Sarah A. Flanery, Kamalesh Mohanasundar, Christiana Chamon, Srujan Kotikela · 5 authors
With the natural evolution of the web, the need for decentralization has rendered the current centralized education system out of date. The student does not "own" their credentials, as the only way their accomplishments are directly linked to their person and considered valuable is by verification through a stamp of an expensive, prestigious institution. However, going to a university is no longer the only way to acquire an education; open-source learning material is widely available and accessible through the internet. However, our society does not deem these methods of education as verifiable if they do not include a degree or certificate. Additionally, a valid certificate for the vast majority of open-source courses costs a few hundred dollars to obtain. The centralized nature of education inadvertently places students in underprivileged communities at a disadvantage in comparison to students in economically advantaged communities, thus a decentralized approach to education would eliminate the vast majority of such discrepancies. In the present paper, we integrate Decentralized Identity (DID) with Web 3.0 to upload credentials linked directly to the user. Each credential is appended to an Ethereum blockchain that, by design, cannot be altered once uploaded. We include DID document based access controls to display the candidate's upload and verification history. Finally, we utilize TLS protocols to provide a secure connection to the internet for ensuring non-fungibility of credentials and authentication of users.
The e-book services we use today have a serious drawback in that we will no longer be able to read the books we have purchased when the service is terminated. One way to solve this problem is to build a decentralized system that does not depend on a specific company or organization by combining smart contracts running on the Ethereum blockchain and distributed storage such as an IPFS. However, a simple combination of existing technologies does not make the stored e-book data persistent, so the risk of purchased e-books becoming unreadable remains. In this paper, we propose a decentralized distributed storage called d-book-repository, which has both access management function and data durability for purchased e-books. This system uses NFTs as access rights to realize strict access control by preventing clients who do not have NFTs from downloading e-book data. In addition, e-book data stored on storage nodes in the distributed storage is divided into shards using Reed–Solomon codes, and each storage node stores only a single shard, thereby preventing the creation of nodes that can restore the entire content from locally stored data. The storage of each shard is not handled by a single node but by a group of nodes, and the shard is propagated to all nodes in the group using the gossip protocol, where erasure codes are utilized to increase the resilience against node departure. Furthermore, an incentive mechanism to encourage participation as a storage node is implemented using smart contracts. We built a prototype of the proposed system on AWS and evaluated its performance. The results showed that both downloading and uploading 100 MB of e-book data (equivalent to one comic book) were completed within 10 s using an instance type of m5.xlarge. This value is only 1.3 s longer for downloading and 2.2 s longer for uploading than the time required for a simple download/upload without access control, confirming that the overhead associated with the proposed method is sufficiently small.
The social network Twitter possesses a key characteristic: it is centralized, allowing Twitter Corporation to control data substitution and set moderation rules. However, this issue can only be resolved through the complete decentralization of the platform. To achieve this, blockchain technology is crucial as it enables the operation of decentralized applications with smart contracts serving as the foundation for system-user interaction. In this paper, we propose the minimum viable implementation of a similar social network called Brain Logger, which stores all necessary data in the NEAR blockchain network. Introducing a small fee for modifying data on the network ensures a solution to the aforementioned problems. The implementation includes a smart contract for blockchain networks and a web application frontend. The smart contract was developed using the NEAR software development kit in Rust, while the frontend was created in JavaScript using the React framework and Redux for local data storage. The code can be accessed on Github.
Saidu Sokoto, Michał Król, Vladimir Stanković, Étienne Rivière
Distributed Hash Tables (DHTs) serve as the backbone of numerous modern decentralized systems like the InterPlanetary File System (IPFS) and Ethereum. As these systems evolve and expand, there is a growing need to enhance and optimize their underlying network support. In response to these challenges, we embark on the development of a new class of DHTs, marked by efficiency, security, and suitability for real-world deployments. We achieve this by making changes in the routing procedures, incorporating latency-aware routing, and harnessing recent hardware advancements.
Web3, the next generation of the Internet, represents a decentralized and democratized web. Although it has garnered significant public interest and found numerous real-world applications, there is a limited understanding of people's perceptions and experiences with Web3. In this study, we conducted an empirical study to investigate the categories of Web3 applications and their popularity, as well as the potential challenges and opportunities within this emerging landscape. Our research was carried out in two phases. In the first phase, we analyzed 200 popular Web3 projects associated with 10 leading Web3 venture capital firms. In the second phase, we collected and examined code-related data from GitHub and market-related data from blockchain browsers (e.g., Etherscan) for these projects. Our analysis revealed that the Web3 ecosystem can be categorized into two groups, i.e., Web3 infrastructure and Web3 applications, with each consisting of several subcategories or subdomains. We also gained insights into the popularity of these Web3 projects at both the code and market levels and pointed out the challenges in the Web3 ecosystem at the system, developer, and user levels, as well as the opportunities it presents. Our findings contribute to a better understanding of Web3 for researchers and developers, which in turn promotes further exploration and advancement in this innovative field.
