David Zhao, Alessandro Rinaldo, Christopher Brookins
Few assets in financial history have been as notoriously volatile as cryptocurrencies. While the long term outlook for this asset class remains unclear, we are successful in making short term price predictions for several major crypto assets. Using historical data from July 2015 to November 2019, we develop a large number of technical indicators to capture patterns in the cryptocurrency market. We then test various classification methods to forecast short-term future price movements based on these indicators. On both PPV and NPV metrics, our classifiers do well in identifying up and down market moves over the next 1 hour. Beyond evaluating classification accuracy, we also develop a strategy for translating 1-hour-ahead class predictions into trading decisions, along with a backtester that simulates trading in a realistic environment. We find that support vector machines yield the most profitable trading strategies, which outperform the market on average for Bitcoin, Ethereum and Litecoin over the past 22 months, since January 2018.
Smart contracts on a blockchain behave precisely as specified by their code. A vulnerability in this code can lead to unexpected behaviour, which is hard to fix because a blockchain does not allow to change smart contract code after its deployment. Such vulnerabilities have led to several incidents. In the aftermath of such an event, a hard-fork between Ethereum and Ethereum classic was the result. This thesis proposes to develop a new smart contract programming language with the primary focus on safety, auditability, and the intention to prevent as many of the known categories of vulnerabilities by design as possible. The programming language's code is validated during deployment and afterwards isolated from other smart contracts running on the same blockchain to enforce compile-time guarantees during runtime. The designed programming language does evaluate new concepts and paradigms rarely used in non-smart contract environments for their potential benefit in a smart contract environment.
Abstract We study the interplay between social ties and financial transactions made through a recent cryptocurrency called $\breve {G}1$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Ğ</mml:mi><mml:mn>1</mml:mn></mml:math> . It has the particularity of combining the usual transaction record with a reliable network of identified users. This gives the opportunity to observe exactly who sent money to whom over a social network. This social network is a key piece of this cryptocurrency, which therefore puts much effort in ensuring that nodes correspond to unique, well identified, real living human users, linked together only if they met at least once in real world. Using this data, we study how social ties impact the structure of transactions and conversely. We show that users make transactions almost exclusively with people they are connected with in the social network. Instead, they tend to build social connections with people they will never make transactions with.
Abstract A stable reference of Internet resources is crucial not only to identify a resource in a trustworthy and certified way but also to guarantee continuous access to it over time. The current practice in scientific publication as the use of a Persistent Identifier (PID) like a DOI or Handle, is becoming attractive also for the datasets. In fact, in the era of Big Data, the aspects of replicability and verification of the scientific result are paramount. In this paper we verify the functional feasibility of permissioned blockchain technology as a tool to implement a Trustworthy Persistent Identifier (T-PID) system for datasets in the scientific domain.
Blockchain offers a decentralized, immutable, transparent system of records. It offers a peer-to-peer network of nodes with no centralised governing entity making it unhackable and therefore, more secure than the traditional paper-based or centralised system of records like banks etc. While there are certain advantages to the paper-based recording approach, it does not work well with digital relationships where the data is in constant flux. Unlike traditional channels, governed by centralized entities, blockchain offers its users a certain level of anonymity by providing capabilities to interact without disclosing their personal identities and allows them to build trust without a third-party governing entity. Due to the aforementioned characteristics of blockchain, more and more users around the globe are inclined towards making a digital transaction via blockchain than via rudimentary channels. Therefore, there is a dire need for us to gain insight on how these transactions are processed by the blockchain and how much time it may take for a peer to confirm a transaction and add it to the blockchain network. This paper presents a novel approach that would allow one to estimate the time, in block time or otherwise, it would take for a mining node to accept and confirm a transaction to a block using machine learning. The paper also aims to compare the predictive accuracy of two machine learning regression models- Random Forest Regressor and Multilayer Perceptron against previously proposed statistical regression model under a set evaluation criterion. The objective is to determine whether machine learning offers a more accurate predictive model than conventional statistical models. The proposed model results in improved accuracy in prediction.
