Damiano Di Francesco Maesa, Andrea Lisi, Paolo Mori, Laura Ricci · 5 authors
In this paper we focus on the mutability of Non Fungible Tokens associated to digital assets in the metaverse. We argue that mutability is a key property of digital assets if we want to provide users with a virtual experience in the metaverse as close as possible to the real world. We discuss the shortcomings of current dynamic Non Fungible Token proposals, and present the advantages of a new mutable Non Fungible Token approach based on decoupling the asset ownership and descriptor in separate smart contracts. To show a possible usage of mutable Non Fungible Tokens in a metaverse, we provide a reference example about a university gadget. Finally, we present a proof of concept implementation of our reference example on the Decentraland metaverse and the Goerli Ethereum testnet to showcase its feasibility.
Recently, the birth of non-fungible tokens (NFTs) has attracted great attention. NFTs are capable of representing users’ ownership on the blockchain and have experienced tremendous market sales due to their popularity. Unfortunately, the high value of NFTs also makes them a target for attackers. The defects in NFT smart contracts could be exploited by attackers to harm the security and reliability of the NFT ecosystem. Despite the significance of this issue, there is a lack of systematic work that focuses on analyzing NFT smart contracts, which may raise worries about the security of users’ NFTs. To address this gap, in this paper, we introduce 5 defects in NFT smart contracts. Each defect is defined and illustrated with a code example highlighting its features and consequences, paired with possible solutions to fix it. Furthermore, we propose a tool named NFTGuard to detect our defined defects based on a symbolic execution framework. Specifically, NFTGuard extracts the information of the state variables from the contract abstract syntax tree (AST), which is critical for identifying variable-loading and storing operations during symbolic execution. Furthermore, NFTGuard recovers source-code-level features from the bytecode to effectively locate defects and report them based on predefined detection patterns. We run NFTGuard on 16,527 real-world smart contracts and perform an evaluation based on the manually labeled results. We find that 1,331 contracts contain at least one of the 5 defects, and the overall precision achieved by our tool is 92.6%.
Aidin Rasti, Amal Ahmed Anda, Sofana Alfuhaid, Alireza Parvizimosaed · 8 authors
Complementary materials for the paper that extends the conference paper : "Symboleo2SC: From Legal Contract Specifications to Smart Contracts" <code>symboleo-js-core</code> includes the implementation of the ontology of Symboleo. <code>Symboleo2SC-demo</code> includes the five evaluated Symboleo contracts, their generated smart contracts, and their unit tests.
One blockchain technological update thus far includes smart contract functionality implemented in Ethereum. One of its use cases, the ERC721 Non-Fungible Token Standard (NFT), has gained attention from current industries. NFTs demonstrated digital content transactions with guaranteed uniqueness using unchangeable timestamp on the blockchain. However, the functional limitations of NFT assurance are rarely in focus, and contrary to excessive NFT user expectations, security risks that must be addressed include complex issues. One such risk is NFT fraudulent trading using forged content. Specifically, hard forks in blockchains are extremely important triggers for attacks, as they allow the exact same NFT to be operated on multiple chains. This could depreciate NFT value, and presents a risk that must be addressed to ensure sound NFT transactions. In this study, NFT operational issues in the case of a blockchain fork are summarized, and a cross-referencing scheme using network identities is proposed to prevent the impact of a hard fork.
Blockchain Technology Applications and Security
Digital Rights Management and Security
Advanced Steganography and Watermarking Techniques
A Smart Legal Contract (SLC) is a specialized digital agreement comprising natural language and computable components. The Accord Project provides an open-source SLC framework containing three main modules: Cicero, Concerto, and Ergo. Currently, we need lawyers, programmers, and clients to work together with great effort to create a usable SLC using the Accord Project. This paper proposes a pipeline to automate the SLC creation process with several Natural Language Processing (NLP) models to convert law contracts to the Accord Project’s Concerto model. After evaluating the proposed pipeline, we discovered that our NER pipeline accurately detects CiceroMark from Accord Project template text with an accuracy of 0.8. Additionally, our Question Answering method can extract one-third of the Concerto variables from the template text. We also delve into some limitations and possible future research for the proposed pipeline. Finally, we describe a web interface enabling users to build SLCs. This interface leverages the proposed pipeline to convert text documents to Smart Legal Contracts by using NLP models.
