This research examines 42 countries and investigates the relationship between geopolitical risk and global non-fungible token (NFT) investor attention. We use Google search volumes related to NFTs across different regions as a proxy for such attention. Our findings indicate that geopolitical risk positively impacts global NFT investor attention, suggesting that investors in countries with higher geopolitical risk may pay more attention to the NFT market. We further explore the effects across different NFT segments and find that geopolitical risk particularly influences investor attention in the metaverse segment. This positive nexus is further amplified during the Russia-Ukraine war and the COVID-19 pandemic.
Swati Sachan, Dale Fickett, Richard Buchinger, Theo Miller
Recent advances in error-corrected qubits have accelerated the timeline for practical quantum computing. It poses a threat to cryptographic primitives used to secure financial systems, government infrastructure, communication networks, and DeFi (Decentralized Finance) ecosystems. This paper introduces a post-quantum secure federated DeFi framework that enables inter-bank collaboration to improve the inclusivity of individuals underserved by local lenders due to limited financial histories. Multiple banks contribute encrypted information batches to a virtual server, where lattice-based Fully Homomorphic Encryption (FHE) enables end-to-end homomorphic computation. The server fuses local data-driven probabilistic assessments, expert beliefs, and verifiable evidence generated by the NASA-IBM Prithvi Geospatial Foundation Model (GFM), in encrypted format. Decentralized technologies are employed to ensure tamper-proof evidence and auditable accountability for all encrypted data exchanges between institutions and the server. The framework is tested on agricultural lending decisions for rural borrowers in Virginia.
Deoxyribonucleic acid provides unmatched information density and longevity for data storage, yet its easy amplification by polymerase chain reaction enables unauthorized replication at negligible cost. We introduce ZAT-DNA, which encodes information in patterns of canonical adenine and noncanonical 2-aminoadenine. As DNA polymerases cannot distinguish adenine from 2-aminoadenine, polymerase-based amplification erases these patterns, enforcing molecular-layer non-replicability intrinsic to the base-pairing ambiguity. We validate ZAT-DNA for secure key storage, demonstrating error-free encoding, storage, and high-fidelity nanopore retrieval of 32-bit and 64-bit cryptographic keys. ZAT-DNA blocks polymerase-based copying and protects non-fungible tokens by preventing functional duplication. For larger datasets, we present a hybrid “Babel-DNA” architecture: multiple encrypted images are co-encoded in a single regular DNA pool, with each selectively decryptable only via its cognate, non-replicable ZAT-DNA key. This provides a practical framework for molecular access control, secure DNA-encoded databases, and scarce molecular tokens. ZAT-DNA encodes data in A/Z base patterns that PCR erases, ensuring molecular non-replicability. It enables secure 32/64-bit key storage and nanopore retrieval, blocks copying, and protects NFTs. The Babel-DNA hybrid allows selective access to multiple encrypted datasets from a single DNA pool using unique ZAT-DNA keys.
Open access
DNA and Biological Computing
Nanopore and Nanochannel Transport Studies
Physical Unclonable Functions (PUFs) and Hardware Security
This study develops a formally grounded verification framework for blockchain consensus mechanisms and smart contract behavior using Event-B and the Rodin platform. Unlike prior approaches that rely primarily on simulation or case-based validation of isolated contracts, this work integrates Finite State Machine (FSM) abstraction, invariant-driven proof, refinement modeling, and temporal logic verification to analyze Proof of Work (PoW), Proof of Stake (PoS), and mechanisms for double-spending prevention. Solidity smart contracts are abstracted into FSMs and encoded as Event-B machines, enabling the formal specification of state transitions and safety constraints. Safety properties-including transaction uniqueness, state consistency, access control enforcement, and ledger invariant preservation-are verified through automatically generated proof obligations in Rodin. A total of 312 proof obligations were generated, of which 287 (92%) were automatically discharged, and 25 were proven interactively, resulting in complete invariant coverage. Liveness properties were specified in Computation Tree Logic (CTL) and validated via model checking, confirming deadlock freedom and eventual validator selection under PoS conditions. Double-spending prevention was formally enforced using state-consistent ledger modeling, where uniqueness constraints were proven across all reachable states. Protocol-level consensus logic for PoW and PoS was refined across three abstraction levels, ensuring block integrity and validator correctness through stepwise refinement. The results demonstrate that machine-checked proofs provide verifiable correctness guarantees beyond simulation-based evaluation, establishing a rigorous and reproducible verification pipeline that enhances correctness assurance and protocol-level robustness in blockchain systems.
