Logging is a critical function to enable auditing and enhance security of distributed applications. This paper describes the design of Mnemosyne, a distributed logger running over Named Data Networking(NDN), to meet this need for NDN-based distributed applications. Mnemosyne assures the immutability of logged events by interlocking all event records in a DAG-based ledger. Mnemosyne provides a high logging throughput and system resiliency against network component failures. We implemented Mnemosyne and evaluated its design through an emulated deployment setting.
Leonhard Balduf, Maciej Korczyński, Onur Ascigil, Navin V. Keizer · 7 authors
Interplanetary Filesystem (IPFS) is one of the largest peer-to-peer filesystems in operation. The network is the default storage layer for Web3 and is being presented as a solution to the centralization of the web. In this paper, we present a large-scale, multi-modal measurement study of the IPFS network. We analyze the topology, the traffic, the content providers and the entry points from the classical Internet. Our measurements show significant centralization in the IPFS network and a high share of nodes hosted in the cloud. We also shed light on the main stakeholders in the ecosystem. We discuss key challenges that might disrupt continuing efforts to decentralize the Web and highlight multiple properties that are creating pressures toward centralization.
Mikel Cortes-Goicoechea, Tarun Mohandas-Daryanani, José L. Muñoz, Leonardo Bautista-Gomez
Modern public blockchains like Ethereum rely on p2p networks to run distributed and censorship-resistant applications. With its wide adoption, it operates as a highly critical public ledger. On its transition to become more scalable and sustainable, shifting to PoS without sacrificing the security and resilience of PoW, Ethereum offers a range of consensus clients to participate in the network. In this paper, we present a methodology to measure the performance of the consensus clients based on the latency to receive messages from the p2p network. The paper includes a study that identifies the incentives and limitations that the network experiences, presenting insights about the latency impact derived from running the software in different locations.
This work aims to discuss the currently ongoing efforts towards the implementation of a fully autonomous and decentralized consensus mechanism based on Proof-of-Stake. We focus on the technical challenges arising from adopting a committeeless Proof-of-Stake consensus protocol (CPoS) where the global state of the entire peer-to-peer network is used to converge to a distributed consensus instead of relying on a validation committee. Specifically, we analyse the performance and security tradeoffs of the protocol. Since the CPoS protocol is very sensitive to its configuration parameters, we investigate their full impact on the blockchain performance and propose improvements to previous works in the area.
With the widespread adoption of Renewable Energy Sources (RESs) in low-voltage distribution systems, opportunities for energy trading among peers have emerged. In particular, the advent of distributed ledgers and blockchain technologies has catalyzed the application of Peer-to-Peer (P2P) economic concepts in decentralized, small-scale energy trading. This paper focuses on the critical physical layer aspects of transactions within the context of P2P energy trading, with a specific emphasis on addressing network constraints. Key challenges include maintaining margins for over/under voltage, voltage balance, and preventing congestion, all of which must be upheld during P2P energy exchanges. To address these challenges, we propose a novel analytical approach tailored to distribution networks. Furthermore, we introduce the Block Double Auction (BDA) mechanism as the P2P market mechanism for determining the acceptance or rejection of P2P transactions. The effectiveness of our proposed method is validated using the IEEE 33-node distribution test system, demonstrating its robust capabilities.
Soosan Naderi Mighan, Jelena Mišić, Vojislav B. Mišić
We present a comprehensive analytical model for block and transaction distribution in the Ethereum P2P network. We model the data distribution protocol in which a node forwards a full block (transaction) to some of its peers and its hash to others, and combine this model with the connectivity and transmission models to obtain input and output data rates, which are then fed into a priority M/G/1 Jackson network queuing system in which blocks are given preference over transactions, and transactions are further grouped into two priority classes according to gasprice. Block and transaction delivery times are found to be mainly determined by node connectivity and network size, and prioritization provides faster service for higher priority transactions. We also model an Eclipse-like attack that degrades data delivery times and block finalization time, i.e., the time for a block to be officially confirmed, by reducing network connectivity, and show that its impact can be countered by adjusting the portion of peers which receive a full block. Lastly, we determine the probability of uncle blocks being included in the longer chain and demonstrate how the Eclipse attack affects this probability.
