Gyeong Min Baek, Young Ah Shin, Gye Hyun Jang, Ik Rae Jeong
Bitcoin address clustering is a technique used for Bitcoin deanonymization to determine address ownership. It serves as a valuable method for assessing the level of anonymity within the system and detecting addresses associated with illicit activities. The recent Taproot soft fork in Bitcoin has introduced significant privacy enhancements, making deanonymization more challenging. In this paper, we propose a novel on-chain heuristic approach, block number-based address clustering, which leverages the fundamental principle of 6 block confirmations for double-spending prevention. By relying on the trust relationships between transacting parties, our method enables the generation of clusters even upon the soft fork, where existing methods encounter challenges. To evaluate our heuristics, we analyze our approach using the address reduction ratio and pure contribution as key metrics. The results show the effectiveness of our method both before and after the soft fork, which implies that our approach remains unaffected by the usage of Taproot transactions. Furthermore, we provide real-world empirical cases that validate the practicality of our heuristics. As shown in the investigation cases conducted by the Korean National Police Agency, our method can generate new clusters and improve address ownership identification compared to the previous approaches.
Open access
Blockchain Technology Applications and Security
Peer-to-Peer Network Technologies
Advanced Steganography and Watermarking Techniques
Михайленко, Олександр Ігорович, Гороховський, Кирило Семенович, Гороховський, Семен Самуїлович
The paper explores the possibility of expanding the use of end-to-end encryption protocols based on the Double Ratchet algorithm in applications with low trust in the server, particularly in turn-based games and strategic interactions. The relevance of the research is due to the growing need for secure communication in cyberattacks, especially during military operations. The field of end-to-end encryption requires the study of additional applications beyond the usual ones, such as encrypted communication in text messengers. The developed implementation of the protocol can be safely used in any applications that aim to implement end-to-end encryption and satisfy the criterion of session ephemerality (in cases where secrets are stored outside a secure environment). The implemented server supports ephemeral sessions, which guarantee minimal risks of information compromise, and uses digital signatures (EdDSA) for user authentication. Logical routing of requests ensures efficient message transmission in secure scenarios. The choice of the classic game of checkers as an example allowed the authors to effectively demonstrate the advantages of end-to-end encryption and the capabilities of the implemented protocol. All cryptographic operations, including key generation, encryption and decryption of messages, are successfully performed on client devices. It is important to improve error handling mechanisms and optimize the operation of WebAssembly. An interesting area of further research is the creation of zero-knowledge proof mechanisms to prevent Man-In-The-Middle attacks during the creation of a shared secret, optimizing integration with cryptographic hardware security modules (HSM), and exploring the scalability of the solution. The proposed approach can be used to solve real-world information security problems where trust in the data transmission channel is critically important. Thus, the work has created a comprehensive solution that includes a cryptographic protocol, a backend, and a web client, which demonstrates the viability of end-to-end encryption in browser environments and multiplayer games. The work can be used as a basis for further research and development in the field of security of communication systems and privacy in multiplayer games.
Eclipse attack is a major threat to the blockchain network layer, wherein an attacker isolates a target node by monopolizing all its connections, cutting it off from the rest of the network.Despite the attack's demonstrated effectiveness in Bitcoin (Usenix'15, SP'20, Usenix'21, CCS'21, SP'23) and partially in Ethereum (NDSS'23, SP'23), its applicability to a wider range of blockchain systems remains uncertain.In this paper, we investigate eclipse attacks against Monero, a blockchain system known for its strong anonymity and pioneering the use of Dandelion++ (the state-of-the-art blockchain network layer protocol for transaction privacy protection).Our analysis of Monero's connection management mechanism reveals that existing eclipse attacks are surprisingly ineffective against Monero.We accordingly introduce the first practical eclipse attack against Monero by proposing a connection reset approach, which forces the target node to drop all benign connections and reconnect with malicious nodes.Specifically, we outline two methods for executing such an attack.The first one exploits the private transaction mechanisms, while the second method leverages the differences in propagation between stem transactions and fluff transactions under Dandelion++.Our attack is not only applicable to Monero but to all blockchain systems utilizing Dandelion++ and similar connection management strategies.We conduct experiments on the Monero mainnet.Evaluation results confirm the feasibility of our attack.Unlike existing eclipse attacks, our connection reset-based approach does not require restarting the target node, significantly accelerating the attack process and making it more controllable.We also provide countermeasures to mitigate the proposed eclipse attack while minimizing the impact on Monero.In addition, we have ethically reported our investigation to Monero official team.