This paper introduces the Synchrony Layer, a shared context and coordination standard for AI-generated software. As AI makes it easy for anyone to generate apps, workflows, agents, and automations, software ecosystems risk becoming fragmented across schemas, permissions, APIs, dependencies, provenance, runtime behavior, and approval rules. The Synchrony Layer addresses this by turning generated code into structured Generated Software Objects with formal specs, schemas, permissions, validation rules, compatibility semantics, provenance records, update policies, and execution receipts. The paper presents STACY Sync as a reference implementation for web, mobile, backend, workflow, agentic, off-chain, and on-chain software systems. It also explains how blockchain and data-availability layers such as Avail, Celestia, and EigenDA/EigenLayer can support public shared context for marketplaces, agent ecosystems, Web3 applications, attestations, provenance, and auditable execution records. Core thesis:AI makes software abundant. Synchrony makes abundance usable.
Transaction selection in parallel or DAG-based distributed ledger technologies (DLTs) is a crucial challenge that directly impacts throughput, fairness, and validator incentives. In these systems, validators independently choose transactions to include in their blocks, often relying on naive heuristics like uniform or proportional selection. This can lead to inefficient outcomes when validators prioritize their own rewards without considering collective impacts. We analyze two fee allocation mechanisms used in practice: Random Fee Allocation (RFA), where transaction fees are randomly assigned to one validator, and Collaborative Fee Sharing (CFS), where fees are distributed equally among all validators. Using a single-shot game-theoretic framework, we derive symmetric Nash equilibria (NE) for selecting transactions for both mechanisms and propose an optimization-based method to compute these equilibria. Numerical simulations demonstrate that the NE of CFS consistently achieves higher throughput and rewards compared to the NE of RFA, particularly under skewed fee distributions. Additionally, we compare these equilibrium strategies to naive benchmarks (uniform and proportional selection), showing that the proportional strategy outperforms the NE of RSA in many situations. These findings may provide actionable insights into the design of transaction selection and incentive mechanisms, enabling more robust and high-performance DAG-based DLTs.
Sulyab Thottungal Valapu, John Heidemann, Mattijs Jonker, Raffaele Sommese
DNS integrations leverage the discovery, trust, and uniqueness of the global Domain Name System with a linkage to another naming ecosystem, so the DNS name can help identify resources such as a cryptocurrency wallet or software component. While DNS ownership is verified at linkage creation, many ecosystems do not track subsequent DNS changes. The result is zombie linkages, where the DNS ownership has expired or changed, but the mapping to the linked resource persists. We define a threat model for DNS integrations, identifying five classes of attacks that leverage or exploit zombie linkages. We measure zombie occurrence across three DNS integrations -- Web PKI; ENS, a blockchain naming system; and Maven Central, a Java software repository. We show that zombies exist in every ecosystem, but at very different fractions -- zombies make up roughly 3% of TLS certificates for new domains, 24% of ENS on-chain imports, and 15% of Maven Central namespaces. We evaluate how integration design choices affect outcomes, with validate-once integrations (ENS on-chain, Maven Central) accumulating long-lasting zombies, linkages with expiration (Web PKI) limiting damage, while integrations that validate on every use (ENS gasless) are zombie-free by design. We look for specific attacks, finding attacks actively available for exploitation in both Web PKI and Maven Central. Finally, we recommend steps to reduce zombie occurrence.
