Follow blockchain research across journals, conferences, and preprint repositories.
1,187 results · page 12 of 50
Ulf T. Mattsson
We will discuss Web3 Storage, Sharding and Pruning, Security Risks to Blockchain Ecosystems, Secure transaction ledgers, Blockchains in the Quantum Era, and Storing private keys.
Andrew Cullen, Lianna Zhao, Luigi Vigneri, Robert Shorten
Usability of distributed ledgers is crucial to their mainstream adoption, especially for enterprise applications in which most users do not wish to operate full-node infrastructure. Some attempts have been made to solve the problem of user-node interaction for blockchains in which leaders assemble users’ transactions into blocks, but in the case of leaderless DAG-based ledgers such as IOTA, many of these solutions cannot be applied due to the absence of a shared mempool and the ability of nodes to issue blocks in parallel. In this work, we propose a user-node interaction mechanism for ledgers of this kind that is designed to balance user traffic across nodes and ensure the risk of a user experiencing a poor quality of service is low. Our mechanism involves users selecting nodes to issue their transactions to the ledger based on quality of service indicators advertised by the nodes. Simulation results are presented to illustrate the efficacy of the proposed policies.
Ferenc Béres, István András Seres, Domokos M. Kelen, András A. Benczúr
Network-level privacy is the Achilles heel of financial privacy in cryptocurrencies. Financial privacy amounts to achieving and maintaining blockchain- and network-level privacy. Blockchain-level privacy recently received substantial attention. Specifically, several privacy-enhancing technologies were proposed and deployed to enhance blockchain-level privacy. On the other hand, network-level privacy, i.e., privacy on the peer-to-peer layer, has seen far less attention and development. In this work, we aim to provide a peer-to-peer network simulator, ethp2psim, that allows researchers to evaluate the privacy guarantees of privacy-enhanced broadcast and message routing algorithms. Our goal is two-fold. First, we want to enable researchers to implement their proposed protocols in our modular simulator framework. Second, our simulator allows researchers to evaluate the privacy guarantees of privacy-enhanced routing algorithms. Finally, ethp2psim can help choose the right protocol parameters for efficient, robust, and private deployment.
Michał Król, Onur Ascigil, Sergi Reñé, Étienne Rivière · 9 authors
Despite their increasing popularity, blockchains still suffer from severe scalability limitations. Recently, Ethereum proposed a novel approach to block validation based on Data Availability Sampling (DAS), that has the potential to improve its transaction per second rate by more than two orders of magnitude. DAS should also significantly reduce per-transaction validation costs. At the same time, DAS introduces new communication patterns in the Ethereum Peer-to-Peer (P2P) network. These drastically increase the amount of exchanged data and impose stringent latency objectives. In this paper, we review the new requirements for P2P networking associated with DAS, discuss open challenges, and identify new research directions.
Tao Feng, Yufeng Liu
In the blockchain network, the communication delay between different nodes is a great threat to the distributed ledger consistency of each miner. Blockchain is the core technology of Bitcoin. At present, some research has proven the security of the PoW protocol when the number of delay rounds is small, but in complex asynchronous networks, the research is insufficient on the security of the PoW protocol when the number of delay rounds is large. This paper improves the proposed blockchain main chain record model under the PoW protocol and then proposes the TOD model, which makes the main chain record in the model more close to the actual situation and reduces the errors caused by the establishment of the model in the analysis process. By comparing the differences between the TOD model and the original model, it is verified that the improved model has a higher success rate of attack when the probability of mining the delayable block increases. Then, the long delay attack is improved on the balance attack in this paper, which makes the adversary control part of the computing power and improves the success rate of the adversary attack within a certain limit.
