Blockchain Technology: Architecture, Applications, and Challenges

Blockchain technology is transforming industries like finance, supply chain, governance, and healthcare. This paper analyzes blockchain architecture, applications, challenges, and performance. Key attributes—decentralization, immutability, transparency, and security—enable secure peer-to-peer transactions without intermediaries. Consensus mechanisms such as Proof of Work (PoW) and Proof of Stake (PoS) are examined for their trade-offs in scalability, energy efficiency, and security. In healthcare, blockchain addresses security and interoperability issues in centralized Personal Health Record (PHR) systems. Solutions using Ethereum, Hyperledger, smart contracts, and IPFS enhance Electronic Health Record (EHR) management by improving data integrity, privacy, and access control while reducing costs. A containerized microservices architecture further enhances scalability. Blockchain performance, evaluated using the BLOCKBENCH framework, highlights gaps in transaction throughput compared to traditional databases. Despite scalability, interoperability, and regulatory challenges, ongoing research focuses on optimizing consensus mechanisms, integrating database principles, and improving healthcare interoperability, advancing blockchain’s real-world applications

Consensus plays a crucial role in blockchain technology, with the delegated proof of stake (DPoS) consensus mechanism commonly utilized in both public and hybrid chains. However, the current DPoS mechanism faces challenges such as low node engagement in voting and potential security risks posed by malicious nodes. In response, we propose the DL-DPoS (deep link–delegated proof of stake) mechanism, which builds upon the DPoS framework. The DL-DPoS incorporates the LINK incentive mechanism to encourage inactive nodes to participate in voting and leader selection. Furthermore, a comprehensive credit scoring system based on wealth, performance, and stability is introduced to enhance the security of elected nodes. The verification process is optimized to involve all nodes except the leader node, and mechanisms are in place to handle malicious attacks by degrading or removing offending nodes and redistributing their responsibilities to the LINK group. Performance testing of the DL-DPoS mechanism, conducted through blockchain simulation tests using the GO language, shows a 23% increase in throughput compared to DPoS, with over 95% node participation and improved distribution of rights and equity. These results indicate the enhanced performance, security, and stability of the DL-DPoS consensus mechanism.

Blockchain technology has become one of the most disruptive innovations of the 21st century, reshaping industries such as finance, supply chain management, healthcare, and governance. However, the conventional blockchain ecosystem—particularly models based on Proof of Work (PoW)—has been widely criticized for its excessive energy consumption and ecological footprint. As societies move toward sustainability and carbon-neutral goals, the exploration of energy-efficient blockchain models becomes not just an academic pursuit but also an ethical imperative. This manuscript investigates the evolution of energy-efficient consensus mechanisms and their integration into “green smart contracts,” which enable automated, verifiable, and sustainable digital agreements. It highlights consensus algorithms such as Proof of Stake (PoS), Delegated Proof of Stake (DPoS), Proof of Authority (PoA), Proof of Space-Time (PoST), Practical Byzantine Fault Tolerance (PBFT), and emerging hybrid mechanisms. The manuscript offers a comprehensive literature review, outlines statistical insights comparing energy and performance trade-offs, and proposes methodologies for integrating eco-friendly smart contract architectures. The results emphasize that while PoW-based systems consume up to 99% more energy than PoS-based models, hybrid approaches demonstrate a promising balance between security, decentralization, and efficiency. The study concludes that energy-efficient blockchain models, when strategically aligned with sustainability frameworks, can redefine smart contract ecosystems to meet global climate commitments while maintaining reliability, transparency, and scalability.

