtain either developer or network consensus). The third is that regulators assume methods for overseeing extraordinary transaction are necessary to avoid widespread, near-effortless money laundering. Yet, each of the other social worlds is operating under the assumption that this trade-off has already been accepted. These findings demonstrate subtle power transitions and changes in privacy attitudes that have implications for research on blockchain, management, and boundary objects in general.

Pascal Meier, Jan Heinrich Beinke, Christian Fitte, Jan Schulte to Brinke · 5 authors

Abstract In the course of digitization in healthcare, personal health records (PHRs) are handled as a key solution. Despite the indisputable benefits, the adoption of PHRs is hampered by data security and data privacy concerns. Blockchain technology offers promising potential to address these issues by enabling secure transactions of sensitive data. With regards to PHRs, the blockchain can be used to manage the access to health-related data. Besides existing generic PHR architectures, we systematically identified issues for the healthcare sector that need to be considered for the development of a PHR. We subsequently derived eight meta-requirements that were consolidated into three design principles. Within a 1-year design science research project, we developed the blockchain-secured PHR prototype, OSHealthRec, and evaluated the system in four evaluation cycles. The findings of our research are twofold. On the one hand, we contribute to the design knowledge base by presenting three design principles. On the other hand, we present the development of a real, operational blockchain-secured PHR and the findings from its continuous evaluation, which may serve as useful advice for further solutions.

Imdad Ullah, Salil S. Kanhere, Roksana Boreli

The targeted advertising is based on preference profiles inferred via relationships among individuals, their monitored responses to previous advertising and temporal activity over the Internet, which has raised critical privacy concerns. In this paper, we present a novel proposal for a Blockchain-based advertising platform that provides: a system for privacy preserving user profiling, privately requesting ads from the advertising system, the billing mechanisms for presented and clicked ads, the advertising system that uploads ads to the cloud according to profiling interests, various types of transactions to enable advertising operations in Blockchain-based network, and the method that allows a cloud system to privately compute the access policies for various resources (such as ads, mobile user profiles). Our main goal is to design a decentralized framework for targeted ads, which enables private delivery of ads to users whose behavioral profiles accurately match the presented ads, defined by the ad system. We implement a POC of our proposed framework i.e. a Bespoke Miner and experimentally evaluate various components of Blockchain-based in-app advertising system, implementing various critical components; such as, evaluating user profiles, implementing access policies, encryption and decryption of users' profiles. We observe that the processing delay for traversing policies of various tree sizes, the encryption/decryption time of user profiling with various key-sizes and user profiles of various interests evaluates to an acceptable amount of processing time as that of the currently implemented ad systems.

Hasventhran Baskaran, Salman Yussof, Fiza Abdul Rahim, Asmidar Abu Bakar

Blockchain is a time stamped ledger that is used to keep immutable records. This technology has gained immense popularity due to the use of its decentralized architecture in cryptocurrency platforms. Blockchain has been increasingly adopted in other sectors due to its ability to ensure data integrity. The increasing use of blockchain by the public has made it become a subject to data privacy laws. Based on the study conducted by other researchers, there are features of blockchain that conflict with certain elements in data privacy laws. The European Union's General Data Protection Regulation (GDPR), which becomes a model for data privacy act of many other countries, has been identified to be incompatible with blockchain. One of the research works in the area of blockchain is to figure out how blockchain can be made to comply with such privacy laws. In Malaysia, blockchain is still relatively new and a study needs to be done to evaluate its compatibility with Personal Data Protection Act 2010 (PDPA). Hence, the aim of this paper is to identify the gaps between blockchain and PDP A in terms of their compatibility and to propose solutions to bridge the gaps. Based on the gaps identified, the paper proposed the use permissioned or private blockchain, off-chain storage and stealth address to enable a blockchain application to be compliant with PDPA.

