Blockchain Papers

Pengfei Huang, Wanqing Jie, Arthur Sandor Voundi Koe, Ruitao Hou · 9 authors

No abstract is available for this record.

Itzhak Aviv, Artem Barger, Alexander Kofman, Roye Weisfeld

The blockchain paradigm and its application of Distributed Ledger Technology (DLT) are now enabling technologies for the worldwide development of trustworthy and decentralized solutions. DLT offers enormous potential to accommodate the intricate architectural patterns of individual Distributed Information Systems (DIS). Despite its immense potential, the current research effort is not focused on deploying DLT inside the DIS area. We identified sixteen essential DIS Architectural Properties (APs) that offer issues for DIS system architects using Grounded Theory. Then, we assessed the capabilities of the major DLT platform and highlighted its prospects and limits with regard to supporting DIS APs. Using the meta-analysis research technique, we demonstrated that DLT might serve as a development platform for a blockchain-native DIS (BN-DIS) that enables design and development processes. A BN-DIS utilizes DLT infrastructure and blockchain design principles to expand internationally, support thousands of distributed nodes, and employ DIS APs unique to the Blockchain. Lastly, we give a case study illustrating how DLT handles DIS APs in a real-world context, giving empirical proof of the DLT’s efficacy in servicing DIS APs.

An Cong Tran, Vu Vo Thanh, Nghi C. Tran, Hai Thanh Nguyen

No abstract is available for this record.

Rafael Descio-Trineto, Maurício A. Pillon, Guilherme Koslovski, Charles C. Miers

No abstract is available for this record.

Xiaowen Hu, Bernd Burgstaller, Bernhard Scholz

Ethereum is one of the first blockchains executing smart contracts (financial applications directly executed on the ledger using a virtual machine). The performance of the Ethereum virtual machine has become a bottleneck caused by high volumes of transactions due to blockchain applications, including decentralized finance and non-fungible tokens. Hence, there is a need to detail the execution characteristics of the Ethereum virtual machine before its performance can be improved. This work introduces an off-line Ethereum virtual machine tracer called EVMTracer that produces runtime data dependence graphs from executed transactions as an alternative program representation. From the runtime dependence graphs, we can deduce valuable metrics about program execution characteristics, including the degree of parallelization and computational redundancies in smart contracts. Our experiments encompass all blocks up to 12M on the Ethereum mainnet. We found a geometric mean of 1.90× theoretical maximum speedup when executing the smart contracts in parallel and identified 34.97% of SLOAD instructions as redundant.

Harjot Singh

No abstract is available for this record.

Sowelu Avanzo, Alex Norta, Claudio Schifanella

No abstract is available for this record.

Ken Huang

No abstract is available for this record.

Maher Alharby

No abstract is available for this record.

Nana Kwadwo Akrasi‐Mensah, Andrew Selasi Agbemenu, Henry Nunoo‐Mensah, Eric Tutu Tchao · 9 authors

Blockchain-IIoT integration into industrial processes promises greater security, transparency, and traceability. However, this advancement faces significant storage and scalability issues with existing blockchain technologies. Each peer in the blockchain network maintains a full copy of the ledger which is updated through consensus. This full replication approach places a burden on the storage space of the peers and would quickly outstrip the storage capacity of resource-constrained IIoT devices. Various solutions utilizing compression, summarization or different storage schemes have been proposed in literature. The use of cloud resources for blockchain storage has been extensively studied in recent years. Nonetheless, block selection remains a substantial challenge associated with cloud resources and blockchain integration. This paper proposes a deep reinforcement learning (DRL) approach as an alternative to solving the block selection problem, which involves identifying the blocks to be transferred to the cloud. We propose a DRL approach to solve our problem by converting the multi-objective optimization of block selection into a Markov decision process (MDP). We design a simulated blockchain environment for training and testing our proposed DRL approach. We utilize two DRL algorithms, Advantage Actor-Critic (A2C), and Proximal Policy Optimization (PPO) to solve the block selection problem and analyze their performance gains. PPO and A2C achieve 47.8% and 42.9% storage reduction on the blockchain peer compared to the full replication approach of conventional blockchain systems. The slowest DRL algorithm, A2C, achieves a run-time 7.2 times shorter than the benchmark evolutionary algorithms used in earlier works, which validates the gains introduced by the DRL algorithms. The simulation results further show that our DRL algorithms provide an adaptive and dynamic solution to the time-sensitive blockchain-IIoT environment.

Amit Biswas, Ravi Yadav, Gaurav Baranwal, Anil Kumar Tripathi

In blockchain-based systems, participants can be malicious. Therefore, this work first characterizes several properties expected in systems where the honest behaviour of involved parties plays significant role in the success. Considering these properties, a new consensus mechanism, Proof of Karma (PoK), is proposed based on karma (actions) of nodes. PoK incorporates a self-stabilizing leader election algorithm based on karma score to ensure consistency in the system. In PoK, both new and existing nodes get a fair chance to earn profit by becoming a leader and adding a valid block to the blockchain. PoK gives incentives and imposes penalties to encourage and discourage the nodes’ honest and malicious actions, respectively. PoK is analyzed with respect to the CAP theorem. The work provides security analysis to demonstrate the resistance of PoK against various blockchain specific attacks and karma specific attacks. Several experiments are also performed to assess the performance of PoK and compare it with the baseline model. The results show the feasibility, effectiveness, usability and scalability of PoK. PoK is also compared based on the characterized properties with various existing consensus mechanisms that consider malicious actions of nodes. PoK achieves consensus finality, decentralization and fairness, outperforming existing works.

