The Ethereum blockchain’s smart contract is a programmable transaction that performs general-purpose computations and can be executed automatically on the blockchain. Leveraging this component, blockchain technology (BT) has grown beyond the scope of cryptocurrencies and can now be applicable in various industries other than finance. In this paper, we investigated the current trends in Ethereum-based decentralized applications (DApps) to be able to categorize and analyze the DApps to measure the complexity of smart contracts behind them, their level of security and their correlation to the maintainability of the DApps. We leveraged the source code analysis, security analysis, and the developmental metadata of the DApps to infer this correlation. Based on our findings, we concluded that the maintainability of Ethereum DApps is proportional to the code size, number of functions, and, most importantly, the number of outgoing invocations and statements in the smart contracts.
At present, academics have researched the directions that may become performance bottlenecks in blockchain systems, such as consensus protocols, encryption algorithms and contract execution. For example, in recent years, many improvements to consensus protocols have greatly improved the throughput of blockchain systems. However, the bottleneck of blockchain smart contract execution has not been well solved. Currently, the miner-validator architecture based on serial contract execution limits the throughput of smart contract execution to a great extent. This paper proposes a new smart contract parallel execution architecture, which migrates the concurrency control methods used in mature databases to the blockchain. The test of Ethereum data and a benchmark specifically for blockchain show that its throughput is greatly improved compared with the traditional serial execution mode.
Web3 aims at creating a decentralized platform that is competitive with modern cloud infrastructures that support today's Internet. However, Web3 is still limited, supporting only applications in the domains of content creation and sharing, decentralized financing, and decentralized communication. This is mainly due to the technologies supporting Web3: blockchain, IPFS, and libp2p, that although provide a good collection of tools to develop Web3 applications, are still limited in terms of design and performance. This motivates the need to better understand these technologies as to enable novel optimizations that can push Web3 to its full potential. Unfortunately, understanding the current behavior of a fully decentralized large-scale distributed system is a difficult task, as there is no centralized authority that has full knowledge of the system operation. To this end, in this paper we characterize the workload of IPFS, a key enabler of Web3. To achieve this, we have collected traces from accesses performed by users to one of the most popular IPFS gateways located in North America for a period of two weeks. Through the fine analysis of these traces, we gathered the amount of requests to the system, and found the providers of the requested content. With this data, we characterize both the popularity of requested and provided content, as well as their geo-location (by matching IP address with the MaxMind database). Our results show that most of the requests in IPFS are only to a few different content, that is provided by large portion of peers in the system. Furthermore, our analysis also shows that most requests are provided by the two largest portions of providers in the system, located in North America and Europe. With these insights, we conclude that the current IPFS architecture is sub-optimal and propose a research agenda for the future.
An optimistic rollup (ORU) scales a blockchain's throughput by delegating computation to an untrusted remote chain (L2), refereeing any state claim disagreements between mutually distrusting L2 operators via an interactive dispute resolution protocol. State-of-the-art ORUs employ a monolithic dispute resolution protocol that tightly couples an L1 referee with a specific L2 client binary--oblivious to the system's higher-level semantics. We argue that this approach (1) magnifies monoculture failure risk, by precluding trust-minimized and permissionless participation using operator-chosen client software; (2) leads to an unnecessarily large and difficult-to-audit TCB; and, (3) suffers from a frequently-triggered, yet opaque upgrade process--both further increasing auditing overhead, and broadening the governance attack surface. To address these concerns, we outline a methodology for designing a secure and resilient ORU with a minimal TCB, by facilitating opportunistic 1-of-N-version programming. Due to its unique challenges and opportunities, we ground this work concretely in the context of the Ethereum ecosystem--where ORUs have gained significant traction. Specifically, we design a semantically-aware proof system, natively targeting the EVM and its instruction set. We present an implementation in a new ORU, Specular, that opportunistically leverages Ethereum's existing client diversity with minimal source modification, demonstrating our approach's feasibility.
Architectural design contexts contain a set of factors that greatly influence software application development. Among them, organizational design contexts consist of high-level company concerns and how it is structured, for example, stakeholders and development schedules heavily impacting design considerations. The Decentralized Autonomous Organization (DAO), as a vital concept in the Web3 space, represents an organization constructed by automatically executed rules, such as via smart contracts, holding features of the permissionless committee, transparent proposals, and fair contribution by participated stakeholders. In this work, we conduct a systematic literature review of existing DAO literature to summarize its structural features, benefits and challenges, and potential development directions in the context of Web3 applications.