The peer-to-peer (P2P) lending model has emerged as a transformative alternative to traditional financial institutions, enabling direct interactions between lenders and borrowers.However, P2P lending platforms face significant challenges, including trust deficits, fraud, high administrative costs, and inefficiencies from manual oversight.Fintech advancements, particularly integrating blockchain technology and smart contracts, offer innovative solutions to these issues.Blockchain provides a decentralized and tamper-proof ledger, ensuring data integrity and transparency in P2P lending transactions.By leveraging smart contracts, loan agreements can be automated and enforced through predefined conditions, eliminating the need for intermediaries and reducing operational delays.Smart contracts enable secure fund disbursement, automated repayments, and fraud prevention while maintaining the transparency required to build trust between parties.This study explores implementing fintech technologies, blockchain, and smart contracts to enhance the efficiency, scalability, and security of P2P lending platforms.The proposed framework minimizes administrative overhead, mitigates trust issues, and fosters greater accessibility, particularly for underserved populations.By addressing the inherent limitations of traditional P2P lending, this approach transforms the lending ecosystem and contributes to the broader adoption of decentralized finance (DeFi) solutions, promising a more inclusive and efficient financial future.
This empirical study investigates the transformative potential of overlay networks built on Distributed Ledger Technology (DLT) for the implementation of Central Bank Digital Currencies (CBDCs) in Europe. Amidst the evolving digital economy, the adoption of CBDCs offers a promising avenue for modernising financial infrastructures, enhancing payment efficiency, and strengthening financial security. However, the deployment of CBDCs poses significant challenges, including scalability, cost efficiency, and security concerns. This research aims to address these challenges by exploring the efficacy of DLT-based overlay networks in improving the operational capabilities of CBDCs. The study employs a comprehensive methodology that combines quantitative analysis with a quasi-experimental design, using simulations based on a production system to assess the impact of DLT-based overlay networks on the efficiency, cost, and security of a proposed CBDC in Europe. The research juxtaposes the performance of CBDC networks with and without the implementation of these advanced technological frameworks, drawing on data from simulated transactions and user feedback. Findings from the study reveal that overlay networks built on DLT significantly enhance the efficiency and security of CBDC networks while concurrently reducing operational costs. These improvements are attributed to the inherent characteristics of DLT, including its decentralised nature, immutability, and transparency. The research underscores the pivotal role of DLT in facilitating fast, secure, and cost-effective transactions, thereby addressing the primary concerns associated with CBDC implementation. The implications of this study extend beyond theoretical contributions, offering actionable insights for policymakers and financial institutions in Europe contemplating the adoption of CBDCs. By demonstrating the tangible benefits of integrating DLT-based overlay networks, this research provides a solid foundation for informed decision-making in the development and deployment of CBDCs. Furthermore, the study identifies areas for future research, particularly in exploring the long-term economic impacts of CBDCs on the European financial topography and the potential for global interoperability of DLT-based payment systems.
Hora, Harneesh Singh, Sahani, Rahul, Suthar, Aryan, Rizwan Khan, Sahil
<i>We present a decentralized NFT (Non-Fungible Token) marketplace built on the Ethereum blockchain. The platform allows users to mint, buy, and sell unique digital assets (e.g., art, collectibles) using Solidity smart contracts and a Web3-enabled frontend. All ownership records are stored on-chain for transparency and immutability, while large media data (images, metadata) are stored off-chain using IPFS. Users connect their wallets (e.g., MetaMask) via a React interface using Ethers.js, enabling peer-to-peer transactions without intermediaries. Key features include real-time transaction updates via blockchain event listeners and gas-optimized contract design. Security is enforced through standard libraries and audit practices to prevent common exploits (e.g., reentrancy, overflow). Performance evaluations show reasonable gas costs per transaction, demonstrating feasibility on Ethereum’s current throughput. Future work includes expanding cross-chain support and enhanced scalability.</i>
Ensuring the reproducibility of scientific simulations is a persistent challenge, despite current best practices like version control and containerization. Factors such as floating-point arithmetic variations, hardware differences, and concurrency issues often prevent bit-for-bit replication of results. This paper investigates the techniques that distributed ledger technologies employ to achieve deterministic computations and application of these techniques to enhance the reproducibility, trustworthiness and verifiability of scientific simulations. We explore two primary approaches: executing simulations directly “on-chain” for complete transparency and deterministic replay, and performing computations “off-chain” while anchoring their integrity to a blockchain via cryptographic proofs, such as Zero-Knowledge Proofs (ZKPs) and Merkle trees.
Sabbir M. Saleh, Nazim H. Madhavji, John Steinbacher
Security is becoming a pivotal point in cloud platforms. Several divisions, such as business organisations, health care, government, etc., have experienced cyber-attacks on their infrastructures. This research focuses on security issues within Continuous Integration and Deployment (CI/CD) pipelines in a cloud platform as a reaction to recent cyber breaches. This research proposes a blockchain-based solution to enhance CI/CD pipeline security. This research aims to develop a framework that leverages blockchain's distributed ledger technology and tamper-resistant features to improve CI/CD pipeline security. The goal is to emphasise secure software deployment by integrating threat modelling frameworks and adherence to coding standards. It also aims to employ tools to automate security testing to detect publicly disclosed vulnerabilities and flaws, such as an outdated version of Java Spring Framework, a JavaScript library from an unverified source, or a database library that allows SQL injection attacks in the deployed software through the framework.