This chapter delves into the development of decentralized governance models for Web 3 ecosystems. It analyzes the shortcomings of traditional governance models and how decentralized models can overcome them. The chapter then investigates several decentralized governance models, such as reputation-based systems, liquid democracy, and decentralized autonomous organizations (DAOs), as well as their benefits and drawbacks. The challenges associated with establishing decentralized governance models are also explored. Lastly, the chapter explores potential future advancements as well as best practices for creating and implementing decentralized governance models in Web 3 ecosystems. All in all, the importance of decentralized governance models in encouraging openness, participation, and accountability in Web 3 ecosystems is highlighted in this chapter.
A Distributed Concensus System (DCS) is a key component for a distributed system, maintaining and consenting over distributed state, as often required in distributed filesystems, cryptocurrencies and other applications. The prevalent mechanism to distribute the information needed to reach consensus in a DCS is through an iterative diffusion with the goal of distributing the (updated) information to at least the majority of DCS participants. Such diffusion is not just costly in maintaining the needed communication relations but also incurs latency in performing the diffusion itself. When looking closer at the goal of achieving the majority rule, however, one may wonder of the lack of multicast being used for achieving the same goal. This paper thus returns to the original intention of how to distribute information to a large set of users and outlines reasons for why multicast has not been widely used thus far. We evaluate the potential gain in doing so, based on an analytical model for the diffusion latency in an iterative diffusion DCS, bounded through empirical studies in an Ethereum system.
As a subset of distributed systems, blockchain technology is equally bound by the CAP trilemma. Specifically, no distributed system can satisfy consistency, availability, and partition tolerance simultaneously. Informally, the innovative blockchain trilemma has been theorized to include security, scalability, and decentralization. While many software approaches on blockchains claim to solve the trilemma problem, almost all known approaches have been proven to involve tradeoffs and fail to reach the upper bounds, meaning they do not achieve the theoretical limit value in each term of a trilemma. In this article, we propose a general trilemma based on the above two trilemmas. For permissioned blockchains, we then describe a system framework called GBT-CHAIN to solve the G eneral B lockchain T rilemma. In the proposed framework, the consensus and data layer, the network layer, and the physical layer work in cooperation. According to our theoretical proof and experimental analysis, the three properties of the trilemma consisting of consistency, scalability, and partition tolerance are perfectly satisfied without tradeoffs. Our results demonstrate that the general blockchain trilemma is resolved by combining consensus algorithms and physical topologies, in particular for permissioned blockchains.
Web 3.0 is an emerging Internet paradigm based predominantly on the blockchain technology. Because Web 3.0 applications are designed to operate over trustless and permissionless networks, they can have significant advantages, such as decentralized control structures and transparency. Hence, existing web applications are being reproduced using Web 3.0 technologies. In contrast, real-time services are still implemented with the Web 2.0 architecture. In particular, implementing Web 3.0 media streaming requires modifications to the service architecture of existing media streaming systems because some technical difficulties exist. For example, as data moves from centralized data centers to distributed storage, the user's quality of experience may be severely degraded. In addition, the software components comprising the Web 3.0 stack, such as interplanetary file system, cryptocurrency wallets, and the Ethereum JavaScript API are not compatible with various combinations of OSs, media players, and browsers. Therefore, in this study, we propose an end-to-end system architecture designed for Web 3.0 real-time services, which prevents degradation of service quality. Further, we present a media NFT marketplace named Retriever (https://retriever.live) fully developed using Web 3.0 technologies. Retriever allows users to enjoy watching video content and further to directly trade their content without intermediaries by ensuring the privacy of the data and managing digital intellectual property. In particular, Retriever does not sacrifice the user experience and is compatible with multiple mobile devices.
DPoS is a consensus algorithm designed to address scalability and speed issues in PoS. It achieves this by predefining a maximum number of validators who participate in block generation while delegating stakes and sharing block rewards. However, DPoS has faced security vulnerabilities, where Block Producers can manipulate votes through fraud, bribery, and lack of community communication. While there has been research on the centralization resulting from DPoS voting, there has been limited discussion on the voting coefficient. In this paper, we propose a model that reduces the influence of wealthy individuals and gathers community opinions by adjusting the voting coefficient using quadratic delegates. We apply this model to EOS's Block Producer voting and demonstrate a significant reduction in the influence of the wealthy few, while ensuring the community's preferences are reflected. These findings contribute to protecting DPoS elections from security threats and encouraging decentralized voting participation by users.