Swati Megha, Joseph Lamptey, Hamza Salem, Manuel Mazzara
The energy industry needs to shift to a new paradigm from its classical model of energy generation, distribution, and management. This shift is necessary to handle digitization, increased renewable energy generation, and to achieve goals of environmental sustainability. This shift has several challenges on its way and has been seen through research and development that blockchain which is one of the budding technology in this era could be suitable for addressing those challenges. This paper is aimed at the survey of all the research and development related to blockchain in the energy industry and uses a software engineering approach to categories all the existing work in several clusters such as challenges addressed, quality attribute promoted, the maturity level of the solutions, etc. This survey provides researchers in this field a well-defined categorization and insight into the existing work in this field from 3 different perspectives (challenges, quality attributes, maturity).
With the emergence of cross-organization attack-prone byzantine fault-tolerant (BFT) systems, so-called Blockchains, providing asynchronous state machine replication (SMR) solutions is no longer a theoretical concern. This paper introduces ACE: a general framework for the software design of fault-tolerant SMR systems. We first propose a new leader-based-view (LBV) abstraction that encapsulates the core properties provided by each view in a partially synchronous consensus algorithm, designed according to the leader-based view-by-view paradigm (e.g., PBFT and Paxos). Then, we compose several LBV instances in a non-trivial way in order to boost asynchronous liveness of existing SMR solutions. ACE is model agnostic - it abstracts away any model assumptions that consensus protocols may have, e.g., the ratio and types of faulty parties. For example, when the LBV abstraction is instantiated with a partially synchronous consensus algorithm designed to tolerate crash failures, e.g., Paxos or Raft, ACE yields an asynchronous SMR for $n = 2f+1$ parties. However, if the LBV abstraction is instantiated with a byzantine protocol like PBFT or HotStuff, then ACE yields an asynchronous byzantine SMR for $n = 3f+1$ parties. To demonstrate the power of ACE, we implement it in C++, instantiate the LBV abstraction with a view implementation of HotStuff -- a state of the art partially synchronous byzantine agreement protocol -- and compare it with the base HotStuff implementation under different adversarial scenarios. Our evaluation shows that while ACE is outperformed by HotStuff in the optimistic, synchronous, failure-free case, ACE has absolute superiority during network asynchrony and attacks.
Peter Mell, Aurélien Delaitre, Frederic de Vaulx, Philippe Dessauw
Previous work presented a theoretical model based on the implicit Bitcoin specification for how an entity might issue a protocol native cryptocurrency that mimics features of fiat currencies. Protocol native means that it is built into the blockchain platform itself and is not simply a token running on another platform. Novel to this work were mechanisms by which the issuing entity could manage the cryptocurrency but where their power was limited and transparency was enforced by the cryptocurrency being implemented using a publicly mined blockchain. In this work we demonstrate the feasibility of this theoretical model by implementing such a managed cryptocurrency architecture through forking the Bitcoin code base. We discovered that the theoretical model contains several vulnerabilities and security issues that needed to be mitigated. It also contains architectural features that presented significant implementation challenges; some aspects of the proposed changes to the Bitcoin specification were not practical or even workable. In this work we describe how we mitigated the security vulnerabilities and overcame the architectural hurdles to build a working prototype.
Open access
3 source records
cs.CR
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
One of the key challenges in the collaboration within heterogeneous multi-robot systems is the optimization of the amount and type of data to be shared between robots with different sensing capabilities and computational resources. In this paper, we present a novel approach to managing collaboration terms in heterogeneous multi-robot systems with blockchain technology. Leveraging the extensive research of consensus algorithms in the blockchain domain, we exploit key technologies in this field to be integrated for consensus in robotic systems. We propose the utilization of proof of work systems to have an online estimation of the available computational resources at different robots. Furthermore, we define smart contracts that integrate information about the environment from different robots in order to evaluate and rank the quality and accuracy of each of the robots' sensor data. This means that the key parameters involved in heterogeneous robotic collaboration are integrated within the Blockchain and estimated at all robots equally without explicitly sharing information about the robots' hardware or sensors. Trustability is based on the verification of data samples that are submitted to the blockchain within each data exchange transaction and validated by other robots operating in the same environment. Initial results are reported which show the viability of the concepts presented in this paper.
