Praveen M. Dhulavvagol, Vijayakumar H Bhajantri, Shashikumar G. Totad
Blockchain technology is evolving and revolutionizing the IT industry with better security, efficiency, and resilience. Blockchain technology is being used in many applications majorly in cryptocurrencies and bitcoin applications. Verified transactions which make a block and group of such transactions or blocks are immutable making the blockchain more secured and reliable. Blockchain achieves decentralization of power, trust, and secured of being hacked, which solves major problems or issues with the current systems. Ethereum, the most widely used blockchain platform because of its unlimited block size. Many complex problems with smart contracts can be implemented with Ethereum and the eradication of third party organizations interfering in transactions helps solving the issues of financial crisis and it is easy to implement compared to other blockchain technologies. There are certain limitations/issues in processing large number of transactions due to lack of speed in processing the transactions. Ethereum Blockchain code will be executed by different clients with varying speed and the performance level will be different. The goal of this paper is to understand Ethereum transactions and perform the comparative analysis of Geth and Parity ethereum clients on the private blockchain. In this paper, a private blockchain network is setup where the nodes will share the data among peer nodes or blocks within the network. Using this network setup a democracy voting application is developed which makes use of the blockchain to store and process the data, smart contracts are deployed to execute the transactions. Performance analysis of the two most popular ethereum clients Geth and Parity is carried out considering time, consistency and scalability parameters. Results interpret that the overall transactions are 91% on average faster in parity client as compared to Geth client.
Kentaroh Toyoda, Koji Machi, Yutaka Ohtake, Allan N. Zhang
Private Ethereum blockchain-based systems are demanded in many industry sectors. However, the throughput performance of these systems does not meet their expectations. Many researchers have analyzed the performance of private blockchains, but their studies have failed to analyze root causes. In this paper, we perform a deep function-level bottleneck analysis for the private Ethereum blockchain. As the Ethereum client application is developed with golang, we leverage pprof, which is a resource-profiling tool for golang, and custom golang functions to measure the time taken by functions. To easily configure parameters and conduct our test, we code a shell script that automates the building process of a private Ethereum blockchain with docker containers. We conducted a series of experiments and identified the bottleneck function that is called every time a transaction arrives at an Ethereum node. In addition, we also found that the multi-threading is not well utilized, meaning that there is much room for improvement.
On February 28, 2012, an 18-year-old high school student wrote “If BitcoinBitcoin is to achieve mainstream success, it cannot stop at the limited crowds of InternetInternet geeks, libertarians, and privacy advocates that it is hitting now, and it must find some way to attract the mainstream public” (Buterin in Bitcoin adoption opportunity: teenagers, 2012).
Current permissionless cryptocurrencies such as Bitcoin suffer from a limited transaction rate and slow confirmation time, which hinders further adoption. Payment channels are one of the most promising solutions to address these problems, as they allow the parties of the channel to perform arbitrarily many payments in a peer-to-peer fashion while uploading only two transactions on the blockchain. This concept has been generalized into payment channel networks where a path of payment channels is used to settle the payment between two users that might not share a direct channel between them. However, this approach requires the active involvement of each user in the path, making the system less reliable (they might be offline), more expensive (they charge fees per payment), and slower (intermediaries need to be actively involved in the payment). To mitigate this issue, recent work has introduced the concept of virtual channels (IEEE S&P’19), which involve intermediaries only in the initial creation of a bridge between payer and payee, who can later on independently perform arbitrarily many off-chain transactions. Unfortunately, existing constructions are only available for Ethereum, as they rely on its account model and Turing-complete scripting language. The realization of virtual channels in other blockchain technologies with limited scripting capabilities, like Bitcoin, was so far considered an open challenge.In this work, we present the first virtual channel protocols that are built on the UTXO-model and require a scripting language supporting only a digital signature scheme and a timelock functionality, being thus backward compatible with virtually every cryptocurrency, including Bitcoin. We formalize the security properties of virtual channels as an ideal functionality in the Universal Composability framework and prove that our protocol constitutes a secure realization thereof. We have prototyped and evaluated our protocol on the Bitcoin blockchain, demonstrating its efficiency: for n sequential payments, they require an off-chain exchange of 9+2n transactions or a total of 3524+695n bytes, with no on-chain footprint in the optimistic case. This is a substantial improvement compared to routing payments in a payment channel network, which requires 8n transactions with a total of 3026n bytes to be exchanged.
