Blockchain and Artificial Intelligence (AI) are two transformative technologies that are reshaping modern digital systems. While AI enables intelligent decision-making through data-driven models, blockchain provides decentralized, transparent, and tamper-resistant data management. Their integration has gained increasing attention as a means to address limitations inherent in each technology when deployed independently. This review paper presents a comprehensive survey of blockchain–AI integration, focusing on architectural models, enabling techniques, application domains, and current challenges. The study examines how blockchain enhances trust, data integrity, and accountability in AI systems, while AI improves scalability, efficiency, and automation within blockchain networks. Key application areas including healthcare, finance, Internet of Things, supply chain management, and smart cities are discussed. The paper further identifies open research challenges and future directions necessary to realize secure, scalable, and intelligent decentralized systems.

]]> Blockchain, Artificial Intelligence, Distributed Ledger, Machine Learning, Smart Contracts, Decentralized Systems, Trustworthy AI Review Article Wed, 31 Dec 2025 00:00:00 IST Decentralized Finance (DeFi) represents a paradigm shift in financial services by leveraging blockchain technology and smart contracts to provide open, permissionless, and trust-minimized alternatives to traditional financial systems. Over the past few years, DeFi has experienced rapid growth, enabling decentralized exchanges, lending platforms, stablecoins, and synthetic assets without centralized intermediaries. Despite its transformative potential, DeFi faces significant challenges related to security vulnerabilities, systemic risks, governance limitations, and regulatory uncertainty. This review paper provides a comprehensive analysis of DeFi protocols, examines key technical and economic risks, and critically evaluates emerging regulatory responses across jurisdictions. The paper further identifies open research gaps and future directions necessary for the sustainable development of decentralized financial ecosystems.

]]> Decentralized Finance, Blockchain, Smart Contracts, DeFi Risks, Financial Regulation, Cryptocurrencies Review Article Wed, 31 Dec 2025 00:00:00 IST The current stage of quantum computing development is defined by Noisy Intermediate-Scale Quantum (NISQ) devices, which operate with a moderate number of qubits that are inherently susceptible to noise and decoherence. Despite the absence of full error correction, NISQ systems have demonstrated the ability to perform computational tasks that challenge classical simulation under certain conditions. This paper explores the concept of quantum advantage in the NISQ era by analysing prominent algorithmic approaches, benchmarking methodologies, and the practical constraints imposed by contemporary hardware. Hybrid quantum–classical algorithms, sampling-based experiments, and performance metrics are examined to assess the extent to which near-term quantum devices can outperform classical systems. The study finds that while progress toward quantum advantage is evident, significant technical and algorithmic limitations prevent its widespread realization. The paper concludes by identifying key research directions required to bridge the gap between experimental demonstrations and practical quantum computing applications.

]]> Quantum Advantage, NISQ Devices, Variational Algorithms, Quantum Benchmarking, Quantum Noise, Hybrid Quantum–Classical Computing Review Article Wed, 31 Dec 2025 00:00:00 IST Quantum computing has progressed from theoretical speculation to experimental realization, leading to milestone demonstrations that claim computational superiority over classical systems. Among these milestones, quantum supremacy experiments have attracted considerable attention by showcasing tasks that are infeasible for classical computation within reasonable time limits. However, the practical value of such demonstrations remains a subject of debate. This paper critically evaluates the distinction between quantum supremacy and quantum utility, emphasizing their conceptual differences, experimental foundations, and real-world relevance. By examining key experimental results, algorithmic developments, and benchmarking approaches, the study argues that quantum utility-defined by practical, application-oriented performance-provides a more meaningful metric for long-term progress. The paper highlights the limitations of supremacy-based demonstrations and discusses pathways toward achieving utility-driven quantum advantage in the near and long term.

]]> Quantum Supremacy, Quantum Utility, NISQ Devices, Quantum Advantage, Benchmarking, Hybrid Quantum Algorithms Review Article Wed, 31 Dec 2025 00:00:00 IST Blockchain technology has evolved significantly since its introduction as the underlying framework for cryptocurrencies. In recent years, it has expanded into a versatile distributed ledger technology supporting decentralized applications across finance, healthcare, supply chains, governance, and the Internet of Things. This review paper presents a comprehensive survey of recent advances in blockchain technology, focusing on architectural developments, consensus mechanisms, scalability solutions, security enhancements, and emerging application domains. The study critically examines current challenges such as performance limitations, energy consumption, interoperability, privacy concerns, and regulatory uncertainties. By analysing recent literature and technological trends, the paper identifies key research gaps and outlines promising directions for future investigation. The findings aim to support researchers and practitioners in understanding the current state of blockchain technology and its trajectory toward large-scale, sustainable adoption.

]]> Blockchain Technology, Distributed Ledger, Consensus Mechanisms, Scalability, Smart Contracts, Web3, Research Gaps Review Article Wed, 31 Dec 2025 00:00:00 IST