Daniël Reijsbergen, Bretislav Hajek, Tien Tuan Anh Dinh, Jussi Keppo · 6 authors
Decentralized Finance (DeFi), in which digital assets are exchanged without trusted intermediaries, has grown rapidly in value in recent years. The global DeFi ecosystem is fragmented into multiple blockchains, fueling the demand for cross-chain commerce. Existing approaches for cross-chain transactions, e.g., bridges and cross-chain deals, achieve atomicity by locking assets in escrow. However, locking up assets increases the financial risks for the participants, especially due to price fluctuations and the long latency of cross-chain transactions. Stablecoins, which are pegged to a non-volatile asset such as the US dollar, help mitigate the risk associated with price fluctuations. However, existing stablecoin designs are tied to individual blockchain platforms, and trusted parties or complex protocols are needed to exchange stablecoin tokens between blockchains. Our goal is to design a practical stablecoin for cross-chain commerce. Realizing this goal requires addressing two challenges. The first challenge is to support a large and growing number of blockchains efficiently. The second challenge is to be resilient to price fluctuations and blockchain platform failures. We present CroCoDai to address these challenges. We also present three prototype implementations of our stablecoin system, and show that it incurs small execution overhead.
Hidenori Nakazato, Mingyu Ma, Jichen Xu
Web3, decentralized web, is one of the buzz words brought up in the field of IT business as well as IT technology. Data ownership is supposed to be democratized by Web3, which means data is kept at its owner and the availability of the data is controlled and managed by the owner in the world of Web3. One of the mechanisms providing democratization of data ownership is InterPlanetary File System (IPFS) which leaves data as well as its meta data at its owner and only pointers to data are distributed over the network for data sharing. This paper discusses network layer support for IPFS to improve its performance. In particular, we propose to use Information Centric Networking as the network layer of IPFS to speed up data search in IPFS.
Nathanaël Denis, Maryline Laurent, Sophie Chabridon
The Internet of Things (IoT) brings new ways to collect privacy-sensitive data from billions of devices. Well-tailored distributed ledger technologies (DLTs) can provide high transaction processing capacities to IoT devices in a decentralized fashion. However, privacy aspects are often neglected or unsatisfying, with a focus mainly on performance and security. In this article, we introduce decentralized usage control mechanisms to empower IoT devices to control the data they generate. Usage control defines obligations, i.e., actions to be fulfilled to be granted access, and conditions on the system in addition to data dissemination control. The originality of this article is to consider the usage control system as a component of distributed ledger networks, instead of an external tool. With this integration, both technologies work in synergy, benefiting their privacy, security, and performance. We evaluated the performance improvements of integration using the IOTA technology, particularly suitable due to the participation of small devices in the consensus. The results of the tests on a private network show an approximate 90% decrease of the time needed for the usage control system to push a transaction and make its access decision in the integrated setting, regardless of the number of nodes in the network.
Elias Rohrer, Florian Tschorsch
In order to propagate transactions and blocks, today’s blockchain systems rely on unstructured peer-to-peer overlay networks. In such networks, broadcast is known to be an inefficient operation in terms of message complexity and overhead. In addition to the impact on the system performance, inefficient or delayed block propagation may have severe consequences regarding security and fairness of the consensus layer. In contrast, the Kadcast protocol is a structured peer-to-peer protocol for block and transaction propagation in blockchain networks. Kadcast utilizes the well-known overlay topology of Kademlia to realize an efficient broadcast operation with tunable overhead. We study the security and privacy of the Kadcast protocol based on probabilistic models and analyze its resilience to packet losses and node failures. Moreover, we evaluate Kadcast’s block delivery performance, broadcast reliability, efficiency, and security based on advanced network simulations. Lastly, we introduce a QUIC-based prototype implementation of the Kadcast protocol and show its merits through deployment in a global-scale cloud-based testbed.
Hao Xu, Yunqing Sun, Zihao Li, Yao Sun · 6 authors
Web3 brings an emerging outlook for the value of decentralization, boosting the decentralized infrastructure. People can benefit from Web3, facilitated by the advances in distributed ledger technology, to read, write and own web content, services and applications more freely without revealing their real identities. Although the features and merits of Web3 have been widely discussed, the network architecture of Web3 and how to achieve complete decentralization considering law compliance in Web3 are still unclear. Here, we propose a perspective of Web3 architecture, deController, consisting of underlay and overlay network as Web3 infrastructures to underpin services and applications. The functions of underlay and overlay and their interactions are illustrated. Meanwhile, the security and privacy of Web3 are analyzed based on a novel design of three-tier identities cooperating with deController. Furthermore, the impacts of laws on privacy and cyber sovereignty to achieve Web3 are discussed.