The global supply chain landscape has evolved significantly in recent years, becoming increasingly complex and vulnerable to various challenges such as fraud, counterfeiting, information asymmetry, and inefficient processes The purpose of this research is to ascertain how blockchain technology might raise the efficacy and security of supply chain management. This article integrates concepts from information technology, logistics, and business management to investigate the potential applications of blockchain in supply chain management. It looks at organisational and regulatory issues along with technological aspects of blockchain implementation, like consensus algorithms and smart contracts. Furthermore, the research project assesses case studies and real-world examples where blockchain has been successfully deployed in supply chain operations. By analyzing these cases, the project aims to identify best practices, potential pitfalls, and lessons learned, offering insights for organizations considering blockchain adoption in their supply chain processes. Ultimately, this research contributes to the growing body of knowledge about how blockchain technology may revolutionise supply chain management and emphasises the importance of collaboration among industry players.

As global supply chains become increasingly complex, traditional systems face challenges in ensuring efficiency, transparency, and innovation. Block chain technology has emerged as a transformative force in addressing these issues, offering a decentralized and secure framework for supply chain management. This paper presents a comprehensive review of the impact of block chain on supply chains, focusing on its potential to enhance efficiency, transparency, and foster innovation. The efficiency gains facilitated by block chain in supply chain management are examined through the elimination of intermediaries, reduction of paperwork, and real-time visibility into the entire process. These improvements result in streamlined operations, reduced costs, and enhanced responsiveness to market dynamics. Moreover, block chain’s decentralized nature ensures data integrity, mitigating the risk of fraud and errors in the supply chain. Transparency is a critical aspect of modern supply chains, and block chain provides an immutable and transparent ledger that enables end-to-end visibility. The technology ensures traceability and accountability, allowing stakeholders to access real-time information about the origin, movement, and status of products. This transparency not only enhances trust among supply chain participants but also facilitates compliance with regulatory requirements. The role of block chain in fostering innovation within supply chains is explored, emphasizing its potential to enable new business models, collaborative ecosystems, and the integration of emerging technologies such as the Internet of Things (IoT) and Artificial Intelligence (AI). The paper highlights case studies and pilot projects where block chain has been successfully applied to drive innovation in supply chain processes. Challenges and considerations related to the implementation of block chain in supply chain management are also discussed, including interoperability, scalability, and regulatory issues. The paper concludes by outlining future research directions and emphasizing the need for industry-wide collaboration to unlock the full potential of block chain in revolutionizing supply chain management. Overall, this review contributes to the understanding of how block chain can serve as a catalyst for efficiency, transparency, and innovation in contemporary supply chains

The advent of the Bitcoin system has brought another boom in the Internet era. In a very short time, many Blockchain systems come into being successively, whose decentration, consensus mechanisms, intelligent contract, and other characteristics make them applicable to various fields such as finance, education, medical, technology, etc. The consensus mechanism is the core of Blockchain technology. And a good consensus mechanism plays a very important role in the stable operation of the Blockchain system. The continuous improvement of consensus mechanisms such as PoW (proof-of-work), PoS (proof-of-stake), DPoS (delegated-proof-of-stake), and PBFT (Practical Byzantine Fault Tolerance) has led to the evolution of Blockchain technology to Blockchain 3.0. Starting from the issue of Byzantine generals, this article analyzes common consensus mechanisms based on existing Blockchain applications and then evaluates their consistency. This paper has a unique perspective, selection and comment on the latest progress and important literature in the field of block chain. At last, it also has a high degree of summary and prospect to the existing problems and the future development trend.