The promise of a fully decentralized web is too big to ignore. The bridging of Web2 and Web3 infrastructure is crucial for realizing this decentralized future. However, the current computational and storage demands in blockchain systems often result in challenges for users, leading to reliance on centralized endpoint API services in Web3 application designs. This dependence raises concerns about privacy, availability, and security. This doctoral study aims to enhance the accessibility and decentralization of blockchains, especially by facilitating the participation of resource-constrained devices such as smartphones and browsers. The goal is to facilitate the widespread adoption of decentralized systems that are secure, reliable, and scalable.
Flaviene Scheidt de Cristo, Wazen M. Shbair, Lucian Trestioreanu, Radu State
The XRP Ledger is one of the oldest and most well-established blockchains, using a particular type of consensus mechanism that differs from the typical Proof of Work and Proof of Stake. The underlying p2p network uses flooding to dis-seminate certain types of messages during the consensus rounds, leading to performance and scalability issues. In this work, we propose the use of publisher/subscriber dissemination on the XRPL using GossipSub to diminish the message overhead. We use Flexi-pipe, a tool that allows integration between the XRPL validator and GossipSub, to evaluate the improvements brought.
We present and analyze an attack on Ethereum 1's consensus mechanism, which allows miners to obtain higher mining rewards compared to their honest peers. This attack is novel in that it relies on manipulating block timestamps and the difficulty-adjustment algorithm (DAA) to give the miner an advantage whenever block races ensue. We call our attack Uncle Maker, as it induces a higher rate of uncle blocks. We describe several variants of the attack. Among these, one that is risk-free for miners.
Yang Liu, Zhiyuan Lin, Yuxi Zhang, Lin Jiang · 5 authors
Ethereum, currently the most widely utilized smart contracts platform, anchors the security of myriad smart contracts upon its own robustness. Its foundational peer-to-peer network facilitates a dependable node connection mechanism, whereas an efficient data-sharing protocol constitutes as the bedrock of Blockchain network security. In this paper, we propose NodeHunter, an Ethereum network detector implemented through the application of simulation technology, which is capable of aggregating all node records within the network and the interconnectedness between them. Utilizing this connection information, NodeHunter can procure more comprehensive insights for network status analysis compared to preceding detection methodologies. Throughout a three-month period of unbroken surveillance of the Ethereum network, we obtained an excess of two million node records along with over one hundred million node acquaintances. Analysis of the gathered data revealed that an alarming 49% or more of these node records were maliciously forged.
Abstract Distributed ledgers, including blockchain and other decentralized databases, are designed to store information online where all trusted network members can update the data with transparency. The dynamics of a ledger’s development can be mathematically represented by a directed acyclic graph (DAG). In this paper, we study a DAG model that considers batch arrivals and random delay of attachment. We analyze the asymptotic behavior of this model by letting the arrival rate go to infinity and the inter-arrival time go to zero. We establish that the number of leaves in the DAG, as well as various random variables characterizing the vertices in the DAG, can be approximated by its fluid limit, represented as the solution to a set of delayed partial differential equations. Furthermore, we establish the stable state of this fluid limit and validate our findings through simulations.
Trustworthy oracles are an essential component of blockchain technology, providing a mechanism for blockchain applications to access data from the real world and verify it on-chain. With the continuous development of blockchain technology, trustworthy oracles have become one of the hot research topics in the blockchain industry. This article reviews the current research status and challenges of trustworthy oracles, summarizing the major research progress in the oracle field in recent years from aspects such as architecture and key technologies. Based on this, we propose a system architecture called SmartLLM that allows smart contracts to call large language models based on a trustworthy oracle mechanism. There are two types of architectures: one is chain-native, and the other is a combination of on-chain and off-chain. This architecture provides technical support for smart contracts to use large language models, enriching the use cases of smart contracts.