The rise of distributed ledger technologies, such as R3 Corda, Hyperledger Fabric and Ethereum, has lead to a surge of interest in digitalizing different forms of contractual cooperation. By allowing for ledgers of collaboration-critical data to be reliably maintained between stakeholders without intermediaries, these solutions might enable unprecedented degrees of automation across organizational boundaries, which could have major implications for supply chain integration, medical journal sharing and many other use cases. However, these technologies tend to break with prevailing business practices by relying on code-as-contracts and distributed consensus algorithms, which can impose disruptive requirements on contract language, cooperation governance and interaction privacy. In this paper, we show how our Exchange Network architecture could be applied to avoid these disruptors. To be able to reason about the adequacy of our architecture, we present six requirements for effective contractual collaboration, which notably includes negotiable terms and effective adjudication. After outlining the architecture and our implementation of it, we describe how the latter meets our requirements by facilitating (1) negotiation, (2) user registries, (3) ownership ledgers and (4) definition sharing, as well as by only replicating ledgers between stakeholder pairs. To show how our approach compares to other solutions, we also consider how Corda, Fabric and Ethereum meet our requirements. We conclude that digital negotiation and ownership could replace many proposed uses of code-as-contracts for better compatibility with current contractual practices, as well as noting that distributed consensus algorithms are not mandatory for digital cooperation.
Jan 1, 2020·Proceedings of the ... Annual Hawaii International Conference on System Sciences/Proceedings of the Annual Hawaii International Conference on System Sciences
Florian Gräbe, Niclas Kannengießer, Sebastian Lins, Ali Sunyaev
Distributed Ledger Technology (DLT) enables a new way of inter-organizational collaboration via a shared and distributed infrastructure. Meanwhile, there is plenty of DLT designs (e.g., Ethereum, IOTA), which differ in their capabilities to meet use case requirements. A structured comparison of DLT designs is required to support the decision for an appropriate DLT design. However, existing criteria and processes are abstract or not suitable for an in-depth comparison of DLT designs. We select and operationalize DLT characteristics relevant for a comprehensive comparison of DLT designs. Furthermore, we propose a comparison process, which enables the structured comparison of a set of DLT designs according to application requirements. The proposed process is validated with a use case analysis of three use cases. We contribute to research and praxis by introducing ways to operationalize DLT characteristics and generate a process to compare different DLT designs accordingly to their suitability in a use case.
Data are becoming the cornerstone of many businesses and entire systems infrastructure. Intelligent Transportation Systems (ITS) are no different. The ability of intelligent vehicles and devices to acquire and share environmental measurements in the form of data is leading to the creation of smart services for the benefit of individuals. In this paper, we present a system architecture to promote the development of ITS using distributed ledgers and related technologies. Thanks to these, it becomes possible to create, store and share data generated by users through the sensors on their devices or vehicles, while on the move. We propose an architecture based on Distributed Ledger Technologies (DLTs) to offer features such as immutability, traceability and verifiability of data. IOTA, a promising DLT for IoT, is used together with Decentralized File Storages (DFSes) to store and certify data (and their related metadata) coming from vehicles or by the users' devices themselves (smartphones). Ethereum is then exploited as the smart contract platform that coordinates the data sharing through access control mechanisms. Privacy guarantees are provided by the usage of distributed key management systems and Zero Knowledge Proof. We provide experimental results of a testbed based on real traces, in order to understand if DLT and DFS technologies are ready to support complex services, such as those that pertain to ITS. Results clearly show that, while the viability of the proposal cannot be rejected, further work is needed on the responsiveness of DLT infrastructures.
Jan 1, 2020·Proceedings of the ... Annual Hawaii International Conference on System Sciences/Proceedings of the Annual Hawaii International Conference on System Sciences
Since the emergence of blockchain in 2008, today, we see a kaleidoscopic variety of applications built on distributed ledger technology (DLT), including applications for financial services, healthcare, or the Internet of Things. Yet, each application comes with specific requirements for DLT characteristics (e.g., high throughput, scalability). However, trade-offs between DLT characteristics restrict the development of a DLT design (e.g., Ethereum, IOTA) that fits all use cases’ requirements simultaneously. Consequently, separated DLT designs emerged, each specialized to suite dedicated application requirements. To enable the development of more powerful applications on DLT, such DLT islands must be bridged. However, knowledge on cross-chain technology (CCT) is scattered across scientific and practical sources. Therefore, we examine this diverse body of knowledge and provide comprehensive insights into CCT by synthesizing underlying characteristics, evolving patterns, and use cases. Our findings resolve existing contradictions in the literature and provide avenues for future research in an emerging scientific field.