The emergence of the Web3 paradigm has led to more and more systems built on blockchain technology and relying on cryptocurrency tokens – both fungible and non-fungible – to sustain themselves and generate profit. The growth and success of these platforms are strongly dependent on the growth and evolution of the trade relationships among users. In this context, it is of paramount importance to understand the mechanism behind the evolution and growth dynamics of these economic ties: however, in these systems the trade relationships are strictly intertwined with social dynamics, posing significant challenges in the analysis. One of the most important mechanisms behind the evolution of social networks is the triadic closure principle: given the strict link between social and economic spheres, the mechanism emerges as a potential candidate among mechanisms in literature. Therefore in this work, we extend the existing methodology for triadic closure studies and adapt it to directed networks. We performed an analysis centered around 3-node subgraphs known as “triads” and statistically significant triads referred to as “triadic motifs”, both from a static and temporal perspective. The methodology was applied to various decentralized socio-economic networks with distinct levels of social components. These networks include currency transfers from the blockchain-based online social media platform Steemit, trade relationships among NFT sellers and buyers on the Ethereum blockchain, and a blockchain-based currency designed for humanitarian aid called Sarafu. Our measurements show how triadic closure is relevant during the evolution of these platforms and, for a few aspects, more impactful than centralized online social networks, where triadic closure is also incentivized by recommendation systems. Moreover, we are able to highlight both similarities and differences across networks with different levels of social components, both from a static and temporal standpoint. Overall our work presents strong evidence that triadic closure is an important evolutionary mechanism in decentralized socio-economic networks. Our findings provide a stepping stone in the study of decentralized socio-economic networks. Understanding the evolution of other decentralized networks, not following the same Web3 paradigm or with different social components will provide valuable insight into the understanding of dynamics in decentralized systems and potentially improve their design process.
The decentralized financial (DeFi) market has witnessed remarkable growth in recent years, transforming how people access, manage, and exchange digital financial services. DeFi essentially refers to decentralized economic activities facilitated by blockchain technology. The tokenization of real-world assets contributes to the popularity of digital financial services, enabling unlimited sets of innovative ways to represent assets and interchange them. The DeFi peer-to-peer nature has been seen as a disruptor for traditional financial services due to its flexibility, openness, programmability, financial inclusion, censorship-resistant, transparency, and cost-effectiveness. To better understand the evolving DeFi ecosystem and its potential, analyzing transaction data using social network analysis (SNA) can offer valuable insights. The main goal of this research is to identify influential participants and uncover groups of related transactions, providing valuable information to market participants, regulators, and innovators on how to enhance the stability of DeFi and reduce risks. Three DeFi token-based Ethereum protocols have been analyzed: Dai (DAI), Uniswap (UNI), and Wrapped Bitcoin (WBTC). The study unveiled key players associated with each token by applying centrality calculations. Additionally, the modularity metric is employed to identify transaction clusters formed within each token, shedding light on the patterns and relationships within the network of the token economy.
Joachim Neu, Srivatsan Sridhar, Lei Yang, David Tse
Classic BFT consensus protocols guarantee safety and liveness for all clients if fewer than one-third of replicas are faulty. However, in applications such as high-value payments, some clients may want to prioritize safety over liveness. Flexible consensus allows each client to opt for a higher safety resilience, albeit at the expense of reduced liveness resilience. We present the first construction that allows optimal safety--liveness tradeoff for every client simultaneously. This construction is modular and is realized as an add-on applied on top of an existing consensus protocol. The add-on consists of an additional round of voting and permanent locking done by the replicas, to sidestep a sub-optimal quorum-intersection-based constraint present in previous solutions. We adapt our construction to the existing Ethereum protocol to derive optimal flexible confirmation rules that clients can adopt unilaterally without requiring system-wide changes. This is possible because existing Ethereum protocol features can double as the extra voting and locking. We demonstrate an implementation using Ethereum's consensus API.
Dan Zhuo, Jia‐Wei Tang, Yang Chen, Shaobin Wang · 5 authors
The InterPlanetary File System (IPFS) is a representative decentralized data storage system that has been widely used in recent years. IPFS plays an important role in the emerging Web3-related applications. As a global peer-to-peer system, a good understanding of IPFS nodes’ session time is meaningful. In this work, we introduce a measurement study to uncover the issues that are related to the session time of IPFS nodes. Based on the collected massive data of all online IPFS nodes for over one month, we gain a comprehensive understanding of the relationship between various node attributes and session time. In addition, we build a supervised machine learning-based model to predict the session time with a high prediction performance.
