Blockchain Papers

Magda Foti, Manolis Vavalis

No abstract is available for this record.

Γεώργιος Μαρούλης

Στα πλαίσια της παρούσας διπλωματικής εργασίας, αναλύθηκε, σχεδιάστηκε και υλοποιήθηκε πλήρως κατανεμημένη εφαρμογή εύρεσής εργασίας βασισμένη στην τεχνολογία του Blockchain. Η εφαρμογή αναπτύχθηκε στο σύστημα Ethereum το οποίο εφαρμόζει την τεχνολογία του Blockchain και υποστηρίζει έξυπνα συμβόλαια. Τα έξυπνα συμβόλαια αποτελούν τον πυρήνα της υλοποίησης καθώς είναι υπεύθυνα για όλες τις διεργασίες της εφαρμογής. Τα συμβόλαια έχουν αναπτυχθεί στην γλώσσα προγραμματισμού έξυπνων συμβολαίων του Ethereum Solidity. Το κομμάτι διεπαφής με το χρήστη υλοποιήθηκε με χρήση των WEB τεχνολογιών HTML, CSS και JavaScript λόγω της υποστήριξής τους από σχεδόν όλες τις συσκευές. Οι δυνατότητες της εφαρμογής καλύπτουν όλο το φάσμα των λειτουργειών που θα αναζητούσε κανείς σε μια εφαρμογή εύρεσής εργασίας. Κάποιες ενδεικτικές λειτουργίες είναι η αναζήτηση εργαζομένων, η δημοσίευση θέσεων εργασίας, η οργάνωση συνεντεύξεων και η αντιστοίχιση εργαζομένων με θέσεις εργασίας τις οποίες μπορούν να καλύψουν. Σκοπός της εφαρμογής είναι η διαφανής, ασφαλής και δίκαιη διαδικασία εύρεσης εργασίας τόσο για τους εργαζόμενους όσο και για την εταιρία. Με την χρήση του blockchain διασφαλίζεται η διαφάνεια εφόσον όλα τα δεδομένα σε αυτό είναι δημόσια ενώ τα έξυπνα συμβόλαια εφαρμόζοντας τις κατάλληλες μεθόδους επιβάλουν την τήρηση των συμφωνιών τόσο σε οικονομικό όσο και σε επίπεδο διάρκειας συνεργασίας μεταξύ ενός εργαζομένου και μιας εταιρίας.

Jafar Haritsah

Abstrak File sharing memang sangat berguna untuk berkomunikasi dan juga bertukar data, data yang dimaksud bisa berupa angka, sumber, skala dan juga suatu informasi yang penting untuk dijaga keamanannya. Dikarenakan saat ini semakin banyak teknologi yang menunjang file sharing, maka salah satu solusi untuk menjaga kemanan dari suatu data adalah Interpanetary File System (IPFS). IPFS hadir untuk memberikan solusi permasalahan sebagai sistem file terdistribusi peer-to-peer yang secure dengan menggunakan sistem file terenskripsi (hash) yang menghubungkan semua perangkat komputasi dengan sistem file yang sama. Blockchain atau dapat disebut sebagai teknologi pembukuan terdistribusi Distributed Ledger Technologi (DLT) merupakan suatu sistem untuk menyimpan informasi yang disebarluaskan pada komputer agar informasi lebih aman dan terjaga untuk mencegah terjadinya pengambilan data dari orang – orang yang ingin mengambil tanpa izin. Selain penyimpanan nya yang secure blockchain juga berguna untuk menyimpan data yang lebih sedikit, seperti informasi nilai hash, transaksi dan juga metadata. Untuk mengimplementasikan IPFS pada smart contract ethereum kita harus menganalisis proses sistem nya untuk mengetahui bagaimana proses transaksi maupun penyimpanan data, smart contract yaitu sistem untuk membantu dalam menerima dan mengirimkan data. Ethereum yaitu sebuah platform berbasis blockchain. Oleh karena itu, penelitian ini dilakukan untuk mengetahui proses sistem untuk IPFS agar smart contract ethereum dapat berjalan dengan baik dan sebagaimana mestinya. Kata Kunci : Blockchain,Smart Contract, Ethereum, Peer-to-peer, Proses Sistem Abstract File sharing is really very useful for communicating and also exchanging data, the data in question can be in the form of numbers, sources, scales and also information that is important to maintain security. Because currently more and more technology is supporting file sharing, one of the solutions to safeguarding data from is Interpanetary File System (IPFS). IPFS is here to provide solutions to problems as a secure distributed peer-to-peer file system using an encrypted file system (hash) that connects all computing devices with the same file system. Blockchain or can be referred to as bookkeeping technology distributed Distributed Ledger Technology (DLT) is a system for storing information that is disseminated on a computer so that information is safer and safer to prevent data retrieval from people who want to take it without permission. Besides the storage, the secure blockchain is also useful for storing less data, such as hash value information, transactions and also metadata. To implement IPFS on smart contract ethereum we have to analyze the system process to find out how the transaction process and data storage, smart contract, is a system to assist in receiving and sending data. Ethereum is a blockchain based platform. Therefore, this study was conducted to determine the system process for IPFS so that the smart contract ethereum can run properly and properly. Key Word : Blockchain, Smart Contract, Ethereum, Peer-to-peer, Process System

