F. Schüßler, Pezhman Nasirifard, Hans‐Arno Jacobsen
Despite the very high volatility of the cryptocurrency markets, the interest in the development and adaptation of existing cryptocurrencies such as Bitcoin as well as new distributed ledger technologies is increasing. Therefore, understanding the security and vulnerability issues of such blockchain systems plays a critical role. In this work, we propose a configurable distributed simulation framework for analyzing Bitcoin-like blockchain systems which are based on Proof-of-Work protocols. The simulator facilitates investigating security properties of blockchain systems by enabling users to configure several characteristics of the blockchain network and executing different attack scenarios, such as double-spending attacks and flood attacks and observing the effects of the attacks on the blockchain network.
Aditya M. Deshpande, Pezhman Nasirifard, Hans‐Arno Jacobsen
Cryptocurrencies and Distributed Ledger Technologies, such as Ethereum have received extensive attention over the past few years. With the increasing popularity of Ethereum, comprehensive understanding of its various properties plays a critical role in the widespread adaptation. However, due to the significant requirements for deploying a full Ethereum blockchain and high running costs, it is challenging to study the dynamic properties of the Ethereum. In this work, we propose eVIBES, a configurable simulation framework for gaining empirical insights into the dynamic properties of Ethereum.
Mohamed Riswan Abdul Lathif, Pezhman Nasirifard, Hans‐Arno Jacobsen
Directed Acyclic Graph (DAG) based Distributed Ledger Technologies (DLT) such as IOTA Tangle has been proposed to address the inefficiencies of traditional blockchains, including the issues with scalability, high resource consumptions, and the increasing transaction fees. Despite the promising features introduced by IOTA, the properties of DAG-based distributed ledgers are not yet comprehensively studied. In this work, we propose CIDDS, a configurable and interactive DAG-based DLT simulation framework. CIDDS enables the user to perform large-scale simulations with thousands of nodes and to investigate different characteristics of the network under controlled conditions.
Elisabeth Kapsammer, Birgit Pröll, Werner Retschitzegger, Wieland Schwinger · 6 authors
Since the emergence of Bitcoin, blockchains (BCs) have been applied not only in the finance sector, but also in various other domains like health care, education or Industry 4.0 resulting in numerous different BC platforms and substantial research work. This plenty of efforts yielded to several valuable scientific surveys classifying and evaluating existing BC platforms. Although each of them puts forward a somewhat consolidated view on the field, it is still challenging to get rid of the "blockchain muddle" preventing even a common perception of the core functionality of BCs. Instead of providing yet another BC overview we conduct a meta survey of existing BC studies and report on lessons learned in this paper, being the basis for our vision towards a UML-based reference model considering both, structural and behavioral aspects of BCs and thereby identifying the nucleus of BCs.
Blockchains yield to new workloads in database management systems and K/V-Stores. Distributed Ledger Technology (DLT) is a technique for managing transactions in 'trustless' distributed systems. Yet, clients of nodes in blockchain networks are backed by 'trustworthy' K/V-Stores, like LevelDB or RocksDB in Ethereum, which are based on Log-Structured Merge Trees (LSM-Trees). However, LSM-Trees do not fully match the properties of blockchains and enterprise workloads.
With the growing usage of Bitcoin and other cryptocurrencies, many scalability challenges have emerged. A promising scaling solution, exemplified by the Lightning Network, uses a network of bidirectional payment channels that allows fast transactions between two parties. However, routing payments on these networks efficiently is non-trivial, since payments require finding paths with sufficient funds, and channels can become unidirectional over time blocking further transactions through them. Today's payment channel networks exacerbate these problems by attempting to deliver all payments atomically.
Phuc Thai, Laurent Njilla, Tuyet Duong, Lei Fan · 5 authors
Cryptocurrencies have recently gained huge popularity. It is desirable to come up with effective approaches to constructing better blockchain protocols. In this paper, inspired by the 2-hop design by Duong et al (ePrint 2016/716), we put forth a generic paradigm for blockchain design, called n-hop blockchain. It includes one main chain, which is supported by (n -- 1) supporting chains; hence, the main chain can achieve better security performance. In our paradigm, we show that our n-hop design can be easily extended to (n + 1)-hop design. To demonstrate the power of our paradigm, we showcase two instantiations: 2-hop blockchain variant, a combination of proof-of-stake and proof-of-work, and 3-hop blockchain variant, which is extended from 2-hop blockchain variant by adding Byzantine fault tolerance blockchain in 3rd hop.
