Smart contracts, as self-executing code on blockchain platforms, are transforming digital agreements across multiple industries. This paper reviews the technical foundations, applications, security challenges, and emerging directions of smart contract technology through an analysis of recent academic literature and real-world implementations. While smart contracts demonstrate significant potential in decentralized finance, supply chain management, and healthcare, they face critical challenges, including security vulnerabilities, ecosystem centralization risks, and legal uncertainties. Layer-2 scaling solutions, cross-chain interoperability protocols, and AI-assisted security auditing represent promising directions for addressing these challenges. Our analysis reveals that despite technological advances, fundamental issues in security verification and regulatory frameworks require continued research attention.
Mohammad Nasrinasrabadi, Maryam A. Hejazi, Arefeh Jaberi, Hamed Hashemi‐Dezaki · 5 authors
Cryptocurrencies utilize blockchain technology to ensure transparency, decentralization, and immutability in financial transactions. It is expected that blockchain applications will significantly impact renewable energy markets. However, there is a lack of studies addressing the energy requirements of digital currencies. This research proposes optimizing a hybrid energy system consisting of distributed renewable and non-renewable energy sources, focusing on cryptocurrency mining. Although previous studies have not yet addressed energy system optimization considering cryptocurrency mining farms, the increasing prominence of such farms highlights the growing need for research in this area. The primary renewable sources in the proposed hybrid system include photovoltaic (PV) panels and wind turbines. We employ diesel generators as backup systems to compensate for the intermittent nature of solar and wind energy production. Besides meeting the demands of urban loads, cryptocurrency mining devices will be considered a major energy consumer. In this article, the optimal configuration of the energy system will be determined based on technical and economic indicators. Additionally, economic evaluations will be conducted to assess the income generated from cryptocurrency mining farms, and appropriate approaches will be identified from both technical and financial perspectives, focusing on return on investment (ROI).
This study examines the intricate relationships between cryptocurrency and various uncertainties related to economic policy and global risk factors. It explores the interactions between cryptocurrency and global risk factors, comparing these with their relationships to different measures of economic policy uncertainty (EPU). We find that cryptocurrency returns are more sensitive to global risk factors than to the country-level EPU. Notably, gold exhibits bidirectional causality with cryptocurrency in returns and volatility. The research sheds light on the dynamic interactions within cryptocurrency markets, underscoring the importance of continuous monitoring and adaptive strategies to navigate the evolving financial landscape of the digital ecosystem.
This study explores how integrating cryptocurrencies into traditional financial portfolios can influence investment performance. Focusing on Bitcoin and Ethereum alongside key European stock indices (BUX, DAX, and FTSE), the analysis examines whether blockchain-based assets can enhance diversification and improve the balance between risk and return. Using weekly market data from 2019 to 2023, the research applies Markowitz mean–variance optimization to identify optimal asset allocations under different objectives such as maximizing the Sharpe ratio, minimizing risk, and maximizing returns. The findings reveal that cryptocurrencies show weak correlations with European stock indices, suggesting meaningful diversification potential. When included in portfolios, Bitcoin and Ethereum can significantly boost returns, though they also increase volatility. Portfolios optimized for risk reduction favored traditional indices, while those targeting higher returns relied predominantly on cryptocurrencies. Overall, combining digital and conventional assets produced a more balanced performance, with the Sharpe-ratio–maximized portfolio demonstrating the best trade‐off between stability and profitability. These results indicate that cryptocurrencies can play a valuable complementary role in modern portfolio construction. They are most suitable for investors willing to accept higher risk in exchange for potentially greater rewards, while more risk‐averse investors may benefit from maintaining a stronger focus on traditional equity indices. The study contributes to understanding how blockchain‐driven assets can expand financial opportunities and supports a broader view of diversification in contemporary investment strategies.