Abstract The audiovisual media content (AMC) industry, focused on film and television drama production, is confronted with a broken business model due to the dominance of centralized streaming platforms. The top platforms dominate global distribution but only offer slices of produced and heritage content. In addition, they compete with the AMC industry by producing a majority of content distributed. This leaves fewer gatekeepers deciding on the content to be distributed and less diverse content easily accessible to audiences Consequently, audiences are compelled to engage in pirating movies despite a willingness to pay. Recent blockchain innovations towards the so-called Web3 promise to restore this broken business model by re-establishing direct contact between the producers of films and their audiences. The benefits of networks (peer-to-peer or community based) in combination with Web3 follow the principle of decentralized disintermediation while comprising elements such as FIAT to crypto-payment mechanisms, self-sovereign identity authentication, blockchain oracles, decentralized autonomous organizations (DAO), and so on. A gap exists with regard to methodological designs of Web3 decentralized applications (DApp) and their ecosystems for restoring a viable AMC business model that not only eliminates the need for piracy activities but even the need for platforms. The DApp architecture designs for the film- and media industry ecosystem creation in this paper allow, on the one hand, for a legal compliance check ahead of a costly deployment. On the other hand, the DApp designs of this paper also allow for a tailored blockchain technology stack development. Ultimately, this research is a continuation of an earlier whitepaper to establish a participatory economy in the film industry from peer-to-peer streaming.
Non-fungible tokens (NFTs) are digital assets that provide unique ownership and authenticity of digital media such as art, music, and collectibles.NFT Marketplace is a blockchain-based platform that enables the creation, trading, and collecting of NFTs.The platform leverages blockchain technology to ensure the authenticity and ownership of NFTs, providing a secure and transparent way to transact digital assets.In this major project report, we explore the NFT Marketplace and its underlying blockchain technology.We provide an overview of the platform's features, including the ability to tokenize any digital asset, create customizable smart contracts, and sell NFTs with low fees and instant trades.We also discuss the advantages and disadvantages of the platform, including its ease of use, potential for fraud, and scalability challenges.The Non-Fungible Tokens (NFTs) have revolutionized the digital realm, redefining the concept of ownership and trade of unique digital assets.NFTs represent one-of-a-kind tokens, each verifiably and indelibly linked to a specific digital or physical asset, encompassing diverse forms of content, including video, audio, and images.These unique tokens have paved the way for creators to monetize their digital creations while providing collectors with an innovative means to invest, trade, and showcase their multimedia NFT collections.Central to the NFT ecosystem are NFT marketplaces, digital platforms designed to facilitate the creation, sale, and management of NFTs in various multimedia formats.These marketplaces have proliferated, providing creators with the means to mint NFTs, buyers with the opportunity to acquire them, and collectors with platforms to curate and trade their diverse NFT portfolios.We explore the multifaceted world of NFT marketplaces, focusing on their pivotal role in the creation, sale, and management of video, audio, and image NFTs.We analyze the economic implications, including pricing strategies and royalties, while addressing environmental sustainability concerns associated with NFTs.Challenges and opportunities encountered within this dynamic ecosystem are critically examined, including scalability, intellectual property rights, and the emergence of decentralized NFT marketplaces.Through in-depth case studies, we offer insights into the unique features and innovative approaches adopted by leading NFT marketplaces, shedding light on the transformative potential of this digital metaverse.This report serves as a valuable resource for those seeking a comprehensive understanding of NFT marketplaces catering to video, audio, and image NFTs, emphasizing the profound impact these tokens have on the creation, trade, and experience of digital content across various media formats.Navigating this dynamic digital frontier necessitates a nuanced perspective, and our survey aims to provide a holistic view of this rapidly evolving landscape.