Wenjie Cao, Felix Kottmann, T. B. Richard
The metaverse introduces new challenges to the Internet infrastructure and architecture. While virtual reality (VR) applications on mobile devices dominate the current projections, their Quality of Service (QoS) requirements result in increased demand in global low-latency and local high-bandwidth connections. With the introduction of new Internet architectures, the procurement of bandwidth which guarantees such QoS requirements becomes feasible. Time, location and application-dependent QoS requirements and different budgets of user applications create the competition for such bandwidth resources. As such, a market for routing paths and their bandwidth helps to resolve the competition among user applications by determining the market prices and allocations for all demanded links. This work establishes such a market model by leveraging a Fisher market in which prices and fair allocation are determined. To enable the global, cross-jurisdictional nature of connectivity, a distributed solution for global connectivity is presented through a smart contract on the Ethereum blockchain, enabling optimal updates for selfish buyers and feasible prices and bandwidth allocations at every step.
Asmit Srivastava
Abstract: The advancement of blockchain innovation has prompted the making of decentralized applications (DApps), which permit client collaboration without the utilization of mediators. One of the most generally used blockchain stages for making DApps is Ethereum, which conducts business utilizing its own cash, Ether. Using Metamask, React.js, Node.js, and Solidity, we demonstrate the design and implementation of a decentralised system for Ethereum transfer in this paper. Our technology allows users to safely move Ether between accounts without the usage of intermediaries. We use React.js and Node.js to make the web application, a program module called Metamask to communicate with Ethereum, and Solidity to make the brilliant agreements that make exchanges conceivable.
Hongtian Shi, Ting Xiao, Jaiyi Zhang
Ethereum is a blockchian-based technology that enables a public ledger to be created and maintained without a trusted third party. Ethereum uses elliptic curve cryptography to create accounts and signature, the consensus of PoW as well as PoS to verify transactions and create blocks, and stores data in the modified Merkle Patricia tree. This paper introduced the main three technical aspects of Ethereum and updated some concepts as its technology is updating over time. At the time of Ethereum's transition from PoW to PoS, this paper compared the two mechanism and concluded that PoS is more vulnerable to security issues and more analysis is needed to maintain its long-time security. The paper also discussed uncle block attack and proposed two possible strategies to prevent.
Daniel Olshansky, Ramiro RodrÃguez Colmeiro
Relay Mining presents a scalable solution employing probabilistic mechanisms, crypto-economic incentives, and new cryptographic primitives to estimate and prove the volume of Remote Procedure Calls (RPCs) made from a client to a server. Distributed ledgers are designed to secure permissionless state transitions (writes), highlighting a gap for incentivizing full non-validating nodes to service non-transactional (read) RPCs. This leads applications to have a dependency on altruistic or centralized off-chain Node RPC Providers. We present a solution that enables multiple RPC providers to service requests from independent applications on a permissionless network. We leverage digital signatures, commit-and-reveal schemes, and Sparse Merkle Sum Tries (SMSTs) to prove the amount of work done. This is enabled through the introduction of a novel ClosestMerkleProof proof-of-inclusion scheme. A native cryptocurrency on a distributed ledger is used to rate limit applications and disincentivize over-usage. Building upon established research in token bucket algorithms and distributed rate-limiting penalty models, our approach harnesses a feedback loop control mechanism to adjust the difficulty of mining relay rewards, dynamically scaling with network usage growth. By leveraging crypto-economic incentives, we reduce coordination overhead costs and introduce a mechanism for providing RPC services that are both geopolitically and geographically distributed. We use common formulations from rate limiting research to demonstrate how this solution in the Web3 ecosystem translates to distributed verifiable multi-tenant rate limiting in Web2.
