Akash Shinde, K. S. Radha, Eesh Pratap Singh, Amresh Kushwaha
Event ticketing systems have long faced challenges such as counterfeiting, scalping, and lack of transparency in resale markets. To address these issues, this research presents the design and development of a blockchain-based ticketing platform that leverages Non-Fungible Tokens (NFTs) to ensure secure, transparent, and verifiable ticket distribution. The primary aim of the study is to explore how blockchain technology can enhance trust, eliminate fraud, and provide users with full ownership of their tickets. The proposed system employs smart contracts to automate ticket creation, distribution, and resale, thereby minimizing the need for intermediaries. Each ticket is represented as a unique NFT, guaranteeing authenticity and enabling traceability throughout its lifecycle. The methodology involves implementing a decentralized application where event organizers can mint NFT tickets, and users can securely purchase, transfer, or resell them using blockchain infrastructure. The results demonstrate that NFT-based tickets effectively prevent duplication and unauthorized sales while providing an immutable record of ownership. Additionally, organizers gain better control over pricing policies, while buyers benefit from secure transfers and enhanced transparency. In conclusion, this platform contributes to solving long-standing issues in the ticketing industry by combining blockchain’s immutability with NFTs’ uniqueness. The study highlights the potential of decentralized technologies to revolutionize digital ticketing, improve user trust, and create a more efficient event management ecosystem.
Anak Agung Lingga Pratyaksa Nugraha, Ni Wayan Emmy Rosiana Dewi, Fajar Purnama
The development of the entertainment industry, especially music concerts, has driven the transformation of ticket sales systems from conventional to digital methods. Although online concert ticket sales offer greater convenience and reach, they still face the risks of fraud, counterfeit tickets, and unfair distribution. This study, Blockchain Smart Contract Implementation for NFT-Based Online Music Concert Ticket Transactions, aims to develop a ticket sales system using blockchain technology by integrating smart contracts and Non-Fungible Tokens (NFTs). The main objectives are to design and implement smart contracts on the Ethereum network, implement ERC-721-based digital tickets, ensure transparency in transaction history, and verify ticket authenticity through unique identifiers. This study adopts the Agile method, with implementation on the Ethereum Sepolia Testnet and testing using the meta mask digital wallet. The results show that the developed system can automatically hold funds through an escrow mechanism until the ticket is downloaded, generate unique and tamper-proof NFT tickets, display transaction details transparently, and facilitate ticket verification effectively. In conclusion, the use of smart contracts and NFTs significantly improves the security, transparency, and trustworthiness of online music concert ticket transactions.
Against the background of the digital economy, the conventional matching strategy of supply and demand is unable to meet the requirements of matching supply and demand industrial interconnection with digitalization as the core element. To solve the trust problem of supply and demand matching contract of digital industrial interconnection, a decision-making framework of supply and demand matching of industrial interconnection based on smart contract is proposed. Based on the massive resource data, a resource characteristic attribute matrix is constructed, and the Fuzzy C-Means algorithm is used to classify and reduce the dimension of massive resource data. Based on the attribute expectation of supply and demand, the objective function with maximum satisfaction is created to realise bidirectional matching. Finally, the effectiveness of the proposed method is demonstrated by an example.
The existing methods do not effectively meet the security and performance demands for Internet of Vehicles (IoV) applications. They also do not provide low-latency, secure edge-computing solutions for end-users in vehicular environments. The study presented in this paper proposes a blockchain-based edge computing framework that utilises Double Deep Q-Network (DDQN) for reinforcement learning and lightweight Practical Byzantine Fault Tolerance (PBFT) consensus for simultaneously optimising latency, energy consumption, and security. For efficient microservice orchestration and task off-loading, the containerised architecture utilises Kubernetes with Hyperledger Fabric. The experiments conducted in urban, suburban, and highway scenarios confirmed that the proposed framework outperformed baseline algorithms with end-to-end latency reduction of 30–45% while also lowering energy consumption by up to 55% under moderate-to-heavy loads. With less than 1.2 seconds per block on the blockchain consensus, the system also maintained task completion rates exceeding 95% during peak conditions. The framework demonstrates consistent performance across various vehicular densities and consumes zero-knowledge proofs with attribute-based encryption for data against cybersecurity threats. These results confirm that the integration of DDQN and blockchain technology effectively tackles primary obstacles IoV faces by providing secure edge computing for next generation vehicular networks.