Raffaele Ciriello, Alexandra Cecilie Gjøl Torbensen, Magnus Rotvit Perlt Hansen, Christoph Müller-Bloch
Abstract Initially designed to protect intellectual property (IP) of digitalized information goods such as music, games, or books, existing centralized digital rights management (DRM) systems mostly serve the interests of major publishers, with scant inclusion of rights owners, creators, and consumers. Although various blockchain-based DRM systems have been proposed, most of them mirror existing counterproductive IP restrictions. Analyzing the music industry as a case in point, this paper proposes design principles for blockchain-based DRM systems that provide an integrated and flexible solution by enabling transparent music licensing structures, consistent and complete rights metadata, and efficient and transparent royalty payout. The solution can be achieved by storing rights metadata on a public distributed ledger, by validating metadata through a consensus mechanism on a permissioned blockchain, and by algorithmically enforcing royalty payout via stablecoin through a smart contract. The design principles were evaluated by industry experts, validating their benefit for the music industry by increasing surplus value that is currently destroyed through previous suboptimal designs.
Context: Smart contracts are computerized self-executing contracts that contain clauses, which are enforced once certain conditions are met. Smart contracts are immutable by design and cannot be modified once deployed, which ensures trustlessness. Despite smart contracts' immutability benefits, upgrading contract code is still necessary for bug fixes and potential feature improvements. In the past few years, the smart contract community introduced several practices for upgrading smart contracts. Upgradeable contracts are smart contracts that exhibit these practices and are designed with upgradeability in mind. During the upgrade process, a new smart contract version is deployed with the desired modification, and subsequent user requests will be forwarded to the latest version (upgraded contract). Nevertheless, little is known about the characteristics of the upgrading practices, how developers apply them, and how upgrading impacts contract usage. Objectives: This paper aims to characterize smart contract upgrading patterns and analyze their prevalence based on the deployed contracts that exhibit these patterns. Furthermore, we intend to investigate the reasons why developers upgrade contracts (e.g., introduce features, fix vulnerabilities) and how upgrades affect the adoption and life span of a contract in practice. Method: We collect deployed smart contracts metadata and source codes to identify contracts that exhibit certain upgrade patterns (upgradeable contracts) based on a set of policies. Then we trace smart contract versions for each upgradable contract and identify the changes in contract versions using similarity and vulnerabilities detection tools. Finally, we plan to analyze the impact of upgrading on contract usage based on the number of transactions received and the lifetime of the contract version.
<title>Abstract</title> Digital assets backed up by blockchain technology are termed Non-Fungible Tokens (NFTs). Every NFT is uniquely identified by its metadata, stored in the smart contract. This metadata can consist of associated images, descriptions , attributes, and other relevant details in a JavaScript Object Notation (JSON) object. Most of these NFTs are static; therefore, their metadata remains immutable. Due to rising blockchain use cases like real-world token regulation and blockchain-based ticketing platforms, a need arises to modify the existing metadata and require interaction for community engagement. Here, Dynamic NFTs (DNFTs) bring the notion of adding upgradeability and interactivity to existing NFTs. We propose a DNFT generation system built on top of decentralized oracle networks and utilizing on-chain metadata using smart contracts, which could be used as a base for future dynamic NFT generation models. Furthermore , we are bringing the web2 equivalent experience to viewable content, which can be used for ad spaces and real-time messaging in the form of NFTs. Henceforth, we are augmenting NFTs for versatile use cases, such that they are more than just static assets.