Kashif Mehboob Khan, Muhammad Abdullah Hayat, Rana Muhammad Ibrahim

In the current era, blockchain has emerged as one the best and promising technology. All the cryptocurrencies have also gained a lot of popularity around the globe which are based on blockchain technology. Blockchain provides a distributed architecture, in which transactions are verified by different validators using different algorithms and then are stored in distributed ledger. The verification of transactions is done using consensus algorithms which verifies that incoming transaction is correct and reliable by different distributed nodes working in a peer-to-peer network. Consensus algorithms ensure the integrity and security of blockchain. There are various types of consensus algorithms used in blockchain technology which are used depending on the architecture and usage, some of the consensus algorithms are Proof of Work (PoW), Proof of Stake (PoS) etc. The Proof of Work algorithm is most widely used across the globe by the community. It is used by many popular cryptocurrency networks like Litecoin and Bitcoin. It requires larger computation power while verifying transactions. The selection of a consensus algorithm is one the most important parts of blockchain, as the consensus mechanism is considered to be the core of a network. It is easier to predict and guarantee the security, reliability, fault tolerance, and recoverability of the system if the correct consensus protocol is selected. A single algorithm can never fulfill all the requirements, there is always a tradeoff in the selection of consensus algorithms. Therefore, it is very important to select the best suited consensus algorithm for the network as the consensus mechanism validates transactions without any third-party platform and prevents malicious activities in the network. This paper investigates the comparison among types of consensus algorithms and their effectiveness and viability.

Sivaram Rajeyyagari, Regonda Nagaraju, Meenu Chopra, Cosmena Mahapatra · 6 authors

In the least tough of terms, blockchain can be portrayed as documents you can solely add to, proper now not reduce, or change. Subsequently, the time body is "chain" due to the reality you are making a chain of data. Not being there for the talent to replacement the principal blocks make it so secure. Moreover, blockchains are understanding-driven, so no one issue can take manipulate the data. With blockchain, you do not be given that a depended upon untouchable ought to oversee or assist trades. Blockchain development achieves decentralized safety and have faith in extra approaches than one. Regardless, new blocks are always taken care of straightly and successively. That is, they are constantly introduced to the "end" of the blockchain.

Yuanzhe Zhang, Shirui Pan, Jiangshan Yu

The scalability problem has been one of the most significant barriers limiting the adoption of blockchains. Blockchain sharding is a promising approach to this problem. However, the sharding mechanism introduces a significant number of cross-shard transactions, which are expensive to process. This paper focuses on the transaction allocation problem to reduce the number of cross-shard transactions for better scalability. In particular, we systematically formulate the transaction allocation problem and convert it to the community detection problem on a graph. A deterministic and fast allocation scheme TxAllo is proposed to dynamically infer the allocation of accounts and their associated transactions. It directly optimizes the system throughput, considering both the number of cross-shard transactions and the workload balance among shards. We evaluate the performance of TxAllo on an Ethereum dataset containing over 91 million transactions. Our evaluation results show that for a blockchain with 60 shards, TxAllo reduces the cross-shard transaction ratio from 98% (by using traditional hash-based allocation) to about 12%. In the meantime, the workload balance is well maintained. Compared with other methods, the execution time of TxAllo is almost negligible. For example, when updating the allocation every hour, the execution of TxAllo only takes 0.5 seconds on average, whereas other concurrent works, such as BrokerChain (INFOCOM'22) leveraging the classic METIS method, require 422 seconds.

Hind S. Hassan, Rehab F. Hassan, Ekhlas Khalaf Gbashi

Electronic voting methods are gaining popularity in contemporary culture. It has the potential to reduce administrative expenses and enhance voter participation. Electronic voting systems must be lawful, accurate, secure, and convenient when utilized in elections. This paper aims to establish a project to make electoral systems more decentralized and scalable. As functionality increases, it significantly enhances the Proof-of-Work idea embraced by Bitcoin and Ethereum. Through Solana, it will be simple to implement business logic and ensure that it assists in resolving the world's common problems. We used Solana libraries and the Anchor framework to implement our system to provide convenient tools for developing secure Solana programs and rust programming language.

Qin Wang, Jiangshan Yu, Shiping Chen, Yang Xiang

Limitations on high latency and low scalability of classical blockchain systems retard their adoptions and applications. Reconstructed blockchain systems have been proposed to avoid the consumption of competitive transactions caused by linear sequenced blocks. These systems, instead, structure transactions/blocks in the form of Directed Acyclic Graph (DAG) and consequently rebuild upper layer components. The promise of DAG-based blockchain systems is to enable fast confirmation (complete transactions within million seconds) and high scalability (attach transactions in parallel) without significantly compromising security. However, this field still lacks systematic work that summarises DAG techniques. To bridge the gap, this Systematization of Knowledge (SoK) provides a comprehensive analysis of ever-existing and ongoing DAG-based blockchain systems. We abstract a general model to capture the main features and identify six types of design patterns. Then, we evaluate these systems from the perspectives of structure, consensus, property, security, and performance. We further discuss the trade-off between different factors, open challenges, and the potentiality of DAG-based solutions, indicating their promising directions for future research.

