Maxim Ya. Afanasev, Anastasiya A. Krylova, Sergey A. Shorokhov, Yuri V. Fedosov · 5 authors
The concept of cyber-physical production systems is highly discussed amongst researchers and industry experts, however, the implementation options for these systems rely mainly on obsolete technologies. Despite the fact that the blockchain is most often associated with cryptocurrency, it is fundamentally wrong to deny the universality of this technology and the prospects for its application in other industries. For example, in the insurance sector or in a number of identity verification services. This article discusses the deployment of the CPPS backbone network based on the Ethereum private blockchain system. The structure of the network is described as well as its interaction with the help of smart contracts, based on the consumption of cryptocurrency for various operations.
In recent years, cryptocurrencies gained popularity with Bitcoin. The main promising technology behind Bitcoin was `Blockchain'. Blockchain provided unique features like transactional privacy, system transparency, immutability of data, security with cryptography, etc. These features paved way for Blockchain in advancing many technologies like voting systems, IOT applications, supply chain management, banking, healthcare, insurance, etc. Blockchain development was boosted with the increasing demand of the technological update. Many blockchain platforms are available like hyperledger fabric, ethereum, corda, etc. We always end up with perplexity while choosing a platform for blockchain development. Through our survey, we provide a comparative analysis of all the hyperledger platforms, ethereum, corda to make a choice of the platform easily according to the requirement.
Motivated by the great success and adoption of Bitcoin, a number of cryptocurrencies such as Litecoin, Dogecoin, and Ethereum are becoming increasingly popular. Although existing blockchain-based cryptocurrency schemes can ensure reasonable security for transactions, they do not consider any notion of fairness. Fair exchange allows two players to exchange digital “items,” such as digital signatures, over insecure networks fairly, so that either each player gets the other's item, or neither player does. Given that blockchain participants typically do not trust each other, enabling fairness in existing cryptocurrencies is an essential but insufficiently explored problem. In this article, we explore the solution space for enabling the fair exchange of a cryptocurrency payment for a receipt. We identify the timeliness of an exchange as an important property especially when one of the parties involved in the exchange is resource-constrained. We introduce the notion of strong timeliness for a fair exchange protocol and propose two fair payment-for-receipt protocol instantiations that leverage functionality of the blockchain to achieve strong timeliness. We implement both and compare their security and efficiency.
Tourism destinations are always seeking new and innovative ways to better market tourism offerings and increase tourism revenues. This paper seeks to highlight a future tourism marketing trend through the use of virtual environments (VE) backed by Distributed Ledger Technologies (DLT’s) such as Blockchain. VE is the umbrella term referring to virtual reality (VR), augmented reality (AR) and mixed reality (MR), also known as merged reality. The virtual reality market is said to be the next frontier in digital marketing and in recent years the tourism industry has slowly taken advantage of developments in the virtual space. On the other hand, DLT’s such as Blockchain technology is bound to revolutionize and disrupt various business sectors such as the financial and supply chain management sectors, among many. An indicator of this is the number of Fortune 500 companies that are members of the Enterprise Ethereum Alliance – an alliance that is seeking to build enterprise-grade software on the Ethereum Blockchain. The analysis suggest that VR based tourism utilizing DLT’s can positively impact the tourism industry and provide a means for additional revenue.
The use of technology has become important at this point in helping to meet human needs.Due to the increasing use of technology, new challenges are brought in the process of democracy as most people today don’t trust their governments, making elections is very important in modern democracy . Elections have a great importance in determining who will rule a nation or an organization or it can be said as it is an event that decides the fate of any nation. In modern democracy, elections are very important but large sections of society around the world do not trust their election system which is a major concern for democracy. Even the world’s largest democracies like India, United States, still suffer from a flawed electoral system. Vote rigging, hacking of EVM (Electronic voting machine), election manipulation, and polling booth capturing are the major issues in the current voting system The blockchain is said as emerging, decentralized, and distributed technology that promises to enhance different aspects of many industries. Expanding e-voting into blockchain technology could be the solution to eliminate the present concerns in e-voting system There is no doubt that the ever changing concept of the blockchain, which is the backbone of the famous cryptocurrency Bitcoin has triggered the start of a new era in the Internet and the online services. While most people focus only on bitcoin and other cryptocurrencies; there are in fact, many operations, both administrative and fintech that can only be done online/offline can now safely be moved to the Internet as online services because of immutability of blockchain. What makes blockchain a powerful tool is its smarts contracts and many features which overcomes traditional systems. Smart contracts are meaningful pieces of codes, to be integrated in the blockchain and executed as scheduled in every step of blockchain updates. E-votin, is another trending, yet critical, topic related to the online services. The blockchain with the smart contracts, emerges as a good candidate to use in developments of safer, cheaper, more secure, more transparent, and easier-to-use e-voting systems.Due to its consistency, widespread use, and provision of smart contracts logic, Ethereum and its network is one of the most suitable ones. An e-voting system must be secure, as it should not allow duplicated votes and be fully transparent, while protecting the privacy of the attendees. In this project, we have implemented and tested an e-voting application as a smart contract for the Ethereum network using the Ethereum and the Solidity language.