Kaidong Wu, Yun Ma, Gang Huang, Xuanzhe Liu

Summary With the increasing popularity of blockchain technologies in recent years, blockchain‐based decentralized applications (DApps for short in this paper) have been rapidly developed and widely adopted in many areas, being a hot topic in both academia and industry. Despite of the importance of DApps, we still have quite little understanding of DApps along with its ecosystem. To bridge the knowledge gap, this paper presents the first comprehensive empirical study of blockchain‐based DApps to date, based on an extensive dataset of 995 Ethereum DApps and 29,846,075 transaction logs over them. We make a descriptive analysis of the popularity of DApps, summarize the patterns of how DApps use smart contracts to access the underlying blockchain, and explore the worth‐addressing issues of deploying and operating DApps. Based on the findings, we propose some implications for DApp users to select proper DApps, for DApp developers to improve the efficiency of DApps, and for blockchain vendors to enhance the support of DApps.

Guangquan Xu, Bingjiang Guo, Chunhua Su, Xi Zheng · 7 authors

No abstract is available for this record.

Guoliang Zhou, Linjie Lv, Gang Li, Yimin Huang · 6 authors

As one of the underlying supporting technologies of Energy Internet, energy blockchain has attracted more and more attention. How to combine energy blockchain with specific application scenarios is a difficult problem in current research. Firstly, the technical feasibility of the application of energy blockchain in the field of energy trading is analyzed in detail. Then, taking the scenario of electric vehicle charging and discharging trading as the breakthrough point, considering the convenience and security of both sides of the transaction, a blockchain system framework supporting consensus algorithm and intelligent contract is proposed, which includes blockchain layer and intelligent contract. There are four layers of architecture: extension layer, application layer and presentation layer. Finally, from the perspective of system platform development, the technical connotation and application demonstration based on ethereum architecture are introduced. The system architecture and its application effect provide technical reference for promoting the integration of energy system and information technology and improving energy efficiency.

Vikram Kanth

As the threat of cyber attack grows ever larger, new approaches to security are required. While there are several different types of intrusion detection systems (IDS), collaborative IDS (CIDS) offers particular promise in identifying distributed, coordinated attacks that might otherwise elude detection. Even for this type of IDS, there are unresolved issues associated with trusting participants and aggregating data. Blockchain technology appears capable of addressing those issues. This thesis is focused on presenting a proof-of-concept experiment leveraging an Ethereum-based private blockchain for a CIDS that uses pluggable authentication modules (PAM) to track login activity toward detection of doorknob rattling attacks.

Asma Lahbib, Khalifa Toumi, Anis Laouiti, Steven Martin

While smart factories are becoming widely recognized as a fundamental concept of Industry 4.0, their implementation has posed several challenges insofar that they generate, process, and exchange vast amounts of security critical and privacy sensitive data, which makes them attractive targets of attacks and unauthorized access. Security requirements in such scenario include integrity, confidentiality, traceability and notarization of exchanged data in the one hand plus access control, privacy and trust in the other one. In this context, we design a distributed resource management framework using the emerging smart contracts technology for Industry 4.0 applications and more specifically for smart factories environments. This last, named DRMF, utilizes three Ethereum smart contracts specifically a Governance Contract (GC), an Access Contract (AC) and a Lookup Contract (LC) that are respectively responsible for the registration of new joining entities as well as those requesting consensus partaking permissions, second the dynamic access authorization and third the mapping between the required services and contracts ensuring their management. Using the blockchain technology, this framework is expected to achieve distributed, flexible, verifiable and trustworthy access control in addition to a transparent, traceable and notarized resource usage and sharing. Results from a real implementation plus performance evaluation prove the proposed concept and demonstrate its feasibility.