Keir Finlow-Bates, Markus Jakobsson, Hossein Siadati
The transition to post-quantum cryptography in blockchain systems such as Bitcoin and Ethereum is often framed as a purely cryptographic problem. In practice, it also presents significant economic and infrastructural challenges: in globally replicated networks, increases in transaction size and verification cost are multiplied across all participating nodes. Existing post-quantum signature schemes, including lattice-based constructions such as CRYSTALS-Dilithium and stateless hash-based schemes such as SPHINCS+, introduce substantial increases in signature size. At blockchain scale, these increases translate into higher storage, bandwidth, and validation requirements, potentially requiring multiple generations of hardware improvement to become operationally routine. Historical experience suggests that even moderate increases in data footprint can be contentious, as illustrated by the Bitcoin block size debates (2015--2017). We propose a hash-based commit--reveal construction that replaces a single signature-bearing transaction with two lightweight transactions, each containing a fixed-size (32-byte) hash output derived from well-established primitives such as SHA-256, BLAKE, or Keccak. This approach achieves post-quantum security under standard hash assumptions while increasing the effective transaction footprint by only approximately 1.5$\times$ to 2$\times$ per authorization event. These results indicate that practical post-quantum migration may benefit from rethinking transaction semantics rather than directly adopting larger signature schemes, and that viable designs for decentralized systems must account for system-wide cost amplification.
Maryam Bahrani, Michael Neuder, S. Matthew Weinberg
An emerging blockchain protocol design pattern leverages the asymmetry between the computational effort in performing versus verifying tasks. For example, cryptographic validity proofs (e.g., SNARKS) require the prover to expend significant effort demonstrating the correctness of their claim, while the verifiers benefit from extremely easy validation. The operationalization of this paradigm requires efficiently soliciting the performance of expensive tasks in pseudonymous, adversarial environments. We formalize this as a mechanism design question. The protocol balances the economic cost of a liveness fault, where the work is not completed, with the payments required to incentivize specific behavior from candidate suppliers. We show that the loss of the optimal protocol scales logarithmically in the cost of a liveness fault, scaled up by the adversarial fraction of the network. Further, we find that the optimal equilibria have an intuitive structure, allowing us to provide concrete advice to practitioners. Specifically, in many regimes, the optimum designates a single, random node as the primary worker and a committee as a fallback, which is reminiscent of leader-based consensus mechanisms. We also characterize the asymptotic regimes where having negative payments (i.e., slashing in blockchain parlance) is especially helpful.
Este artigo apresenta uma análise comparativa de desempenho entre rollups otimistas e execução nativa em Ethereum Virtual Machine (EVM). O estudo investiga as diferenças em termos de custo de gás, avaliando o impacto das soluções de Layer 2 na escalabilidade da blockchain Ethereum. Os resultados experimentais fornecem insights sobre os trade-offs entre execução on-chain tradicional e rollups otimistas, contribuindo para a compreensão das estratégias de escalabilidade em ambientes blockchain.
The growth of crypto-asset markets and the rise of environmental, social, and governance (ESG) investing reflect two significant transformations at the intersection of technology and finance. While crypto markets are driven by decentralized digital innovation, ESG investment is shaped by societal demands for sustainable capital allocation. This study examines how participation in a high-risk technology-driven market, such as crypto-assets, is associated with sustainability-oriented investment preferences through the development of both financial and digital finance skills. Using survey data collected in February 2024 in Thailand, a country characterized by strong policy support for ESG investment products and rapid crypto adoption, we employed partial least squares structural equation modeling (PLS-SEM) to test a sequential mediation model. The results reveal that crypto-asset ownership is positively associated with financial literacy, which in turn enhances digital financial literacy, leading to stronger ESG investment preferences. The study's findings highlight how technology-enabled financial engagement can foster the skills required for responsible investing, suggesting that digital finance participation and sustainable investment promotion are interconnected pathways rather than separate domains. Policy implications include integrating digital capacity-building into ESG promotion and leveraging technologically engaged investors as a channel for advancing sustainability goals in capital markets.
This chapter provides further detail on decentralised finance (DeFi), smart contracts, and decentralised applications (dApp) forensics, focusing on Open Source Intelligence (OSINT) tools, transaction analysis, code analysis, stylometric analysis, and semantic analysis. It also introduces dApp ecosystem analysis.