Crowdfunding websites tend to have centralized escrow infrastructure, which can create concerns over the lack of transparency, security threats, and fraud vulnerability. The proposed system, a hybrid blockchain–AI architecture, combines Ethereum-based smart contracts and machine learning-based fraud detection to result in a decentralized and transparent crowdfunding space. The blockchain layer ensures accountability with controlled release of funds based on milestones, limiting the tendency to spend funds more due to the cryptocurrency nature with the AI module detecting fraudulent activity based on analysis of textual, transactional, temporal, and reputation data. Experimentation proves that the proposed system promotes higher trust, reduces transaction cost, and signifies a robust fraud detection model compared to conventional crowdfunding models. The results suggest creating a combination of the immutability of blockchains with the analytical power of AI as a potential route to safer and more effective decentralized finance apps.
Nara Raquel D. Andrade, Oscar William N. de Carvalho, Carlos H. G. Ferreira, Glauber Dias Gonçalves
The market for Non-Fungible Tokens (NFTs) continues to evolve, yet it still lacks robust methodologies to estimate the future value of its assets. Unlike traditional financial markets, NFT pricing is challenged by intangible factors such as the artistic nature of the items and the influence of social and transactional networks among buyers and sellers. This study investigates whether the structural position of participants in the transaction network can serve as a relevant predictor of the future value of NFTs. To this end, we reconstructed the NFT trading network for the period 2020–2021, extracted both structural and transactional metrics of the participants, and applied supervised machine learning models, including deep neural networks. The results demonstrate the feasibility of the proposed approach, achieving 74% accuracy and a global F1-Score of 72%. Interpretability analysis using SHAP values revealed that, in addition to historical price averages, network metrics such as degree and neighborhood significantly contribute to prediction. These findings highlight the role of network dynamics in NFT valuation and point toward promising directions for more transparent and evidence-based pricing methodologies.
The research explores the features of administrative-territorial reform in Ukraine within the context of European integration and active decentralization processes. The author examines the legislative framework for local self-government reform, including the Concept of Local Self-Government Reform and the Implementation Plan, as well as practical measures aimed at territorial consolidation and strengthening the financial capacity of newly established territorial communities. Special attention is given to improving resource management efficiency, developing municipal services, enhancing the organizational and institutional capacity of local government bodies, and ensuring citizen participation in decision-making at the local level, including expanding practices of direct democracy. The research analyzes the dynamics of local budgets, the growth of capital expenditures, and the level of public support for the reform, demonstrating the effectiveness of the implemented measures. The role of international assistance and inter-municipal cooperation in enhancing community capacity is highlighted, along with the importance of professional training and development of local officials. The research emphasizes the relevance of a comprehensive approach to creating financially autonomous and effective territorial communities, including the development of methodological foundations for assessing their capacity to manage local finances and socio-economic development. This research is valuable for scholars, local government practitioners, and international experts interested in decentralization, administrative-territorial reform, and the improvement of municipal financial sustainability.
Polygon Chain Development Kit (CDK) Validium is a Layer 2 blockchain scaling solution that processes transactions off-chain. It uses Polygon’s distinctive approach to Zero-Knowledge Proofs (ZKPs) implemented within their Zero-Knowledge Ethereum Virtual Machine (zkEVM). A key factor in its successful deployment is robustness, ensuring that users can trust their transactions will be processed accurately and promptly. This research concerns developing robust validation methodologies and comprehensive testing strategies targeting the “double-spending” problem within Polygon CDK Validium. We indicate theoretical scenarios where double-spending vulnerabilities could arise in Polygon CDK Validium by identifying how execution errors can combine with a specific category of flawed constraints to create vulnerabilities. When combined with what we classify as Invalid PIL Constraints For EVM Specification Vulnerabilities (IPCFESV), these errors can trigger problematic behaviours. We further illustrate how erroneous behaviour resulting from IPCFESV can lead to cascading involvement in withdrawal operations resulting in irreversible cross-layer double-spending. We also illustrate how a protocol anti-censorship mechanism bypasses standard validation checks, thereby intensifying reliance on constraint correctness. We then propose ways to determine the correct behaviour. We propose a method to utilise Polygon’s integration testing framework for generating execution traces for de-facto ERC-20 fungible token standard. The outcomes of this study will form the foundational basis for the subsequent development of practical testing and verification methods for Polygon CDK Validium. Implementation and empirical validation remain as future work.