Efficient data storage and query processing systems play a vital role in many different research areas. Blockchain technology and distributed ledgers attract massive attention and trigger multiple projects in various industries. Nevertheless, blockchain still lacks the features of a Database Management System (DBMS or simply databases), such as high throughput, low latency, and high capacity. For that purpose, there have been many proposed approaches for handling data storage and query processing solutions in the blockchain. This paper presents a complete overview of many different DBMS types and how these systems can be used to implement, enhance, and further improve blockchain technology. More concretely, we give an overview of 10 transactional, an extensive overview of 14 analytical, 9 hybrids, i.e., translytical, and 13 blockchain DBMSs. We explain how database technology has influenced the development of blockchain technology by unlocking different features, such as Atomicity, Consistency, Isolation, and Durability (ACID), transaction consistency, rich queries, real-time analysis, and low latency. Using a relaxation approach analogous to the one used to prove the Consistency, Availability, Partition tolerance (CAP)-theorem, we postulate a “Decentralization, Consistency, and Scalability (DCS)-satisfiability conjecture” and give concrete strategies for achieving the relaxed DCS conditions. We also provide an overview of the different DBMSs, emphasizing their architecture, storage manager, query processing, and implementation.
We study security-latency bounds for Nakamoto consensus, i.e., how secure a block is after it becomes k-deep in the chain. We improve the state-of-the-art bounds by analyzing the race between adversarial and honest chains in three different phases. We find the probability distribution of the growth of the adversarial chains under models similar to those in Guo and Ren (2022) when a target block becomes k-deep in the chain. We analyze certain properties of this race to model each phase with random walks that provide tighter bounds than the existing results. Combining all three phases provides novel upper and lower bounds for blockchains with small$\lambda \Delta $.
P. Mohan, Vivek Balachandran, Ong Ze Quan, Jas Pang Ze Xin · 5 authors
Blockchain is one of the most promising technology trends that has the potential to be extensively adopted in the education sector. In this work, we investigate the feasibility of utilizing an Ethereum blockchain for developing a trusted frame-work using ERC-721 non-fungible tokens (NFTs) for a Module credit management system – NFT-Merit. In this framework, the NFTs minted by a university represents the module credits issued by its faculty and owned by its students upon satisfying module requirements in the credit management system. Once a student has collected all the NFTs required for graduating the degree, a smart contract automatically generates a degree certificate which can be integrated with the well-known OpenCert formats. With cases of degree fraud on the rise, the current methods of degree issuance and verification are inadequate in this digital age. This research involves the design and development of a web-based decentralized application (dApp) on the Ethereum blockchain test network. The NFT-merit dApp is hosted on the InterPlanetary File System (IPFS) as a decentralized network of nodes instead of a single centralized node to enable redundancy, improve scalability and minimize network bandwidth usage for data access. We perform an extensive analysis of the costs involved in deploying NFT-merit and the duration of minting NFTs. Our experimental results show that minting NFTs in batches would require almost the same time as minting a single NFT in a transaction, whereas the cost savings in the former scenario is more than 22% as compared to the latter.
Abstract—As fully autonomous ride-hailing services continue to scale, occupant-facing microservices have emerged as a linch- pin for multi-rider resource allocation, real-time commerce, and occupant privacy. In previous frameworks, occupant concurrency engines leveraged ephemeral occupant data and aggregator-based telepresence for conflict resolution, yet trust and transparency of occupant identity remain underexplored. This paper proposes a blockchain-powered approach to occupant identity, enabling de- centralized authentication, payment, and data-sharing flows that are impervious to single-point failures. By registering occupant profiles on a distributed ledger, occupant concurrency logic can verify ride privileges, cost splits, and occupant-lingual disclaimers without storing sensitive occupant data in a central aggregator. We describe how occupant concurrency gates, occupant seat usage, ephemeral occupant camera frames, and aggregator route expansions, while deferring occupant identity and micropayment transactions to a blockchain-based ledger. This method unifies occupant-lingual disclaimers with cryptographic wallet checks, ensuring the occupant sees a transparent log of e-commerce or route negotiations. Preliminary simulation results suggest that decentralized occupant identity reduces aggregator overhead by 25%, while occupant-lingual disclaimers adoption remains high due to ephemeral occupant data policies. We further demonstrate how partial offline fallback can cache occupant ledger proofs, re- syncing only hashed occupant usage logs upon coverage reestablishment. By designing occupant concurrency logic around distributed identity, occupant-lingual expansions—like seat reassignments or multi-tenant microservices—achieve global security invariants across multiple brands, fleets, or regional operators. This paper marks a critical step in bridging occupant concur- rency with blockchain and distributed identity, heralding a future of trust-minimized occupant microservices for the driverless era. Keywords—Blockchain, Distributed Identity, Occupant Con- currency, Ephemeral Data, Occupant-Lingual Disclaimers, Autonomous Ride-Hailing
Abstract Industry and research communities have widely studied Blockchain technology, and the consortium blockchain is currently the most used category with a wide range of applications. However, issues, such as the performance of consensus mechanisms, have become essential constraints on promoting and applying the consortium blockchain. To improve the performance of the consortium blockchain consensus, we use the practical Byzantine fault tolerance (PBFT) consensus widely used in consortium blockchains to reduce the number of consensus nodes to optimize performance. Using the PBFT consensus, we screen high-performance nodes and obtain a reliable and limited number of consensus nodes. We propose a genetic algorithm-based blockchain consensus algorithm improvement scheme, design the fitness function of blockchain nodes and the genetic algorithm to iterate out consensus node groups with excellent indicators continuously, and finally iterate the nodes participating in the consensus. This algorithm can increase the speed and efficiency of the consensus, block generation, and computation. The algorithm in this article is tested on the FISCO BCOS (i.e., a consortium blockchain platform built by the FISCO open-source working group), and controlled experiments and the experimental results illustrate the safety and practicability of the method.