Over the last decade there has been a continuing decline in social trust on the part of individuals with regards to the handling and fair use of personal data, digital assets and other related rights in general. At the same time, there has been a change in the employment patterns for many people through the emergence of the gig economy. These gig workers include artists, songwriters and musicians in the music industry. We discuss the notion of the data cooperative with fiduciary responsibilities to its members, which is similar in purpose to credit unions in the financial sector. A data cooperative for artists and musicians allows the community to share IT resources, such as data storage, analytics processing, blockchains and distributed ledgers. A cooperative can also employ smart contracts to remedy the various challenges currently faced by the music industry with regards to the license tracking management.
Assistant Professor, SLRTCE Mumbai (Maharashtra), India., Neha Jain
Data security is the key to the development of modern internet technology. By allowing digital information to be distributed but not copied, blockchain technology created the backbone of a new type of internet. It allows storage of all transactions into immutable records and every record distributed across many participant’s nodes. As there is huge increase in the use cases for blockchain technology, nowadays, the primary issue is to enable secure data sharing, data integrity and authentication. The goal of this study paper is to provide a systematic literature survey exploring the use of blockchain as a base technology for securing financial as well as non-financial applications. The purpose is to identify the whether blockchain technology is capable to provide the desired security solutions in various application. The advantages, challenges and the solution provided by previous research is discussed. The survey was focused on various security issues like Confidentiality, Integrity, Availability, Authenticity, Accountability, and Reliability. The study shows that the Blockchain technology is prospective for financial and non-financial services since it can provide solutions for majority of security issues. Future research needs to provide the implementations of desired solutions discussed in security challenges of Blockchain technology.
From its origins in virtual financial transactions, emerging initiatives are seeking to acquire a new identity for blockchain as capable of addressing anxieties over the capacity of digital media to permanently and accurately store information. In this article, we explore the ensuing mediation between blockchain enterprises and new professional communities to which they are catering. Drawing on thematic analysis, we analyze how this process is being carried out through the discursive construction of trust, leveraged rhetorically in academic, trade, and news publications to extend an application for financial transactions to cultural institutions. We describe how trust is used not only to mediate the introduction of an application that prioritizes decentralization and cryptography, but is the turf on which traditional institutions are staking a claim as the trustworthy managers of digital records through their use of blockchain. The concept of the archival imaginary—a vision of what archives and blockchain should be and mean that pivots on imagined needs and technological capacities based on the current information ecology, institutional control, and expert systems—offers a way to illuminate this process.
Cryptomonnaies et efficience des marchés Les innovations apportées par les cryptomonnaies et leur technologie sous-jacente, la blockchain, ouvrent de nouvelles voies de recherches en finance. Cette thèse de doctorat est composée de trois essais portant sur les cryptomonnaies et est centrée autour de la notion d’efficience informationnelle des marchés. La première étude vise à expliquer comment la blockchain, développée au sein de communautés informelles, est adoptée et intégrée par les organisations. Cette étude apporte un cadre théorique à la technologie blockchain, cadre qui s’appuie sur les approches contractuelle et cognitive de la théorie des organisations. Grâce à une revue de la littérature illustrée, une analyse à deux dimensions présente les possibles utilisations de la blockchain fondées sur l’accès à l’information pour les participants. L’objectif de la seconde étude est double. Premièrement, elle soulève la problématique de la réelle nature du Bitcoin. Après avoir comparé le Bitcoin aux monnaies, à l’or et aux actions, nous basons notre analyse sur l’hypothèse que les cryptomonnaies peuvent être assimilées aux actions. Deuxièmement, la performance financière (la rentabilité ajustée au risque) du Bitcoin est mesurée en utilisant des modèles traditionnels tels que le MEDAF et le model de Fama-French à trois facteurs. Nous trouvons que l’intégration du Bitcoin dans un portefeuille améliore considérablement sa diversification, tout en apportant des rentabilités ajustées au risque positives et significatives dans le monde, l’Europe et l’Asie-Pacifique. La forte volatilité du Bitcoin ainsi que sa haute performance nous conduisent à analyser le caractère de bulle spéculative des cryptomonnaies, ce qui est l'objet de la troisième étude. Nous analysons cet aspect en utilisant le modèle PSY de Phillips and Shi, 2018. Deuxièmement, nous analysons le plus important pic/éclatement du marché des cryptomonnaies à la fin des années 2017 à l’aide du modèle LPPL (Log Periodic Power Law). Les résultats suggèrent des périodes de bulles avec effet de contagion entre les cryptomonnaies. Les analyses théoriques et empiriques de cette thèse contribuent à la littérature académique sur les cryptomonnaies. Nos résultats sont également importants pour les entreprises et pour les investisseurs qui s’intéressent au potentiel des cryptomonnaies et de la blockchain, ainsi que pour les décideurs politiques responsables de leur régulation.