Although data exchange and transparency are encouraged by the Internet, digital information is not protected by it. It has become challenging to publish the Digital Rights Management system in today’s digital environment that can be regarded as well-protected. The value of digital work that is quickly accessible in open-source settings will eventually be zero to the creator. Nonetheless, anyone can download and make copies of content because it is available online. Since the value of data is typically based on how difficult it is to access, the worth of online content gradually declines.It may serve as a good alternative to the aforementioned issues. In this paper, we suggest a blockchain-based approach for a DCM system. In order to keep information transparent and secure, we store thedetails of copyright transactions on the blockchain. Smart Contact replaces the requirement for centralised servers to validate identities and issue licences by ensuring the validity of copyright transactions and issuing licences automatically. The possibility for using blockchain based to address the issue of managing digital copyright. This paper outlines a complete digital copyright management system (DCMS) centred on a public blockchain.
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Francesco Spegni, Lorenzo Fratini, Massimiliano Pirani, Luca Spalazzi
This work deals with the automatic generation of smart contracts to enforce compliance to a given BPMN choreography of requests sent by a set of independent actors. The choice of smart contracts is justified by the desire not to centralize the enforcement process when there are multiple independent actors characterized by low mutual trust. The choice of BPMN choreographies as an alternative to BPMN processes and collaborations is instead justified by the desire to leave the actors free to dynamically organize their internal processes in the way they prefer, provided that the interactions with the other actors respect some agreed protocol. This work proposes a formal framework to interpret choreographies and translate them onto smart contract enforcers. The framework has been implemented on a free open-source tool named ChoEn and tested by means of a running example.
Sotiris P. Gayialis, Evripidis P. Kechagias, Georgios Α. Papadopoulos
Undoubtedly, supply chain operations management is becoming more demanding for product tracing due to regulatory frameworks and fraudulent incidents. Therefore, rapidly increasing challenges arise in transparency, tracking, and data storage in many product supply chains. Especially in the case of wine supply chains, timely and accurate traceability is vital, as this industry is plagued by frequent counterfeiting activities that pose significant risks to both consumer health and business viability and prosperity. Blockchain technology can serve as a crucial aid for constructing modern wine supply chains by offering increased security and trust between all supply chain stakeholders. This paper presents a framework for developing Ethereum-based Blockchain distributed applications and demonstrates a use case for creating such an application for a wine traceability system. The developed distributed application enables the participants of the wine supply chain to track wines by adding and monitoring data about each individual wine bottle's production, fermentation, aging, bottling, and distribution, providing full supervision of its production and distribution. The demonstrated use case shows the different types of users and their interactions with the system to fully comprehend the advantages it can offer to all supply chain stakeholders as well as consumers and controlling authorities.
A smart contract is a translation of a standard paper-based contract that can be enforced and executed by a contract management system. At a high level of abstraction, a contract is only a document that describes how the signing parties are to behave in different scenarios; nevertheless, the translation of a typical paper-based contract to its electronic counterpart has proved to be both time-consuming and difficult. The requirement for a language capable of capturing the core of a contract in simple phrases and definitions has been a focus of study for many years. EROP (Events, Rights, Obligations, Prohibitions) is a contract specification language that breaks a contract down into sets of events, rights, obligations, and prohibitions.
A Blockchain technology guarantees to be highly trending and empowering in financial domain computing programs.The virtual economic system is becoming an fundamental a part of present day life.in order the use of the digital global increases there are more probabilities of lower is the safety stage.So greater using digitization more the frauds and less the safety.In a few cases of personal information, leakage has brought back into the focus the security troubles with the extraordinary identification sharing mechanisms.A client is predicted to provide his identification for authentication by means of unique agencies.So the KYC process offers with the identity of the user.And in flip, provides the desired security.The KYC strategies which are used by the banks are absolutely dependent on the encryption that's sluggish and it is able to result in the lack of patron info to other their birthday celebration economic establishments.This device can be efficient by means of using Blockchain technology, which has the ability to automate numerous manual approaches and it's also proof against hacks of any type.The immutable blockchain block and its distributed ledger is the best complement to the system of KYC.With the addition of clever contacts, fraud detection may be computerized.For KYC identification info garage, we are able to employ any types of KYC.So, the banks can develop a shared non-public blockchain within the financial institution premise and the equal can be used for verifying the documents.This permits the user to get control in their touchy files and also makes it easier for banks to reap the documents they want for compliance.