Abstract: This e-commerce platform is specifically designed for agriculture-based trade, leveraging advanced blockchain technology and decentralized file storage to create a transparent, secure, and efficient marketplace for farmers, buyers, and suppliers. The platform utilizes Ganache, a simulation of Ethereum transactions, to ensure that all transactions are secure, immutable, and verifiable on the blockchain. The decentralized architecture is further enhanced with IPFS (Interplanetary File System), enabling farmers to securely store their product information, including images and descriptions, in a way that prevents alteration or loss. This ensures that the product listings are transparent and tamper-proof. The platform also incorporates cryptocurrency payments, enabling fast, secure, and borderless transactions between buyers and sellers. Utilizing smart contracts, the system automates payment flows based on predefined conditions, reducing the reliance on intermediaries and minimizing fraud risks. This fosters a trusted environment for agricultural trade, where both buyers and sellers can engage in transparent, efficient, and secure transactions. In addition to these core features, the platform includes a staking mechanism, allowing users to lock tokens to gain transaction privileges, influence governance decisions, and access premium features. This incentivizes long-term commitment and creates a sense of ownership within the platform. Active participants, such as those verifying transactions or maintaining data integrity, are rewarded with tokens, further promoting continuous engagement. The system also supports multilingual user interfaces, making it accessible to a global audience, and includes real-time updates for seamless interaction. Through transparent governance, decentralized voting, and economic incentives, the platform ensures a resilient and future-ready ecosystem for agro-commerce, empowering stakeholders to participate in decision-making and market dynamics, while addressing the challenges faced by farmers in accessing reliable markets and efficient payment systems.
Against the backdrop of increasingly severe global climate change and environmental challenges, green finance, as a bridge connecting capital and sustainable development, is facing problems such as information asymmetry, transaction frictions and regulatory challenges. This study systematically explores the innovative applications of blockchain technology in the field of green finance and its economic effects. Through literature research and case analysis, we found that blockchain technology, with its characteristics of decentralization, immutability and smart contracts, has shown significant advantages in improving transparency, reducing transaction costs and alleviating the phenomenon of "greenwashing". Research shows that the application of blockchain in areas such as green bonds, carbon trading, renewable energy certification and green supply chain finance has produced economic benefits such as reduced financing costs, improved market efficiency and enhanced information transparency. This paper constructs a comprehensive assessment framework to provide guidance for policymakers and market participants to promote the innovative development of green finance.
Mingyue Xie, Jun Liu, Shuyu Chen, Ming‐Wei Lin · 7 authors
Blockchain-based IoT applications in agriculture have drawn extensive attention in recent years, allowing the implementation of smart agriculture solutions. By transmitting collected relevant data to a control center through the blockchain, corresponding regulation can be realized in agricultural production management systems. However, existing efforts for directly adopting the technique to data transmission are obstructed by several issues. The traceability of agricultural data stored in the blockchain leads to the exposure of the identity of the data collecting devices. And the tracing difficulty of completely invisible data for identity protection also exists in the smart agricultural system. To tackle these limitations, we propose a novel blockchain-based smart agricultural IoT system framework for regulating the agricultural production environment through trusted data. First, the elliptic curve integrated encryption scheme (ECIES) and the group signature scheme are integrated to guarantee the traceability and identity protection of the data and equipment, respectively. Then, to enhance the security of session key transmission in the ECIES scheme, we further design an on-chain-off-chain key agreement protocol (ECIES-OOKA). In addition, we propose a novel group manager selection method based on probabilistic linguistic term sets (PLTSs) for the group signature implementation. Finally, a practical example is provided to demonstrate the group manager selection process and verify the feasibility of the proposed method. The security and performance analysis for the system framework are also presented.
In recent years, the integration of smart contracts into supply chain management has garnered significant attention due to their potential to enhance efficiency, transparency, and reliability. This study explores the application of smart contracts within supply chains, focusing on their impact on inventory management, process optimization, and overall operational effectiveness. Through a comprehensive analysis of existing literature and case studies, we identify key benefits and challenges associated with implementing smart contracts in supply chain contexts. Our findings suggest that while smart contracts offer substantial improvements in automating processes and reducing errors, considerations regarding technological infrastructure and stakeholder readiness remain critical for successful adoption.