Swarm robotics is an emerging robotic domain that aims to accomplish complex tasks with the cooperative effort of a group of simple robots. These robots communicate and share information to coordinate their actions for achieving a common goal. However, existing mechanisms of control and communications are not very secure, efficient, and also rely on centralized controlling authority. It is not flexible, and also has low transparency and tracking capabilities. Blockchain, a decentralized technology based on peer to peer communication along with smart contracts, can be a potential contender for addressing these challenges. However, blockchains are resource‐intensive and not found suitable for resource‐constrained devices. We propose a blockchain‐based framework, which is based on Proof‐of‐Authority (PoA) consensus mechanism to ensure efficiency. We experiment with test‐bed implementation using RaspberryPi. The results obtained demonstrate that the PoA mechanism is not a resource‐hungry one (unlike other state‐of‐the‐art consensus mechanisms). The blockchain with PoA in swarm robotics can provide the necessary security, transparency, decentralization, reliability, autonomy, etc.
The agent based approach is a well established methodology to model distributed intelligent systems. Multi-Agent Systems (MAS) are increasingly employed in applications dealing with safety and information critical tasks (e.g., in eHealth, financial, and energy domains). Therefore, transparency and the trustworthiness of the agents and their behaviors must be enforced. For example, employing reputation based mechanisms can promote the development of trust. Nevertheless, besides recent early stage studies, the existing methods and systems are still unable to guarantee the desired accountability and transparency adequately. In line with the recent trends, we advocate that combining blockchain technology (BCT) and MAS can achieve the distribution of the trust, removing the need for trusted third parties (TTP), potential single points of failure. This paper elaborates on the notions of trust, BCT, MAS, and their integration. Furthermore, to attain a trusted environment, this manuscript details the design and implementation of a system reconciling MAS (based on the Java Agent DEvelopment Framework (JADE)) and BTC (based on Hyperledger Fabric). In particular, the agents’ interactions, computation, tracking the reputation, and possible policies for disagreement-management are implemented via smart contracts and stored on an immutable distributed ledger. The results obtained by the presented system and similar solutions are also discussed. Finally, ethical implications (i.e., opportunities and challenges) are elaborated before concluding the paper.
Dunia saat ini sedang menghadapi fenomena disrupsi, dimana pergerakan dunia industri bergerak sangat cepat dari tatanan lama menuju tatanan yang baru. Dalam perkembangan di bidang ekonomi pada era ini sejalan dengan perkembangan teknologi, dan salah satu perkembangan di bidang ekonomi adalah munculnya Bitcoin. Bitcoin adalah uang virtual yang menggunakan teknologi Cryptocurrency, sebagai salah satu uang virtual yang terkenal menjadi tren baru sebagai pembayaran internasional dengan semua manfaatnya. Di antara Cryptocurrency yang ada yang paling menonjol adalah Bitcoin. Di Indonesia, Bitcoin telah menarik perhatian dikarenakan beberapa kelebihan yang dimilikinya serta sudah mulai melakukan ekspansi besar dan sudah tersedia marketplace tersendiri. Dalam peredarannya di Indonesia Bitcoin menjadi polemik tersendiri di dunia maupun Indonesia. Ada beberapa negara di dunia yang melegalkan peredaran Bitcoin serta memiliki regulasi hukum dan juga ada negara yang melarang keras peredarannya. Di Indonesia sendiri belum ada kejelasan apakah Bitcoin boleh digunakan atau tidak sebagai suatu mata uang, serta sikap pemerintah yang menyatakan bahwa segala resiko penggunaan Bitcoin ditanggung oleh pemilik dan penggunaan Bitcoin di Indonesia yang justru bertentangan dengan pasal 28 UUD 1945 yang menyatakan bahwa negara harus menjamin kepastian hukum dan perlindungan hukum bagi setiap warga negaranya.