Traditional blockchain consensus mechanisms, such as Proof of Work (PoW) and Proof of Stake (PoS), face significant challenges related to the centralisation of validators and miners, environmental impact, and trustworthiness. While PoW is highly secure, it is energy-intensive, and PoS tends to favour wealthy stakeholders, leading to validator centralisation. Existing mechanisms lack fairness, and the aspect of sustainability is not considered. Moreover, it fails to address social trust dynamics within validator selection. To bridge this research gap, this paper proposes Proof of Friendship (PoF)—a novel consensus mechanism that leverages social trust by improving decentralisation, enhancing fairness and sustainability among the validators. Unlike traditional methods that rely solely on computational power or financial stakes, PoF integrates friendship-based trust scores with geo-location diversity, transaction reliability, and sustainable energy adoption. By incorporating a trust graph, where validators are selected based on their verified relationships within the network, PoF mitigates the risks of Sybil attacks, promotes community-driven decentralisation, and enhances the resilience of the blockchain against adversarial manipulation. This research introduces the formal model of PoF, evaluates its security, decentralisation, and sustainability trade-offs, and demonstrates its effectiveness compared to existing consensus mechanisms. Our investigation and results indicate that PoF achieves higher decentralisation, improved trustworthiness, reduced validator monopolisation, and enhanced sustainability while maintaining strong network security. This study opens new avenues for socially aware blockchain governance, making consensus mechanisms more equitable, efficient, and environmentally responsible. This consensus mechanism demonstrates a holistic approach to modern blockchain design, addressing key challenges in trust, performance, and sustainability. The mechanism is tested theoretically and experimentally to validate its robustness and functionality. Processing latency (PL), network latency (NL) [transaction size/network speed], synchronisation delays (SDs), and cumulative delay per transaction are 85 ms, 172 ms, 1802 ms, [PL + NL + SD] 2059 ms, respectively.

Blockchain technology, originally developed for digital currencies, has evolved to offer transformative prospects for enhancing financial security and efficiency beyond its initial application. This review paper explores the expansive utility of blockchain technology across various domains, with a special focus on its implications for green logistics innovations within the oil industry, drawing a comparative analysis between Nigeria and the USA. Through a comprehensive review of existing literature, this study aims to uncover the multifaceted impact of blockchain on streamlining operations, ensuring transparency, and fostering sustainability in the oil sector's supply chain management.
 The methodology hinges on synthesizing findings from peer-reviewed articles, industry reports, and case studies to construct a holistic view of blockchain's role in mitigating traditional challenges faced by the oil industry, such as fraud, inefficiencies, and environmental concerns. By comparing the progress and setbacks in Nigeria and the USA, the paper delineates the influence of regulatory frameworks, technological infrastructure, and stakeholder engagement on the adoption and effectiveness of blockchain solutions.
 Key findings reveal that blockchain technology can significantly elevate financial security and operational efficiency, offering a robust framework for transparent, immutable transactions and supply chain oversight. However, the comparative analysis highlights a notable divergence in adoption levels and outcomes, attributed to varying degrees of technological readiness, regulatory environments, and commitment to sustainability goals between the two countries.
 Conclusively, the paper emphasizes that the broader application of blockchain in enhancing green logistics and sustainability within the oil industry requires a concerted effort among policymakers, industry leaders, and technology providers. It advocates for targeted investments in technology infrastructure, clearer regulatory guidelines, and stronger collaborations to harness blockchain's full potential, suggesting a pathway towards more secure, efficient, and sustainable industry practices.
 Keywords: Blockchain Technology, Financial Services, Smart Contracts, Decentralized Finance (Defi), Regulatory Landscape, Ethical Considerations, Privacy Concerns, Data Protection, User Anonymity, Operational Efficiency, Financial Security, Scalability Issues, Energy Consumption, Consensus Mechanisms, International Regulations, Jurisdiction-Specific Challenges, Technology Adoption, Integration Strategies, Innovation, Collaboration, Financial Ecosystem.

This research explores the transformative role of blockchain technology in ensuring secure and trustworthy digital transactions. With the increasing reliance on digital platforms across industries such as finance, healthcare, and supply chains, blockchain has emerged as a solution to the challenges posed by traditional centralized systems, including data breaches, fraud, and lack of transparency. The study investigates blockchain's decentralized structure, cryptographic security features, consensus mechanisms, and smart contracts to evaluate how it enhances data integrity and trust in digital transactions. A qualitative approach was employed, utilizing case studies and a comprehensive review of existing literature. The results show that blockchain’s decentralization significantly reduces single points of failure, while its consensus mechanisms and smart contracts increase trust and automate transactions. However, challenges such as scalability, energy consumption, and regulatory concerns remain. The research highlights blockchain’s potential for transforming digital transactions but calls for further innovation to address these issues. The findings suggest that blockchain has the capacity to revolutionize secure transactions across various sectors but requires continued development to achieve widespread adoption and scalability.