The research examines the increased popularity of electronic currencies as well as the radical change towards a digital economy.In the last decade, the use of cryptocurrencies like Bitcoin, Ethereum, and newly formed central bank digital currencies (CBDCs) has gained momentum, capturing extraordinary shifts in financial frameworks as well as in global economic models.The study examines the factors driving the growing adoption of digital currencies, noting their advantages including decentralization, improved security, lower transaction costs, and the capacity to enable cross-border payments.Aside from analysing the economic and technological drivers of digital currency adoption, the research looks at the general implications of digital finance on the existing banking systems, monetary policy, and regulatory regimes.The research also discusses the potential role of digital currencies in promoting financial inclusion, especially in areas with limited access to mainstream banking services.In addition, the research examines how the growth of the digital economy, typified by the convergence of digital currencies, blockchain technology, and decentralized finance (DeFi), is changing business models and consumer behaviours in various industries.The research, conducted through a mixture of surveys, case studies, and interviews with experts, cites major challenges including volatility, regulatory ambiguity, and security risks that may affect future stability and development of digital currencies. REVIEW OF LITERATUREDevlin (2019) -An Analysis of main and subsidiary credit card holding and spending.This research aims to investigate why the majority of multiple credit card holders hold a "main" card (i.e., one that is more frequently used than the others) and "subsidiary" cards (i.e., ones used less frequently or in an emergency situation) and the spending behaviour on main and subsidiary cards.
The urgency of this research is to increase efficiency, transparency and sustainability in increasingly complex and challenging agribusiness supply chains. The aim of this research is to develop an integrated system that combines IoT capabilities in collecting agricultural data in real-time, AI to analyze data and provide recommendations for action, as well as security and transparency guaranteed by blockchain technology. The method used is a mixed methods approach, this approach combines qualitative and quantitative elements to obtain a deeper understanding. A qualitative approach is used to gain a contextual perspective, while a quantitative approach is used to measure performance empirically. This research uses a case study design on a sensor-based agricultural monitoring system because of its ability to provide in-depth and holistic insights. The research population consists of users and stakeholders in sensor-based agricultural monitoring systems. The sample was selected purposively to cover various aspects of the supply chain. Data was collected through in-depth interviews, direct observation, surveys of system users and collection of sensor and transaction data from agricultural monitoring systems. The research results show that the integration of IoT, AI, and blockchain significantly improves operational efficiency in agribusiness supply chains. Implementation of this integrated system resulted in an increase in productivity of up to 22%, a reduction in pesticide use by 35%, an increase in water use efficiency by 30%, and a reduction in operational costs by 18%. Statistical analysis confirmed a strong positive correlation between the use of integrated technology and increased operational efficiency (R=0.85, p<0.01).
Blockchain technology, characterized by its immutability, decentralization, transparency, security, and traceability, has shown vast potential for applications in secure IoT communications and data protection through its deployed smart contracts. While machine learning-based code generation systems aim to automate high-quality programming solutions, they face significant challenges when addressing blockchain-related issues. This paper analyzes the limitations of machine learning in identifying vulnerabilities within blockchain smart contracts and proposes robust solutions. To achieve this, this paper suggests organizing multiple security experts for labeling, developing efficient labeling tools, employing semi-supervised learning to reduce dependency on labeled data, and establishing a continuous update mechanism for labeled datasets to adapt to evolving threat landscapes. To address the scarcity of training samples in the blockchain domain, this paper introduces a method for generating additional Solidity smart contract training samples using data augmentation techniques. Given that traditional data augmentation methods are not suitable for Solidity, the approach involves converting Solidity contracts into Python code for processing, then reverting them back to Solidity post-augmentation, with provided code examples. Furthermore, leveraging established non-blockchain code to train blockchain-related models enhances model performance and generalization capabilities. These strategies effectively tackle the issue of insufficient training samples in the blockchain field and offer new perspectives on the conversion between Solidity and Python.