The blockchain data structure maintained via the longest-chain rule---popularized by Bitcoin---is a powerful algorithmic tool for consensus algorithms. Such algorithms achieve consistency for blocks in the chain as a function of their depth from the end of the chain. While the analysis of Bitcoin guarantees consistency with error $2^{-k}$ for blocks of depth $O(k)$, the state-of-the-art of proof-of-stake (PoS) blockchains suffers from a quadratic dependence on $k$: these protocols, exemplified by Ouroboros (Crypto 2017), Ouroboros Praos (Eurocrypt 2018) and Sleepy Consensus (Asiacrypt 2017), can only establish that depth $Θ(k^2)$ is sufficient. Whether this quadratic gap is an intrinsic limitation of PoS---due to issues such as the nothing-at-stake problem---has been an urgent open question, as deployed PoS blockchains further rely on consistency for protocol correctness. We give an axiomatic theory of blockchain dynamics that permits rigorous reasoning about the longest-chain rule and achieve, in broad generality, $Θ(k)$ dependence on depth in order to achieve consistency error $2^{-k}$. In particular, for the first time, we show that PoS protocols can match proof-of-work protocols for linear consistency. We analyze the associated stochastic process, give a recursive relation for the critical functionals of this process, and derive tail bounds in both i.i.d. and martingale settings via associated generating functions.
Battery Energy Storage Systems (BESSs) are an integral part of a sustainable and resilient smart grid. The security of such critical cyber-physical infrastructure is considered as a major priority for both industry and academia. In this paper, we propose a new distributed smart-contract based control approach of BESSs to enable collaborative and secure operations among them. We present a comprehensive discussion on how control strategies can be implemented as smart contracts and deployed on a distributed network of BESSs nodes in order to operate these storage systems according to secure consensus. To verify the effectiveness of the proposed method, we analyze the vulnerabilities of BESSs when controlled according to traditional schemes vs. smart-contract enabled control. Simulation results show that if individual BESSs achieve a certain maximum threshold of exploitability, then the network of distributed BESSs is more robust to cyber-attacks in smart contract-defined control.
Abeer ElBahrawy, Laura Alessandretti, Leonid Rusnac, Daniel Goldsmith · 6 authors
Dark markets are commercial websites that use Bitcoin to sell or broker transactions involving\ndrugs, weapons, and other illicit goods. Being illegal, they do not offer any user protection, and\nseveral police raids and scams have caused large losses to both customers and vendors over the past\nyears. However, this uncertainty has not prevented a steady growth of the dark market phenomenon\nand a proliferation of new markets. The origin of this resilience have remained unclear so far, also due\nto the difficulty of identifying relevant Bitcoin transaction data. Here, we investigate how the dark\nmarket ecosystem re-organises following the disappearance of a market, due to factors including raids\nand scams. To do so, we analyse 24 episodes of unexpected market closure through a novel datasets\nof 133 million Bitcoin transactions involving 31 dark markets and their users, totalling 4 billion USD.\nWe show that coordinated user migration from the closed market to coexisting markets guarantees\noverall systemic resilience beyond the intrinsic fragility of individual markets. The migration is\nswift, efficient and common to all market closures. We find that migrants are on average more active\nusers in comparison to non-migrants and move preferentially towards the coexisting market with\nthe highest trading volume. Our findings shed light on the resilience of the dark market ecosystem\nand we anticipate that they may inform future research on the self-organisation of emerging online\nmarkets.