Eman M. Abou-Nassar, Abdullah M. Iliyasu, Passent Elkafrawy, Oh-Young Song · 6 authors
Today, internet and device ubiquity are paramount in individual, formal and societal considerations. Next generation communication technologies, such as Blockchains (BC), Internet of Things (IoT), cloud computing, etc. offer limitless capabilities for different applications and scenarios including industries, cities, healthcare systems, etc. Sustainable integration of healthcare nodes (i.e. devices, users, providers, etc.) resulting in healthcare IoT (or simply IoHT) provides a platform for efficient service delivery for the benefit of care givers (doctors, nurses, etc.) and patients. Whereas confidentiality, accessibility and reliability of medical data are accorded high premium in IoHT, semantic gaps and lack of appropriate assets or properties remain impediments to reliable information exchange in federated trust management frameworks. Consequently, We propose a Blockchain Decentralised Interoperable Trust framework (DIT) for IoT zones where a smart contract guarantees authentication of budgets and Indirect Trust Inference System (ITIS) reduces semantic gaps and enhances trustworthy factor (TF) estimation via the network nodes and edges. Our DIT IoHT makes use of a private Blockchain ripple chain to establish trustworthy communication by validating nodes based on their inter-operable structure so that controlled communication required to solve fusion and integration issues are facilitated via different zones of the IoHT infrastructure. Further, C# implementation using Ethereum and ripple Blockchain are introduced as frameworks to associate and aggregate requests over trusted zones.
Affaf Shahid, Ahmad Almogren, Nadeem Javaid, Fahad Ahmed Al-Zahrani · 6 authors
Supply chains are evolving into automated and highly complex networks and are becoming an important source of potential benefits in the modern world. At the same time, consumers are now more interested in food product quality. However, it is challenging to track the provenance of data and maintain its traceability throughout the supply chain network. The traditional supply chains are centralized and they depend on a third party for trading. These centralized systems lack transparency, accountability and auditability. In our proposed solution, we have presented a complete solution for blockchain-based Agriculture and Food (Agri-Food) supply chain. It leverages the key features of blockchain and smart contracts, deployed over ethereum blockchain network. Although blockchain provides immutability of data and records in the network, it still fails to solve some major problems in supply chain management like credibility of the involved entities, accountability of the trading process and traceability of the products. Therefore, there is a need of a reliable system that ensures traceability, trust and delivery mechanism in Agri-Food supply chain. In the proposed system, all transactions are written to blockchain which ultimately uploads the data to Interplanetary File Storage System (IPFS). The storage system returns a hash of the data which is stored on blockchain and ensures efficient, secure and reliable solution. Our system provides smart contracts along with their algorithms to show interaction of entities in the system. Furthermore, simulations and evaluation of smart contracts along with the security and vulnerability analyses are also presented in this work.
Blockchain (e.g., Bitcoin and Ethereum) has drawn much attention and has been widely-deployed in recent years. However, blockchain scalability is emerging as a challenging issue. This paper outlines the existing solutions to blockchain scalability, which can be classified into two categories: first layer and second layer solutions. First layer solutions propose modifications to the blockchain (i.e., changing the blockchain structure, such as block size) while second layer solutions propose mechanisms that are implemented outside of the blockchain. In particular, we focus on sharding as a promising first layer solution to the scalability issue; the basic idea behind sharding is to divide the blockchain network into multiple committees, each processing a separate set of transactions. More specifically, (a) we propose a taxonomy based on committee formation and intra-committee consensus; and (b) we compare the main existing sharding-based blockchain protocols. We also present a performance-based comparative analysis (i.e., throughput and latency), of the advantages, and disadvantages in existing scalability solutions.
The term decentralized finance (DeFi) refers to an alternative financial infrastructure built on top of the Ethereum blockchain. DeFi uses smart contracts to create protocols that replicate existing financial services in a more open, interoperable, and transparent way. This article highlights opportunities and potential risks of the DeFi ecosystem. I propose a multi-layered framework to analyze the implicit architecture and the various DeFi building blocks, including token standards, decentralized exchanges, decentralized debt markets, blockchain derivatives, and on-chain asset management protocols.