This paper proposes a supply chain transparency improvement and smart contract optimization method based on blockchain, artificial intelligence and communication network. First, combining the decentralized characteristics of blockchain, a transparent and tamper-proof data management platform is designed to automatically execute supply chain transactions through smart contracts, and at the same time, the efficient data transmission characteristics of the communication network are used to achieve rapid synchronization of information between multiple nodes. Secondly, machine learning and deep learning algorithms are used to optimize demand forecasting, resource scheduling and smart contract terms in the supply chain, and real-time data collection and transmission are achieved through the communication network, further improving the overall operation efficiency of the supply chain. Experimental simulation results show that the supply chain system based on this method has significant advantages in improving transparency, the execution efficiency of smart contracts is improved by 30%, and the overall response time is shortened by 20%.
This study explores the optimization path of the e-commerce supply chain logistics management model using blockchain technology, breaks the bottlenecks of information barriers, low operational efficiency and high costs in the traditional operation model, adopts design strategies to build a blockchain technology application architecture, integrates distributed ledger technology, smart contract functions, Internet of Things technology and decentralized identity authentication methods, and implements refined improvements in each stage of the e-commerce supply chain. Data collection is conducted on the order execution process, logistics distribution links and cost components of the three e-commerce platforms A, B and C, and an in-depth comparative analysis is conducted on the differences between the traditional model and the blockchain optimization model in terms of efficiency, economic cost and customer satisfaction. The research results show that the optimization measures using blockchain technology have significantly improved the efficiency of order processing and distribution, effectively reduced logistics cost expenditures, and significantly increased customer satisfaction levels.
随着全球数字贸易的深化发展，跨境电商作为国际贸易新业态正面临信任机制重构的重要转折点。本文聚焦区块链技术在跨境电商信任机制中的创新应用及其现实挑战，旨在探索技术赋能与制度创新的协同路径。通过系统分析区块链的分布式账本、智能合约等核心技术特征，揭示其在商品溯源、支付结算、供应链管理等关键场景中的信任构建机理，提出信息透明化、流程自动化等突破性解决方案，研究进一步剖析区块链技术落地的多维瓶颈，包括跨境法律冲突、隐私保护悖论、行业标准缺失等复合型挑战，并针对性提出跨链技术优化、智能合约法律确权、零知识证明加密等创新性改进策略。研究不仅为区块链驱动的信任机制优化提供理论框架，更从技术适配与制度调适的双重视角，为跨境电商企业构建合规高效的区块链应用体系提供实践指引，推动跨境贸易生态向可信化、智能化方向演进。As global digital trade continues to evolve, cross-border e-commerce is at a crucial juncture regarding the establishment of trust mechanisms. This paper examines the innovative use of blockchain technology in enhancing trust within cross-border e-commerce and the practical challenges it faces. The goal is to investigate how technology and institutional innovation can work together. By analyzing key features of blockchain, such as distributed ledgers and smart contracts, the paper highlights how these elements can foster trust in critical areas like product traceability, payment processing, and supply chain management. It suggests solutions like increased information transparency and automated processes while also addressing various implementation challenges, including international legal issues, privacy concerns, and the absence of industry standards. The paper proposes strategies for improvement, such as optimizing cross-chain technology, confirming legal rights for smart contracts, and employing zero-knowledge proof encryption. This research not only offers a theoretical framework for enhancing blockchain-based trust mechanisms but also provides practical advice for cross-border e-commerce businesses to develop compliant and efficient blockchain systems, ultimately steering the evolution of cross-border trade towards a more trustworthy and intelligent future.
The cryptocurrency market, with its 24/7 trading and high volatility, challenges traditional quantitative strategies in path dependency, high-frequency optimization, and risk control. A "prediction-decision" framework is proposed, integrating Gradient Boosting Regression Trees (GBRT) for short-term forecasting and deep reinforcement learning techniques including Rainbow Deep Q-Network (Rainbow DQN) and Soft Actor-Critic (SAC) algorithms for dynamic optimization. The framework combines the complementary strengths of GBRT's pattern recognition capabilities and deep reinforcement learning's adaptive decision-making mechanisms. A spatiotemporal experience replay mechanism tailored to cryptocurrency fat-tailed distributions boosts BTC/USDT annual returns by 37.2% and enhances TD3's drawdown control by 63% during the LUNA crisis. Empirical results show SAC achieves 152% excess returns (Sharpe 2.81) in ETH/USDT trading, while Rainbow DQN yields 287% returns in trend markets. A dynamic reward function reduces maximum drawdown from 42.7% to 19.3%, and the hybrid architecture curtails losses by 23.8% during the 2020 "March 12" crash. Curriculum learning accelerates TD3 convergence by 59% with 37% GPU memory reduction. This study establishes a verifiable algorithmic framework and advances high-frequency trading through synergistic ML/RL integration, offering a dynamic decision-making paradigm for evolving financial markets.