Wei Feng, Zheng Yan, Laurence T. Yang, Qinghua Zheng

Mobile crowdsourcing (MCS) has become an effective data collection method due to its mobility, low cost, and flexibility. However, since centralized MCS confronts severe security and privacy risks in reality, many researchers are devoted to building a decentralized MCS system based on blockchain. Despite the effectiveness of these schemes, they fail to offer anonymous authentication on the trust of MCS nodes, although privacy is a main concern in MCS and trust plays an important role in a series of MCS activities, such as worker selection and truth discovery. Nevertheless, anonymous authentication on trust is not a trivial issue since trust evaluation usually conflicts with anonymity, which is a necessary privacy requirement in an open MCS environment. To tackle this problem, we leverage Intel software guard extension (SGX) and propose a scheme to anonymously authenticate trust with trustworthy trust evaluation in a blockchain-based MCS system. The scheme employs an SGX-enabled cloud server to periodically alter user public/private key pairs and mix newly altered keys among a number of faked keys in order to ensure unlinkability. Besides, we consider the unique features of MCS and work out a novel trust evaluation method by aggregating both subjective feedback and objective behaviors. Finally, we conduct several analyses and experiments to illustrate its security and efficiency.

Muhammad Khalid Anser, Ghulam Hussain Khan Zaigham, Muhammad Imran Rasheed, Abdul Hameed Pitafi · 6 authors

Summary Despite the increasing popularity and recognition of cryptocurrencies, little is known about the contextual and psychological variables that predict the behavioral intentions of individuals toward adopting a cryptocurrency such as Bitcoin. Utilizing the extended theory of planned behavior (TPB), authors have developed and tested a theoretical model to investigate the relationship between the usage of social media and the intentions of individuals toward adopting Bitcoin. We empirically tested our conceptualized research model using the primary data collected from 443 respondents through a survey conducted in China. Results have shown that the usage of social media is positively associated with users' intentions toward adopting Bitcoin through their attitudes, subjective norms, and perceived behavioral control. Individuals' intentions are subsequently associated with their actual behavior toward the adoption of Bitcoin, while we found perceived risk associated with Bitcoin as a moderator on the relationship between the intentions of individuals and their actual behavior. This study extended the TPB in understanding various psychological and contextual factors that predict the adoption of Bitcoin. Moreover, important theoretical and practical implications, as well as the limitations of the study, are discussed.

Yu-Jie Jessica Kuo, Jiann‐Cherng Shieh

The blockchain technology designed by information security experts empowers in library service and healthcare service via smart contracts. Advanced blockchain technology provides a mechanism for smart contracts. Through intelligent threshold design and the open and tamper-proof nature of the blockchain, smart contracts have become a new generation of information security technology. In the next-generation library services, traditional borrowing materials from the library have evolved into a limited-time sharing service for electronic materials. These electronic materials have various loan periods and sharing time-varying by different borrower privileges. This study designs a patron-centric account's smart contract to disseminate library information more effectively and collect accurate library data. The smart contract automatically triggers the loan period and extends this mechanism to designing a personal health privacy sharing protocol for improving the one-time authorization sharing mechanism. As a result, this study may provide blockchain smart contract designs shared by library information and healthcare through cross-domain consideration and scheme.

Unal Tatar, Yasir Gökçe, Brian Nussbaum

No abstract is available for this record.

Alexandra Mai, Katharina Pfeffer, Matthias Gusenbauer, Edgar Weippl · 5 authors

Frequent reports of monetary loss, fraud, and user-caused security incidents in the context of cryptocurrencies emphasize the need for human-centered research in this domain. We contribute the first qualitative user study (N=29) on user mental models of cryptocurrency systems and the associated threat landscape. Using Grounded Theory, we reveal misconceptions affecting users' security and privacy. Our results suggest that current cryptocurrency tools (e.g., wallets and exchanges) are not capable of counteracting threats caused by these misconceptions. Hence, users frequently fail to securely manage their private keys or assume to be anonymous when they are not. Based on our findings, we contribute actionable advice, grounded in the mental models of users, to improve the usability and secure usage of cryptocurrency systems.