Günümüzde kripto para birimlerinin önemi gittikçe artmaktadır. Kripto para birimleri sanal oyun platformlarında kullanılırken, şu an pek çok kurum ve kuruluş tarafından ödeme aracı olarak kullanılmaktadır. Güvenlik risklerine karşı blockchain (Blok Zinciri) adı verilen algoritması ile üretimi sağlanmaktadır. Kripto para fiyatlarının doğru olarak tahmin edilmesi yatırımcı ve karar vericiler açısından büyük önem taşımaktadır. Bu çalışma kapsamında en çok kullanılan dört kripto para birimine (Bitcoin, Ethereum, Ripple, Litecoin) ait fiyat değerleri tahmin edilmiştir. Çoklu kırılma testinden yararlanılarak her seriye ait kırılmalar belirlenerek analiz genişletilmiştir. Ele alınan sanal para değerlerini doğru bir şekilde tahmin etmek amacıyla hem klasik zaman serisi modellerinden hem de üç farklı tür yapay sinir ağı modelinden faydalanılmıştır. Ayrıca elde edilen tahminler üzerinde basit birleştirilme teknikleri uygulanmıştır. Rassal yürüyüşün egemen olduğu bu seriler arasından, özellikle işlem hacmi ve bilinilirliği en fazla olan Bitcoin sanal parasında rassal yürüyüş modelinden daha iyi sonuçlar elde edildiği gözlemlenmiştir.
With the advent of IoT, gadgets are now becoming more smart and independent. Truth is that the transformation towards the innovation is in progress yet there are still flaws, mainly in security areas like dependence on the data. Keeping in mind the advancement of IoT in the future, trusting in this vast approaching data source is of great importance. Blockchain is reached up to the position where it became the key innovation that will change the way we share data. Providing trust in conveyed situations, without using any advanced technical team is a development, which could change the way of working of numerous enterprises, the IoT amongst them. We can say with confidence that the concept of Blockchain, which is the technology behind crypto currency [3] Bitcoin [1], introduced a new era in the world of Internet and online services. In this paper, we will talk about develop a secure E-voting system using Blockchain technology where nobody can manipulate the votes and every user can vote only once. This is possible using the advantage of Ethereum smart contracts [2]. Smart contracts make it a powerful tool for the digitization of services in the Ethereum platform. Blockchain with smart contracts develops a safe, cheap, secure and transparent E-voting system. Ethereum and its network are suitable for it. Due to its consistency, large scale use and provision of smart contract logic. E-voting is an application that is possible using Blockchain technology with infused smart contracts. It needs to be digitalized over the Internet & that's what we will be working upon.
The aim of this study is to examine cryptocurrencies that use blockchain technology, reveal the current situation and discuss the future. In the study, cryptocurrencies are examined in detail with their definition, history, legal status, factors affecting their value, features and functions, advantages and disadvantages, and usage areas. As a result of the discussions in the study, five main conclusions were reached. (1) Cryptocurrencies cannot be defined as money, since they cannot fully fulfil the features and functions of money with their current status. (2) Although the values of cryptocurrencies are shaped depending on the supply and demand conditions, they are significantly affected by factors such as security, legal status, volume, and speculative and manipulative initiatives. (3) Cryptocurrencies do not yet have a widespread legal status worldwide. (4) Among the many advantages and disadvantages of cryptocurrencies, the most prominent advantage is security, and the most striking disadvantage is volatility. (5) Cryptocurrencies, with what they have demonstrated to date and promise for the future, will have the ability to be used wherever money is used, and even more.
Smart contract-based development of decentralized applications is increasing with the development of blockchain technology. Although blockchainbased smart contracts are expected to revolutionize the digital economy, several security issues need to be addressed before this technology can be used reliably. The recent discovery of security weaknesses in Ethereum smart contracts questions the reliability of smart contracts. Therefore, there is a need to create and diagnose security weaknesses in Ethereum smart contracts to mitigate security risks. In this study, we assessed the potential security weaknesses of running smart contracts on Ethereum.