Volunteer computing became popular during the late 1990s with software like SETI@home. In the early days of bitcoin mining, CPUs and GPUs were used similarly to volunteer computing: spare computing cycles are used to solve a problem (securing a blockchain in the case of cryptocurrency mining). Then came the specialized hardware of FPGAs and ASICs, and using CPUs and GPUs for bitcoin mining was not profitable anymore. We argue that bitcoin mining has revolutionized the development of specialized hardware and could continue doing so in the industry of unconventional computing. There is also a significant source of unused spare computing cycles in home computers and smartphones that could be used for grid computing purposes with the help of cryptocurrency mining. The notable result from our present analysis is the connection between cryptocurrency mining, grid/volunteer computing, and unconventional computing.
Mainstream blockchain games have drawn criticism for prioritizing economic systems over gameplay experience. Influenced by these economically-centered games, existing research on blockchain games predominantly focuses on the financial sector. We have developed BranchClash, a fully on-chain tower defense game on the Sepolia testnet of Ethereum. It introduces chain collaboration, a novel non-economically-centered game mechanism inspired by blockchain technology. BranchClash aims to expand unique game mechanics in blockchain games and explore innovative cooperative modes within the decentralized ecosystem.
The Internet of Things (IoT) is marked by the presence of a versatile network of devices employing various forms of communication and data types. Due to their distributed nature and the generation of extensive data, IoT nodes often encounter obstacles such as hardware and storage limitations, security vulnerabilities, and lack of interoperability. To mitigate these challenges, researchers have proposed the integration of Distributed Ledger Technologies (DLTs), such as blockchain or Directed Acyclic Graph (DAG). To this end, researchers have begun analyzing the applicability of DLTs for IoT applications on a case-specific basis. However, DLTs differ with respect to the consensus protocols implied. Hence, there is a need for developing a framework defining categories for evaluating the integration of different DLT consensus protocols for IoT applications. This research-in-progress paper should be seen as a first approach to a framework that can evaluate the suitability of different DLTs for IoT applications.
Blockchain technology has gained popularity in various applications, including finance transactions and beyond. However, developing blockchain application systems is challenging due to stringent quality requirements, such as performance, scalability, and security. Software architecture plays a critical role in realizing key quality requirements. Nonetheless, little work has been performed on software architectures for blockchain applications since blockchain application development is still a new field. This paper proposes twelve architectural patterns for blockchain application software architectures based on 400 cross-industry real-world applications available on the Internet. We determine the key components of each application guided by a blockchain application taxonomy we developed. We then identify typical architectural patterns from the interactions of these components guided by well-known software patterns, such as peer-to-peer, layered, pipe-filter, and access control. Based on the roles of these patterns, we organize them into four architectural views comprising four structural, two interactional, four transactional, and two security patterns. We describe each pattern in detail using a standard form and demonstrate the patterns through a real-world blockchain application. The use of patterns can be valuable in addressing blockchain’s unique challenges, but creativity remains essential in crafting innovative solutions. Mixing architectural patterns according to varying requirements can help developers communicate effectively.
The broad topic of this thesis is the design and analysis of Bitcoin custody systems. Both the technology and threat landscape are evolving constantly. Therefore, custody systems, defence strategies, and risk models should be adaptive too. We introduce Bitcoin custody by describing the different types, design principles, phases and functions of custody systems. We review the technology stack of these systems and focus on the fundamentals; key-management and privacy. We present a perspective we call the systems view. It is an attempt to capture the full complexity of a custody system, including technology, people, and processes. We review existing custody systems and standards. We explore Bitcoin covenants. This is a mechanism to enforce constraints on transaction sequences. Although previous work has proposed how to construct and apply Bitcoin covenants, these require modifying the consensus rules of Bitcoin, a notoriously difficult task. We introduce the first detailed exposition and security analysis of a deleted-key covenant protocol, which is compatible with current consensus rules. We demonstrate a range of security models for deleted-key covenants which seem practical, in particular, when applied in autonomous (user-controlled) custody systems. We conclude with a comparative analysis with previous proposals. Covenants are often proclaimed to be an important primitive for custody systems, but no complete design has been proposed to validate that claim. To address this, we propose an autonomous custody system called Ajolote which uses deleted-key covenants to enforce a vault sequence. We evaluate Ajolote with; a model of its state dynamics, a privacy analysis, and a risk model. We propose a threat model for custody systems which captures a realistic attacker for a system with offline devices and user-verification. We perform ceremony analysis to construct the risk model.