Contemporarily, blockchain techniques have been developed rapidly. This study describes the development of a blockchain-based website designed to display cryptocurrency information securely and transparently. The site utilizes Ethereum and smart contracts to ensure data immutability and transaction transparency. The front end is developed using the React framework to enhance the user experience, and the back end uses Web3.js for real-time blockchain interaction. A detailed case study of the cryptocurrency demo evaluated the performance of the website and the practical application of blockchain technology. The findings demonstrate the effectiveness of blockchain in securely managing and displaying sensitive financial data. In addition, the study highlights blockchain's potential to revolutionize fintech infrastructure by improving security and transparency, which are essential for the dissemination of financial information. These results makes a significant contribution to the use of blockchain in web development, drawing a blueprint for future research directions with a focus on optimizing transaction processes and improving user accessibility. Overall, the study demonstrates the transformative potential of blockchain technology in digital transactions and sets the stage for future innovation in this rapidly evolving field.
As an important product of the Internet era, the essence of green sharing economy is to rely on Internet technology. In particular, big data technology will re-use idle social resources and create new market value. However, with the increasing application of sharing economy in the field of green industry, the problems of data security, circulation, sharing and privacy protection gradually appear. Big data technology has become the biggest bottleneck for the further development of sharing economy. Blockchain technology is a new Internet architecture composed of various technologies and communication protocols. Through its encryption sharing, distributed ledger and other characteristics, it provides new methods and ideas for data circulation and sharing, which complement big data technology. Therefore, the integration of blockchain technology and big data technology can subvert the traditional business model of sharing economy. This can innovate the mode and development of traditional green industry, and provide new opportunities for the development of green sharing economy.
T A Mohanaprakash, Ranganayaki V.C, M. S. Minu, D. A. · 5 authors
Many have long aimed to create a safe electronic voting system that maintains the confidentiality and integrity of traditional voting methods while using the convenience and openness of modern technology. Ballot paper or electronic voting machines are the current voting schemes in every nation, and democratic voting is a significant event in every country. Problems with these procedures abound, including lack of openness, poor voter turnout, vote manipulation, mistrust of the election body, forgery of unique identification (voter ID card), delays in disseminating results, and, most importantly, security breaches. Prioritizing the security of digital voting is of utmost importance when contemplating implementing a digital voting system. The article assesses the objective of building a blockchain-based e-voting system [BC-E-VOT] that uses digital voting technology. Electronic voting methods that leverage the distributed ledger attract much attention because they can make digital voting more transparent, secure, and honest. As shown in this research, a successful strategy for electronic voting may be achieved by using Blockchain's cryptographic underpinnings and transparency. Due to its complete transparency, the suggested approach satisfies the essential criteria for electronic voting systems. Since Blockchain employs a decentralized mechanism for data storage rather than storing all of the data in one central place, it becomes challenging to tamper with the data when utilizing this technology to build a decentralized application. By creating a decentralized system using the WSN platform, a third party is no longer needed to oversee the election's access control. This article provides a system for electronic voting that guarantees privacy, trustworthiness, and security. The suggested approach is practical and secure, according to the findings.
