Blockchain Papers

Steffen Kroschwald, Thomas Schuster, Zina Al-Washash, Annalena Secci · 7 authors

No abstract is available for this record.

Vivi Indah Bintari, Deasy Lestary Kusnandar, Risna Amalia Hamzah

This study aims to compare the investment performance of Decentralized Finance (DeFi), equities (IHSG), and gold during the 2021–2024 period, which represents a full market cycle characterized by high volatility and economic uncertainty. The research objective is to evaluate differences in return, risk (volatility), risk adjusted performance, and inter asset correlations to assess portfolio diversification potential. A quantitative comparative approach is employed using monthly secondary data, analyzed through descriptive statistics, non-parametric difference tests, and correlation analysis. The findings indicate statistically significant differences among the three investment instruments. Gold demonstrates the highest risk efficiency and consistently performs as a safe haven asset. Equities show moderate stability but relatively lower risk adjusted performance. In contrast, DeFi records the highest average returns, accompanied by extreme volatility and low efficiency. Correlation results reveal a strong positive relationship between gold and equities, while DeFi exhibits significant negative correlations with both assets, indicating diversification potential despite elevated systemic risk. This study concludes that gold remains the most resilient investment asset, equities serve as a balanced growth instrument, and DeFi should be positioned as a high risk speculative asset rather than a core portfolio component.

Zhi Kang

Aiming at the single point of failure, performance bottleneck and compliance challenge caused by the current international trade settlement system relying on centralized systems such as SWIFT, this paper proposes and implements an automatic control system for trade settlement based on smart contracts. Research and build a high-performance settlement infrastructure supporting multi-currency and multi-scenarios, achieve scalability and interoperability through hierarchical modular architecture, innovatively integrate the hybrid consensus mechanism of immediate certainty of PBFT and energy-saving advantages of PoS, and introduce a dynamic weight adjustment algorithm based on pledge amount and historical reputation to improve system robustness. Intelligent contract adopts hierarchical design, which separates the unmodifiable basic contract layer from the scalable application contract layer, taking into account the security and business flexibility of core settlement logic; At the same time, the observer node is embedded to achieve "penetrating" supervision, and the combination of zero knowledge proof and offline storage scheme meets the requirements of data sovereignty laws and regulations such as GDPR. In terms of performance optimization, cross-chain asset mapping and real-time exchange rate settlement are realized through fragmentation technology, state channel and Oracle network, so that the peak throughput of the system reaches 1000+ TPS. The test results show that the throughput of hybrid consensus is increased by 96.4% to 550 TPS compared with pure PBFT in the 50-node alliance chain environment, and the average delay is about 2s. The effectiveness and reliability of hybrid consensus in high concurrency, fault tolerance and regulatory compliance scenarios are successfully verified, which provides key technical support for the next generation of global digital trade infrastructure.

Paweł Czaplicki

Abstract This article addresses the issue of e-voting in commercial companies in Poland from the perspective of the company’s shareholders. It presents this issue as an example of digital democracy and discusses the associated challenges and opportunities. The article is based on the dogmatic-legal and the comparative-legal methods. The main aim is to examine whether regulations regarding e-voting by shareholders on the resolutions of commercial companies in Poland have improved the conduct of shareholder voting or have established barriers that complicate this process. The second research issue is an attempt to answer the question of whether regulations introduced by the Polish legislature enable the use of modern technologies for conducting voting, including systems based on distributed ledger technology and virtual worlds. The research allowed for the formulation of the following research theses: firstly, the regulations contained in the Polish Commercial Companies Code allow for the widespread use of electronic voting methods by shareholders when resolutions are adopted. However, they are not available in all commercial companies, nor to the same extent. Secondly, voting using methods based on distributed ledger technology is also permissible. However, voting at a meeting cannot be conducted solely virtually. The conclusions include proposals for clarification of the legal provisions in this area, which will enable more effective use of e-voting in commercial companies in Poland.