Domain Name Service (DNS) has become an essential element of the Internet in current era. The traditional DNS extends its authority down to the Top Level Domains (TLDs) and individual names before returning to the Root Server. To avoid the cons related to centralized authority scheme of the traditional DNS, recently many techniques based on the decentralized Internet with support of Blockchain (BC) are emerging. Hence, currently a variety of protocols and mechanisms are focusing on implementation of the Decentralized Naming Services which in turn supports concept of decentralized internet services. These Decentralized Naming Services are totally based on Blockchain architectures and provides various pros like resistance to single point of failure, resistance to censorship and permanent proof of ownership. Blockchain Domain Names act as Digital Identity in Decentralized Internet. Security is major concern in any DNS system and the similar challenges exists in the Blockchain DNS system too. Further, there is a lot of diversity being observed in decentralized internet space as a Domain name in a Blockchain DNS can refer to a website/portal or a wallet or a Non-Fungible Token (NFT) or simply be parked. Also, currently, there is rampant growth in development of decentralized applications with no standards implemented - neither across Blockchains nor regions. Hence, there is a need to detect security exploits carried out using malicious domains in Blockchain DNS system and implement mitigation measures accordingly. In this research work, we study and analyze malicious domain names in decentralized BC system. We explored Ethereum transaction dataset for detecting malicious transactions using Machine Learning (ML) and Deep Learning (DL) algorithms with good accuracy of 99% and 95% using Decision Tree and 1 Dimensional Convolutional Neural Network (CNN) respectively. We also applied ML techniques on Ethereum wallet dark list dataset for detection of domain names that were vii used for phishing attacks. We received 96% accuracy after handling data imbalance by Random Forest model. Model predicted nature of domain based on 17 features that were extracted from Ethereum wallet dark list dataset like number of consonants, vowels, digits, symbols and their ratios to length of domain.
The peer-to-peer (P2P) based distributed file system known as IPFS (InterPlanetary File System) has recently garnered significant attention as a decentralized storage solution in the Web3 landscape. However, IPFS operates on a voluntary participation basis, which can limit data availability. To enhance automated data availability on IPFS, an extended solution known as IPFS Cluster is being developed. This solution leverages a data replication approach. This paper proposes a Reed-Solomon based distributed content storage mechanism for IPFS, enhancing data availability and significantly improving storage efficiency compared to traditional replication methods. This technology is anticipated to serve as a fundamental building block for efficiently storing, managing, and utilizing large-scale, high-capacity digital content in various Web3 environments.
This paper presents MindTheDApp, a toolchain designed specifically for the structural analysis of Ethereum-based Decentralized Applications (DApps), with a distinct focus on a complex network-driven approach. Unlike existing tools, our toolchain combines the power of ANTLR4 and Abstract Syntax Tree (AST) traversal techniques to transform the architecture and interactions within smart contracts into a specialized bipartite graph. This enables advanced network analytics to highlight operational efficiencies within the DApp's architecture. The bipartite graph generated by the proposed tool comprises two sets of nodes: one representing smart contracts, interfaces, and libraries, and the other including functions, events, and modifiers. Edges in the graph connect functions to smart contracts they interact with, offering a granular view of interdependencies and execution flow within the DApp. This network-centric approach allows researchers and practitioners to apply complex network theory in understanding the robustness, adaptability, and intricacies of decentralized systems. Our work contributes to the enhancement of security in smart contracts by allowing the visualisation of the network, and it provides a deep understanding of the architecture and operational logic within DApps. Given the growing importance of smart contracts in the blockchain ecosystem and the emerging application of complex network theory in technology, our toolchain offers a timely contribution to both academic research and practical applications in the field of blockchain technology.
Ethereum introduced decentralized applications (DApps) to leverage blockchain's potential, distinct from the cryptocurrency buzz dominating discussions. Ethereum offers a robust platform for DApp development, utilizing the Ethereum Virtual Machine (EVM). With increasing smart contract integration, Ethereum's ecosystem strengthens, as these self-executing contracts govern transactions while ensuring consensus among all participants. In democratic societies, the demand for a transparent and secure electronic voting platform is high. Ethereum, with its expansive network, is an ideal choice for such projects. Our implementation focuses on a decentralized, blockchain-based voting system. Multiple nodes collectively store voting data, ensuring redundancy. In case of node issues, users can access their data from operational nodes, enhancing system reliability. This contrasts with traditional centralized servers, prone to hacking or failures that compromise data accessibility and integrity. Blockchain's immutable data storage prevents tampering, as nodes independently verify each block using cryptographic hash codes. Unauthorized changes trigger immediate alerts, enhancing security and trust in the voting system.