Ferenc Béres, István András Seres, András A. Benczúr
Lightning Network (LN) is designed to amend the scalability and privacy issues of Bitcoin. It's a payment channel network where Bitcoin transactions are issued off chain, onion routed through a private payment path with the aim to settle transactions in a faster, cheaper, and private manner, as they're not recorded in a costly-to-maintain, slow, and public ledger. In this work, we design a traffic simulator to empirically study LN's transaction fees and privacy provisions. The simulator relies on publicly available data of the network structure and generates transactions under assumptions we attempt to validate based on information spread by certain blog posts of LN node owners. Our findings on the estimated revenue from transaction fees are in line with widespread opinion that participation is economically irrational for the majority of large routing nodes who currently hold the network together. Either traffic or transaction fees must increase by orders of magnitude to make payment routing economically viable. We give worst-case estimates for the potential fee increase by assuming strong price competition among the routers. We estimate how current channel structures and pricing policies respond to a potential increase in traffic, how reduction in locked funds on channels would affect the network, and show examples of nodes who are estimated to operate with economically feasible revenue. Even if transactions are onion routed, strong statistical evidence on payment source and destination can be inferred, as many transaction paths only consist of a single intermediary by the side effect of LN's small-world nature. Based on our simulation experiments, we quantitatively characterize the privacy shortcomings of current LN operation, and propose a method to inject additional hops in routing paths to demonstrate how privacy can be strengthened with very little additional transactional cost.
Recently, blockchain technology has become a topic in the spotlight but also a hotbed of various cybercrimes. Among them, phishing scams on blockchain have been found making a notable amount of money, thus emerging as a serious threat to the trading security of the blockchain ecosystem. In order to create a favorable environment for investment, an effective method for detecting phishing scams is urgently needed in the blockchain ecosystem. To this end, this paper proposes an approach to detect phishing scams on Ethereum by mining its transaction records. Specifically, we first crawl the labeled phishing addresses from two authorized websites and reconstruct the transaction network according to the collected transaction records. Then, by taking the transaction amount and timestamp into consideration, we propose a novel network embedding algorithm called trans2vec to extract the features of the addresses for subsequent phishing identification. Finally, we adopt the oneclass support vector machine (SVM) to classify the nodes into normal and phishing ones. Experimental results demonstrate that the phishing detection method works effectively on Ethereum, and indicate the efficacy of trans2vec over existing state-of-the-art algorithms on feature extraction for transaction networks. This work is the first investigation on phishing detection on Ethereum via network embedding and provides insights into how features of large-scale transaction networks can be embedded.
Miss. Komal Kundan Sharma, Jyoti Raghatwan, Prof. Mrunalinee Patole, Prof. Vina M. Lomte
Nowadays, crypto currency has become a trending theme within the software package globe. Crypto currency may be a digital quality that’s meant to operate as a dealings medium that utilizes sturdy cryptography to secure asset exchange and make sure plus transfer. Crypto currency is in addition spoken as digital suburbanised cash. Block chain stores knowledge concerning dealings which will be accustomed assess transaction trait. This voting system deals with multi chain block chain technology. We can define block chain as a digital transaction which is used to record financial transactions also as totally different transactions. As a result of the knowledge keep within the block chain isn’t related to personal identifiable information, it’s such a fanonymity attribute. Blockchain allows dealings and verification to be clear. The options of this block chain technology are useful in powerful voting system,robustness, obscurity and transparency. The electoral system is our country’s core. Veri- fication of fingerprints employed in this theme to authenticate identity of electors.
Marcelo Jasmim Meiriño, Mírian Picinini Méxas, Alexandre do Valle Faria, Rodrigo Picinini Méxas · 5 authors
Goal: The objective of this article is to raise the state of the art of the applications of blockchain described in the scientific literature.
 Design/methodology/approach: A bibliographic research on the Scopus database was carried out from November, 2017 to May, 2018, supported by the scientific research technique called Bibliometry. The compilation of 102 articles found in the scientific literature were presented in the Blockchain context, providing a reference for the fields of blockchain applications.
 Results: The results indicate a large increase in the number of articles published since 2017, the largest number of publications were written by authors affiliated with institutions located in China, as well as the most referenced applications are related to cryptocurrencies, smart contracts and IoT.
 Limitations of the investigation: The limitation lies in using only the Scopus database for bibliometry, despite being a renowned scientific base.
 Practical implications: This study can serve as a bibliographic reference with a global view of the main Blockchain applications that can be applied by different types of organizations
 Originality/value: Blockchain is a technology that aims to securely store data, such as financial data, contracts, proof of identity, documents of possession, medical information, etc. To do so, a framework based on laws of mathematics and cryptography is used to ensure the security of transactions of different applications, such as Bitcoin, which is a digital currency that guarantees the safe transfer of financial data. However, being a new technology, there is still little research on the subject. On the other hand, there are different types of applications that are already benefiting from the blockchain structure.