Miguel Pincheira, Muhammad Salek Ali, Massimo Vecchio, Raffaele Giaffreda
The recent, exponential rise in adoption of the most disparate Internet of Things (IoT) devices and technologies has reached also Agriculture and Food (Agri-Food) supply chains, drumming up substantial research and innovation interest towards developing reliable, auditable and transparent traceability systems. Current IoT-based traceability and provenance systems for Agri-Food supply chains are built on top of centralized infrastructures and this leaves room for unsolved issues and major concerns, including data integrity, tampering and single points of failure. Blockchains, the distributed ledger technology underpinning cryptocurrencies such as Bitcoin, represent a new and innovative technological approach to realizing decentralized trustless systems. Indeed, the inherent properties of this digital technology provide fault-tolerance, immutability, transparency and full traceability of the stored transaction records, as well as coherent digital representations of physical assets and autonomous transaction executions. This paper presents AgriBlockIoT, a fully decentralized, blockchain-based traceability solution for Agri-Food supply chain management, able to seamless integrate IoT devices producing and consuming digital data along the chain. To effectively assess AgriBlockIoT, first, we defined a classical use-case within the given vertical domain, namely from-farm-to-fork. Then, we developed and deployed such use-case, achieving traceability using two different blockchain implementations, namely Ethereum and Hyperledger Sawtooth. Finally, we evaluated and compared the performance of both the deployments, in terms of latency, CPU, and network usage, also highlighting their main pros and cons.
With the tremendous development of internet, we can share any media from anywhere in the world. This paved the way for data sharing illegally versions of data shared among persons. In our proposed system, the original data (use case taken Song) will be embedded with a hash value and then deployed to Inter Planetary File System (IPFS) and shared through Ethereum Blockchain, enabling deployed data unaltered. The IPFS returns a 46-bit length hash for each of the file being upload. Usage of Ethereum blockchain ensures each every transaction cryptographically hashed and logged. Also, the data deployed on IPFS sharable but with hidden hash identity for each of it, which is not known by the person who gets that data. The owner of the original data thus shares the data and w having the log maintaining hash identity for each of the person to whom the data owner shares. The IPFS storage enables Peer to Peer (P2P) data transfer through decentralized network. The person will be given the IPFS hash to download the data. When data if pirated is known to the owner, he computes the hash value from the pirated version and identifies the person pirated that data and avoids sharing data to that person next time
Nowadays, blockchain is becoming a synonym for distributed ledger technology. However, blockchain is only one of the specializations in the field and is currently well-covered in existing literature, but mostly from a cryptographic point of view. Besides blockchain technology, a new paradigm is gaining momentum: directed acyclic graphs. The contribution presented in this paper is twofold. Firstly, the paper analyzes distributed ledger technology with an emphasis on the features relevant to distributed systems. Secondly, the paper analyses the usage of directed acyclic graph paradigm in the context of distributed ledgers, and compares it with the blockchain-based solutions. The two paradigms are compared using representative implementations: Bitcoin, Ethereum and Nano. We examine representative solutions in terms of the applied data structures for maintaining the ledger, consensus mechanisms, transaction confirmation confidence, ledger size, and scalability.
Nowadays, blockchain is becoming a synonym for distributed ledger technology.\nHowever, blockchain is only one of the specializations in the field and is\ncurrently well-covered in existing literature, but mostly from a cryptographic\npoint of view. Besides blockchain technology, a new paradigm is gaining\nmomentum: directed acyclic graphs. The contribution presented in this paper is\ntwofold. Firstly, the paper analyzes distributed ledger technology with an\nemphasis on the features relevant to distributed systems. Secondly, the paper\nanalyses the usage of directed acyclic graph paradigm in the context of\ndistributed ledgers, and compares it with the blockchain-based solutions. The\ntwo paradigms are compared using representative implementations: Bitcoin,\nEthereum and Nano. We examine representative solutions in terms of the applied\ndata structures for maintaining the ledger, consensus mechanisms, transaction\nconfirmation confidence, ledger size, and scalability.\n
Subasri Mathiyalahan, Shobana Manivannan, Mahalakshmi Nagasundaram, R. Ezhilarasie
Data integrity of outsourced data is main problem in CSP (cloud service provider). Space overhead and computation complexity are very high issue in recent PDP(Provable Data Possession) verification schemes. To overcome such issues MPDP (Mobile Provable Data Possession) schemes using hash tree data structure and Boneh-Lynn-Snacham short signature scheme have been used over decade. Data dynamics is well supported in MPDP scheme via block less verification, dynamic data operations, stateless verification, and verification out sourcing. But still there are some operations which can be performed much more efficiently in some other way than that of the two methods prescribed above. Operations in particular, data modification operations like insertion and deletion operations is somewhat difficult or in other words time consuming in hash tree data structure. In this paper, we have deployed an improved hash tree structure called MPT (Merkle Patricia Tree) for integrity checking.MPT is combination of MHT (Merkle Hash Tree) and patricia tree where each node consists of key-value pairs. As of now, MPT has been used only in block chain technology for providing authentication of transactions through Ethereum.