Junwei Zhang, Fan Yang, Zhuo Ma, Zhuzhu Wang · 6 authors

With the rapid development of Internet of Vehicles (IoV), vehicle-based spatial crowdsourcing (SC) applications have been proposed and widely applied to various fields. However, location privacy leakage is a serious issue in spatial crowdsourcing because workers who participate in a crowdsourcing task are required to upload their driving locations. In this paper, we propose a decentralized location privacy-preserving SC for IoV, which allows vehicle users to securely participate in SC with ensuring the task's location policy privacy and providing multi-level privacy preservation for workers' locations. Specifically, we introduce blockchain technology into SC, which can eliminate the control of vehicle user data by SC-server. We combine the additively homomorphic encryption and circle-based location verification to ensure the confidentiality of task's location policy. To achieve multi-level privacy preservation for workers' driving locations, we only reveal a grid where workers are located in. The size of the grid represents the level of privacy preservation. We leverage the order-preserving encryption and non-interactive zero-knowledge proof to prevent workers from illegally obtaining rewards by forging their driving locations. The security analysis results show that our framework can satisfy the above requirements. In addition, the experiment results demonstrate that our framework is efficient and feasible in practice.

Gianluigi M. Riva

Blockchain is a disruptive technology presented in 2008 that allows both scarcity and timestamps to be introduced to the digital world. Whereas many technological applications may benefit from this architecture, it involves direct conflict with both Privacy rights and Data Protection rules, as introduced by the General Data Protection Regulation (GDPR). This study first provides an overview of what blockchain is, how it works, and how it can affect privacy. It describes how this technology functions, thanks to binary ledgers distributed amongst the system nodes, and what role they play in validating the succession of blocks. The work analyses how blockchain can be applied to innovative fields and investigates related Privacy issues. Indeed, the chain can certify the time, the parties and the object included in a ‘block’ but cannot guarantee the legal validity, the veracity or correctness of the content. Furthermore, its immutability is in direct conflict with the right to be forgotten. In addition, due to the distributed nature of the system, it does not allow identification of data controllers and, consequentially, the accountable subject for the personal data processed within the digital ledger. The aim of the study is to highlight the characteristics of the proposed solution, i.e. supporting centralised governance of blockchain infrastructures to ensure control over the distributed nodes, as well as having the capability to intervene in modifying the chain when the law requires it. This set of interventions would also render publicly available the personal information within the blockchain with different levels of accessibility (‘Privacy by Layers’ (PbL)) and, therefore, provide log control that can ensure compliance with the Data Protection regulatory framework. To provide complete analysis on the matter, the study also addresses how Intelligent Systems running on a blockchain-based infrastructure that holds pieces of personal information can clash with Article 22 of the GDPR on automated decisions when it affects the fundamental rights of individuals. Finally, the conclusions crystallise the legal remarks by stressing the essential elements of the analysis that emerged during the study and framing them within the bigger picture of how the Law addresses social or technological phenomena.

Chenquan Gan, Akanksha Saini, Qingyi Zhu, Yong Xiang · 5 authors

No abstract is available for this record.

A. Priyadharshini, M. Prasad, R. Joshua Samuel Raj, S. Geetha

No abstract is available for this record.

Jan Stodt, Christoph Reich

Increased collaborative production and dynamic selection of production partners within industry 4.0 manufacturing leads to ever-increasing automatic data exchange between companies. Automatic and unsupervised data exchange creates new attack vectors, which could be used by a malicious insider to leak secrets via an otherwise considered secure channel without anyone noticing. In this paper we reflect upon approaches to prevent the exposure of secret data via blockchain technology, while also providing auditable proof of data exchange. We show that previous blockchain based privacy protection approaches offer protection, but give the control of the data to (potentially not trustworthy) third parties, which also can be considered a privacy violation. The approach taken in this paper is not utilize centralized data storage for data. It realizes data confidentiality of P2P communication and data processing in smart contracts of blockchains.