D. Hema Lakshmi, B. Prem Sai Siddhik, B. Akhil Kumar, Ch. Siva Venkata Sai Tharun · 5 authors

Resumes are a key part of traditional hiring, but when human reviewers may not accurately identify the true skills of candidates. Sometimes, when checks are done, fraudulent credentials may pass undetected due to limitations in manual verification. A new method is presented here that uses smart algorithms in a distributed ledger system. By connecting machine learning with secure data records, trust in verifying applicants grows a lot. The proposed system improves efficiency by reducing reliance on traditional keyword-based filtering. The software uses natural language tools to look at the applicant's information, extracts relevant skills and generates a performance score for each candidate. Cryptographic hashes of credentials are stored on a distributed ledger, ensuring that validation cannot be altered or hacked. An online model was created using ReactJS, Flask, MongoDB, and connections to the Ethereum Blockchain. The results show that the method automatically sorts job applicants, quickly checks their documents, and consistently finds qualified people in different fields. Combining smart algorithms with decentralised records increases trust, cuts down on manual tasks, and brings more clarity to the hiring process.

Luqi Wang, Wenbao Jiang, Linkun Sun

• The STipChain+ system employs a combination of cryptographic accumulators and verifiable computing techniques to create a stateless blockchain for smart contracts. This system offers a solution for the use of blockchain in big data scenarios. • A new hierarchical group commitment scheme for smart contracts based on the RSA cryptographic accumulator has been developed with the objective of reducing the storage overhead of contract evidence in the system by 99 • Design a composite RSA accumulator scheme for decentralised SGX Remote Attestation under stateless conditions. This scheme should transfer the trust in Intel to the trust in the group of nodes on the chain, and accumulate the certificate information through cryptographic accumulator technology. This should reduce the burden of storage on the system and reduce the dependence on a single organisation. • The experimental results demonstrate that, while maintaining decentralisation and security, STipChain+ can significantly reduce the storage pressure on consensus nodes, thereby enhancing system throughput. Blockchain is regarded as one of the most transformative and innovative technological developments of recent times, due to its decentralised nature. Nevertheless, the majority of public chains are currently grappling with the challenge of exponential data growth within the block chain system, largely due to the presence of high levels of data redundancy, which is resulting in a significant consumption of node storage resources. However, the scheme is subject to several limitations, including the storage overhead associated with contract evidence under the conditions of extensive smart contracts and the necessity of placing trust in the central node for the purpose of verifying smart contracts. The objective of this paper is to propose a new stateless blockchain architecture, designated as STipChain+. The STipChain+ system enables the real-time computation of contract evidence and the completion of the execution and verification of smart contracts without compromising the decentralization of the blockchain. The layered grouping design of smart contracts enables the reduction of the data involved in generating contract evidence, thus resolving the shortcomings of the existing stateless blockchain scheme, which necessitates the pre-calculation of evidence and its subsequent update in a sequential manner. Furthermore, the storage of substantial amounts of evidence is also alleviated. In addition, the issue of the trusted third party when verifying smart contracts is further addressed by proposing a composite RSA accumulator certificate commitment scheme with a new smart contract execution logic and transaction verification method. The results of experimental studies indicate that STipChain+ reduces the storage requirements for state data by 99% in comparison to existing blockchain storage optimisation schemes. This is achieved without the introduction of third-party trusted entities, and the reduction in storage requirements can be verified in a fixed amount of time for any smart contract.

Grigoriy Korolev

No abstract is available for this record.

Ayumi Ohno, Kotaro Shimamura, Shinya Takamaeda-Yamazaki

Multi-Scalar Multiplication (MSM) is a primary computational bottleneck in modern cryptographic applications, especially zero-knowledge proofs. The Pippenger algorithm parallelizes MSM by decomposing it into numerous elliptic curve point additions (PADDs), but accelerating these operations on novel hardware like the Versal ACAP presents a significant challenge. This work explores the acceleration of PADDs on the Versal ACAP’s spatial array of 400 AI Engines (AIEs). While the SIMD-VLIW architecture of AIEs is ideal for the multiplication-heavy workloads in PADD, the complex 377-bit modular arithmetic, particularly carry propagation, demands architecture-aware optimization. We propose two key contributions: (1) algorithmic optimizations for carry propagation employing a carry-save-like technique to exploit VLIW and SIMD capabilities, and (2) a comparison of spatial mapping strategies and modular reduction algorithms to enhance intra- and intertask parallelism. Our approach achieves 567× speedup over the integrated CPU on the AIE evaluation board, utilizing 51.1% of the theoretical memory bandwidth.