Kawaldeep Kaur, Shubham Tomar, Meenakshi Tripathi

Smart contracts are full-fledged programs that runs on Blockchains. The largest Blockchain-based platform is Ethereum. It facilitates Smart Contracts, written in a programming language called Solidity, to run on the virtual machine. Ethereum charges developers an execution fee in the form of Gas used to purchase computing resources. In this paper, we discovered that the Solidity compiler could not do loop optimization, Code refactoring, and Dead code elimination. Solidity can not perform other optimization like detecting duplicate writes, inefficient use of data types, Inefficient use of global variables, etc. Furthermore, thus Smart Contracts which are not optimized cost more Gas. Smart contracts contain costly Gas byte codes, contributing to various Gas expensive patterns. In this study, we found that many Smart Contracts contain mergeable loops. Based on symbolic execution, we developed a method called GASaVER to detect merge-able loops that can merge to reduce the bytecode size and the Gas fee charged, achievable because costly Gas patterns have a sequence that can be replaced by ones with the same semantics but requires less Gas.

Inwon Kang, Aparna Gupta, Oshani Seneviratne

Blockchain has become a popular emergent technology in many industries. It is suitable for a broad range of applications, from its base role as an immutable distributed ledger to the deployment of distributed applications. Many organizations are adopting the technology, but choosing a specific blockchain implementation in an emerging field exposes them to significant technology risk. Selecting the wrong implementation could expose an organization to security vulnerabilities, reduce access to its target audience, or cause issues in the future when switching to a more mature protocol. Blockchain interoperability aims to solve this adaptability problem by increasing the extensibility of blockchain, enabling the addition of new use cases and features without sacrificing the performance of the original blockchain. However, most existing blockchain platforms need to be designed for interoperability, and simple operations like sending assets across platforms create problems. Cryptographic protocols that are secure in isolation may become insecure when several different (individually secure) protocols are composed. Similarly, utilizing trusted custodians may undercut most of the benefits of decentralization offered by blockchain-based systems. Even though there is some research and development in the field of blockchain interoperability, a characterization of the interoperability solutions for various infrastructure options is lacking. This paper presents a methodology for characterizing blockchain interoperability solutions that will help focus on new developments and evaluate existing and future solutions in this space.

Noama Fatima Samreen, Manar H. Alalfi

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.

Tianjing Xu, Yiming Zhang

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.

Xiaotian Qiu, Hu Xia, Jianbin Gao, Qi Xia

As a distributed ledger jointly maintained by multiple parties that do not trust each other [1], the data services provided by the blockchain system must ensure that the results cannot be tampered with. However, the query on blockchain is affected by the chain structure. This paper adds relational semantics to block data. So, it can support three basic query methods and accelerate a unique query method for blockchain. In addition, we design four types of indexes to ensure the efficiency of data query. We optimized the query processing and tested it in the edge device scenario and taking the Internet of Vehicles as an example. The result shows that the response time for the query is significantly reduced.

Pedro Ákos Costa, João Leitão, Yannis Psaras

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.

Lingling Lu, Zhenyu Wen, Ye Yuan, Binru Dai · 10 authors

Blockchain, a distributed and shared ledger, provides a credible and transparent solution to increase application auditability by querying the immutable records written in the ledger. Unfortunately, existing query APIs offered by the blockchain are inflexible and unscalable. Some studies propose off-chain solutions to provide more flexible and scalable query services. However, the query service providers (SPs) may deliver fake results without executing the real computation tasks and collude to cheat users. In this article, we propose a novel intelligent blockchain analytics platform termediQuery, in which we design a game theory based smart contract to ensure the trustworthiness of the query results at a reasonable monetary cost. Furthermore, the contract introduces the second opinion game that employs a randomized SP selection approach coupled with non-ordered asynchronous querying primitive to prevent collusion. We achieve a fixed price equilibrium, destroy the economic foundation of collusion, and can incentivize all rational SPs to act diligently with proper financial rewards. In particular,iQuerycan flexibly support semantic and analytical queries for generic consortium or public blockchains, achieving query scalability to massive blockchain data. Extensive experimental evaluations show thatiQueryis significantly faster than state-of-the-art systems. Specifically, in terms of the conditional, analytical, and multi-origin query semantics,iQueryis 2 ×, 7 ×, and 1.5 × faster than advanced blockchain and blockchain databases. Meanwhile, to guarantee 100% trustworthiness, only two copies of query results need to be verified iniQuery, whileiQuery's latency is$2 \sim 134$× smaller than the state-of-the-art systems.

Zhe Ye, Ujval Misra, Jiajun Cheng, Wenyang Zhou · 5 authors

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.