Mingxun Zhou, Liyi Zeng, Yilin Han, Peilun Li · 8 authors
Blockchain systems must be secure and offer high performance. These systems rely on transaction broadcast mechanisms to provide both of these features. Unfortunately, in today’s systems, the broadcast mechanisms are highly inefficient.We present Mercury, a new transaction broadcast protocol designed for high performance blockchains. Mercury shortens the transaction propagation delay using two techniques: a virtual coordinate system and an early outburst strategy. Simulation results show that Mercury outperforms prior propagation schemes and decreases overall propagation latency by up to 44%. When implemented in Conflux, an open-source high-throughput blockchain system, Mercury reduces transaction propagation latency by over 50% with less than 5% bandwidth overhead.
Jakob Svennevik Notland, Mariusz Nowostawski, Jingyue Li
Blockchain systems run consensus rules as code to agree on the state of the distributed ledger and secure the network. Changing these rules can be risky and challenging. In addition, it can often be controversial and take much effort to make all the necessary participants agree to adopt a change. Arguably, Bitcoin has seen centralisation tendencies in pools and in development. However, how these tendencies influence blockchain governance has received minimal community and academic attention. Our study analyses the governmental structures in a blockchain by looking into the history of Bitcoin. We investigate the process of changing consensus rules through a grounded theory analysis comprising quantitative and qualitative data from 34 consensus forks in Bitcoin and Bitcoin Cash. The results reveal the decentralised behaviour in Bitcoin and blockchain. Our results are in contrast to related work, emphasising centralisation among miners and developers. Furthermore, our results show how the consensus-driven deployment techniques and governance of consensus rules are intertwined.
Shivam Pandey, Mayank Sinha, G. Ramya
A new social media platform will be developed that utilizes blockchain technology to ensure user privacy and security. The platform will use the user's meta-mask wallet ID, which cannot be hacked, to connect to their profile on the blockchain, providing an immutable and tamper-proof ledger for their data. The platform will also allow for cryptocurrency transactions, which are secured by cryptography and do not require a centralized intermediary, adding another layer of security. Smart contracts will be used to enable decentralized and automated crowd funding and giveaways, among other features. The smart contracts will be designed using Solidity, a programming language specific to the Ethereum blockchain. When a user creates an account on the platform, their meta-mask wallet ID will be used for user identification and to verify transactions, ensuring that every transaction is validated by the blockchain.
Luyao Zhang, Fan Zhang
Blockchain enables peer-to-peer transactions in cyberspace without a trusted third party. The rapid growth of Ethereum and smart contract blockchains generally calls for well-designed Transaction Fee Mechanisms (TFMs) to allocate limited storage and computation resources. However, existing research on TFMs must consider the waiting time for transactions, which is essential for computer security and economic efficiency. Integrating data from the Ethereum blockchain and memory pool (mempool), we explore how two types of events affect transaction latency. First, we apply regression discontinuity design (RDD) to study the causal inference of the Merge, the most recent significant upgrade of Ethereum. Our results show that the Merge significantly reduces the long waiting time, network loads, and market congestion. In addition, we verify our results' robustness by inspecting other compounding factors, such as censorship and unobserved delays of transactions via private changes. Second, examining three major protocol changes during the merge, we identify block interval shortening as the most plausible cause for our empirical results. Furthermore, in a mathematical model, we show block interval as a unique mechanism design choice for EIP1559 TFM to achieve better security and efficiency, generally applicable to the market congestion caused by demand surges. Finally, we apply time series analysis to research the interaction of Non-Fungible token (NFT) drops and market congestion using Facebook Prophet, an open-source algorithm for generating time-series models. Our study identified NFT drops as a unique source of market congestion -- holiday effects -- beyond trend and season effects. Finally, we envision three future research directions of TFM.
Arad Kotzer, Ori Rottenstreich
Layer-2 is a popular approach to deal with the scalability limitation of blockchain networks. It allows users to execute transactions without committing them to the blockchain by relying on predefined payment channels. Users together with the payment channels form a graph, known as the offchain network topology. Transactions between pairs of users without a connecting channel are also supported through a path of multiple channels. Serving such transactions involves fees paid to intermediate users. In this paper we uncover the potential existence of the Braess paradox in payment networks: Sometimes establishing a new payment channel can increase the fees paid for serving some fixed transactions. We study conditions for the paradox to appear and provide indications for the appearance of the paradox based on real data of Bitcoin's Lightning, a popular layer-2 network. Last, we discuss methods to mitigate the paradox upon establishing a new payment channel.
