OEURO is a EUR-denominated clearing token designed for direct account-to-account settlement.It is implemented as a restricted ERC-20 token with 6 decimals and a deliberately narrow functional scope.Its primary purpose is clearing and settlement, rather than market trading or speculative use.Ordinary transfers are designed for direct EOA-to-EOA circulation.The reference implementation disables approve() and transferFrom().Ordinary transfers to smart-contract recipients are rejected. Minting and burning are explicit operations controlled by the manager.Authorized oracles may submit MINT or BURN requests but cannot directly alter token supply.Oracle requests remain valid for 24 hours and must be executed or rejected by the manager.External clearing references are protected against replay through single-use proof handling.The architecture therefore separates attestation authority from final settlement authority.OEURO uses a restricted recipient model for sensitive infrastructure addresses.The reference contract uses OpenZeppelin ERC-20 and Ownable2Step components.Ethereum Sepolia is used as the current public reference testnet environment.This Zenodo archive contains the Solidity source code, ABI, flattened contract and the OEURO technical white paper and audit reference.
konstantinos votis, Panagiotis Symeonidis, Centre for Research and Technology Hellas
This deliverable provides an overview of the Digital Product Passport, Distributed Ledger Technology, and blockchain applied to the needs of ALUMIL in order to demonstrate the use of DPPs in the Aluminium industry sector.
Open access
Physical Unclonable Functions (PUFs) and Hardware Security
AbstractData security has become a growing concern for individuals, businesses, and governments because of increasing cyberattacks, data tampering, and unauthorized access in centralized systems. According to the National Institute of Standards and Technology, blockchain technology addresses these challenges by providing a tamper-evident and tamper-resistant distributed ledger that is implemented without a central authority and records transactions across multiple computers. Its decentralized structure eliminates reliance on a single authority, reducing the risk of system failures and targeted attacks. This Article reviews core blockchain security features, including cryptographic protection, decentralization, consensus mechanisms, immutability, transparency, and smart contract security. Cryptographic tools such as hashing and public-private key systems protect data confidentiality, ensure integrity, and verify user identities. Consensus models like Proof of Work, Proof of Stake, and Practical Byzantine Fault Tolerance enable secure transaction validation. The immutability of blockchain records makes unauthorized changes difficult, supporting trust and auditability. The study also examines threats such as 51% attacks, Sybil attacks, private key theft, and smart contract vulnerabilities, and recommends security practices to mitigate these risks. Finally, the Article explores blockchain applications in healthcare, banking, supply chains, voting, and digital identity. The findings indicate that, despite technical and operational challenges, blockchain offers a promising approach to securing digital transactions, protecting sensitive data, and building trust in the digital environment.
Кваліфікаційна робота бакалавра складається зі вступу, чотирьох розділів, висновків, списку використаних джерел та додатків. Перший розділ кваліфікаційної роботи присвячено дослідженню актуального стану досліджуваної проблематики, обґрунтуванню обраного напряму роботи, а також визначенню та відбору методів і засобів проектування. У другому розділі розглянуто та обґрунтовано підходи й технології для вирішення поставлених завдань. Також наведено функціонально-структурну схему об’єкта проектування та ER-діаграму бази даних. Третій розділ охоплює безпосередню розробку програмного забезпечення та практичне втілення проєктованого об’єкта. Четвертий розділ містить SEO-оптимізацію інформаційно-комп’ютерної системи. У висновках підсумовано результати, отримані в ході виконання всіх попередніх розділів роботи.
Cryptocurrency networks operate on decentralized systems that require efficient performance monitoring for transparency, security, and real-time insights. The establishment of a frontend-only, lightweight dashboard for displaying network metrics linked to popular digital currencies is addressed in this research paper. It collects live data from public APIs and visualizes key performance indicators such as token prices, transaction volume, and ownership distribution using open-source tools like Chart.js. The design emphasizes responsiveness, usability, and data accessibility, targeting users interested in monitoring trends and network health without backend dependencies. This dashboard simplifies data interpretation for end- users and promotes real-time decision-making.
U ovom završnom radu opisan je postupak izrade funkcionalnog Bitcoin novčanika. Novčanik je kreiran u razvojnom okruženju Android Studio, programskome jeziku Kotlin, izrađen je za sve uređaje koji imaju operativni sustav Android 10 (API 29) ili više, pisan je u MVVM arhitekturi (engl. Model–view–viewmodel), a za verzioniranje je korišten sustav GitHub. Svrha ovog novčanika je primanje i slanje bitcoina na glavnoj i testnoj mreži te pregled povijesti transakcija. Za pohranjivanje privatnih i javnih ključeva i ostalih osjetljivih podataka se koristi android keystore i shared preferences. Podatci koji se dohvaćaju s lanca blokova (engl. Blockchain) se pohranjuju u SQLite bazu podataka na uređaju. Vizualno sučelje aplikacije je izrađeno u XML-u kroz razvojno okruženje Android Studio.
