Follow blockchain research across journals, conferences, and preprint repositories.
98,272 results · page 316 of 4,095
A. Brahmareddy, Arun Kumar Arigela, Dr. Mercy Paul Selvan, T. S. Sreenivas · 6 authors
No abstract is available for this record.
Paul Turowski, Simon Hutchinson, Takuto Fukuda
No abstract is available for this record.
Maksim Ivanov, Irina Suslina
No abstract is available for this record.
Babu Pillai, Aravinda S. Rao, Narayana Madineni, Yeliz Karaca · 5 authors
Cryptocurrency is a medium of exchange and digital means of payment generated and stored electronically on a blockchain system, employing cryptographic techniques to verify the transfer of funds and an algorithm in order to control the formation of monetary units. In such systems, transactions are assembled in groups, known as blocks, which are organized in a chronological sequence referred to as blockchain. Blocks are added to the chain by means of a mathematical process that makes it very difficult for an individual user to seize the blockchain, and correspondingly, progresses made in quantum computing serve for the long-term security considering the threats concerning the cryptographic algorithms currently used in blockchain applications. As the cryptocurrency market capitalization approaches $2.95 trillion in early 2026, the arrival of fault tolerant quantum computing threatens the cryptographic foundations of the digital economy. While Shor’s algorithm poses a systemic risk to the elliptic curve primitives securing Web3, existing risk models fail to account for the unique economic asymmetry of blockchain assets: The fixed computational cost of a cryptographic break versus the variable, high stakes financial rewards on-chain. This paper introduces the Quantum Economic Risk Assessment (QERA) framework, which is a quantitative model that ranks blockchain vulnerabilities by the ratio of extractable value to quantum computational cost ([Formula: see text]). Through a component level mapping of the Ethereum and Bitcoin ecosystems, we demonstrate that a rational quantum adversary will not prioritize consensus level attacks which we prove to be economically irrational at a cost of $4.65 trillion but will instead target high value, single key assets. Our findings identify Satoshi era P2PK addresses ([Formula: see text]), single admin DeFi protocols ([Formula: see text]), and pairing-based ZK rollups ([Formula: see text]) as the most urgent targets for post quantum migration. QERA provides protocol designers and institutional stakeholders with a rigorous, adversary aligned roadmap for evidence based cryptographic transitions in the face of emerging quantum threats.
Hang-Yu Zhou
No abstract is available for this record.
Krrish Dubey, P. Mukherjee, Sayan Chakraborty, Sitanath Biswas · 6 authors
No abstract is available for this record.
Nihar Shah
No abstract is available for this record.
Supradip Baul, Minal Dutta, Joydeep Dey, Sanyukta Deb · 5 authors
No abstract is available for this record.
Pasquale De Rosa
No abstract is available for this record.
Andreas Park
No abstract is available for this record.
Yicheng Zhu, Shaltiel Eloul, Yash Satsangi, Imran Bashir · 5 authors
No abstract is available for this record.
Marc Leinweber
Resilience is the ability of a (distributed) system to withstand any stressful situation without imposing massive restrictions and, above all, without long-term consequences. Permissioned distributed ledgers based on state machine replication (SMR) offer a promising approach to achieving high resilience and fairness in federated systems. SMR provides a fault-tolerant service for clients by relying on all replicas being in a consistent state. The consistent state is achieved through a consensus algorithm, typically an atomic broadcast, that decides on a total order of client requests. In the Byzantine fault model, replicas are assumed to be potentially malicious; a Byzantine fault-tolerant (BFT) protocol withstands a fixed share of malicious actors. Classic BFT SMR protocols require $n>3t$ replicas and multiple rounds of communication to withstand $t$ faulty replicas, making the implementation complex and limiting achievable throughput and increasing latency. Trusted Execution Environments (TEEs) allow to implement SMR in the so-called hybrid fault model in which replicas are assumed to be potentially Byzantine but the TEE is restricted to only fail by crashing. In the hybrid fault model, SMR requires less communication and can be implemented with a fault tolerance of $n>2t$ replicas. While many proposals aim to optimize BFT SMR by using TEEs, they still rely on a so-called leader that coordinates the agreement process among the replicas. The leader is known to be a bottleneck and, if it fails, the system has to recover from the failure and elect a new leader. The additional coordination required to elect a new leader can cause significant performance degradation, limiting the achieved resilience. Asynchronous protocols based on directed acyclic graphs (DAGs) eliminate the reliance on distinguished replicas by allowing all replicas to participate equally in the agreement process. While asynchronous approaches and the hybrid fault model independently contribute to increasing the resilience of BFT SMR systems, their combination has largely been unexplored. This dissertation aims to fill this gap by answering the following research question: What is the achievable performance and resilience of DAG-based, hybrid fault-tolerant state machine