Miaoyong Xu, Qing Wang, Haohan Sun, Jianru Lin · 5 authors
Scalability trilemma is a classical research topic in the area of blockchains. To defeat such trilemma, many previous solutions have been proposed. However, none of those previous solutions can break such scalability trilemma. In this paper, we present a new Layer2 blockchain called W3Chain, which is promising to deliver high transactions per second (TPS) while defeating the scalability trilemma of a public blockchain. To enable the claimed performance, we particularly design our W3Chain by decoupling the correctness of the blockchain into two parts and adopting several crucial technical issues such as the reconfiguration of committees, the design of query APIs, and the handling of cross-shard transactions. We also propose a Time-Beacon Chain (TBChain) to record pivotal data of W3Chain. To show the correctness and safety features, we rigorously analyze multiple properties of W3Chain, including decentralization, scalability, and security under typical attacks. Finally, we conduct extensive simulations using Ethereum's historical transactions to examine the proposed W3Chain. The evaluation results show that our W3Chain can achieve a TPS as high as 10K+, and much lower transaction confirmation latency compared with Ethereum.
Qin Wang, Guangsheng Yu, Yilin Sai, Caijun Sun · 7 authors
Decentralized autonomous organizations (DAOs) are critical to the blockchain ecosystem as they enable decentralized decision-making and governance, and facilitate the creation of decentralized applications (DApps) and organizations. However, despite significant importance, there is currently a lack of a comprehensive overview and detailed understanding of DAOs. To address the gap, this work presents a primary investigation of DAOs (35+). We category, examine and evaluate existing DAOs regarding their operational features, (non-)functionalities and real-world performance. In addition, we provide a consolidated exploration of DAOs by conducting a literature review [1] and an empirical study on mainstream projects, particularly Snapshot [2]. Our research contributes to a better understanding of DAOs and their potential impact on the blockchain ecosystem.
Benjamin Kraner, Nicolò Vallarano, Caspar Schwarz-Schilling, Claudio J. Tessone
This paper presents a study of the Poof-of-Stake (PoW) Ethereum consensus protocol, following the recent switch from Proof-of-Work (PoS) to Proof-of-Stake within Merge upgrade. The new protocol has resulted in reduced energy consumption and a shift in economic incentives, but it has also introduced new threat sources such as chain reorganizations and balancing attacks. Using a simple and flexible agent-based model, this study employs a time-continuous simulation algorithm to analyze the evolution of the blocktree and assess the impact of initial conditions on consensus quality. The model simulates validator node behavior and the information propagation throughout the peer-to-peer network of validators to analyze the resulting blockchain structure. Key variables in the model include the topology of the peer-to-peer network and average block and attestation latencies. Metrics to evaluate consensus quality are established, and means to observe the model's responsiveness to changes in parameters are provided. The simulations reveal a phase transition in which the system switches from a consensus state to a non-consensus state, with a theoretical justification presented for this observation.
Bing-Yang Lin, Daria Dziubałtowska, Piotr Macek, Andreas Penzkofer · 5 authors
DAG-based DLTs allow for parallel, asynchronous writing access to a ledger. Consequently, the perception of the most recent blocks may differ considerably between nodes, and the underlying network properties of the P2P layer have a direct impact on the performance of the protocol. Moreover, the stronger inter-dependencies of several core components demand a more complex and complete approach to studying such DLTs. This paper presents an agent-based, open-sourced simulator for large-scale networks that implement the leaderless Tangle 2.0 consensus protocol. Its scope includes modelling the underlying peer-to-peer communication with network topology, package loss, heterogeneous latency, the gossip protocol with reliable broadcast qualities, the underlying DAG-based data structure, and the consensus protocol. The simulator allows us to explore the performance of the protocol in different network environments, as well as different attack scenarios.
Renke Huang, Jiachi Chen, Yanlin Wang, Tingting Bi · 5 authors
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 application 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, promoting further exploration and advancement in this innovative field.