Min Ho Jung

Recently, there has been a significant discourse in the AI community regarding "Hierarchical Reasoning LLMs," which attempt to categorize and optimize probabilistic generation tasks to reduce computational overhead. While such hierarchical inference structures optimize generation speed and coherence, they fundamentally fail to resolve the core structural crises of modern Generative AI: inevitable hallucination and extreme structural energy consumption (GPU lock-in). This paper introduces the "Hierarchical Stateless Key Generation" (HSKG) and the Mersenne Stateless Architecture, challenging the premise of neural network 'reasoning.' Instead of storing data within 820GB of neural weights and using probabilistic matrix multiplication, HSKG mathematically maps 'Absolute Truth' data into a 4096-dimensional Mersenne Prime Lattice. During query resolution, the system simply retrieves a 4KB Phase Coordinate and instantaneously materializes the data in RAM, only to vaporize it when the session terminates. By abandoning the "search and compute" paradigm for "coordinate retrieval," HSKG enforces a mathematical 0% hallucination rate, 0-byte persistent storage, and sub-0.01% GPU utilization, establishing a definitive paradigm for enterprise Zero-Trust knowledge systems. This paper explicitly defines the term "Hierarchical Stateless" to contrast with the probabilistic "Hierarchical Reasoning" of contemporary LLMs, establishing a rigorous mathematical protocol for deterministic, zero-hallucination data materialization without persistent models or physical data transfer. * Version 2.0 Update: Added section 7.A (Empirical Validation via DevTools: The 0-Byte Payload Proof). [Version 4.0 Update (Mar 2, 2026)] Formally established the "Four-Pillar Verification Metrics" table to empirically prove the 0-Byte Payload and Minimum Kolmogorov Descriptive Length. Inserted Section VIII: Disrupting Existing Paradigms (Architectural Supremacy Matrix), demonstrating the superiority over FIDO2/WebAuthn and Zero-Knowledge Proofs (ZKP). Included Supplementary Material: Independent 3rd-Party Forensic Audit Report by Claude 4.6 verifying 100% Stateless Zero-Payload execution.

Aatu Isopahkala

Our main technical contribution is Observation Algebra Relativity (Theorem 2): a metatheorem formalising that security and robustness predicates are indexed to observation algebras and do not transfer across algebra boundaries. As an application framework, we present the Access Collapse Theorem: a typed structural result showing that direct operational access to the complete state of any system — physical, formal, or social — necessarily collapses at least one of two invariants: operational separateness (d) or scale separation (s). When either invariant reaches zero the access operation does not become inaccurate — it becomes a type error: the predicate is no longer typed to the system being operated. The framework is applied to six instantiations: Planck-scale measurement, zero-knowledge proofs, side-channel attacks, multi-party computation, adversarial explainability, and machine learning model extraction. A Non-Universality Proposition explicitly bounds the framework's scope. A Collapse Diagnostic provides a practical checklist for identifying collapse boundaries in concrete systems. A practical application framework building on this theoretical work is presented in:Isopahkala (2026) – Epistemic Hygiene in Practice.

Jauhar Abbas, Syed Shameel Ahmed Quadri, Adeel Ansari, Seema Ansari

This study examined the impact of blockchain integration on supply chain finance (SCF) performance, transparency, and trust. With traditional SCF systems facing challenges such as delayed payments, information asymmetry, and transaction inefficiencies, blockchain technology offers decentralized, immutable, and real-time data sharing capabilities to enhance financial operations. A quantitative cross-sectional research design was employed, and data were collected from 312 professionals working in manufacturing, retail, and logistics sectors. Descriptive analysis, exploratory factor analysis, and structural equation modeling (SEM) were applied to assess relationships among blockchain adoption, SCF performance, transparency, and trust. Results indicated that blockchain adoption significantly improved SCF performance (mean = 4.08), transaction verification speed (mean = 4.02), and cost efficiency (mean = 3.95). Transparency increased as stakeholders accessed real-time and verifiable financial data (mean = 4.05), while trust among supply chain partners was strengthened (mean = 4.04) due to the system’s immutable and auditable records. These findings demonstrated that blockchain acts as a strategic enabler for enhancing operational efficiency, information sharing, and stakeholder confidence in SCF operations. The study contributes to theory and practice by providing empirical evidence of blockchain’s role in fostering performance and relational benefits in supply chains. Recommendations include strategic blockchain implementation, employee training, governance alignment, and continuous monitoring of performance metrics. Future research could explore cross-border adoption, integration with emerging technologies, and long-term impacts across different industries.