This paper introduces a small Java application named ChainTutor for learning basic Blockchain concepts. Although the term Blockchain is widely known and Blockchain technologies are finding applications in various areas such as banking, health care and Internet of Things, some concepts of Blockchain are not easy for beginners to understand. Fully text-based tutorials are often difficult to follow. General picture of Blockchain operations gets lost in lengthy textual descriptions. With the Java application introduced in this paper, users can experiment with key Blockchain concepts through a graphical user interface. They can generate keys, hashes, transactions, blocks and wallets. They can see the low level details of a blockchain such as encryption keys and hashes. They can see how mining works and how blocks are added to a blockchain. Parameters of a blockchain can also be varied in order to observe their impact on performance or even to make a blockchain invalid. The Java application is intended to be used in classroom environment by instructors when they teach introductory Blockchain courses.
It has been a long time since Nakamoto Satoshi introduced Bitcoin [1]. However, the underlying technology, blockchain, has been getting more and more attention. It is regarded as one of the most important technology for the fourth industrial revolution, although there exit few the real-world production-level applications due to the hardly tolerant performance of most of the existing blockchain systems. Therefore, how to improve its performance has been identified as one of the most significant research directions in order to use blockchain for practical applications. In this paper, we present a method to build a scalable and extendible blockchain system by multiple chains and sharding techniques.
Blockchain is one of the most heavily invested technologies in recent years. Due to its tamper-proof and decentralization properties, blockchain has become an ideal utility for data storage that is applicable in many real world industrial scenarios. One important scenario is web log, which is treated as sources of technical significance and commercial revenues in major internet companies. In this paper, we illustrate our design of a web log storage system based on HyperLedger. HyperLedger yields higher throughput and lower latency compared with other blockchain systems. Alongside its efficiency advantages., HyperLeger is a permissioned blockchain, which is an ideal fit for enterprise software design scenario.
Blockchain is an innovative distributed ledger technology which has attracted a wide range of interests for building the next generation of applications to address lack-of-trust issues in business. Blockchain as a service (BaaS) is a promising solution to improve the productivity of blockchain application development. The existing BaaS solutions mostly focus on easier and faster deployment of blockchain applications. However, design of blockchain applications is challenging to developers as it requires development experiences and deep understanding of blockchain technologies. Therefore, this paper summarises a set of design patterns and delivers them as a service to support design of blockchain application. We present a service platform which applies design patterns for data management and smart contract design of blockchain applications to address the scalability and security issues of blockchain. The platform also provides two auxiliary services, including key management and file comparison, which are often needed in blockchain applications. The feasibility of the proposed solutions is evaluated using a real-world quality tracing use case.
Daniela Mechkaroska, Vesna Dimitrova, Aleksandra Popovska‐Mitrovikj
Bitcoin and Smart Contract are the first major applications of the BlockChain technology. But, with increasing the number of transactions, the process of verification on every transaction is very slow. This is the reason for a third major innovation called a BlockChain scaling. The scalability is a process of taking certain steps in accelerating the performing of transactions in this new technology. In this paper we analyze the possibilities for BlockChain scalability and we examine the advantages and disadvantages of the proposed solutions.
Nedaa Baker Al Barghuthi, Hussam Juma Mohamed, Huwida Said
The emergence of blockchain technology has created a frenzy and a mind shift for organizations and industries. Governments and international bodies are increasingly discussing the potential implications of blockchain's distributed ledgers on business, governments and the economy. The intended purpose of the blockchain technology is to connect business network members in a decentralized way. The technology enables exchange and sharing of information without the involvement of intermediaries acting as arbitrators. Powered by its decentralized nature, the network will not have any single point of failure and will not rely on any single entity. Hence, blockchain eliminates the risks of centralization. This paper discusses a scenario of a blockchain technology in distributed ledgers to manage a well function and secure supply chain.
Blockchains, a decentralized storage technique, have many applications, including in reengineering cloud datacenters. This article proposes a conceptual model for fusing blockchains and cloud computing for additional value creation. The proposed model comprises three deployment modes: Cloud over Blockchain (CoB), Blockchain over Cloud (BoC), and Mixed Blockchain-Cloud (MBC). The article also highlights the potential benefits of such a fusion and outlines a number of future research directions.