PurposeThis paper aims to investigate the way in which blockchain technology is likely to influence future supply chain practices and policies.Design/methodology/approachA systematic review of both academic and practitioner literature was conducted. Multiple accounts of blockchain adoption within industry were also consulted to gain further insight.FindingsWhile blockchain technologies remain in their infancy, they are gaining momentum within supply chains, trust being the predominant factor driving their adoption. The value of such technologies for supply chain management lies in four areas: extended visibility and traceability, supply chain digitalisation and disintermediation, improved data security and smart contracts. Several challenges and gaps in understanding and opportunities for further research are identified by this research. How a blockchain-enabled supply chain should be configured has also been explored from a design perspective.Research limitations/implicationsThis systematic review focuses on the diffusion of blockchain technology within supply chains, and great care was taken in selecting search terms. However, the authors acknowledge that their choice of terms may have excluded certain blockchain articles from this review.Practical implicationsThis paper offers valuable insight for supply chain practitioners into how blockchain technology has the potential to disrupt existing supply chain provisions as well as a number of challenges to its successful diffusion.Social implicationsThe paper debates the poential social and economic impact brought by blockchain.Originality/valueThis paper is one of the first studies to examine the current state of blockchain diffusion within supply chains. It lays a firm foundation for future research.

Blockchain technology has developed be- yond its original application in cryptocurrencies and is now widely recognized for its potential to completely transform a number of different industries. This survey report supports provides a thorough analysis of blockchain research. Applications in a number of industries, including as healthcare, banking, governance, education, and supply chain management. Blockchain’s decentralized, open, and safe architecture presents encouraging answers to problems like trust, privacy, and data integrity. Blockchain is allowing smart contracts, decreasing fraud, and revolutionizing payments and transactions in the financial industry. It improves patient data management and guarantees the safe exchange of medical records in the healthcare industry. Supply chain operations are being reshaped by the technology’s capacity to track products and authenticate them, and it also makes it easier for academic credentials to be securely recorded in the classroom. Blockchain is also being incorporated into governance frameworks to improve openness and lessen corruption. This study attempts to illustrate the wide-ranging effects of blockchain technology and its potential to transform a variety of industries by examining recent developments, difficulties, and viable paths forward. Index Terms—blockchain, decentralized systems, crypto- graphic security, smart contracts, distributed ledger, data integrity, privacy, transparency, scalability, supply chain management, healthcare, finance, governance, education, Interplanetary File System (IPFS), machine learning integration, consensus mechanisms, digital transformation

In some liberal democracies, governments allow people to legally own guns to protect their lives and property. However, gun crime has been increasing in recent years. Taking the United States, for example, a report pointed out that Americans are 10 times more likely to be shot than citizens of other countries. Murder using guns in the United States is 25 times more than that in the other 22 high-income countries. Most of these guns came from other cities. These illegally circulating guns are directly linked to deadly street violence. This means that effective firearm management can reduce deadly violence. In the past few years, Radio Frequency IDentification (RFID) technology was often used to track the supply chain. However, in the traditional supply chain, only the participants of the supply chain can query information. Furthermore, only the participants can verify the correctness of the data. This result causes information to be not transparent. On the other hand, blockchain technology, with a unique combination of features such as distributed notes, decentralized structure, consensus algorithm, storage mechanism, asymmetric encryption, and smart contract, ensures network visibility, transparency, and security. Therefore, we combine blockchain and RFID technology to propose a traceable firearm management system based on blockchain and Internet of Things (IoT) technology. The proposed method achieves several goals. First of all, the characteristic data through the blockchain can be publicly verified and the information will not be modified. The traceability of the data and the application of RFID can effectively manage the production chain. In addition, we used Burrows–Abadi–Needham logic (BAN logic) logic to prove mutual authentication, and the nonrepudiation and integrity method can also be achieved in our proposed scheme.

