Privacy Preservation & Security Solutions in Blockchain Network

Blockchain has seen exponential progress over the past few years, and today its usage extends well beyond cryptocurrencies. Its features, including openness, transparency, secure communication, difficult falsification, and multi-consensus, have made it one of the most valuable technology in the world. In most open blockchain platforms, any node can access the data on the blockchain, which leads to a potential risk of personal information leakage. So the issue of blockchain privacy and security is particularly prominent and has become an important research topic in the field of blockchain. This dissertation mainly summarizes my research on blockchain privacy and security protection issues throughout recent years. We first summarize the security and privacy vulnerabilities in the mining pools of traditional bitcoin networks and some possible protection measures. We then propose a new type of attack: coin hopping attack, in the case of multiple blockchains under an IoT environment. This attack is only feasible in blockchain-based IoT scenarios, and can significantly reduce the operational efficiency of the entire blockchain network in the long run. We demonstrate the feasibility of this attack by theoretical analysis of four different attack models and propose two possible solutions. We also propose an innovative hybrid blockchain crowdsourcing platform solution to settle the performance bottlenecks and various challenges caused by privacy, scalability, and verification efficiency problems of current blockchain-based crowdsourcing systems. We offer flexible task-based permission control and a zero-knowledge proof mechanism in the implementation of smart contracts to flexibly obtain different levels of privacy protection. By performing several tests on Ethereum and Hyperledger Fabric, EoS.io blockchains, the performance of the proposed platform consensus under different transaction volumes is verified. At last, we also propose further investigation on the topics of the privacy issues when combining AI with blockchain and propose some defense strategies

On the Economics of Bitcoin Mining: A Theoretical Framework and Simulation Evidence

The stability of proof-of-work consensus underlying decentralized networks such as Bitcoin relies on an incentive compatible mining design. While theoretically well studied, the empirical composition of the mining process remains largely opaque due to the un-known distribution of miners and technology. This paper proposes a model that leverages innovation-driven convergence in the Bitcoin ecosystem to reconstruct market conditions and study miners’ behavior. Numerical simulations using 10,000 bootstrap samples sup-port the implications of the model. The results quantify considerable variation in miners’ profits and costs and proof consistent with the proposed theory. The estimates suggest that the cost of a capacity majority, and thus the ability to successfully attack the network, can be astonishingly low (e.g., $2.13 million in May 2020) when adverse events coincide. This pronounces the relevance of cyclical patterns when assessing the immutability of proof-of-work consensus

Blockchain Research in Information Systems: Current Trends and an Inclusive Future Research Agenda

The potential of blockchain has been extensively discussed in practitioner literature, yet rigorous empirical and theory-driven information systems (IS) research on blockchain remains scarce. This special issue addresses the need for innovative research that offers a fresh look at the opportunities and challenges of blockchain. This editorial integrates and goes beyond the papers included in this special issue by providing a framework for blockchain research in IS that emphasizes two important issues. First, we direct the attention of IS research toward the blockchain protocol level, which is characterized by recursive interactions between human agents and the blockchain protocol. Second, we highlight the need for IS research to consider how the protocol level constrains and affords blockchain applications, and how these constraints and other concerns at the application level lead to changes at the protocol level. Rooted in a socio-material view of IS, we offer a multi-paradigmatic IS research agenda that underscores the need for behavioral (individual, group, and organizational), design science, and IS economics research on blockchain. Our research agenda emphasizes issues of blockchain governance, human and material agency, blockchain affordances and constraints, as well as the consequences of its use

Evaluating Blockchain Success: Integrating Organizational Decentralization with the DeLone and McLean IS Success Model

Dissertation presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Information Systems and Technologies ManagementBlockchain technology is a distributed ledger without an intermediate where delivers decentralized consensus. The tremendous potential of this technology including anonymity, persistency, auditability, and traceability along with decentralization caused blockchain to receive attention globally. This study aims to identify the role of decentralization in blockchain success at firms by proposing a theoretical model based on the theory of success in information systems. The research model was empirically tested using 193 responses over an online survey questionnaire. The result reveals that service quality, system quality, and information quality were explained by decentralization. Likewise, decentralization and user’s satisfaction are an important criterion for the Net impact of blockchain success. Furthermore, this study explores the positive influence of decentralization as a moderator between the relationship of the user’s satisfaction and net impact. The findings have theoretical and practical implications for academics and managers