This paper covers a novel solution to reduce the gas consumed by Decentralized Applications (DApps) running on Ethereum Virtual Machine (EVM). Smart contracts extend the capabilities of the Blockchain, but the strict gas policy of the EVM limits the implementation of various DApps. On the other hand, Oracle provides a means to use an external execution environment for smart contracts, but its functional limitations and additional costs limit the growth of the DApp market to DApp users. To address the gas consumption crisis of DApps, we designed an event-based resource offloading solution that allows DApp developers to run their own compute servers. By adopting our solution, DApp users only pay the constant and minimized amount of gas fee, while the external server pays highly reduced amount of gas fee instead. We describe the solution in detail with a sample DApp model and mathematically demonstrate the effectiveness of the solution compared to an Oracle-based implementation. Furthermore, we conducted empirical experiment of actual DApp using EVM and verified the reduction of the gas consumption.
Despite the success in various scenarios, blockchain systems, especially EVM-compatible ones that serially execute transactions, still face the significant challenge of limited throughput. Concurrent transaction execution is a promising technique to accelerate transaction processing and increase the overall throughput. Existing concurrency control algorithms, however, fail to obtain enough speedups in real-world blockchains due to the high-contention workloads. In this paper, we propose a novel operation-level concurrency control algorithm designed for blockchains. The core idea behind our algorithm is that only operations depending on conflicts should be executed serially, while all other conflict-free operations can be executed concurrently. Therefore, in contrast to the traditional approaches, which block or abort the entire transaction when encountering conflicts, our algorithm introduces a redo phase to resolve conflicts at the operation level by re-executing conflicting operations only. We also develop a set of data dependency tracking mechanisms to achieve precise identification and speedy re-execution for conflicting operations. We implement an open-source prototype based on Go Ethereum and evaluate it using real-world Ethereum blocks. The evaluation results show that our algorithm achieves an average speedup of 4.28$\times$. If combined with state prefetching techniques, our approach can further accelerate the transaction execution by 7.11$\times$.
This paper presents an inter-domain transport net-work slice management with Service Level Agreements (SLA) using the ETSI TeraFlowSDN (TFS) controller. Different instances of the TFS controller are deployed for each involved domain. The communication between the TFS instances is supported by a Distributed Ledger Technology (DLT)-based database. The different TFS instances upload the abstracted view of their topologies and retrieve that from remote peers. When the end- to-end SLA of the transport network slice is violated, the slice is reconfigured avoiding the domain that originated the violation.
With features like immutability and transparency, blockchain and Distributed Ledger Technologies (DLT) can enable the telco industry to exchange services using smart contracts. Consequently, various 6G network stakeholders can participate in a marketplace for inter-provider agreements as either service providers or consumers. As, a blockchain-based 6G network can aid administrative domains in sharing resources (virtual network functions, services, or slices). However, such a dynamic environment requires strict Service Level Agreement (SLA) monitoring and management. Therefore, this paper considers a use case of a smart contract-based inter-provider agreement. We use novel solutions like IOTA Tangle to perform transactions, IPFS to store the hash of use case data files, and chainlink to access off-chain data feeds for SLA monitoring, reducing costs and increasing transparency. We also provide experimental evaluations of and divide the emulation into two phases. Phase 1 consists of choosing the approach and creating a smart contract (SC) (i.e., SC-Marketplace or SC-Auction). Furthermore, phase 2 consists of off-chain data feed to monitor SLA through chainlink. Finally, we measure transaction latency, response time, overall time consumption, and transaction & storage cost. The maximum latency observed in phase 1 is$\approx 25\text{ms}$and$\approx 15\mathrm{s}$for phase 2. Similarly, the average response time for both phases is$\approx 14\mathrm{s}$~ 20s. Lastly, the results also explain that using IOTA-EVM, we can have fee-less transactions, and IPFS helps reduce the storage cost by up to$\approx 80\%$. However, it is concluded that adding chainlink adds additional cost for SLA data feeds.