The internet is one of the most influential inventions when we talk about digitization. At the ad mist of<br> this fast development of knowledge, Innovations and communication technologies, several activities in<br> everyone’s life are unified on-line and that they become more fascinated and practical towards it. An<br> enormous and huge growth in variety of on-line users has activated day by day where by it created a<br> replacement of business development and from investments to cash transfer, everything goes paperless in<br> our economy to facilitate these monetary activities like shopping, mercantilism and many more virtual<br> activities. The latest and most promising addition to the digital payment sector is crypto currency Money<br> started being ‘digitalized’. Crypto currency is a digitized or online rather an internet currency that uses<br> cryptography for security purposes. Likewise on the other hand, Non-fungible tokens (NFTs) are gaining<br> in popularity and are already extensively implemented but many of us aren’t aware about the same and its<br> implications or comparisons with respect to digital payments. It’s leading to a constant trend update in the<br> field of NFTs. For the usage or practical implementation of NFTs to progress or develop in an institutional<br> environment, the capacity or adaptability for using NFTs must be scrutinized in detail. Such a discovery<br> has surely added into or prompted a comprehensive examination of NFTs. The scope of this paper is<br> confined to the journal and the keywords “Block chain”, “Block-chain”, “Non-fungible Token”, and<br> “NFT” are used. This research examines the current state and development trends of NFT. In this paper<br> researchers tries to make out the user’s expectations of the future crypto currency leaning to the awareness<br> and perception towards the virtual cash implications, however technological innovations make jobs easier<br> and more beneficial. Besides this the paper aimed on its impact in India in terms of law and legislations<br> towards crypto currencies and its usage of this paperless cash in this current scenario.
There are a huge number of centralized entities that have a stronghold on huge swathes of the sector of the world wide web, taking unilateral action to determine what is and is not permissible. This dilemma is resolved by Web3 which embraces decentralization and is being built, operated, and owned by its users. Web3 places power inside the hands of people rather than agencies. For lovers and customers, NFT (Non-Fungible Token) represents a brand-new era of digital collection. So, it is a new manner to support artists, athletes, and musicians without any third-party intermediaries. For creators, artists, and musicians, NFT is a new manner to share and monetize their work. There were a number of troubles and issues surrounding the sale of digital products because it was very easy to duplicate and claimed through others. Our aim is to provide a decentralized platform to users from which they can list or buy these NFTs from the seller and the transactions between the buyer and seller will not be overlooked by some central authorities.
The language barrier is the biggest obstacle for users watching foreign-language videos. Because of this, videos cannot be famous across borders, and their viewership is limited to a single language and culture. The easiest way to solve this problem is to add subtitles in the language of the viewer. However, the current subtitling system lacks incentives, the ability to build a secure transaction environment, and a trusting relationship between video creators and subtitling makers. In response to the above situation, a tokenized subtitling crowdsourcing system (TSCS) based on blockchain and smart contract technologies is proposed. The source files for the subtitles are stored on the inter-planetary file system (IPFS) in the proposed system. Based on the ERC-721 standard, the returned corresponding address and subtitling-related information are made into a non-fungible token (NFT). At the same time, depending on the expected revenue from video view counts, the video token (VT), based on the ERC-777 standard and endorsed by the video platform, will be used as the payment token. The TSCS has two payment strategies: one-time and dividend. Through such a settlement mechanism, the subtitling maker’s revenue is also guaranteed by the code invariance and rule certainty of smart contract deployment. On the other hand, introducing an incentive mechanism for viewers to audit subtitles enables community autonomy, thus increasing the applicability of subtitles and the activity of users.