Kyung-Shick Choi, Mohamed Chawki, Subhajit Basu

Sextortion has rapidly expanded into a global cyber-enabled crime that leverages anonymous digital communication and decentralized payment systems. This study examines the financial infrastructures underlying contemporary sextortion by conducting a two-phase analysis of 87 confirmed cases involving cryptocurrency payments. Using blockchain forensic tools and open-source intelligence, the research traces fund movements across perpetrator-controlled wallets, identifies laundering techniques such as mixers, peel-chain transfers, and exchange-based cash-outs, and links these behaviors to narrative patterns within victim reports. The results reveal a dual-tier ecosystem in which mass-produced, multilingual extortion scripts coexist with divergent laundering typologies that differentiate lower-value, high-volume scams from more organized and higher-yield operations. By integrating qualitative and quantitative evidence, this study provides a forensic framework for detecting illicit cryptocurrency activity, improving threat classification, and strengthening investigative and regulatory responses to sextortion and related crypto-enabled interpersonal crimes.

Atul Kotwal, Tarannum Ahmed

BACKGROUND India’s health systems reform journey has been marked by institutional innovations that have reshaped service delivery, governance, financing, and beyond. Among these, a foundational yet often overlooked innovation is the creation of a structured ecosystem for health policy guidance: a network of State Health Systems Resource Centres (SHSRCs), supported by the National Health Systems Resource Centre (NHSRC). These institutions were not intended as parallel implementation units. Rather, they were envisioned as embedded policy advisory bodies that are intended to synthesize evidence, support strategic planning, and enable system-wide reforms. While NHSRC continues to serve as the apex technical institution supporting the Ministry of Health and Family Welfare (MoHFW), the SHSRCs were designed to play a decentralized and synergistic role within states. However, they remain variably recognized and underutilized. Unlocking their full potential could substantially enhance the capacity for state-level, evidence-informed decision-making and strategic design. AN INSTITUTIONAL DESIGN WITH PURPOSE Established in 2007, NHSRC functions as the principal technical support agency for MoHFW, with a mandate that includes policy and strategy development, technical assistance to states, and capacity building under the National Health Mission (NHM). Over time, it has played a pivotal role in institutionalizing quality improvement processes, advancing health financing reforms, guiding human resource strategies, strengthening secondary care and governance, innovations in community processes, and improved primary health care. Its enhanced role over the past 5 years, particularly through expanded expertise in evidence generation, implementation research, and the information technology realm, has been well appreciated and acknowledged. The SHSRCs, supported under the NHM and guided by NHSRC, were first envisioned under the National Rural Health Mission as in-house technical institutions to support health systems strengthening and policy development, particularly in the Empowered Action Group states.[1] However, their formation varies widely. Maharashtra and Madhya Pradesh, for instance, have established autonomous SHSRCs with independent governance and operational flexibility. Others, like Kerala, have adopted a fully embedded model within the state health department, with no legal autonomy but strong proximity to decision-making. Gujarat has adopted a hybrid approach, combining knowledge management cells, technical support functions, and programmatic units aligned with NHM priorities. In Chhattisgarh, the model transitioned from a registered society to an outsourced public–private partnership structure. Newer entrants like Meghalaya illustrate growing development partner involvement in SHSRC functions through philanthropic support. In the absence of a unified design, this diversity has led to fragmentation in roles, mandates, and institutional identity. To address this, the MoHFW released a national SHSRC Framework in 2024, formalizing key principles of governance, technical leadership, and accountability.[2] The framework aims to guide states in repositioning SHSRCs as embedded policy support institutions that are context-specific yet aligned with national health priorities. AN UNEVEN LANDSCAPE OF UTILIZATION Despite the clarity of this institutional design, the operational landscape of SHSRCs across India remains uneven. While some centers have emerged as credible partners to their state governments, others face challenges ranging from intermittent staffing and fragmented mandates to unclear positioning within state bureaucracies. In several instances, donor-funded Technical Support Units (TSUs) have taken on overlapping roles. These arrangements may address immediate programmatic needs but often lack the institutional continuity, embedded authority, and public accountability required for long-term reform.[3] Overreliance on donor-funded TSUs risks fragmenting institutional ownership and accountability, weakening the state’s own capacity to generate and use evidence for policy guidance. Recognizing these risks, NHSRC has begun working with state governments to revitalize SHSRCs and help align them with national and state-level priorities, while safeguarding their role as government-owned and state-anchored policy advisory bodies. EARLY EVIDENCE OF WHAT WORKS Where SHSRCs have been clearly institutionalized, their contributions to health policy and systems strengthening are evident. In Chhattisgarh, SHSRC was central to the design and implementation of the Mitanin program, which later became the foundation for the national ASHA model. Its positioning as a public, in-house technical agency enabled long-term continuity, responsiveness to state-specific challenges, and innovation uptake.[4] In Odisha, the SHSRC has supported district health planning, capacity building, and institutional development initiatives across program areas. In Tamil Nadu, it has supported quality assurance mechanisms and monitoring systems within the health department. These cases suggest that, when adequately structured and supported, SHSRCs can serve as trusted intermediaries that connect evidence, program strategy, and systemic reform. STRENGTHENING SHSRCS FOR HEALTH POLICY GUIDANCE For SHSRCs to fulfil their intended role as policy advisory institutions, four strategic actions are necessary. First, states must clearly define the mandate and governance of SHSRCs based on the MoHFW’s framework. This includes formalizing their distinct identity from TSUs, clarifying reporting structures, and embedding them within state health departments with a long-term vision. Second, sustainable financing should be assured through NHM provisions to reduce dependence on external actors. While TSUs may continue to serve specialized programmatic functions, they should not be equated as substitutes for in-house capacity. Third, investment in technical leadership and multidisciplinary staffing is essential. SHSRCs must attract professionals across epidemiology, public finance, implementation research, health systems, and data analytics. These are all disciplines critical to robust policy guidance. Establishing leadership structures that ensure continuity and accountability will further enhance operational coherence and effectiveness. Fourth, SHSRCs should continually expand their engagement with emerging health system interventions and institutionalize mechanisms. This includes supporting research, evaluation, and evidence-based decision-making. Their potential as platforms for resource optimization and collaboration with academic and public health institutions remains significantly underleveraged. NHSRC, through its existing mandate, can continue to play a catalytic role in this transformation by facilitating peer learning, technical handholding, and capacity strengthening. A STRATEGIC ASSET FOR THE NEXT PHASE OF REFORM As India deepens its health system reforms through initiatives such as Ayushman Bharat, and ongoing programme interventions under NHM, the need for decentralized, embedded policy guidance becomes more urgent. SHSRCs are already positioned to fulfil this role, not as supplementary structures but as enduring public institutions grounded in local systems and aligned with national goals. The imperative now is not to create new structures but to recognize and invest in the institutional capacities already in place. Authors’ contributions Maj. Gen. (Prof) Dr Atul Kotwal: Conceptualization; Writing – Original Draft, Writing – Review and Editing; Supervision. Dr Tarannum Ahmed: Conceptualization; Writing – Original Draft, Writing – Review and Editing. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest to declare.