Dalia Elwi, Osama Abu-Elnasr, A. S. Tolba, Samir Elmougy
Abstract Bitcoin is a digital cryptocurrency which had become the focus of scientific research in the modern era. Blockchain is the underlying technology of Bitcoin because of its decentralization, transparency, trust-less, and immutability features. However, blockchain can be considered the cause of Bitcoin scalability issues especially storage. Nodes in Bitcoin network need to store the full blockchain to validate transactions. By time, the blockchain size will be extremely huge. So, the full nodes will prefer to leave the network, and this leads to the blockchain being centralized and trusted. Therefore, security will be adversely affected. In this paper, we propose a Stateful Layered Chain Model which is based on storing accounts’ balances to reduce the size of the Bitcoin blockchain. This model changes the structure of the traditional blockchain from blocks to layers. The experimental results demonstrated that the proposed model reduces the size of blockchain by about 50.6%. Imlicitly, the transaction throughput can also be nearly doubled.
Damilare Peter Oyinloye, Je Sen Teh, Norziana Jamil, Jiashen Teh
Blockchain is a distributed ledger in which participating users with varying levels of trust agree on the ledger’s content using a consensus mechanism called consensus protocols. There has been a rising interest in the design of consensus protocols since they play a central role in blockchain architecture. However, many recently proposed consensus protocols lack experimental verification which hampers the possible deployment of these protocols in real-world blockchain networks. In this article, we propose a simple tool called simplified consensus protocol simulator (SIM-P) that can accurately simulate the behavior of these consensus protocols with ease. It is an agent-based stochastic simulator that relies on the sequential Monte Carlo method to model how block publishers are selected. The likelihood of each node (represented as agents) being selected as a block publisher is represented by independent trials in a binomial experiment. We provide a base SIM-P model that simulates Proof of Work (PoW) for benchmarking purposes. The PoW model also serves as the basic structure of the simulator that can be adapted to other protocols. We showcase the flexibility of SIM-P by proposing two additional simulation models for Proof of Reputation-X and Proof of Contribution, both of which lack experimental verification in their original design specifications. We show how the simulator can be used to produce vital metrics, such as throughput, resistance against the 51% attack, and energy consumption. We verify the accuracy of SIM-P by comparing PoW’s simulated results with theoretical estimates and historical Bitcoin data.
In this work, we propose a stateless blockchain called CompactChain, which compacts the entire state of the UTXO (Unspent Transaction Output) based blockchain systems into two RSA accumulators. The first accumulator is called Transaction Output (TXO) commitment which represents the TXO set. The second one is called Spent Transaction Output (STXO) commitment which represents the STXO set. In this work, we discuss three algorithms - (i) To update the TXO and STXO commitments by the miner. The miner also provides the proofs for the correctness of the updated commitments; (ii) To prove the transaction's validity by providing a membership witness in TXO commitment and non-membership witness against STXO commitment for a coin being spent by a user; (iii) To update the witness for the coin that is not yet spent; The experimental results evaluate the performance of the CompactChain in terms of time taken by a miner to update the commitments and time taken by a validator to verify the commitments and validate the transactions. We compare the performance of CompactChain with the existing state-of-art works on stateless blockchains. CompactChain shows a reduction in commitments update complexity and transaction witness size which inturn reduces the mempool size and propagation latency without compromising the system throughput (Transactions per second (TPS)).
Since executing a smart contract on the Ethereum blockchain costs money (measured in gas ), smart contract developers spend significant effort in reducing gas usage. In this paper, we propose a new technique for reducing the gas usage of smart contracts by changing the underlying data layout. Given a smart contract P and a type-level transformation, our method automatically synthesizes a new contract P ′ that is functionally equivalent to P . Our approach provides a convenient DSL for expressing data type refactorings and employs program synthesis to generate the new version of the contract. We have implemented our approach in a tool called Solidare and demonstrate its capabilities on real-world smart contracts from Etherscan and GasStation. In particular, we show that our approach is effective at automating the desired data layout transformation and that it is useful for reducing gas usage of smart contracts that use rich data structures.