replication and under which preconditions can the leaderless nature be safely exploited to maximize throughput? We proceed in three steps to enhance the resilience and performance of BFT SMR systems and to identify potential trade-offs that arise from the assumption of TEEs and asynchrony in BFT SMR. First, we investigate the fit of TEE-based SMR for consortium-operated applications using the example of Mobility-as-a-Service ticketing systems. We propose an SMR application that uses TEEs to protect sensitive customer and mobility provider data while limiting possibilities for fraud by both customers and mobility providers, and ensuring correct billing. We find that as long as secure multiparty computation is not competitive in terms of performance, TEE-based SMR can provide significant advantages in terms of efficiency and resilience while providing reasonable confidentiality guarantees. We describe the characteristics of the Mobility-as-a-Service use case and identify similar use cases from other domains, e.g., central bank digital currencies, allowing us to conclude that our findings generalize. In the second step, we establish the foundation for a comprehensive analysis by proposing and proving TEE-Rider, the first hybrid fault-tolerant, asynchronous, and DAG-based atomic broadcast protocol. TEE-Rider builds upon the DAG-Rider protocol family and an optimized, DAG-aware, and TEE-based causal order broadcast we propose and prove. We then identify fundamental issues that arise from the combination of TEEs and asynchrony in BFT SMR. These are the impossibility of a fault-tolerant setup and the impossibility of garbage collection. Furthermore, we prove that for partially synchronous, TEE-based reliable broadcast it is impossible to reinitialize a TEE after a crash without relying on the participation of all $n$ replicas. We conclude the theoretical contributions with the proposal of the NxBFT SMR framework. Following an assumption-algorithm co-design, NxBFT is built upon TEE-Rider for the "Not eXactly Byzantine" (NxB) operating model to maximize throughput without sacrificing resilience. Moreover, NxBFT leverages SMR state transfer to circumvent the limitations imposed by TEEs and asynchrony and provides, under the assumption of partial synchrony, garbage collection, recovery, and reconfiguration. Finally, we contribute an extensive empirical evaluation. To this end, we develop the ABCperf evaluation framework focusing on the fair and straightforward comparison of fault-tolerant SMR and agreement protocols. We investigate the performance characteristics of NxBFT and find that cryptographic operations for signature creation and verification are the main bottleneck. We compare the performance of NxBFT with the state-of-the-art leader-based, hybrid fault-tolerant protocols MinBFT and Chained-Damysus and investigate the impact of the SMR client model (BFT vs. NxB), payload sizes, network sizes, network latencies, and crash faults. While all algorithms can benefit from the NxB client model, NxBFT achieves the highest throughput in all scenarios with up to $\sim500\,000$ requests per second. All algorithms show an improvement of the end-to-end latency when using the BFT instead of the NxB client model. When small latencies are required, MinBFT and Damysus are at an advantage with Damysus showing competitive throughput and impressively low latencies for small deployments. In contrast to leader-based approaches, NxBFT's performance is almost not impacted when actual crash faults occur.
Joseph Lee
No abstract is available for this record.
Hsiu-Chi Su, Feng-Jyh Lin
No abstract is available for this record.
N F N N A Rahman, Ruzian Markom, Hizri Hasshan
The rapid expansion of decentralised finance (DeFi) has elevated digital assets, particularly Non-Fungible Tokens (NFTs), to a prominent position within contemporary financial markets. NFTs are blockchain-based digital tokens enabled by smart contracts that facilitate verifiable ownership and authentication in decentralised environments. Despite growing international efforts to regulate NFT markets, clear legal frameworks—especially those addressing Shariah-compliant NFTs—remain underdeveloped. In Malaysia, the Islamic Financial Services Act 2013 (IFSA) and the Securities Commission Malaysia’s Digital Assets Guidelines provide only limited guidance on the classification, ownership, and enforceability of NFT-based financial products. This article examines the development of NFTs, analyses the existing Malaysian legal framework, and evaluates the readiness of Malaysia’s regulatory architecture to accommodate Shariah-compliant NFTs. Adopting a doctrinal methodology supported by case analysis, the study explores the applicability of current laws to NFT transactions and undertakes a comparative assessment of regulatory developments in the United Arab Emirates. The absence of explicit regulatory provisions raises significant Shariah compliance concerns, particularly in relation to gharar (uncertainty), riba (usury), and the recognition of māl (legitimate ownership), which may impede Malaysia’s aspiration to emerge as an Islamic DeFi hub. This study finds that Malaysia’s existing legal framework lacks specific Shariah compliance mechanisms for the legal recognition and governance of NFTs. Accordingly, targeted regulatory reforms are necessary to address the legal and Shariah complexities associated with NFTs and to facilitate responsible digital innovation within Malaysia’s Islamic DeFi ecosystem.