The articles in this special section focus on distributed ledger technologies (DLT). DLT, of which blockchain is a popular example, are increasingly becoming a popular means to maintain transactional integrity and achieve consensus among competing parties in many modern distributed data exchanges. Indeed, a Gartner survey estimates that by 2020, DLT and blockchain will support the global movement and tracking of $2 trillion of goods and services annually. Unlike centralized files and databases, distributed ledgers rely on peering nodes to record, share, and synchronize transactions and data in their individually maintained local ledgers. In the case of blockchain, information is organized into blocks that are securely and transparently chained together. These blocks become immutable global knowledge among all peers using consensus algorithms to achieve data synchronization. The “append-only, globally accepted” transactions supported by blockchain technologies have given rise to both opportunities and challenges compared to traditional data storage systems. One of the challenges faced by current information sharing systems, and a key concept that makes DLT appealing is the support for the creation of large scale systems from nodes and components that do not trust each other. Being able to reach consensus and share a commonly verifiable ledger is a very powerful primitive, which is already being considered for data sharing applications in energy, pharmaceuticals, and many other domains.
Sa sve većom prisutnosti kriptovaluta, pojedinac osjeća potrebu sudjelovanja u trgovanju i korištenju kriptovaluta. S obzirom na visoke troškove i rizike ulaganja, javlja se potreba za edukacijom i treningom korisnika prije sudjelovanja na financijskom tržištu. U sklopu ovog rada, izrađena je mobilna aplikacija Euphoria namijenjena upravo simuliranom trgovanju. Programski kod aplikacije pisan je u programskom jeziku Kotlin, baza podataka u SQL-u, a dizajn u XML-u. Pregled cijena kriptovaluta u stvarnom vremenu postignut je spajanjem na coinmarketcap.com API servis uz pomoć Retrofit biblioteke i HTTP GET metode. Aplikacija omogućuje pregled cijena kriptovaluta i njihovu kupovinu i prodaju, te izradu portfelja korisnika. Baza podataka same aplikacije implementirana je uz pomoć Room biblioteke. Uz implementaciju baze podataka, omogućeno je korištenje i pregled portfelja korisnika.
U ovom završnom radu obrađen je pojam hardvera za rudarenje kriptovaluta. Nakon uvoda u prvom poglavlju opisana je prva kriptovaluta "Bitcoin". U drugom poglavlju objašnjen je protokol "Blockchain" na koji Bitcoin funkcionira. U trećem poglavlju opisane su transakcije, te posao rudara u bitcoin mreži. U četvrtom poglavlju je opisana povijest hardvera, te detaljan opis hardvera ovisno o generaciji. U zadnjem poglavlju je opisan suvremeni hardver te najbolje rješenje za Bitcoin i Ethereum, drugu najvrjedniju kriptovalutu.
Bitcoin (BTC) je digitalna, decentralizirana, anonimna platna mreža, a ujedno i kripto valuta koja je korištena u toj mreži. BTC se koristi za elektronsko plaćanje usluga. U pojedinim mjestima, također, je moguće platiti noćenje u lancu hotela, kupiti pizzu, kupiti VPB servis... Diplomski rad podijeljen je na dva glavna dijela. U prvom dijelu objašnjeno je sve što potrebno za razumjeti što je to Bitcoin. U drugom dijelu opisani su bitniji dijelovi koda Bitcoin algoritam
Purwono Purwono, Alfian Ma’arif, Wahyu Rahmaniar, Qazi Mazhar ul Haq · 6 authors
Blockchain technology has a promising future in a number of industries and enterprises. Formerly connected to virtual currency like Bitcoin, blockchain has evolved into a versatile technology with many applications. In the upcoming years, it is predicted that blockchain will revolutionize a variety of industries, including banking, supply chain management, healthcare, voting systems, and more. The future of blockchain technology depends critically on its ability to increase security and transparency. By providing a decentralized and unchangeable record, eliminating the need for middlemen, and boosting participant confidence, blockchain promotes secure and traceable transactions. This transparency has the potential to transform whole industries by reducing fraud, streamlining processes, and increasing output. Blockchain also has the power to change financial systems. Blockchain-based smart contracts facilitate faster, more efficient transactions by automating and enforcing contractual agreements without the need for middlemen. By enabling speedier cross-border transactions, reducing costs, and boosting financial inclusion, tokenization and blockchain-based digital currencies have the potential to overturn conventional banking institutions. Blockchain’s key attributes, including decentralization, transparency, immutability, and security, make it a desirable choice for a range of organizations. Cross-border payments, trade finance, and smart contracts are just a few of the financial sector processes that blockchain technology has the potential to enhance and automate, lowering costs and increasing productivity. Additionally, the tamper-resistance of blockchain technology can boost transaction security and reliability, allowing for a wider use in traditional financial institutions. Outside of the financial industry, blockchain technology has a lot of promise, particularly in industries like supply chain management, healthcare, energy, intellectual property, and governance. By enabling transparent and traceable transactions, blockchain may improve supply chain efficiency, ensure product authenticity, and boost customer trust. By facilitating the secure exchange of patient data and research data, the decentralized nature of blockchain technology can enhance data security, interoperability, and privacy in the healthcare sector. A more decentralized and sustainable energy ecosystem may be supported by blockchain technology through peer-to-peer energy exchange, grid management, and monitoring of renewable energy certificates in the energy sector. Additionally, blockchain technology has the potential to transform decentralized governance structures, voting procedures, intellectual property rights, and digital identity management. By allowing people to own and manage their digital identities, blockchain can enhance privacy and reduce identity theft. Blockchain-based voting systems can offer transparency, security, and verifiability, thereby increasing voter turnout and public trust in democratic institutions. Blockchain can also enable the secure and transparent management of intellectual property rights, fostering author credit and just compensation.