Blockchain and distributed ledger technologies are gaining the interest of the academy, companies, and institutions. Nonetheless, the path toward blockchain adoption is not straightforward, as blockchain is a complex technology that requires revisiting the standard way of addressing problems and tackling them from a decentralized perspective. Thus, decision-makers adopt blockchain technology for the wrong reasons or prefer it to more suitable ones. This work presents a decision framework for blockchain adoption to help decision-makers decide whether blockchain is applicable, valuable, and preferable to other technologies. In particular, The decision framework is composed of a small set of questions that can be answered from a managerial standpoint and that do not require a deep technical knowledge of blockchain-related topics.
As transaction fees skyrocket today, blockchains become increasingly expensive, hurting their adoption in broader applications. This work tackles the saving of transaction fees for economic blockchain applications. The key insight is that other than the existing "default" mode to execute application logic fully on-chain, i.e., in smart contracts, and in fine granularity, i.e., user request per transaction, there are alternative execution modes with advantages in cost-effectiveness. On Ethereum, we propose a holistic middleware platform supporting flexible and secure transaction executions, including off-chain states and batching of user requests. Furthermore, we propose control-plane schemes to adapt the execution mode to the current workload for optimal runtime cost. We present a case study on the institutional accounts (e.g., coinbase.com) intensively sending Ether on Ethereum blockchains. By collecting real-life transactions, we construct workload benchmarks and show that our work saves 18% ~ 47% per invocation than the default baseline while introducing 1.81 ~ 16.59 blocks delay.
Sustainable, immutable, and affordable data storage to leading universities, research institutions, enterprises, and Web3 organizations. The next generation of platforms will be built on the decentralized web. Unlocking the benefits of the next economy: True ownership, security, and verifiability of data.
This research presents a novel method to assess inter-chain message relay time in the Cosmos blockchain network, which employs the Inter-Blockchain Communication (IBC) protocol for blockchain interoperability. While inter-chain transactions in Cosmos lag behind intra-chain transactions, this research conducts a thorough performance evaluation, emphasizing message relay time across diverse Cosmos chains. The results show a strong association between inter-chain transaction frequency and overall transaction processing speed (TPS), underscoring the inherent trade-off between scalability and compatibility in inter-chain communication protocols. A thorough understanding of inter-chain transaction performance is essential for advancing interoperability and improving cross-blockchain network designs. As a result, this research improves our understanding of Cosmos’ functionality and provides insightful recommendations for boosting the effectiveness and scalability of inter-chain communication. The study also sheds light on message delivery patterns in the Cosmos ecosystem, showing that IBC message relay time has an average duration of 55.448 s and is distributed lognormally. Notably, the time between the commitment of the IBC RecvPacket transaction and the commitment of the IBC Acknowledgement transaction (R to A time) considerably impacts the effectiveness of message transmission, which causes delays in the IBC message relay process.
Xi Chen, David Simchi‐Levi, Zishuo Zhao, Yuan Zhou
In blockchain systems, the design of transaction fee mechanisms is essential for stability and satisfaction for both miners and users. A recent work has proven the impossibility of collusion-proof mechanisms that achieve both non-zero miner revenue and Dominating-Strategy-Incentive-Compatible (DSIC) for users. However, a positive miner revenue is important in practice to motivate miners. To address this challenge, we consider a Bayesian game setting and relax the DSIC requirement for users to Bayesian-Nash-Incentive-Compatibility (BNIC). In particular, we propose an auxiliary mechanism method that makes connections between BNIC and DSIC mechanisms. With the auxiliary mechanism method, we design a transaction fee mechanism (TFM) based on the multinomial logit (MNL) choice model, and prove that the TFM has both BNIC and collusion-proof properties with an asymptotic constant-factor approximation of optimal miner revenue for i.i.d. bounded valuations. Our result breaks the zero-revenue barrier while preserving truthfulness and collusion-proof properties.
Abstract This study proposes a primary node election method based on probabilistic linguistic term set (PLTS) for the practical Byzantine fault tolerance (PBFT) consensus mechanism to effectively enhance the efficiency of reaching consensus. Specifically, a novel concept of the probabilistic linguistic term set with a confidence interval (PLTS-CI) is presented to express the uncertain complex voting information of nodes during primary node election. Then, a novel score function based on the exponential semantic value and confidence approximation value for the PLTS-CI, called Score-ESCA, is used to solve the problems of comparing different nodes with various voting attitudes. This method helps select the node with the highest score by utilizing complex decision attitudes, making it an accurate primary node election solution. Furthermore, the feasibility of our proposed method is proved by both theoretical analysis and experimental evaluations.