A. Marques, Luiz Eduardo Terra de Faria, Diogo S. Mendonça
The exponential growth of the cryptoasset market and the advancement of decentralized technologies have challenged traditional models of tax collection. In particular, self-custody wallets, which allow users to maintain direct control over their digital assets without the mediation of financial institutions, pose significant obstacles to oversight and tax compliance. This paper proposes an approach for the automatic collection of taxes on foreign exchange operations with stablecoins, using smart contracts on decentralized exchanges (DEXs). Through the implementation of a Proof of Concept (PoC), based on the Split Payment logic, we demonstrate the technical feasibility of applying a tax rate, analogous to the IOF, directly during transactions carried out by self-custody wallets, without the need for prior user identification. Experimental results, validated on the Polygon mainnet, reinforce the potential of the proposed model as a practical solution aligned with the principles of Web3, contributing to the debate on automated tax compliance mechanisms in decentralized environments.
Non-fungible tokens (NFTs) are unique digital assets that play an increasingly important role in decentralized markets, supporting new forms of ownership, valuation, and exchange. Their inherently multimodal structure, which encompasses visual content, metadata, and trading history, has led to a growing academic interest in modeling NFT pricing and market behavior. However, existing research is limited by the lack of comprehensive datasets that unify these modalities with consistent formatting and longitudinal coverage. To address this gap, we introduce MultiNFT, a large-scale multimodal dataset comprising 50 curated profile picture (PFP) NFT collections, including 523,020 unique assets and 2.38 million transaction records from April 2021 to September 2025. MultiNFT integrates standardized images, structured metadata, and time-series trading data, along with rarity scores and aesthetic features, offering a unified foundation for multimodal learning and NFT analytics. Unlike prior datasets that focus on visual similarity or static snapshots, MultiNFT captures evolving valuation dynamics across market cycles and connects them to trait-level characteristics. We demonstrate the utility of the dataset through three case studies, including within-collection rarity-price analysis, visual feature clustering across collections, and quantifying feature contributions in a comprehensive pricing model. By bridging computer vision, behavioral modeling, and financial forecasting, MultiNFT supports a wide range of interdisciplinary research and practical use cases. The dataset is publicly available and is intended to promote reproducible experimentation and further exploration of the mechanisms driving value in digital asset ecosystems.
This paper introduces a structured approach to improving decision making in Decentralized Autonomous Organizations (DAO) through the integration of the Question-Option-Criteria (QOC) model and AI agents. We outline a stepwise governance framework that evolves from human led evaluations to fully autonomous, AI-driven processes. By decomposing decisions into weighted, criterion based evaluations, the QOC model enhances transparency, fairness, and explainability in DAO voting. We demonstrate how large language models (LLMs) and stakeholder aligned AI agents can support or automate evaluations, while statistical safeguards help detect manipulation. The proposed framework lays the foundation for scalable and trustworthy governance in the Web3 ecosystem.
Fabrício Barbosa Viegas, Murilo Costa Salem, Tatiana Aires Tavares
Digital messaging plays a central role in modern society, but it is currently dominated by centralized platforms that compromise user privacy and control. This position paper argues that decentralized messaging systems, based on open protocols and free software, can serve as public communication infrastructure and exemplify Web3 as a digital common good. We discuss the limitations of current services (identity lock-in, user fragmentation, data exposure) and present decentralized approaches (peer-to-peer, federated, blockchain-based) according to recent literature. We relate these models to the concept of public digital infrastructure, essential communication systems managed in a non-exclusive manner, and the notions of digital commons. As illustrative cases, we cite open protocols like Matrix and Web3 initiatives that adopt blockchain-based identity (e.g., XMTP), showing that such systems exhibit the characteristics of common resources: public specification, collective governance, and open-source software.