Eva Chovancová, Martin Chovanec, Ján Hurtuk, Peter Pekarčík
The work is devoted to the analysis of technologies and the design of a responsive social network application with elements of decentralization. Despite all the positives that social networks bring, we can’t forget the potential problems associated with their use. Some of the problems can be minimized by using decentralization, which has the effect of limiting third-party control.The centralized part is created using the Vue.js and Laravel frameworks, which provide basic functions. In the context of decentralization, is very important the creation of a smart contract that is stored in the Ethereum blockchain. By using the Web3.js library, it is possible with a smart contract and a MetaMask wallet to carry out the transactions necessary for storing data on the blockchain.To increase efficiency, the IPFS distributed file system is used, which offers storage of larger files or texts and generates their content, while it is possible to access this data. By decentralizing these functions, data immutability is achieved, censorship is excluded, and data security is also provided.
This paper introduces TeleBTC, a fully decentralized protocol designed to wrap Bitcoin (BTC) on programmable blockchains. The creation of a decentralized wrapped BTC presents challenges due to the non-programmable nature of Bitcoin, making it difficult to custody BTCs in a decentralized way. Existing solutions have addressed this challenge by introducing an external layer of validators who take custody of users' BTCs. However, the security and decentralization of this layer are inferior to the underlying blockchains on which wrapped BTC is built. Moreover, the process of joining or leaving for a validator has become overly complex and expensive. To overcome these limitations, we propose a novel approach that eliminates the need for such an external layer by leveraging the light client bridge protocol. Additionally, we employ economic mechanisms such as incentivization and slashing, resulting in a secure and trust-minimized wrapped BTC solution. With TeleBTC, users can seamlessly transfer their BTC to other blockchains and utilize it within decentralized applications. Furthermore, they can unwrap their TeleBTC and reclaim the native BTC. To address the high costs associated with light client bridges, we present an optimistic approach that minimizes the cost. This approach significantly reduces the operational expenses of running the protocol.
Blockchain leader-based protocols elect leaders for proposing the next block of transactions. Proposed blocks need to pass a validation routine in order to be added to the blockchain. Proposers may prioritize certain transactions based on their fees or accounts, which enables attackers to gain profits through block building, while simultaneously causing negative impacts on other users. A fair block selection follows a random selection of pending transactions among those that a proposer is aware of. We propose CFTO, a protocol that aims at encouraging fair block selection in a leader-based blockchain network while taking into account real network conditions, such as the network’s topology structure and the forwarding protocol. CFTO offers two main contributions. First, it provides incentives for acting honestly and diminishing malicious and dishonest nodes. To accomplish this, we use a reputation system, whereby each node is given a reputation score based on its actions. Second, it consists of an algorithm that evaluates the proposed blocks based on the zone structure of the network. Furthermore, we adapt the evaluation algorithm to fit the additional order constraints implied in Ethereum transaction ordering. We demonstrate the improved accuracy of CFTO in detecting fair blocks, in terms of increasing the probability of approving fair blocks and decreasing the probability of approving unfair blocks, by implementing experiments and comparing them with Helix (Yakira et al., 2021), a previously proposed consensus algorithm for fair block selection. As part of our experiments, we also compare certain features with those of previous studies.
Srivatsan Sridhar, Onur Ascigil, Navin V. Keizer, François Genon · 8 authors
The InterPlanetary File System (IPFS) is currently the largest decentralized storage solution in operation, with thousands of active participants and millions of daily content transfers. IPFS is used as remote data storage for numerous blockchain-based smart contracts, Non-Fungible Tokens (NFT), and decentralized applications. We present a content censorship attack that can be executed with minimal effort and cost, and that prevents the retrieval of any chosen content in the IPFS network. The attack exploits a conceptual issue in a core component of IPFS, the Kademlia Distributed Hash Table (DHT), which is used to resolve content IDs to peer addresses. We provide efficient detection and mitigation mechanisms for this vulnerability. Our mechanisms achieve a 99.6\% detection rate and mitigate 100\% of the detected attacks with minimal signaling and computational overhead. We followed responsible disclosure procedures, and our countermeasures are scheduled for deployment in the future versions of IPFS.