Digital and Cyber Forensics
Blockchain Technology Applications and Security
Physical Unclonable Functions (PUFs) and Hardware Security
In this paper, we examine the patterns and determinants of cross-border cryptocurrency flows. While our analysis focuses primarily on Bitcoin flows, the cryptocurrency with the largest market capitalization, we show that our key results also extend to four major stablecoins. After documenting global patterns of cross-border Bitcoin flows and contrasting them with those of traditional capital flows, we employ a cross-country panel approach to identify the key drivers of cross-border crypto flows for up to 162 countries. Our results provide evidence for the presence of multiple coexisting motives. The most significant motives comprise strategies to adjust to unfavorable macro and financial developments, as well as the need to conduct international payment and remittance transfers. Moreover, by conducting a case study of cross-border Bitcoin flows after the COVID-19 shock, we find that these motives were particularly relevant at a time when economic conditions were weak and the need for remittances appeared high. Gaining a better understanding of the motives behind cross-border cryptocurrency transactions is crucial for informing the public debate on cryptocurrencies and their potential use cases.
This chapter provides a comprehensive exploration of alternative cryptocurrencies, commonly referred to as altcoins, within the context of digital forensic investigations. It begins by establishing a foundational understanding of what altcoins are, delineating them from Bitcoin, and classifying their various types based on technological features and use cases. The chapter then addresses the unique forensic challenges posed by altcoins, including privacy mechanisms, transaction obfuscation techniques, and decentralised architectures that hinder traceability. Subsequent sections outline a structured approach to the technical forensic processes specific to altcoin investigations, followed by real-world case studies that highlight investigative methodologies and outcomes. The chapter concludes with an analysis of forensic tools tailored to altcoin environments and presents a practical forensic puzzle – The Zero-Taint Coin Challenge – to illustrate theoretical concepts through hands-on problem-solving. The overall objective is to equip forensic practitioners with the knowledge and tools necessary to navigate the complexities of altcoin-related investigations.
A non-custodial threshold instrument for Bitcoin would allow value to transfer between parties without network connectivity, fees, or custodial dependency. Digital signatures and multisignature scripts provide part of the solution, but the core benefit is lost if the issuer retains a key capable of unilateral redemption. All prior multisignature schemes have positioned the issuer at or above the spending threshold. We propose a system that inverts this: the holder receives the two keys constituting the spending threshold of a 2-of-3 multisignature script, and the issuer holds one key arithmetically below it.
Distributed ledger technology (DLT) has emerged as a transformative force in decentralized data management across e-transactions, with significant applications in the banking, finance, supply chain, and trade sectors. Recognizing its potential, governments, including Estonia and India, have implemented DLT-based e-services to enhance transparency and privacy in public administration. With numerous platforms arising/available in the DLT segment, such as Hyperledger, Ethereum, Corda, Ripple, Stellar, Dragonchain, IOTA, and Hedera, understanding interoperability mechanisms across heterogeneous platforms has become critical. This comprehensive research provides a systematic analysis of distributed ledger technology fundamentals, consensus mechanisms, smart contracts, and their applications in e-governance services. The study examines leading DLT platforms and their core features, with a specific focus on interoperability capabilities essential for seamless cross-platform integration. Through analysis of existing interoperability solutions, including trade finance platforms, central bank digital currency initiatives, and e-governance implementations, this work identifies critical challenges and evaluation criteria for DLT adoption. The research addresses three primary research questions: (1) what capabilities does DLT provide for implementing effective e-governance strategies? (2) How does interoperability influence the delivery and effectiveness of various e-governance services? (3) What is the current impact and growth trajectory of existing e-governance services providing interoperability capabilities? The primary contributions include systematic exploration of interoperability mechanisms in various DLT platforms, documentation of existing implementations across multiple countries, including Estonia, the European Union, Dubai, and India, identification of technical challenges and security considerations, and development of a future roadmap for DLT-influenced e-governance systems. The research demonstrates that effective interoperability, combined with emerging technologies such as artificial intelligence and quantum-resistant cryptography, can enable citizen-centric, transparent, and secure governance systems while maintaining regulatory compliance and data privacy.