In the white book of Bitcion, Satoshi Nakamoto described a bitcoin system that can realize point-to-point online payment without a third-party organization. After supporting this magical application scenario and subverting the traditional centralized system, the blockchain technology has attracted worldwide attention, triggered a research upsurge of blockchain consensus algorithm, and produced a large number of innovative applications. Although various consensus algorithms continue to evolve with the iteration of blockchain products and applications, Proof of Work (POW) and Proof of Skake (POS) algorithms are still the core of consensus algorithms. This paper discussestwo algorithms of POW and POS in blockchain consensus mechanism, and analyzes the advantages and the existing problems of the two consensus mechanisms. Since consensus mechanism is the main focus of blockchain technology and has many influencing factors, this paper discusses the current problems and some improved ideas, and selectes some typical algorithms for a more systematic introduction. In addition, some important issues related to safety and performance are also discussed. This paper provides the researchers a great reference on blockchain consensus mechanism.

Blockchain technology is being introduced gradually into supply chain management, addressing long-standing problems and waste-related parts of the industry. This study aims to illustrate the various ways that blockchain might improve supply chains' efficiency, traceability, security, and simplicity. Blockchain technology offers a permanent, decentralized record-keeping system that fosters honesty and trust between participants; all important data is stored in an unalterable manner. Additionally, supply chain processes like payment processing and inventory management are automated by intelligent contracts, which significantly lowers both human error and regulatory expenses. Blockchain's capacity to encrypt this data ensures a high level of security by guaranteeing information availability in the event of sophisticated cyber assaults. This increase in security makes the supply chain less vulnerable to sabotage and extortion. Through the provision of an easily accessible and verifiable record of every trade, this innovation significantly streamlines administrative compliance. Furthermore, it provides a means of confirming that the technical support standards and material sources adhere to current standards, which in turn helps to enhance customer trust in a brand and promote brand identity for the product bearing the brand mark. The study shows how blockchain technology has enhanced the capabilities of US logistics companies. It also looks at supply chain management's effectiveness and transparency in terms of blockchain technology implemented in the US.

Blockchain technology has been widely applied in fields such as finance, supply chain, healthcare, and real estate. Aviation fuel is the largest operating cost item for airlines, accounting for 30\%-40\% of China Southern Airlines' operating costs, with an annual expenditure exceeding 30 billion CNY. However, the traditional aviation fuel settlement model suffers from systemic pain points due to paper document circulation, manual reconciliation, and multi-level approval processes, including lengthy procedures (single settlement takes 72 hours), significant capital tie-up (average accounts payable turnover of 45 days annually), and high dispute resolution costs (1.2 % reconciliation error rate). These issues simultaneously lead to prolonged payment cycles for aviation fuel suppliers, lack of high-quality supply chain scenarios for financial institutions, and limited bargaining power for airlines, creating tripartite conflicts. Aiming at the intelligent settlement of aviation fuel for China Southern Airlines, in this paper, we firstly establish a digital aviation fuel settlement platform, which integrates blockchain, smart contracts, and Robotic Process Automation (RPA) technologies through three-dimensional collaborative innovation across technology, process, and finance. Then, we propose a novel real-time settlement model based on blockchain smart contracts, achieving systematic restructuring of the settlement patterns within the aviation fuel supply chain. The research demonstrates that blockchain smart contract technology, by reconstructing the settlement trust mechanism and value distribution rules, can provide a reusable technical paradigm and business logic for the digital transformation of the aviation energy supply chain, and holds significant practical value for improving overall supply chain operational efficiency.