V. U. Wickramarachchi, Chamath Keppitiyagama, Kasun Gunawardana

Financial contracts play a major role in the modern economy. Due to a large variation of contracts being traded in financial markets, a standard representation for contracts was required in order to eliminate the ambiguity imposed by natural languages. Peyton Jones et al. catered this need by proposing a combinator library embedded in Haskell which enabled contract representation and valuation. However, every financial contract represented as such suffered from the same fundamental problem. If a contract is executable, the parties involved in the contract needed to trust a central counterparty to give them the correct results after execution. The interference of this middleman introduced certain risks as well as a significant amount of overhead. In this paper, a novel approach to facilitate autonomous contract execution was proposed, exploiting the features and use cases of the Ethereum blockchain and its scripting language, Solidity. The approach involves transforming contracts written in Peyton Jones Contract Descriptive language (CDL) to Solidity using a special purpose compiler. The result of this transformation is a smart contract equivalent to the traditional financial contract. The transformed smart contract is deployed and executed on the Ethereum blockchain using an Ethereum client. The proposed solution was evaluated against existing attempts to design autonomous financial contracts. The research shows that a contract written using CDL can be transformed into a smart contract which executes autonomously in a trust-less environment. As a result, it was concluded that financial contracts could operate without a central counterparty with increased performance and reduced overheads in comparison to traditional financial contracts.

Γεώργιος Δρακόπουλος, Eleanna Kafeza, Haseena Al Katheeri

Blockchain is a prime example of disruptive technology in multiple levels. With the advent of blockchains becomes obsolete the need for a mutually trusted third party acting as intermediary between agents which do not necessarily trust each other in transactions of any kind, including political or shareholder voting, crowdfunding, financial deals, logistics and supply chain management, and contract formulation. An integral part of the blockchain stack is the proof system, namely the mechanism efficiently verifying the claims of various blockchain stakeholders. Thus, trust is effectively established in a literally trustless environment with purely computational means. This is especially critical in the digital formulation of smart contracts where clauses are to be strictly upheld by intelligent agents. The most prominent proof systems recently proposed in the scientific literature are reviewed. Additionally, the applications of blockchain technology to smart contracts is discussed. The latter allows clause re-negotiation, increasing thus the flexibility factor in transactions. As a concrete example, a simple smart contract written in Solidity, a high level language for the Ethereum Virtual Machine, is presented.

Arun Kumar Tripathi, Apoorv Jain, N. Chandra, Akash Rajak · 5 authors

Blockchain is one of emerging research area and gaining attention due to its wide range of applications. Smart contracts are one of the latest application areas of blockchain, which enables secure, transparent and tamperproof transactions. Smart contracts create and verify the data with the help of hash functions. Hash functions are mathematical algorithms that take input and produces hashed output of specified length. It is very difficult to regenerate the original input from the hashed output. Ethereum is one of the leading blockchain platforms to provide functionality of smart contracts. This paper carries out study of blockchain on Ethereum platform. We have developed authentication-based business application with the help of smart contract for marketing services on Ethereum platform. Solidity is used to generate and manage smart contract.

Dan-Cristian CEARNĂU

Distributed Ledger Technology (DLT), also known as „Blockchain”, represents a new paradigm in how applications are designed and built. Even thoughthe blockchain emerged as a consumer-focused technology (form Bitcoin), it’s adoptionin the enterpriseenvironment has increased dramatically in the last years. The user’sfocus on privacy, security and transparency has motivated corporations to invest in distributed applications throughout their structure and operations. The main frameworks for enterprise blockchain solutions are coming from well established IT&C corporations like Microsoft (partnership with Ethereum), IBM (Hyperledger Fabric), JP Morgan (Quorum) and others.The blockchain technology is pretty new, and it cannot fully replace legacy centralized cloud-based solutions. The scalability issue of DLT is well-known, as the most advanced blockchain technologies can only process a few hundred transactions per second. This is nowhere near the speed of Visa’s payment system that can process more than 2000 transactions per second.

Zuobin Ying, Maode Ma, Longyang Yi

Autonomous Vehicle Platoon (AVP) is the most promising solution to various problems in the Intelligent Transportation System. However, how to effectively manage the join and leaving vehicles, and ensure the profit of the platoon leader remains an open problem. In this paper, we propose a dynamic AVP management protocol by implementing Ethereum. Vehicle who wants to join and leave the platoon has to communicate with the platoon leader, and all messages will be related to the corresponding transactions regulated by the smart contract. Considering the cost efficiency of the AVP system, a hybrid chain model is constructed. The public chain provides with certification records. All platoon message communication records will be stored on the privacy chain and will be upload to the public chain as platoon operation incident record. The evaluation result and security analysis indicate that our proposed scheme is practical for AVP scenario in terms of both efficient and secure.