Existing game tournaments have faced problems where large game companies or a small organizing committee monopolize decision-making on rules and revenue distribution, thereby hindering fairness and creativity.To overcome these limitations, this paper proposes a DAO (Decentralized Autonomous Organization)-based, broadcaster-centric operational model.In this model, all stakeholders in the tournament participate in transparent decision-making and revenue distribution through smart contracts, thereby enhancing fairness and trust.Furthermore, it manages copyright negotiations with game companies and oversees revenue models within the DAO, ultimately promoting ecosystem diversity and sustainability.Through conceptual simulations and case analyses, this study verifies the feasibility of the proposed model.Compared to traditional centralized structures, the findings confirm the model's potential for democratizing the decision-making process, establishing fair compensation frameworks, and proactively resolving copyright issues.
Blockchain-based applications rely on a decentralized structure wherein the transactions are recorded on a public ledger that is maintained by every node in the peer-to-peer (P2P) network. The transactions and blocks are propagated using a multi-hop broadcast and verified by every node in the network. Application Layer Traffic Optimization (ALTO), on the other hand, is a network protocol developed and maintained by the Internet Engineering Task Force (IETF) to provide network related information to the P2P applications to increase their performance. In this study, a novel peer selection method based on the network information provided by ALTO protocol is proposed to decrease the block propagation delay of the Bitcoin P2P network. The simulations show that the proposed peer selection method can effectively decrease the block propagation time and fork rate compared to Bitcoin’s random peer selection and region-based peer selection methods.
Most of today’s online community organization is done in an “implicitly feudal” manner, coordinated on centrally managed digital platforms, operated by platform companies. However, cooperative models represent a viable alternative that deserves wider recognition. This chapter explores community organizing efforts around decentralized technologies that are designed to limit centralized control, emphasize user voice, and foster participation. Specifically, we draw on two cases, https://www.w3.org/1999/xlink" xlink:href=" https://Social.coop ">Social.coop and The Platform, to illustrate the breadth of the cooperative approach. https://www.w3.org/1999/xlink" xlink:href=" https://Social.coop ">Social.coop is a cooperative social network that uses a different set of technologies, combined with fiscal sponsorship for legal recognition, toward similar ends. The Platform is a Decentralized Autonomous Organization incorporated as a multi-stakeholder cooperative, which uses blockchain technology to preserve digital art and to supplement the project’s cooperative governance processes. Our goal is to highlight the potential for increasing effective forms of voice that emerges from coupling decentralized technologies and cooperative governance models. Furthermore, we draw on insights from the cases to elicit critical tensions in the form of legal, technical, and practical hurdles, which currently hinder the growth in the adoption of network-native cooperatives. This chapter closes by providing practical recommendations to address these hurdles and avenues for further research.
Current file sharing solutions have problems such as data loss, unauthorized access and have only one point of failure are insecure and unreliable. To overcome these challenges, this work proposes a Decentralized File Sharing System that optimizes the transfer of data securely and with high reliability. Others include decentralised storage by use of IPFS and Pinata, and safety of the file through AES encryption. Password de- cryption is ensured only by the recipient keeping the password, while MetaMask authentication is connected to the Ethereum network. To protect information integrity every file has a Content Identifier coded as CID. The benchmark assessments reveal that the execution time increases with lower variance for smaller file sizes and varies slightly with larger files. As for decentralized approaches they are protected from focused attacks, more reliable in terms of failures, and have much better scalability than the centralized ones providing a much better solution for file sharing.
DNS is an essential component for internet access, but the traditional centralized structure is not suitable for the rapidly growing Web3 ecosystem. Currently, Web3 services rely on Web2-based access paths, revealing limitations such as the Single Point of Failure (SPoF) issue and the compromise of decentralization principles. To address these issues, this paper proposes Setonix, a blockchain-based decentralized DNS. Experimental results of the implemented Setonix showed that it had only a marginal performance difference of up to approximately 5% compared to Google and Cloudflare DNS. Additionally, it demonstrated over 95% lower latency compared to Handshake DNS, proving its high efficiency. Setonix eliminates dependency on centralized access paths and brings the hierarchical address structure of existing domain names into the blockchain network, adhering to legacy systems to minimize user resistance. Additionally, it provides a blockchain-based architecture that supports cross-compatibility between traditional domain names and Web3 domain names through a simple interface. This design significantly enhances the scalability and accessibility of Web3, presenting a new standard for decentralized internet services. By doing so, it helps to establish a foundation that contributes to the growth and innovation of the Web3 ecosystem.