A central tenet in mechanism design is the ability to irrevocably commit to a mechanism. Commitment is achieved by public declaration, letting players verify incentive properties in advance and the outcome in retrospect. However, public declaration can reveal superfluous information that is private to the mechanism designer, such as her target function or costs. We propose a new approach to commitment, and show how to commit to, and run, any given mechanism without disclosing it, while enabling the verification of incentive properties and the outcome -- all without any mediators. Our framework leverages zero-knowledge proofs -- a cornerstone of modern cryptographic theory.
Smart contracts on the blockchain are computer programmes that encode an agreement between untrustworthy participants.If certain conditions are met, smart contracts are executed on a blockchain system, eliminating the need for a trusted third party.Blockchains and smart contracts have gotten a lot of attention in recent years, including from academics.We conduct a systematic mapping study of all peer-reviewed technology-oriented smart contract research.
Smart contract security is one of the core issues in any application based on blockchain. There are many techniques focusing on smart contract security, however, due to the diversity of Solidity versions and limitations of detection time, it is difficult for them to comprehensively localize defects in different versions of smart contracts. In this article, we propose a static defect detection method based on the knowledge graph of the Solidity language and present a defect detection tool calledSoliDetector. First, we define the ontology layer of the knowledge graph and construct the instance layer in which syntactic and logical relationships are captured. Second, we introduce the defect pattern to describe each defect and design inference rules to infer complex relationships and judge whether a defect exists. Finally, we localize defects by executing SPARQL queries.SoliDetectorcan support the detection of 20 kinds of defects and the automatic SPARQL query generation. We conducted several experiments on multiple datasets.SoliDetectorobtains a highF-score(i.e., 92.97% on Dataset1 and 91.54% on the SmartBug dataset). To compareSoliDetectorwithSmartCheck,Slither, andMythril, we conducted experiments on a labeled benchmark Dataset3 and real-world contracts.SoliDetectorhas a highF-scoreof 94.04% and is faster than other tools with an average time of 0.37 s for each contract.
This thesis addresses the issue of semantic representation of the deployment environment of a smart contract and the integration of semantic licensing from the Data Licenses Clearance Center (DALICC) library. This research is divided into four sections for the following reasons: First, we concentrated on how smart contracts develop on the blockchain and some additional information about this system. Second, we show how blockchain and semantic web technology can work together. It focuses on several methods for indexing and running Ethereum blockchain smart contracts. The third segment, meanwhile, focuses on DALICC as a framework for identifying licensing conflicts and cutting down on the price of rights clearance. In the final piece, we created a DApp to describe a semantic model of these installations and connect semantic licensing with content using smart contracts.
Ada Bagozi, Devis Bianchini, Valeria De Antonellis, Massimiliano Garda · 5 authors
With the advent of blockchain technology, many interorganisational collaborative processes that demand trust requirements (e.g., food supply chain, smart grid energy distribution and clinical trials) are being implemented as decentralised applications (DApps). Indeed, blockchain technology provides decentralised control and immutable transaction history, thereby improving security and accountability between parties. In this vision paper, we consider cooperative processes where a subject, which acts as a regulator of the process, promotes the use of blockchain for increasing transparency, while reducing the burden in controlling trustworthiness among participants. To the scope, the regulator provides a registry of basic smart contracts, including both actual deployed ones and code templates, that can be used and extended by the process stakeholders (e.g., retailers, energy providers, researchers) to build up DApps. The adoption of a blockchain and the definition of the registry favour the compliance with best practices and obligations demanded by the regulator, as well as that all relevant information and documents cannot be tampered. To support semantic-based smart contract search in the registry, we propose a multi-perspective framework that, in addition to classification and technical characteristics of smart contracts, takes into account the past experience of developers who have used smart contracts of the registry to develop DApps.