John Collomosse, Tu Bui, Alan Brown, John Sheridan · 9 authors
We present ARCHANGEL; a de-centralised platform for ensuring the long-term integrity of digital documents stored within public archives. Document integrity is fundamental to public trust in archives. Yet currently that trust is built upon institutional reputation --- trust at face value in a centralised authority, like a national government archive or University. ARCHANGEL proposes a shift to a technological underscoring of that trust, using distributed ledger technology (DLT) to cryptographically guarantee the provenance, immutability and so the integrity of archived documents. We describe the ARCHANGEL architecture, and report on a prototype of that architecture build over the Ethereum infrastructure. We report early evaluation and feedback of ARCHANGEL from stakeholders in the research data archives space.
Blockchain has received much attention in recent years. This immense popularity has raised a number of concerns, scalability of blockchain systems being a common one. In this paper, we seek to understand how Ethereum, a well-established blockchain system, would respond to sharding. Sharding is a prevalent technique to increase the scalability of distributed systems. To understand how sharding would affect Ethereum, we model Ethereum blockchain as a graph and evaluate five methods to partition the graph. We analyze the results using three metrics: the balance among shards, the number of transactions that would involve multiple shards, and the amount of data that would be relocated across shards upon a repartitioning of the system.
Blockchain technology enables the creation of a decentralized environment, where transactions and data are not under the control of any third party organization. Any transaction ever completed is recorded in a public ledger in a verifiable, secure, transparent and permanent way, with a timestamp and other details. Introduced in 2009 as the core mechanism for the Bitcoin cryptocurrency and its worldwide payment system, blockchain has had many applications in domains such as IoT, finance, business, management, health and education. Also new platforms and tools for blockchain implementation were developed. As education becomes more open, diversified, democratised, and decentralised, the blockchain technology is taken in consideration by researchers, teachers and institutions, to maintain reputation, trust in certification, and proof of learning. In the first part of the paper, we explore the blockchain technology. Next, existing global and governmental initiatives, together with potential applications of blockchain in different domains are presented. The need to learn about this emerging technology is demonstrated, together with pioneering cases in different universities. Then we propose a public blockchain called OpenEduChain, designed as a repository for open educational assets (Open Educational Resources - OERs, Massive Open Online Courses - MOOCs, open pedagogies and scenarios), but also to deliver issued certificates and open badges by universities and other educational and training institutions. At university level, OpenEduChain, implemented on Ethereum, is used to store data about the open educational items created by faculty members and students. Also digital certificates or open badges are provided to the participants in the trainings and workshops. After a period of tests, OpenEduChain usage could be extended at national level, but also for new purposes such as e-portfolios or assessment.
Elli Androulaki, Artem Barger, Vita Bortnikov, Christian Cachin · 21 authors
The success of public blockchains, such as Bitcoin and Ethereum, led to growing interest in Blockchain technology and its application as a distributed system in the most innovative business use cases.
A trusted electronic election system requires that all the involved information must go public, that is, it focuses not only on transparency but also privacy issues. In other words, each ballot should be counted anonymously, correctly, and efficiently. In this work, a lightweight E-voting system is proposed for voters to minimize their trust in the authority or government. We ensure the transparency of election by putting all message on the Ethereum blockchain, in the meantime, the privacy of individual voter is protected via an efficient and effective ring signature mechanism. Besides, the attractive self-tallying feature is also built in our system, which guarantees that everyone who can access the blockchain network is able to tally the result on his own, no third party is required after voting phase. More importantly, we ensure the correctness of voting results and keep the Ethereum gas cost of individual participant as low as possible, at the same time. Clearly, the pre-described characteristics make our system more suitable for large-scale election.