Contemporary Online Social Networks (OSNs) present critical vulnerabilities in user authentication and data integrity protocols. Since the social network is a multi-user platform, it requires a well-performing authentication mechanism that works along with the blockchain to ensure secure transactions. The existing methodologies exhibit significant limitations, particularly susceptibility to quantum cryptanalysis and privacy vector compromises. This study proposes a novel blockchain-based framework for decentralized OSNs, implementing smart contracts and InterPlanetary File System (IPFS) protocols to establish a distributed authentication architecture that mitigates these vulnerabilities while maintaining computational efficiency. Initially, we propose a post-quantum digital signature followed by a blockchain system using the signatures. Unlike previous OSNs, our solution uses post-quantum approaches, making it secure against both classical and quantum attacks. To enhance the data authentication of social network users, this research leverages the post-quantum multimodal biometric-based approach, where an improved version of Crystals Dilithium 3 is utilized in place of ECDSA in the XRP Ledger (XRPL) blockchain. We have integrated different post-quantum algorithms with XRPL using the open quantum safe library (liboqs) and compared the results in terms of resource consumption. The research explores the advantages of the proposed approach, highlighting its potential to mitigate the shortcomings of conventional methods and ensure secure data transmission in the era of quantum computing.
Luiz Eduardo Folly de Campos, Reinaldo Cézar de Morais Gomes
Trust on the internet is an essential pillar for online interactions, and blockchain technologies offer a new paradigm of trust based on data integrity and decentralization, enabling innovative solutions such as theWeb3 applications. This paper presents the experimental infrastructure for blockchain research and development currently being built within the ILIADA project at RNP, and its use for the development of new Web3 applications.
Felipe Castaño, Constantinos Patsakis, Francesco Zola, Fran Casino
LockBit has evolved from an obscure Ransomware-as-a-Service newcomer in 2019 to the most prolific ransomware franchise of 2024. Leveraging a recently leaked MySQL dump of the gang's management panel, this study offers an end-to-end reconstruction of LockBit's technical, behavioral, and financial apparatus. We recall the family's version timeline and map its tactics, techniques, and procedures to MITRE ATT&CK, highlighting the incremental hardening that distinguishes LockBit 3.0 from its predecessors. We then analyze 51 negotiation chat logs using natural-language embeddings and clustering to infer a canonical interaction playbook, revealing recurrent rhetorical stages that underpin the double-extortion strategy. Finally, we trace 19 Bitcoin addresses related to ransom payment chains, revealing two distinct patterns based on different laundering phases. In both cases, a small portion of the ransom is immediately split into long-lived addresses (presumably retained by the group as profit and to finance further operations) while the remainder is ultimately aggregated into two high-volume addresses before likely being sent to the affiliate. These two collector addresses appear to belong to distinct exchanges, each processing over 200k BTC. The combined evidence portrays LockBit as a tightly integrated criminal service whose resilience rests on rapid code iteration, script-driven social engineering, and industrial-scale cash-out pipelines.
Prof. C. V. Nalawade, V. S. Bhosale, S. A. Khetre, K. B. Kadam
In recent years, the convergence of Artificial Intelligence (AI), Blockchain, and Biometric technologies has revolutionized digital identity verification and secure electronic voting systems. The demand for transparent, tamper-proof, and fraud-resistant voting mechanisms has prompted researchers to explore distributed ledgers combined with intelligent authentication systems. This paper presents a comprehensive survey of AI-enabled blockchain voting architectures integrating biometric verification. The study explores technical advancements from 2020 to 2025 in decentralized voting, intelligent fraud detection, and privacy-preserving biometric mechanisms. We classify recent research trends, analyze current methodologies, and identify open challenges and future directions in implementing scalable and trustworthy e-voting frameworks. The analysis concludes that integrating blockchain’s immutability with AI-driven fraud detection and biometric identification ensures high security, transparency, and reliability in modern digital democracies.
This study presents a blockchain-backed Role-Based Access Control (RBAC) service for distributed clouds, addressing auditable authorization under multi-region latency and consistency constraints. Although end-to-end costs and tail impacts of permissioned ledgers in RBAC are under-quantified, the present study implements a multi-region deployment with Istanbul Byzantine Fault Tolerance (IBFT), batched commits, and an off-chain cache, with evaluation against centralized and event-sourced baselines, throughput reported in requests per second (RPS), and calibration via Expected Calibration Error (ECE) and Brier Score using multi-seed runs and moving-block bootstrap. At the target load, the candidate achieved 145.0 +/- 4.6 ms 95th percentile (p95) latency and 1008 +/- 13 RPS while meeting the 150.0 ms Service Level Objective at 1000 rps; the 99th percentile (p99) policy-update consistency lag measured 1750.0 +/- 150.0 ms. Connectivity remains the bottleneck. The parts are familiar; the sequencing is not, combining ledger finality with cache-assisted reads and bounded block intervals to narrow the gap to centralized designs under controlled failures. These findings indicate that tamper-evident auditing can be added with modest overhead for enterprise security operators planning multi-region cloud authorization.