Sixth-generation (6G) networks are expected to provide ubiquitous connectivity, AI-native orchestration, and seamless integration across terrestrial and non-terrestrial infrastructures. However, these capabilities introduce new privacy challenges related to the classification and protection of personal, quasi-personal, and non-personal data in complex data-driven environments. This paper presents a systematic review of 78 peer-reviewed studies published between 2019 and 2025. Following a PRISMA-based methodology, this review analyzes privacy-enhancing technologies (PETs), regulatory compliance frameworks, and architectural patterns for privacy preservation in 6G networks. The findings show that differential privacy (DP) and federated learning (FL) dominate current research, accounting for nearly 52% of the reviewed studies. Blockchain auditing and zero-knowledge proofs (ZKPs) collectively represent approximately 30%, while the remaining mechanisms, including physical-layer security (PLS), trusted execution environments (TEEs), homomorphic encryption (HE), secure multi-party computation (SMPC), and anonymization, account for roughly 18%. These mechanisms exhibit varying levels of privacy strength, utility preservation, latency, and energy cost. At the same time, evolving regulatory frameworks, including GDPR, PDPL, CCPA/CPRA, LGPD, and PIPL, increasingly extend privacy obligations to quasi-personal and aggregated data. Building on these findings, this paper proposes a unified taxonomy that clarifies the boundary between personal and non-personal data. It also provides a cross-layer mapping between PETs and compliance requirements across the Core/SBA, RAN, Edge/MEC, and NTN layers. Finally, this paper presents a forward-looking roadmap for 2025–2030, highlighting hybrid PET pipelines, post-quantum auditability, and AI-driven compliance automation as key directions for privacy-preserving 6G standardization.
This chapter explores the use of on-chain and off-chain tools for cryptocurrency investigations, including Maltego, SpiderFoot, and i2 Analyst&s;s Notebook. It also covers the application of machine learning, AI , and data science, as well as network analysis tools, in crypto investigations. The chapter concludes with a discussion of cryptocurrency crime scene investigation.
Polynomial multiplication serves as a fundamental computational primitive in modern cryptography–including fully homomorphic encryption and zero-knowledge proofs –as well as in digital signal processing. Its performance optimization has become increasingly critical amid the rapid development of privacy-preserving computation and blockchain technologies. To address the limitations of traditional algorithms in meeting the demands for high throughput and low latency, this study proposes a high-performance polynomial multiplication accelerator based on the collaborative optimization of GPU-NTT and the Karatsuba algorithm. The method deeply integrates the asymptotically optimal complexity of NTT with the constant-factor efficiency of Karatsuba at moderate scales, and fully exploits the parallel computing power of GPUs to construct a modular, multi-stage pipelined acceleration framework. The divide-and-conquer nature of the Karatsuba algorithm is leveraged for coarse-grained parallelism, splitting large polynomial multiplications into subproblems handled by GPU thread blocks in parallel, while each subproblem is solved with fine-grained parallelism using GPU-accelerated NTT kernels. An innovative zero-padding strategy is introduced to enhance the generality of the NTT kernels, and shared memory caching is employed to alleviate GPU memory bandwidth bottlenecks. Experimental results on the NVIDIA RTX 4060 GPU demonstrate that the proposed method achieves a stable speedup of 1.43 \(\times \) to 1.49 \(\times \) over the baseline GPU-NTT for lower-dimensional polynomials, and outperforms the KNTT algorithm by up to 2.44 \(\times \) for higher dimensions (e.g., \(\log _2 n = 14\) ), showing superior scalability and robustness. Kernel execution time analysis further confirms that the method benefits from efficient kernel fusion and balanced workload distribution, which effectively avoids pipeline stalls and ensures high-throughput execution. This research provides a significant performance optimization solution for the practical deployment of advanced cryptographic technologies such as FHE and ZKP.