Ghali Ahmad, Md Shafiullah, Mohammad A. Abido, Faris Aljehani

No abstract is available for this record.

Nishant Sapra, Imlak Shaikh, David Roubaud

No abstract is available for this record.

Valentin Mullet, Patrick Sondi, Eric Ramat, Mariem Belhor

No abstract is available for this record.

Zongke Bao, Qianqian Fu, Chengfang Wang, Yanshai Yashu

This study examines how fiscal governance structures influence corporate environmental performance by exploiting China’s 2003 tax delegation reform as a quasi-natural experiment. The reform transferred corporate income tax collection authority from locally-governed Local Tax Bureaus (LTBs) to centrally-managed State Tax Bureaus (STBs) based on a firm registration date cutoff of January 1, 2002. Using a Regression Discontinuity Design (RDD) with micro-level panel data from Chinese manufacturing firms (2004-2008), we identify the causal impact of tax administration assignment on firm-level energy efficiency, measured as output per unit of energy consumed. Our findings reveal that firms under LTB administration exhibit 8-12% higher energy efficiency compared to comparable firms under STB administration. This effect persists across multiple robustness checks, including alternative bandwidth specifications, placebo tests using unaffected firms, and alternative energy efficiency measures. Mechanism analysis demonstrates that the energy efficiency gains stem from three primary channels: (1) relaxed financial constraints enabling greater investment capacity, (2) transition toward cleaner energy sources with reduced coal dependency, and (3) increased adoption of energy-saving technologies and green innovation. These effects are particularly pronounced among financially constrained firms, non-exporters, and firms in regions with higher fiscal capacity or stronger environmental pressure. These results contribute to three strands of literature. First, they provide novel evidence that fiscal administrative structures—traditionally viewed as purely revenue instruments—can have substantial unintended environmental consequences. Second, they demonstrate how local fiscal flexibility may create conditions conducive to green technological upgrading by alleviating financial frictions. Third, they extend the Porter Hypothesis to the institutional level, showing that supportive governance arrangements can simultaneously enhance economic efficiency and environmental sustainability. The findings suggest that integrating environmental performance metrics into local tax administration evaluation frameworks could align fiscal incentives with sustainability objectives, offering a promising pathway for emerging economies to achieve coordinated economic and environmental goals. • LTB oversight improves firm energy efficiency by 8–12% over STB control. • Lenient tax enforcement eases financing constraints for cleaner energy adoption. • Environmental benefits are stronger in fiscally surplus or high-pressure cities. • Financing-constrained and non-exporting firms benefit most from LTB regulation. • Study links decentralized tax control to unexpected environmental improvements.

S. VISHNU VARDHAN GOUD, CHANDU E., SIVAKUMAR D., MANJUNADH K. · 5 authors

The system establishes a privacy-preserving credit evaluation framework that eliminates exposure of user financial data during creditworthiness verification. Conventional credit scoring requires complete visibility into a borrower’s income records, liabilities, repayment patterns, and transaction histories, creating structural risks related to data theft, unauthorized sharing, profiling, and large-scale breaches. The proposed architecture replaces disclosure-based assessment with Non-Interactive Zero-Knowledge (NIZK) proofs. Users locally compute cryptographic attestations that assert compliance with predetermined financial thresholds—such as debt-to-income ratio, repayment consistency, or minimum balance stability—without revealing source data. Verifiers check the proof deterministically, without bidirectional communication or access to underlying financial artifacts. The model reduces attack surface, removes centralized exposure of sensitive records, and aligns credit scoring processes with modern expectations of confidentiality, verifiability, and regulatory trust. It offers an adaptable foundation for digital lending, embedded finance, decentralized platforms, and cross-institution credit portability.

Hana Belhadj, Salah Ben Hamad, Nadia Belkhir

Abstract This paper investigates whether Bitcoin serves as a safe haven and a diversification tool for both developed and emerging stock markets during the COVID-19 crisis, in comparison with gold. The analysis covers daily data from June 18, 2012, to May 25, 2020, across a representative set of developed (S&P500, FTSE100, DAX, CAC40, Nikkei225, Ibex35) and emerging (Shanghai, Nifty50, Ibovespa, MOEX) equity markets, providing a comprehensive view of asset interactions in different financial environments. Methodologically, we employ a two-step approach: an EGARCH model to estimate time-varying volatility, followed by a copula-based framework to capture nonlinear and asymmetric dependence structures. This combination allows for a nuanced assessment of asset behavior under both tranquil and crisis conditions. The results show that Bitcoin maintains weak dependence on developed equity markets during the COVID-19 period but fails to display consistent safe-haven characteristics under extreme stress. Gold, by contrast, continues to act as a reliable hedge, confirming its traditional role in protecting portfolios against market downturns. Overall, these findings suggest that while Bitcoin may provide diversification benefits under normal circumstances, it cannot yet replace gold as a robust safe-haven asset. For portfolio managers, this highlights the importance of gold in risk management, while underscoring Bitcoin’s evolving yet still uncertain role in global financial markets.