P. R. Sarode, Aditya Takawale, Sarita Yadav, Meera Sawalkar
Even while modern crowdfunding platforms have become quite popular, they still have problems that won’t go away, especially when it comes to centralized control, possible fund misappropriation, and not being open enough. People who would want to help with a project often don’t because they don’t believe it will work out or because they don’t like how the money is being handled. This article presents Sahaay, an innovative crowdfunding platform aimed at resolving these challenges through the integration of blockchain technology and artificial intelligence (AI). Sahaay employs a decentralized ledger to make sure that all transactions, from pledges to giving out money, are entirely open and can’t be modified. Smart contracts are designed to automatically distribute money to the proper persons when particular project milestones are reached. This means that people are more responsible and don’t have to perform things by hand as often. An AI-based assessment tool also checks the text, team, and market aspects of prospective campaigns to see how likely they are to work. The AI also lets a complicated recommendation system find the best sponsors for initiatives. This article discusses how the Sahaay platform is created in layers, what its primary pieces are (including machine learning models and smart contract logic), and how it functions. We also discuss crucial moral concerns and present a complete set of rules for figuring out how well the system works, how safe it is, and how easy it is to use. Sahaay combines the security of blockchain with the analytical power of AI to make a smart, safe, and efficient ecosystem that is ready to alter crowdfunding by generating trust and making projects more likely to succeed.
Cloud infrastructure refers to the dynamic provisioning of computing resources over the internet, enabling scalable and flexible enterprise operations. However, such environments face significant security challenges, particularly in access management. Cloud infrastructure delivers scalable computing resources, yet traditional Identity and Access Management (IAM) mechanisms face challenges such as centralized control, misconfigurations, and limited auditability. This study addresses these challenges by proposing a Hyperledger Fabric-based decentralized access control framework integrated with Amazon Web Services (AWS) for healthcare data security. The framework employs Zero Knowledge Proof (ZKP) for identity validation, Ciphertext Policy Attribute Based Encryption (CP- ABE) with Proxy Re-Encryption (PRE) for fine-grained data access, and machine learning driven anomaly detection for continuous monitoring. Experimental evaluation achieved throughput of 15000 transactions per second, latency of 350 milliseconds, privacy preservation up to 99.1 percent, and anomaly detection accuracy of 99.63 percent, surpassing prior models significantly. Storage analysis demonstrated predictable scalability with encrypted medical records up to 20 MB, while token revocation time remained within 1.9 seconds under network stress. The results confirm that blockchain-based access control enhances security, privacy, and auditability while maintaining operational efficiency. This research establishes a scalable and tamper-resistant model for secure healthcare data management in cloud environments.
This study investigates the structural transformation of financial intermediation in the context of decentralized finance (DeFi).Building on canonical theories of intermediation, it reframes traditional credit institutions as epistemic architectures, systems that define, validate, and circulate truth about economic behavior.The paper introduces the DeFi Intermediation Matrix (DIM), a conceptual framework that maps the functional equivalence between institutional and protocol-based mechanisms of trust, including risk screening, liquidity transformation, diversification, and compliance.It demonstrates how blockchain architectures redistribute informational power by substituting trust by institution with trust by design, turning verification from a delegated process into a transparent, auditable function.Through this analytical lens, decentralized finance emerges not as a technological disruption but as an epistemological shift: the evolution of finance from a model of delegated expertise to one of reflexive governance.The work concludes that the future of credit systems depends on designing architectures capable of balancing automation and interpretation, ensuring that transparency does not replace judgment, but sustains it.