Cryptocurrency being a digital or virtual currency that uses cryptography to secure transactions and control the creation of new units. Bitcoin, one of the most popular cryptocurrency, offers various advantages such as security, transparency, and efficiency. The value of Bitcoin can change over time, similar to the regular currencies, and the need to predict the value can be as important as those in the regular. The prediction can be done by multiple algorithms. The purpose of this research is to compare five algorithms in predicting bitcoin value based on Root Mean Squared Error (RMSE) and Squared Error (R2). The five algorithms compared can model the prediction of changes in the bitcoin cryptocurrency, effectively. Based on the experiment, Random Forest outperformed the other algorithms based on its RMSE and R2 result
Nedavni tehnološki razvoj utjecao je na turističku industriju, a jedna važna komponenta ovog pomaka bilo je usvajanje kriptovaluta. U ovom radu dan je uvid u razvoj i definiciju kriptovaluta, njihovu primjenu u turizmu te rezultate provedenih istraživanja o primjeni kritpovaluta u Republici Hrvatskoj. Od pojave kriptovaluta, za sektor putovanja i turizma bilo je ključno razmotriti mogu li se integrirati u svoje sustave plaćanja. U posljednjih deset godina kriptovalute su sve popularnije. Kriptovalute i blockchain tehnologija pojavile su se kao transformativne snage u različitim sektorima, nudeći jedinstvene pogodnosti i predstavljajući značajne izazove. Naime, kriptovalute putnicima pružaju sigurnu i učinkovitu alternativu u mogućnosti plaćanja bez upotrebe valute ili tradicionalnih bankovnih usluga. S druge strane, kriptovalute pružaju fleksibilnu i prikladnu opciju turističkim poduzećima za primanje uplata od putnika bez potrebe za tradicionalnim uslugama obrade plaćanja. Korištenje novih tehnologija imalo je više pozitivnih nego negativnih utjecaja na turizam, ali niti jedan nije potaknuo radikalnu promjenu. Općenito, turistička industrija tek treba dodatno poboljšati korištenje blockchain tehnologije u smjeru upravljanja kvalitetom usluga korisnicima. Iako kriptovalute i blockchain tehnologija obećavaju, one su još uvijek u početnoj fazi, s tekućim tehnološkim, regulatornim i društvenim izazovima.
Smart contracts are widely utilized in cross-chain interactions, where their results are transmitted from one blockchain (the producer blockchain) to another (the consumer blockchain). Unfortunately, the consumer blockchain often accepts these results without executing the smart contracts for validation, posing potential security risks. To address this, we propose a method for validating cross-chain smart contract results. Our approach emphasizes consumer blockchain execution of cross-chain smart contracts of producer blockchain, allowing comparison of results with the transmitted ones to detect potential discrepancies and ensure data integrity during cross-chain data dissemination. Additionally, we introduce the confirmation with proof method, which involves incorporating the chain of blocks and relevant cross-chain smart contract data from the producer blockchain into the consumer blockchain as evidence (or proof), establishing a unified and secure perspective of cross-chain smart contract results. Our verification results highlight the feasibility of cross-chain validation at the smart contract level.
Implementacija blockchain i NFT tehnologije u turizmu i ugostiteljstvu predstavlja novi pris-tup digitalnoj transformaciji u spomenutim sektorima, čime se pojavljuje potreba za istraživa-njem ove tematike. Temeljna tehnologija iza ovih pojmova, tzv. blockchian, tehnologija je poznata po kriptografskim blokovima koji osiguravaju siguran prijenos podataka čime je o-mogućen nastanak digitalnih decentraliziranih kriptovaluta i jedinstvene digitalne imovine koja se ne moze replicirati, tzv. NFT (Non-fungible token). U turizmu i ugostiteljstvu, ove tehnologije mogu revolucionirati način poslovanja, omogućiti bržu i sigurniju razmjenu in-formacija između dionika i time otvoriti prostor ka stvaranju inovativnih poslovnih modela. Završni rad analizira aktualne i potencijalne primjene ovih tehnologija, ističući ključne koristi i izazove koji proizlaze iz njihovog usvajanja. Analiza dosadašnje literature na ovu temu ot-kriva da su turizam i ugostiteljstvo među prvima prihvatili digitalne inovacije, prepoznavši potencijal blockchain tehnologije za unapređenje poslovnih procesa jer transformacija klasi-čnih centraliziranih sustava u decentralizirane blockchain platforme pruža dugoročnu konku-rentsku prednost tvrtkama u ovim sektorima. Empirijsko istraživanje provedeno anketnim upitnikom, pokazuje da su turisti donekle upoznati s blockchain tehnologijom, iako se rijetko susreću s njenom primjenom u turističkim iskustvima. Ipak, većina ispitanika pozitivno gleda na širu primjenu blockchain tehnologije u turističkoj ponudi, što ukazuje na veliki tržišni potencijal za daljnji razvoj i istraživanja. Međutim, postoji nekoliko izazova koji prate još uvijek nedovoljnu implementaciju ovih tehnologija, uključujući pitanja sigurnosti, regulacije i interoperabilnosti. Osiguravanje povjerenja korisnika i usklađenost s propisima ključni su faktori za uspješnu integraciju blockchain i NFT tehnologije u turistički sektor.