Ethereum has established itself as a highly decentralized and reliable blockchain network and serves as the de facto standard. However, using public blockchains in enterprise applications can be challenging due to concerns about confidentiality and transaction finality. As a result, consortium and private blockchains, which limit participation to specific nodes, are also commonly used. But these consortium blockchains also have limitations, such as limited node participation due to performance constraints imposed by the consensus algorithm. In this study, by using ZK-rollups as a messaging means, we would connect consortium blockchains via public Ethereum as a hub. We examined a mechanism to balance both mathematically reliable interoperability and maintaining the secrecy of the information and the finality. The concept was actually implemented, to confirm the interoperability of simple money transfer transactions. And also, the way to handle secret information and the finality was theoretically organized.
Mallellu Sai Prashanth, Seetha Srujana, V. Uma Maheswari, Rajanikanth Aluvalu
The increasing reliance on web applications has led to a growing concern for their security vulnerabilities. Traditional security auditing processes often suffer from limitations such as manual intervention, lack of transparency, and centralized control. To address these challenges, we propose a novel approach utilizing blockchain technology and smart contracts to perform security auditing for web applications in a decentralized and transparent manner. The smart contract, named “WebAppSecurityAudit,” facilitates the auditing process by allowing users to conduct security audits on web applications. The contract leverages the Ethereum blockchain and employs the Solidity programming language. The contract’s core functionality includes creating and retrieving audits, storing audit details on the blockchain, and emitting events for audit notifications. The novelty of the proposed approach lies in several aspects. Firstly, by utilizing smart contracts, the proposed model eliminate the need for intermediaries or centralized authorities, ensuring a trustless and transparent auditing process. Auditors can directly interact with the contract, creating audits and storing the results on the blockchain. Web application owners can verify the audit details independently, increasing trust and accountability. Secondly, the proposed approach enables a decentralized audit record system. The use of blockchain technology ensures immutability and tamper-proof storage of audit information. This feature enhances the integrity of audit records, making them resistant to manipulation or unauthorized modifications. Thirdly, the contract introduces the concept of auditors’ addresses and web application addresses, associating audits with specific entities. This association allows for efficient retrieval of audit details and enables traceability in case of disputes or inquiries. In conclusion, the proposed smart contract-based security auditing approach offers a decentralized, transparent, and tamper-proof solution for assessing the security of web applications.
Information is the key to success in every domain; this statement also applies to cryptocurrencies and blockchain domains. Beginning with Bitcoin back in 2009, which the anonymous Japanese Satoshi Nakamoto launched, blockchain technology emerged. This technology has revolutionized and continues to do so in digital transactions. In addition, this technology led to the further development of other cryptocurrencies that are active at these moments on the market. One class of cryptocurrencies obtained differently from classical bitcoin is those obtained due to web-based mining. The most known coins of this type are Monero, Dash, or Electroneum. This paper aims to analyze the web-based mining process of Monero and the whole process’s security. In addition, we want to explore the performance of the mining processes used in the user’s web browser. Moreover, finally, we aim to research the profitability of coins obtained due to web-browser mining, having as an object of study the cryptocurrency Monero.
Blockchains face many challenges in time, among which the ever-growing storage needs for blockchains’ data. In particular, Ethereum is quickly approaching the 1 TB storage limit for a node, what may significantly reduce the candidates able to run an Ethereum fullnode. In this paper, we propose a new synchronization and storage strategy for Ethereum that takes full advantage of the Distributed Hash Table implemented in all clients but left unused. By digging into the history of Ethereum’s synchronization and storage strategies, we justify why such distribution of storage duties among peers makes much sense today. We implemented our solution in the official Ethereum client Geth and validated its smooth operation on a private Ethereum instance. Our solution can save around 60% of the storage of a node (360 GB) which represents a total of 12 PB of data at the network scale, while being fully backward compatible with current clients.
Navin V. Keizer, Onur Ascigil, Michał Król, George Pavlou
The Web has become an integral part of life, and over the past decade, it has become increasingly centralised, leading to a number of challenges such as censorship and control, particularly in search engines. Recently, the paradigm of the decentralised Web (DWeb), or Web3, has emerged, which aims to provide decentralised alternatives to current systems with decentralised control, transparency, and openness. In this paper we introduce Ditto, a decentralised search mechanism for DWeb content, based on similarity search. Ditto uses locality sensitive hashing (LSH) to extract similarity signatures and records from content, which are stored on a decentralised index on top of a distributed hash table (DHT). Ditto uniquely supports numerous underlying content networks and types, and supports various use-cases, including keyword-search. Our evaluation shows that our system is feasible and that our search quality, delay, and overhead are comparable to those currently accepted by users of DWeb and search systems.