Abstract — The Fractal Eavesdrop Detection (FED) protocol defines a cryptographic mutual-authentication... The Fractal Eavesdrop Detection (FED) protocol defines a cryptographic mutual-authentication and integrity validation mechanism between two fractal nodes sharing a recursive lineage. Unlike conventional systems that rely on fixed keys or static hashes, FED uses algorithmic mutability, session-based seed derivation, multi-point challenge validation, and time-bound CRC binding to detect both impersonation and passive eavesdropping. The protocol is designed for lightweight, low-power devices such as ESP32-class microcontrollers and operates without blockchain consensus or zero-knowledge proofs, while still enabling secure proof-of-origin and tamper-awareness. FED serves as the security and validation layer within the EQUORA Institute’s Fractal Economy architecture and complements the BlockFractal cryptographic tokenization layer and the EquoraVault hardware-based proof-of-impact system. This document is released as part of the EQUORA Institute White Paper Series and is a preprint version (v0.8), subject to revision. All versions remain archived for DOI-based citation integrity.
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Chaos-based Image/Signal Encryption
Physical Unclonable Functions (PUFs) and Hardware Security
Mufti Ubaid ul Rahman, Saba Aorangzaib, Shehbaz Shabbir
The growing trends of the digital economy have profoundly influenced all aspects of human life, particularly in the financial sector, where emerging concepts such as blockchain, cryptocurrency, and non-fungible tokens (NFTs) have challenged the traditional notions of ownership, exchange, and investment. In Islamic jurisprudence (fiqh), ownership (milk) holds a fundamental position encompassing not only tangible assets but also intangible and abstract rights. This provides the essential framework for understanding and analyzing digital assets from a Shariah perspective.Blockchain, as a transparent, decentralized, and immutable digital system, has established new standards of trust and integrity in financial transactions. Cryptocurrency, being a product of this system, enables peer-to-peer exchanges without the intervention of central banks or financial institutions. From a fiqhi viewpoint, the permissibility or impermissibility of this system depends on whether it fulfills the Shariah principles of ownership, lawful exchange, and trust (amanah).Similarly, NFTs represent unique and non-replicable forms of digital property, extending the concept of ownership beyond the material realm. The crucial question arises: can assets that exist solely in digital form be recognized as legitimate “property” (mal) under Islamic law? Islamic jurisprudence identifies essential conditions for ownership including the presence of benefit (manfa‘ah), the right of disposal (tasarruf), and the owner’s responsibility (daman). When evaluated through this lens, digital assets that possess real value, are free from fraud, gambling, or usury, and have clearly defined rights, may align with the foundational fiqhi principles of ownership.From this perspective, the digital economy opens new avenues for ijtihad (juridical reasoning). It is increasingly important for Islamic jurists, economists, and technology experts to collaborate in formulating a framework that regulates modern digital assets in accordance with Islamic ethical and legal standards. Such a framework would not only promote transparency and morality in financial dealings but also ensure that technology operates within the moral and spiritual objectives of Islam.Hence, the concept of digital ownership in light of Islamic jurisprudential principles is not only plausible but also consistent with contemporary economic needs provided that its implementation prioritizes the Shariah’s core objectives of justice, trust, transparency, and responsibility.
Anny Nurbasari, Nisa Hanum Harani, Medy Syari Khalifah Anggari Raharjo
This study examines the influence of influencer marketing on Non-Fungible Tokens (NFTs) purchase decisions, both directly and through the mediating role of brand image, with a focus on members of the Ordo Nemesis NFT community. The rapid evolution of blockchain technology has driven the surge in popularity of NFTs, where consumer decisions are profoundly influenced by brand perception and public figures who endorse them. Influencer marketing has emerged as a prevalent strategy to influence these perceptions. A quantitative approach was employed using survey data collected from 100 community members who had previously purchased NFTs. The data were analyzed with Structural Equation Modeling (SEM) using SmartPLS. The findings reveal that influencer marketing significantly strengthens brand image, and brand image exerts a strong positive effect on purchase decisions. However, the direct impact of influencer marketing on purchasing behavior is weaker than its indirect effect through brand image, underscoring the importance of brand perception as a mediating factor. These results suggest that NFT creators and companies should prioritize developing a strong, authentic brand image in collaboration with credible influencers to foster consumer trust and encourage sustainable purchasing behavior.