Reports on the development of Open and Interoperable Distributed Ledger Technology/Blockchain standards. Discusses how these standards drive global blockchain adoption and take development of the technology ecosystem to the next level. The field of blockchain or distributed ledger is growing rapidly. The lack of consensus on definitions, implementation, management, and core attributes is driving the need for standardization. Blockchain is often confused with cryptocurrencies like Bitcoin or Ethereum, but the potential applications of this technology in diverse fields, such as smart contracts, buying and selling energy, and so much more, make distributed ledger technologies one of the high-potential technologies for the future.
Harish Sukhwani, Nan Wang, Kishor S. Trivedi, Andy Rindos
Hyperledger Fabric (HLF) is an open-source implementation of a distributed ledger platform for running smart contracts in a modular architecture. In this paper, we present a performance model of Hyperledger Fabric v1.0+ using Stochastic Reward Nets (SRN). From our detailed model, we can compute the throughput, utilization and mean queue length at each peer and critical processing stages within a peer. To validate our model, we setup an HLF network in our lab and run workload using Hyperledger Caliper. From our analysis results, we find that time to complete the endorsement process is significantly affected by the number of peers and policies such as AND (). The performance bottleneck of the ordering service and ledger write can be mitigated using a larger block size, albeit with an increase in latency. For the committing peer, the transaction validation check (using Validation System Chaincode (VSCC)) is a time-consuming step, but its performance impact can be easily mitigated since it can be parallelized. However, its performance is critical, since it absorbs the shock of bursty block arrivals. We also analyze various what-if scenarios, such as peers processing transactions in a pipeline, and multiple endorsers per organization.
Nov 1, 2018·B. Varghese et al., "Realizing Edge Marketplaces: Challenges and Opportunities," in IEEE Cloud Computing, vol. 5, no. 6, pp. 9-20, Nov./Dec. 2018
Blesson Varghese, Massimo Villari, Omer Rana, Philip James · 7 authors
The edge of the network has the potential to host services for supporting a variety of user applications, ranging in complexity from data preprocessing, image and video rendering, and interactive gaming, to embedded systems in autonomous cars and built environments. However, the computational and data resources over which such services are hosted, and the actors that interact with these services, have an intermittent availability and access profile, introducing significant risk for user applications that must rely on them. This article investigates the development of an edge marketplace, which is able to support multiple providers for offering services at the network edge, and to enable demand supply for influencing the operation of such a marketplace. Resilience, cost, and quality of service and experience will subsequently enable such a marketplace to adapt its services over time. This article also describes how distributed-ledger technologies (such as blockchains) provide a promising approach to support the operation of such a marketplace and regulate its behavior (such as the GDPR in Europe) and operation. Two application scenarios provide context for the discussion of how such a marketplace would function and be utilized in practice.
Ethereum smart contract makes developers can deploy decentralized applications to inherit features from blockchain, such as decentralization and openness. Although Ethereum provided a decentralized platform, Ethereum Virtual Machine for smart contracts, it lacks of ability to fetch off-chain data. The general solution is Oracle data carrier. However, Oracle results in rising deployment costs. It requires Ethereum smart contract developers to follow format in programing contract, this constraint decreases the readability of smart contract. This paper proposes an off-chain data fetching architecture which is cost-effective and highly elastic for smart contract. It also compatible with exited contract, which makes Ethereum smart contract owner able to automate the reply process.
Financial settlement systems have long depended on batch-oriented processing pipelines that introduce substantial operational latency, delayed reconciliation cycles, and significant infrastructure overhead, limiting their ability to support increasingly real-time financial ecosystems. With the rapid growth of digital payments, algorithmic trading, and instantaneous fund transfers, financial institutions now require settlement architectures capable of sustaining high throughput, low-latency execution while ensuring correctness, durability, auditability, and strict regulatory compliance. This paper proposes a fully streaming-based settlement architecture built on Apache Kafka Streams, which provides distributed, stateful stream processing with exactly-once semantics, deterministic event ordering, and fault-tolerant recovery, combined with Apache Cassandra as a linearly scalable, highly available distributed state store for ledger materialization and durable transaction history. We outline essential design patterns such as idempotent event handling, monotonic ordering within partitions, ledger versioning strategies, and continuous reconciliation pipelines and examine how these patterns have been validated through publicly available prototypes and industrial implementations across the financial sector. Experimental findings demonstrate that integrating Kafka Streams with Cassandra enables near-real-time settlement processing with millisecond-range end-to-end latency and predictable fault recovery while preserving strong application-level consistency, ultimately offering a resilient and future-ready foundation for modern financial settlement infrastructures.