S. Zhukov, I. Kopytin, A. Maslennikov

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Iasonas Kouveliotis‐Lysikatos, Isidoros Kokos, Ilias Lamprinos, Nikos Hatziargyriou

Recently, special attention has been brought to blockchain-based platforms for the development of decentralized Smart Grid applications. The scope of this paper is first to review the state-of-the-art assessing the effectiveness of applying blockchain as a vehicle for the decentralization of the energy market and afterwards, to design a simplified decentralized transactive application and investigate its applicability through simulations, focusing on the Ethereum blockchain protocol. The results support the applicability of blockchain in automating electricity supply contracting under the concept of decentralized markets.

Milton Chang

Blockchain technology is believed to be a highly secured solution for it is a decentralized ledger guarded by cryptographic techniques. However, the recent successful ‘51% Attack’ [1] on Ethereum Blockchain network, raised concerns regarding the trustworthiness of this technology. This paper addresses the causes and solutions to that attack. Private Transactions like the techniques implemented in Parity Ethereum and Quorum are introduced. Proof of Stack (POS) is another approach using economic incentives instead of intensive computations to guard against attacks while reducing power consumed. They are considered mitigation to the ‘51% Attack’. The use of Second Factor Authentication at the Smart Contract level is also addressed.

Erick Fernando, Meyliana Meyliana, Surjandy Surjandy

This research tries to prove low-cost computer devices such as mini-computers can be used in the development of blockchain technology. Mini-computer technology is used because of many problems that occur due to the use of hardware resources that are discussed large, specifically in the pharmaceutical industry in the process drug makers, packing drugs (drug packaging identities), checking drugs, installations (printing drug identities), and this use to label drug to read posts on drug strips, to make the products used by customers better. This study uses an experimental design. Experiments were carried out with devices to use and blockchain technology. The device used is a Raspberry Pi mini-computer, and blockchain technology is the Ethereum platform. The results of this study indicate the installation process until the blockchain system can run. The results show that the raspberry pi device can be implemented with Ethereum blockchain technology correctly and adequately.

Jiwon Bang, Mi-Jung Choi

Recently, due to the popularity of Bitcoin, interest in the blockchain which is the core technology of Bitcoin, has also increased. Blockchain is a distributed ledger technology that stores transaction information that occurs in P2P(Peer-to-Peer) networks on the ledger of all nodes in a different way than centralized method and verifies whether they are stored correctly. As a result of blockchain technology, not only Bitcoin but also various cryptocurrencies such as Ethereum, Litecoin, Ripple and Bitcoin Cash are being developed. Blockchain is used in various fields because of its features such as integrity and anonymity, but it is also used for illegal transactions and drug transactions. To solve these problems, monitoring system is needed to collect data from blockchain networks and detect abuse and illegal transactions. In this paper, we propose monitoring system for detecting and tracking illegal transactions by collecting and analyzing information in a blockchain network. In addition, we introduce an efficient storage system implemented by Apache Kafka and Apache Storm among the Blockchain monitoring systems.

Clinton Ehrlich, Anna Guzova

This paper applies biomimetic engineering to the problem of permissionless Byzantine consensus and achieves results that surpass the prior state of the art by four orders of magnitude. It introduces a biologically inspired asymmetric Sybil-resistance mechanism, Proof-of-Balance, which can replace symmetric Proof-of-Work and Proof-of-Stake weighting schemes. The biomimetic mechanism is incorporated into a permissionless blockchain protocol, Key Retroactivity Network Consensus (KRNC), which delivers ~40,000 times the security and speed of today's decentralized ledgers. KRNC allows the fiat money that the public already owns to be upgraded with cryptographic inflation protection, eliminating the problems inherent in bootstrapping new currencies like Bitcoin and Ethereum. The paper includes two independently significant contributions to the literature. First, it replaces the non-structural axioms invoked in prior work with a new formal method for reasoning about trust, liveness, and safety from first principles. Second, it demonstrates how two previously overlooked exploits, book-prize attacks and pseudo-transfer attacks, collectively undermine the security guarantees of all prior permissionless ledgers.