Raymond Cheng, Fan Zhang, Jernej Kos, Warren He · 9 authors
Smart contracts are applications that execute on blockchains. Today they manage billions of dollars in value and motivate visionary plans for pervasive blockchain deployment. While smart contracts inherit the availability and other security assurances of blockchains, however, they are impeded by blockchains' lack of confidentiality and poor performance. We present Ekiden, a system that addresses these critical gaps by combining blockchains with Trusted Execution Environments (TEEs). Ekiden leverages a novel architecture that separates consensus from execution, enabling efficient TEE-backed confidentiality-preserving smart-contracts and high scalability. Our prototype (with Tendermint as the consensus layer) achieves example performance of 600× more throughput and 400× less latency at 1000× less cost than the Ethereum mainnet. Another contribution of this paper is that we systematically identify and treat the pitfalls arising from harmonizing TEEs and blockchains. Treated separately, both TEEs and blockchains provide powerful guarantees, but hybridized, though, they engender new attacks. For example, in naïve designs, privacy in TEE-backed contracts can be jeopardized by forgery of blocks, a seemingly unrelated attack vector. We believe the insights learned from Ekiden will prove to be of broad importance in hybridized TEE-blockchain systems.
Franklin Schrans, Susan Eisenbach, Sophia Drossopoulou
Blockchain-based platforms such as Ethereum support the execution of versatile decentralized applications, known as smart contracts. These typically hold and transfer digital currency (e.g., Ether) to other parties on the platform. Contracts have been subject to numerous attacks, losing hundreds of millions of dollars (in Ether). We propose Flint, a new type-safe, capabilities-secure, contract-oriented programming language specifically designed for writing robust smart contracts. To help programmers reason about access control of functions, Flint programmers use caller capabilities. To prevent vulnerabilities relating to the unintentional loss of currency, transfers of assets in Flint are performed through safe atomic operations, inspired by linear type theory.
Bitcoin und die zugrunde liegende Technologie der Blockchain sind längst keine Randphänomene mehr. Zwar ist Bitcoin in vielerlei Hinsicht neuartig. Das steht aber einer Einordnung als «Geld im weiteren Sinn» bzw. als «Kryptowährung» nicht im Weg. Bitcoin ient zurzeit primär als Spekulationsobjekt, aber auch zur Wertaufbewahrung und als Zahlungsmittel. Während das Bitcoin-System nur die Übertragung von Bitcoins erlaubt, ist die Blockchain von Ethereum, der zweitgrössten Kryptowährung, frei programmierbar and erlaubt die Emission beliebiger «Tokens». Diese können Währungen, Anleihen, Aktien oder beliebige andere Vermögenswerte mit oder ohne vom Emittenten garantierten Wert darstellen. Kryptowährungen haben das Potenzial, einen Digitalisierungsschub im Finanzbereich auszulösen. Um dieses Potenzial zu realisieren, bedarf es aber noch der Klärung verschiedener Rechtsfragen und der Beseitigung rechtlicher Hürden.
We present SBFT: a scalable decentralized trust infrastructure for Blockchains. SBFT implements a new Byzantine fault tolerant algorithm that addresses the challenges of scalability and decentralization. Unlike many previous BFT systems that performed well only when centralized around less than 20 replicas, SBFT is optimized for decentralization and can easily handle more than 100 active replicas. SBFT provides a smart contract execution environment based on Ethereum's EVM byte-code.
We tested SBFT by running 1 million EVM smart contract transactions taken from a 4-month real-world Ethereum workload. In a geo-replicated deployment that has about 100 replicas and can withstand $f=32$ Byzantine faults our system shows speedups both in throughput and in latency. SBFT completed this execution at a rate of 50 transactions per second. This is a $10\times$ speedup compared to Ethereum current limit of $5$ transactions per second. SBFT latency to commit a smart contract execution and make it final is sub-second, this is more than $10\times$ speedup compared to Ethereum current $>15$ second block generation for registering a smart contract execution and several orders of magnitude speedup relative to Proof-of-Work best-practice finality latency of one-hour.
Bitcoin has attracted everyone's attention and interest recently. Ethereum (ETH), a second generation cryptocurrency, extends Bitcoin's design by offering a Turing-complete programming language called Solidity to develop smart contracts. Smart contracts allow creditable execution of contracts on EVM (Ethereum Virtual Machine) without third parties. Developing correct smart contracts is challenging due to its decentralized computation nature. Buggy smart contracts may lead to huge financial loss. Furthermore, smart contracts are very hard, if not impossible, to patch once they are deployed. Thus, there is a recent surge of interest on analyzing/verifying smart contracts. While existing work focuses on EVM opcode, we argue that it is equally important to understand and define the semantics of Solidity since programmers program and reason about smart contracts at the level of source code. In this work, we develop the structural operational semantics for Solidity, which allows us to identify multiple design issues which underlines many problematic smart contracts. Furthermore, our semantics is executable in the K framework, which allows us to verify/falsify contracts automatically.