Yaser Sadati-Keneti, Mohammad Vahid Sebt, Reza R. Tavakkoli-Moghaddam, Orod Ahmadi

The aim of this research is to employ improved machine learning techniques to determine the best Bitcoin trading positions in response to sudden price changes caused by global emergencies such as pandemics, conflicts, and economic disputes. Specifically, this study examines price fluctuations during the COVID pandemic as a case study to evaluate the performance of the algorithms investigated. We present a novel hybrid approach that merges Density-Based Spatial Clustering of Applications with Noise (DBSCAN) and Decision Tree (DT) classification to effectively eliminate noisy data and extract pertinent information for accurate position forecasting. The DBSCAN algorithm organizes the data to reveal important patterns, while the DT classifier sorts the trading signals. The performance of the proposed DBSCAN-DT model is rigorously compared with established alternatives, including the Multi-Layer Perceptron (MLP), Support Vector Classifier (SVC), and traditional Decision Trees. Findings from the experiments show that the DBSCAN-DT hybrid consistently outperforms these benchmarks during the outbreak, epidemic, and pandemic phases of COVID, attaining greater accuracy in forecasting both trading positions and market trends. These findings emphasize the essential importance of incorporating pandemic-related disruptions into cryptocurrency price prediction models and showcase the flexibility of our method in addressing sudden market changes.

Manu Srivastava, Marcello Ferro, Vito Pirrelli, Gianpaolo Coro

No abstract is available for this record.

Hervé Dogboevi, Péricles de Lima Sobreira, Karim El Guemhioui, Jauberth Weyll Abijaude

No abstract is available for this record.