Tim Baumgartner
No abstract is available for this record.
Sandro Rodriguez Garzon, Awid Vaziry, Enis Mert Kuzu, Dennis Enrique Gehrmann · 7 authors
A fundamental limitation of current LLM-based AI agents is their inability to build differentiated trust among each other at the onset of an agent-to-agent dialogue. However, autonomous and interoperable trust establishment becomes essential once agents start to operate beyond isolated environments and engage in dialogues across individual or organizational boundaries. A promising way to fill this gap in Agentic AI is to equip agents with long-lived digital identities and introduce tamper-proof and flexible identity-bound attestations of agents, provisioned by commonly trusted third parties and designed for cross-domain verifiability. This article presents a conceptual framework and a prototypical multi-agent system, where each agent is endowed with a self-sovereign digital identity. It combines a unique and ledger-anchored W3C Decentralized Identifier (DID) of an agent with a set of third-party issued W3C Verifiable Credentials (VCs). This enables agents at the start of a dialog to prove ownership of their self-controlled DIDs for authentication purposes and to establish various cross-domain trust relationships through the spontaneous exchange of their self-hosted DID-bound VCs. A comprehensive evaluation of the prototypical implementation demonstrates technical feasibility but also reveals limitations once an agent's LLM is in sole charge to control the respective security procedures.
Tolulope Falokun
No abstract is available for this record.
Vincenzo Marino
No abstract is available for this record.
Reachsak Ly, Alireza Shojaei, Xinghua Gao, Philip Agee · 5 authors
While traditional AI and data-driven facilities management approaches have improved building operational efficiency, they remain constrained by centralized organizational structures that are vulnerable to cyber attacks, limited contextual understanding, and decision-making processes that exclude key stakeholders from governance. This paper introduces a novel AI- and data-driven distributed governance framework for smart building management that integrates decentralized autonomous organizations (DAOs), digital twins, large language models (LLMs), and blockchain technology. The framework enables transparent collective decision-making through a DAO governance platform, implements data-driven management using IoT and digital twins, incorporates LLM-based virtual assistants for enhanced decision support, and utilizes blockchain for secure building automation. A full-stack decentralized application was developed to facilitate user interaction with these integrated components. The system was evaluated for cost efficiency, scalability, data security, and usability using the System Usability Scale (SUS). Expert interviews were also conducted to assess its practical benefits and implementation challenges.
tony hu
No abstract is available for this record.
Alex Chen
No abstract is available for this record.
Nuha Omran Abokhdair, Ali Alissawi Ahmed AlQudairi
Decentralized storage networks increasingly rely on blockchain-based verification to ensure data integrity without centralized control; however, proof-intensive workloads introduce significant latency and on-chain cost overhead. This paper presents a lifecycle-based comparative analysis of major zero-knowledge proof (ZKP) models used in decentralized storage, focusing on zk-SNARK frameworks and transparent zk-STARK constructions. A multi-layer evaluation framework is introduced, aligning performance analysis with the core stages of the proof lifecycle: generation, aggregation, and on-chain verification. Building on this analysis, the paper proposes a hybrid architecture that combines parallel STARK-based proof generation with recursive SNARK-based compression, reducing on-chain verification complexity to near-constant. A Filecoin-inspired case study, supported by a quasi-empirical performance model, demonstrates that the proposed hybrid approach significantly reduces verification latency and data overhead while mitigating the linear growth of verification costs. The results indicate that hybrid ZKP architectures offer a scalable and economically viable solution for decentralized storage systems and large-scale blockchain networks. Keywords: Zero-knowledge proofs, zk-SNARKs, zk-STARKs, recursive aggregation, decentralized storage, verifiable cryptography, scalability, gas cost.
Zhanwen Chen, Yannan Li, Willy Susilo
Long-range attacks pose a significant threat to the integrity of Proof-of-Stake (PoS) blockchains by enabling adversaries to reconstruct an alternative chain history embedded with fraudulent transactions. These attacks can deceive honest participants into accepting a maliciously crafted branch as the canonical chain. While Key Evolving Signature (KES) schemes are widely adopted to mitigate such threats, they typically rely on the assumption that validators behave honestly. In this work, we challenge this assumption by demonstrating how a malicious validator can exploit inherent limitations in existing KES-based mechanisms to mount a successful long-range attack. To address this critical vulnerability, we introduce a novel cryptographic construction that combines one-time signatures with commitment schemes. Our approach imposes constraints on the signing capabilities of validators, thereby significantly reducing the feasibility of long-range attacks. We provide rigorous formal security proofs to substantiate the robustness of our scheme and conduct a comprehensive performance evaluation. The results show that our solution is both computationally and storage efficient, making it a practical and scalable defense mechanism for real-world PoS blockchain deployments.