The Author states that Nakamoto combined several prior inventions such as b-money and HashCash to create a completely decentralized electronic cash system that does not rely on a central authority for currency issuance or settlement and validation of transactions.The key innovation was to use a distributed computation system (called a 'proof-of-work' algorithm) to conduct a global 'election' every 10 minutes, allowing the decentralized network to arrive at consensus about the state of transactions.This elegantly solves the issue of double-spend where a single currency unit can be spent twice.Previously, the double-spend problem was a weakness of digital currency and was addressed II The Technology behind BlockchainTo better capture the implications of blockchain applications, it is of utmost importance to start with an understanding of the technology that underpins distributed ledger technology ('DLT') (para.I.A), followed by the key features of blockchain (para.I.B). I.A Distributed Ledger TechnologyGiven the definition of a ledger as an information store that keeps final, definitive, and immutable records of transactions 40 , a distributed ledger is a type of ledger that is shared, replicated, and synchronised in a distributed and decentralised manner 41 .
Matteo Aquilina, Giulio Cornelli, Jon Frost, Leonardo Gambacorta
Cryptocurrencies and decentralised finance (DeFi) aim to replicate many of the economic functions of traditional finance (TradFi), but their distinctive features introduce new financial stability risks. We analyse these features, and examine key developments, such as smart contracts, decentralised exchanges (DEXs), stablecoins and new forms of central bank money. Our findings suggest that while the underlying economic drivers are not different than in TradFi, DeFi poses significant challenges, including new forms of information asymmetries, market inefficiencies and the risk of cryptoisation in emerging markets. We propose tailored regulatory interventions, such as embedding rules within smart contracts and strengthening the oversight of stablecoins, to manage financial stability risks. Finally, we provide a framework for prudential regulation that can mitigate risks while fostering innovation in the rapidly evolving crypto ecosystem.
My technical work and my STS research are both fundamentally centered on the advancement of modern flight systems, though they approach the field from distinct perspectives. While my technical project focuses on the engineering requirements, mechanical design, and integration of a hypersonic reentry vehicle to achieve mission success, my STS research examines the need for transparency and risk assessment in these complex technologies. This research explores the moral failings in the design of active flight-control software and how a lack of professional virtue can lead to catastrophic failures in aviation. So, while my technical work and my STS research approach flight systems from different angles, one through the lens of mechanical reliability and the other through the lens of ethical oversight, the theme of advancing safety and accountability in aerospace engineering is consistent across both projects. My technical work explores the design of the Hypersonic ReEntry Deployable Glider Experiment (HEDGE-2). HEDGE-2 is a deployable flight vehicle designed as proof of concept for low-cost hypersonic test vehicles capable of collecting aerothermal data at hypersonic speeds during atmospheric reentry. As the Structures and Integration Lead and Deputy Project Manager, I focused on designing and building a hypersonic test vehicle. Additionally, I designed the deployment mechanism to eject the vehicle from within a NASA RockSat sounding rocket to an aerodynamically stable reentry flight state. The goal of the project was to successfully survive the high-G launch environment, suborbital space and atmospheric reentry conditions to reenter Earth’s atmosphere at Mach 5+ speeds, while transmitting data to our ground station. My STS research also explores flight systems but through a normative ethical lens. My research focuses on the Boeing 737 MAX crashes and investigates the systemic failure of the organization to practice core professional virtues. I employ virtue ethics as a conceptual framework to argue that the disasters resulted from a deficiency in prudence, honesty, and moral courage among the project's key actors. My claim is that Boeing’s internal culture prioritized commercial interests, specifically the "Common Type Rating" and schedule adherence, over the ethical requirements of engineering integrity. By misclassifying the risks of the Maneuvering Characteristics Augmentation System (MCAS) and withholding technical details from pilots, the organization failed to uphold its duty to public safety. Working on these two projects simultaneously added significant value to my development as an engineer. My technical work on HEDGE-2 provided me with a grounded understanding of how small design decisions, such as sensor placement or mass distribution, dictate the safety and stability of a high-speed vehicle. This technical context enriched my STS research by allowing me to evaluate Boeing’s "single-point-of-failure" design through a more critical and practiced lens. Conversely, my research into virtue ethics prompted me to reflect on my own responsibilities as a lead for a NASA-supported project. It reinforced the importance of technical honesty when mission-critical safety is at stake. In summary, these projects together have provided a holistic view of aerospace engineering where technical precision must be balanced by an unwavering commitment to professional ethics.