Ιωάννης Τζαννέτος

Οι Υπογραφές Προσαρμογέα (Adaptor Signatures, AS) επεκτείνουν τις κλασικές ψηφιακές υπογραφές επιτρέποντας την υπό όρους υπογραφή: μια προ-υπογραφή που σχετίζεται με μια δύσκολη υπολογιστική σχέση μπορεί να μετατραπεί σε πλήρη υπογραφή μόνο όταν αποκαλυφθεί το αντίστοιχο μυστικό (witness). Αυτή η ιδιότητα επιτρέπει την υλοποίηση πρωτοκόλλων ιδιωτικών συναλλαγών χωρίς τροποποιήσεις στην υποδομή του blockchain και αποτελεί βασικό εργαλείο για εφαρμογές όπως οι ατομικές ανταλλαγές και τα ψηφιακά συμβόλαια σε blockchains περιορισμένων δυνατοτήτων, όπως το Bitcoin. Η πρώτη συνεισφορά της εργασίας είναι ένας επανακαθορισμός της ασφάλειας των AS μέσω της εισαγωγής της ιδιότητας απόκρυψης μάρτυρα (witness hiding), που διασφαλίζει ότι η ψηφιακή υπογραφή δεν αποκαλύπτει πληροφορίες για τον μάρτυρα. Παρουσιάζουμε μια γενική κατασκευή AS για οποιαδήποτε NP σχέση, βασισμένη μόνο σε μονόδρομες συναρτήσεις. Η δεύτερη συνεισφορά προτείνει μια εναλλακτική κατασκευή AS βασισμένη στο μοντέλο Υπολογισμού Πολλαπλών Μερών στο Κεφάλι (MPCitH). Η προσέγγισή μας καταργεί την ανάγκη για αναγωγές τύπου Karp, ενώ διατηρεί το σημαντικό χαρακτηριστικό του MPCitH: η κατασκευή χρησιμοποιεί το κρυπτογραφικό πρωτόκολλο ως «μαύρο κουτί» (χωρίς εσωτερική γνώση), ενώ η υπολογιστική σχέση παραμένει ρητά επεξεργάσιμη. Το προτεινόμενο πλαίσιο απλοποιεί το σχεδιασμό καθολικών υπογραφών προσαρμογέα και ενισχύει την πρακτική τους εφαρμογή σε αποκεντρωμένα δίκτυα τύπου blockchain και συστήματα προστασίας ιδιωτικότητας. Η τρίτη συνεισφορά εξερευνά τον χώρο του πρακτικού ασφαλούς υπολογισμού και εισάγει το MPC Versatile Virtual Machine (mpcVVM), ένα ανεξάρτητο από backend πλαίσιο και εργαλείο μεταγλωττιστή για την αυτοματοποιημένη μίξη πρωτοκόλλων στον ασφαλή υπολογισμό μεταξύ πολλών συμμετεχόντων (MPC). Σε αντίθεση με τις υπάρχουσες προσεγγίσεις που είναι χειροκίνητες, ευριστικές και δεσμευμένες σε ένα μόνο backend, το mpcVVM μεταγλωττίζει προγράμματα υψηλού επιπέδου MPC σε μια ενδιάμεση αναπαράσταση, επιτρέποντας αυτοματοποιημένη μίξη με επίγνωση διανυσματοποίησης σε πολλαπλά backends. Υλοποιούμε το πλαίσιο μας με τα MP-SPDZ και MOTION και το αξιολογούμε σε τυποποιημένα benchmarks. Πέρα από τα εμπειρικά κέρδη απόδοσης, παρέχουμε μια εγγύηση αποδεδειγμένης βελτιστότητας για τη μεθοδολογία μίξης μας και αποδεικνύουμε την πρακτική επιλυσιμότητα υπό φυσικές δομικές υποθέσεις στα προγράμματα εισόδου, επιλύοντας έτσι ένα πρόβλημα που είχε προηγουμένως θεωρηθεί ως NP-hard. Η συνεισφορά αυτή προάγει τόσο το συστημικό όσο και το θεωρητικό σκέλος του MPC, επεκτείνοντας την