Ankur Sharma, Felix Schuhknecht, Divya Agrawal, Jens Dittrich
Within the last few years, a countless number of blockchain systems have emerged on the market, each one claiming to revolutionize the way of distributed transaction processing in one way or the other. Many blockchain features, such as byzantine fault tolerance (BFT), are indeed valuable additions in modern environments. However, despite all the hype around the technology, many of the challenges that blockchain systems have to face are fundamental transaction management problems. These are largely shared with traditional database systems, which have been around for decades already. These similarities become especially visible for systems, that blur the lines between blockchain systems and classical database systems. A great example of this is Hyperledger Fabric, an open-source permissioned blockchain system under development by IBM. By having a relaxed view on BFT, the transaction pipeline of Fabric highly resembles the workflow of classical distributed databases systems. This raises two questions: (1) Which conceptual similarities and differences do actually exist between a system such as Fabric and a classical distributed database system? (2) Is it possible to improve on the performance of Fabric by transitioning technology from the database world to blockchains and thus blurring the lines between these two types of systems even further? To tackle these questions, we first explore Fabric from the perspective of database research, where we observe weaknesses in the transaction pipeline. We then solve these issues by transitioning well-understood database concepts to Fabric, namely transaction reordering as well as early transaction abort. Our experimental evaluation shows that our improved version Fabric++ significantly increases the throughput of successful transactions over the vanilla version by up to a factor of 3x.
Blockchain is distributed ledger with the advantage of high security, tamper resistant and traceability. However, in the process of the growth of Blockchain, network isolation hinders the cooperative operation among different Blockchains and greatly restricts the development of Blockchain. There is an urgent need to break the barriers among Blockchains[1], thus cross-chain communication become a new trend of the Blockchain technology[2]. In this paper, we propose CVEM, a value exchange mechanism which supports different kind of tokens transfer cross-chain. First, we put the main exchange process execute off-chain and the final result on-chain. Then, we combine Revocable Sequence Maturity Contract (RSMC) with the idea of cross-token exchange of Blockchain, and use the mechanism of multi-signatures address to constrain the users' behaviors. In addition, we introduce the Simple Payment Verification Proof (SPV Proof) to verify transactions. Our work, to some degree, shortens the transaction process delay and also ensures the security and scalability of the value exchange.
Simona Ibba, Andrea Pinna, Maria Ilaria Lunesu, Michele Marchesi · 5 authors
An ICO (Initial Coin Offering) is an innovative way to fund projects based on blockchain. The funding is based on the selling of tokens by means of decentralized applications called smart contracts written in Solidity, a programming language specific for Ethereum blockchain. The ICOs work in a volatile context and it is crucial that the team is capable of handling constant changes. The Agile methods, proven practices enabling to develop software in presence of changing requirements, could be a means for managing uncertainty. The main goals of this work are to understand software engineering activities related to ICOs, recognize the ICOs developed using Agile methods, and make a comparison between ICOs and Agile ICOs. In addition, we perform a deeper analysis of Agile ICOs concerning project planning, software development, and code features. Our work shows that the roles of the people involved in an ICO can be compared to the typical roles of the SCRUM methodology. The majority of Agile ICOs use tool of testing before storing smart contract on blockchain. Finally, the application of volumetric and complexity software metrics shows that the files of Agile ICOs is on average shorter and less complex than in other smart contracts.
Sang‐Min Choi, Jiho Park, Quan Nguyen, André Cronje
We describe \emph{Fantom}, a framework for asynchronous distributed systems. \emph{Fantom} is based on the Lachesis Protocol~\cite{lachesis01}, which uses asynchronous event transmission for practical Byzantine fault tolerance (pBFT) to create a leaderless, scalable, asynchronous Directed Acyclic Graph (DAG). We further optimize the \emph{Lachesis Protocol} by introducing a permission-less network for dynamic participation. Root selection cost is further optimized by the introduction of an n-row flag table, as well as optimizing path selection by introducing domination relationships. We propose an alternative framework for distributed ledgers, based on asynchronous partially ordered sets with logical time ordering instead of blockchains. This paper builds upon the original proposed family of \emph{Lachesis-class} consensus protocols. We formalize our proofs into a model that can be applied to abstract asynchronous distributed system.