blockchain is decentralized immutable ledger technology maintaining integrity. So to conduct tamperproof election it’s one of the approach towards it. Smart contracts are Self executed code that is written on Ethereum platform in blockchain. An E-voting system should be completely secure and does not allow voting twice that is double spending in blockchain. So it should be completely transparent. In research work electronic voting application is implemented and tested using smart contract on Ethereum platform with the help of metamask wallet. The results of ballots and votes will be stored on Ethereum blockchain with the help of consensus algorithm proof of stake. This consensus is used in validating a transaction with concept of majority approval. Current electronic voting system requires a centralized authority to control the procedure from ballot input to result output and for monitoring of election. While blockchain technology provide decentralized system which is open across connected nodes. Blockchain assets provide increased level of system security from hacking and fraud. Every transaction in blockchain is time-stamped and signed digitally with the help of cryptographic algorithms, and it assigns unique hash value to every block so it can be trace easily. Blockchain technology is one of solutions because it embraces a decentralized system and the entire databases are owned by many users. The blockchain technology also has much vulnerability due to which many attacks like 51% attack, Double Spending attack, DDOS attack, Sybil attack, Eclipse attack and Routing attack can be performed on it.
Due to enormous increase in development of technology maintenance of user’s information has become major concern. However, user’s information has been effectively maintained by the third parties but the problems with the current system are cost has been increased for maintaining information, lack of transparency and fairness, overuse of power and nature of opaqueness in the current system. So distributed system/ledger i.e., Blockchain came into existence to solve the problems encountered with the current system. The advantages of the proposed distributed system are cost is negligible by eliminating the need of third parties, effectively enhancing the execution speed of transactions and facilitating its reconciliation, maintaining transparency thereby ensuring integrity of user’s information. In this paper, we introduce Ethereum based blockchain network for maintaining user’s information through smart contracts. Experimental results shows that how effectively user’s information has been maintained through blockchain based networks.
We present the main concepts, components, and usage of GASOL, a Gas AnalysiS and Optimization tooL for Ethereum smart contracts. GASOL offers a wide variety of cost models that allow inferring the gas consumption associated to selected types of EVM instructions and/or inferring the number of times that such types of bytecode instructions are executed. Among others, we have cost models to measure only storage opcodes, to measure a selected family of gas-consumption opcodes following the Ethereum's classification, to estimate the cost of a selected program line, etc. After choosing the desired cost model and the function of interest, GASOL returns to the user an upper bound of the cost for this function. As the gas consumption is often dominated by the instructions that access the storage, GASOL uses the gas analysis to detect under-optimized storage patterns, and includes an (optional) automatic optimization of the selected function. Our tool can be used within an Eclipse plugin for Solidity which displays the gas and instructions bounds and, when applicable, the gas-optimized Solidity function.
With Industry 4.0, IT infrastructure has started to be used more effectively in the manufacturing sector. Cyber physical systems, IoT, cloud manufacturing, big data are some of the technologies that make up the concept of Industry 4.0. These technologies have solved many problems in the manufacturing sector. One of these technologies, cloud manufacturing technology, has emerged with the idea of pay as you go. This technology has enabled manufacturing resources to be leased and shared on a global scale. However, it has problems arising from its central structure and the need for a reliable 3rd party. Reliability, security, continuity, scalability, data lock-in, single point failure, data manipulation are some of the main problems. Blockchain (BC) is a decentralized and distributed technology. The data stored on the BC network cannot be altered in any way. With these features, we believe that BC-supported cloud manufacturing systems can overcome the aforementioned problems and eliminates the need for a reliable 3rd party. Based on this belief, in this study the agreements and communication between the resource provider and the customer, which is one of the basic functions of cloud manufacturing platforms, are realized with a decentralized application using BC-based smart contracts (SCs). The designed application is called the decentralized cloud manufacturing application (DCMApp). DCMApp does not operate on a fully public BC network, it has a hybrid structure and uses the Ethereum network as a public BC network. These features make DCMApp different from other BC-based cloud manufacturing applications. DCMApp's hybrid structure has enabled more transparent, economic and safe manufacturing agreements. It is also possible to store agreements on the BC network at a low cost without installing any server infrastructure. The use of Ethereum network makes it almost impossible to manipulate agreements.
Blaž Podgorelec, Muhamed Turkanović, Sašo Karakatič
The basis of blockchain-related data, stored in distributed ledgers, are digitally signed transactions. Data can be stored on the blockchain ledger only after a digital signing process is performed by a user with a blockchain-based digital identity. However, this process is time-consuming and not user-friendly, which is one of the reasons blockchain technology is not fully accepted. In this paper, we propose a machine learning-based method, which introduces automated signing of blockchain transactions, while including also a personalized identification of anomalous transactions. In order to evaluate the proposed method, an experiment and analysis were performed on data from the Ethereum public main network. The analysis shows promising results and paves the road for a possible future integration of such a method in dedicated digital signing software for blockchain transactions.