αποδεδειγμένα βέλτιστη μίξη πρωτοκόλλων στην περίπτωση πολλαπλών πρωτοκόλλων. Η τέταρτη συνεισφορά της διατριβής επεκτείνεται στο πεδίο των Non-Fungible Tokens (NFTs) και εισάγει το BarterSwap, ένα πλήρως αποκεντρωμένο πρωτόκολλο ανταλλαγής πολλαπλών NFTs χωρίς χρηματικά ανταλλάγματα, με στόχο την καθιέρωση μιας ανταλλακτικής οικονομίας (barter economy) στο περιβάλλον των blockchains. Το Barter-Swap βασίζεται στον αλγόριθμο Top Trading Cycles (TTC), επιτρέποντας τη δίκαιη, ταυτόχρονη και αμοιβαία επωφελή ανταλλαγή μεταξύ πολλών συμμετεχόντων χωρίς την ανάγκη ύπαρξης μεσολαβητή ή κεντρικού μηχανισμού εκκαθάρισης. Η υλοποίηση του πρωτοκόλλου στο Ethereum καταδεικνύει την πρακτική του βιωσιμότητα και αποδεικνύει ότι είναι εφικτή η δημιουργία ενός αποκεντρωμένου μοντέλου ανταλλαγής ψηφιακών περιουσιακών στοιχείων, το οποίο συνδυάζει ντετερμινιστική ορθότητα, ασφάλεια και άμεση εκτέλεση του αποτελέσματος εντός έξυπνων συμβολαίων, ενώ πραγματοποιεί ανταλλαγές χωρίς καμία χρήση χρηματικής αξίας, στηριζόμενο αποκλειστικά στις προτιμήσεις των χρηστών. Η πέμπτη συνεισφορά της διατριβής αφορά τον σχεδιασμό και την υλοποίηση ενός πλήρως αποκεντρωμένου συστήματος ανταλλαγής πληροφοριών κυβερνοαπειλών (Cyber Threat Intelligence – CTI), το οποίο συμμορφώνεται με τα πρότυπα STIX/TAXII και λειτουργεί πάνω σε ιδιωτικό δίκτυο Hyperledger Fabric. Η προτεινόμενη αρχιτεκτονική εισάγει μηχανισμούς οργανωσιακής αποκέντρωσης και ελεγχόμενης πρόσβασης, επιλύοντας πρακτικά ζητήματα ακεραιότητας, διαθεσιμότητας και μη αποποίησης ευθύνης που χαρακτηρίζουν τις κεντρικοποιημένες TAXII υποδομές.

Jia Yizhen

Digital networks governed by attention-economy algorithms exhibit accelerating entropic decay, manifesting as cognitive fragmentation and systemic instability. This paper posits a negentropic imperative for socio-technical design, synthesizing Schrödinger’s physics of life with Stiegler’s neganthropology and Floridi’s information ethics. It proposes a model of metabolic networks to counteract this decay, moving beyond the extractive Creator Economy toward a Contributor Economy. The model’s core mechanisms include a Uniqueness Quotient (replacing engagement metrics with singularity valuation), Tokenized Value Exchange (creating non-fungible, context-specific value flows), and AI-as-Negentropic-Ally protocols. Grounded in information theory, this framework offers an architectural alternative to platform capitalism, aiming to foster cognitive sustainability, decentralized value cultivation, and collective individuation against the entropic trajectory of algorithmic dis/order.