Disha Shinde, Snehal Padekar, Siddharth Raut, Abdul Wasay · 5 authors

Storing sensitive information like property papers needs a secure and untamperable database. Existing centralized systems has numerous drawbacks like performance bottleneck and single point of failure. Hence, a decentralized system with high security is needed. To cater this need, in this paper, we propose blockchain based system for secure storage of property papers. In our system, when a land is bought by a person, the government authority will provide the person with the hard copy of property papers and our system will store the documents into the Inter Planetary File System (IPFS), a decentralised database. The IPFS network will generate the hash of document. This hash will be securely stored into the ethereum blockchain after satisfying the conditions of the smart contracts. The smart contracts will validate and verify the documents from the government authorities. This will create a decentralized, tamper-proof ledger from which we can retrieve the stored data easily.

Haitham Mahmoud, Wenyan Wu, Yonghao Wang

Development of intelligent systems in particular Water Distribution Systems (WDS) increases the demand of implementing a secure scheme that can preserve user's identification and data consumption through maintaining confidentiality, authentication and integrity. Decentralization topology has investigated a lot recently in the literature with the development of bitcoins and Ethereum networks in different IoT disciplines such as power systems and healthcare systems. In this paper, feasibility and uses cases studies on the integration WDS with Blockchain Technology are discussed. Moreover, the customer's data and identity anonymity techniques that can be integrated with the network are discussed. Furthermore, a data aggregation mechanism of the smart meters in Water Distribution System (WDS) based on distributed ledger and Blockchain technologies is proposed. Further, the customer's identity using bloom filter is simulated and optimal parameters of the bloom filter are suggested.

Viktor Valaštín, Kritian Kost'al, Rastislav Bencel, Ivan Kotuliak

The car-sharing market is constantly growing and recently it has become even more popular than car ownership. However, classic car-sharing system is based on a centralized database server which can often lead to hacker attacks or password leaks. Moreover, in a classic car-sharing system, the owners of the cars can misuse customers' data. As seen nowadays from a lot of use cases, the best solution to these problematic issues is to use blockchain technology. Blockchain as decentralized, immutable, public ledger provides the customers with security that is impossible to tamper. The aim of the proposed solution is to create and implement peer-to-peer short term car-sharing application based on blockchain technology and smart contracts. For the implementation of smart contracts, Solidity programming language is used. Solidity works with Ethereum blockchain. The key novelty of the article is introducing a peer-to-peer car sharing service without a central authority, what reflects a decrease of costs and increase of data transparency in that system. Also token based solution gives us ability to cover business-to-business (B2B) and business-to-customer (B2C) use cases.

Hoang-Anh Pham, Trung-Kien Le, Thi-Ngoc-My Pham, Hoai-Quoc-Trung Nguyen · 5 authors

In recent years, the incredible growth and diversity of IoT systems and applications have generated an enormous amount of sensing data which play an essential role in IoT-based smart systems. So far, it has consumed much time and cost to collect these sensing data enough for these intelligent systems, which is the main reason leading to the needs of sharing available data to shorten time-consuming and cost savings for the data collection process. However, there are many challenges in ensuring integrity, security, and fairness in the data sharing process. In this paper, the authors propose a model leveraging the emerging Blockchain technology as an alternative solution to enhance the security of IoT data sharing management in terms of three principal criteria including confidentiality, integrity, and availability. Our prototype on Ethereum Blockchain demonstrates the feasibility of the proposed model.

Huan Zhou, Xue Ouyang, Jinshu Su, Cees de Laat · 5 authors

There lacks trust between the cloud customer and provider to enforce traditional cloud SLA (Service Level Agreement) where the blockchain technique seems a promising solution. However, current explorations still face challenges to prove that the off-chain SLO (Service Level Objective) violations really happen before recorded into the on-chain transactions. In this paper, a witness model is proposed implemented with smart contracts to solve this trust issue. The introduced role, "Witness", gains rewards as an incentive for performing the SLO violation report, and the payoff function is carefully designed in a way that the witness has to tell the truth, for maximizing the rewards. This fact that the witness has to be honest is analyzed and proved using the Nash Equilibrium principle of game theory. For ensuring the chosen witnesses are random and independent, an unbiased selection algorithm is proposed to avoid possible collusions. An auditing mechanism is also introduced to detect potential malicious witnesses. Specifically, we define three types of malicious behaviors and propose quantitative indicators to audit and detect these behaviors. Moreover, experimental studies based on Ethereum blockchain demonstrate the proposed model is feasible, and indicate that the performance, ie, transaction fee, of each interface follows the design expectations.