Non-linearity is characterized by an asymmetric mean-reverting property, which has been found to be inherent in the short-term return dynamics of stocks. In this paper, we explore as to whether cryptocurrency returns, as represented by Bitcoin, exhibit similar asymmetric reverting patterns for minutely, hourly, daily and weekly returns between June 2010 and February 2018. We identify several differences in the behavior of Bitcoin price returns in the pre-and post-$1,000 sub-periods and evidence of asymmetric reverting patterns in the Bitcoin price returns under all the ANAR models employed, regardless of the data frequency considered. We also present evidence indicating stronger reverting behavior of negative price returns in terms of both reverting speed and magnitude compared to positive returns and evidence of positive serial correlation with prior positive price returns. Finally, we also investigated asymmetries in Bitcoin price return series’ persistence by employing higher order ANAR models, finding evidence of a higher persistence of positive returns than negative returns, a result that further supports the existence of asymmetric reverting behavior in the Bitcoin price returns.
Trading of Bitcoin is spread about multiple venues where buying and selling is offered in various currencies. However, all markets trade one common good and by the law of one price, the different prices should not deviate in the long run. In this context we are interested in which platform is the most important one in terms of price discovery. To this end, we use a pairwise approach accounting for a potential impact of exchange rates. The contribution to price discovery is measured by Hasbrouck's and Gonzalo and Granger's information share. We then derive an ordering with respect to the importance of each market which reveals that the Chinese OKCoin platform is the leader in price discovery of Bitcoin, followed by BTC China.
Aim/Purpose: This paper explored the factors (enablers and barriers) that affect Bitcoin adoption in South Africa, a Sub-Saharan country with the high potential for Bitcoin adoption. Background: In recent years, Bitcoin has seen a rapid growth as a virtual cryptocurrency throughout the world. Bitcoin is a protocol which allows value to be exchanged over the internet without a central bank or intermediary. Cryptocurrencies such as Bitcoin are technological tools that arguably can contribute to reducing transactions costs. This paper explored the factors that affect Bitcoin adoption in South Africa, a Sub-Saharan country with the high potential for Bitcoin adoption, as little is known about the factors that affect Bitcoin adoption and the barriers to adoption. Methodology: A quantitative questionnaire was distributed to South African virtual communities where Bitcoin is a topic of interest, and 237 quantitative responses were received, along with 212 open-ended comments. Contribution: This research contributes to the body of knowledge in information systems by providing insights into factors that affect Bitcoin adoption in South Africa. It raises awareness of incentives and barriers to Bitcoin adoption at a time when financial literacy is a crucial issue both in South Africa and worldwide. Findings: The results indicate that perceived benefit, attitude towards Bitcoin, subjective norm, and perceived behavioral control directly affected the participants’ intentions to use Bitcoin. Perceived benefit, usefulness, ease of use, and trust-related risk were found to indirectly affect intention to use Bitcoin. Further, it emerges that the barriers to Bitcoin adoption in South Africa consist of the complex nature of Bitcoin and its high degree of volatility. Recommendations for Practitioners: Bitcoin can contribute to reducing transactions costs, but factors that affect adoption and the barriers to adoption should be taken into consideration. These findings can inform systems and software developers to develop applications that make managing Bitcoin keys and transacting using Bitcoin less complex and more intuitive for end users. Recommendation for Researchers: Bitcoin adoption in South Africa is a topic that has not been previously researched. Researchers could research similarities or differences in the various constructs that were used in this research model. Impact on Society: South African Bitcoin users consider it as a universal currency that makes cross-border payments cheaper. A large number of refugees and workers in South Africa make regular payments across borders. Bitcoin could reduce the costs of these transfers. Future Research: Future research could explore Bitcoin (and other cryptocurrencies) adoption in other developing countries. Researchers could look at factors that influence cryptocurrency adoption in general. The factors affecting adoption of other cryptocurrencies can be compared to the results of this study, and similarities and differences can thus be identified.
The blockchain could be the most consequential development in information technology since the Internet. Created to support the Bitcoin digital currency, the blockchain is actually something deeper: a novel solution to the age-old human problem of trust. Its potential is extraordinary. Yet, this approach may not promote trust at all without effective governance. Wholly divorced from legal enforcement, blockchain-based systems may be counterproductive or even dangerous. And they are less insulated from the law’s reach than it seems. The central question is not how to regulate blockchains but how blockchains regulate. They may supplement, complement, or substitute for legal enforcement. Excessive or premature application of rigid legal obligations will stymie innovation and forego opportunities to leverage technology to achieve public policy objectives. Blockchain developers and legal institutions can work together. Each must recognize the unique affordances of the other system.
Gokhan Sagirlar, Barbara Carminati, Elena Ferrari, John Sheehan · 5 authors
From its early days the Internet of Things (IoT) has evolved into a decentralized system of cooperating smart objects with the requirement, among others, of achieving distributed consensus. Yet, current IoT platform solutions are centralized cloud based computing infrastructures, manifesting a number of significant disadvantages, such as, among others, high cloud server maintenance costs, weakness for supporting time-critical IoT applications, security and trust issues. Enabling blockchain technology into IoT can help to achieve a proper distributed consensus based IoT system that overcomes those disadvantages. While this is an ideal match, it is still a challenging endeavor. In this paper we take a first step towards that goal by designing Hybrid-IoT, a hybrid blockchain architecture for IoT. In Hybrid-IoT, subgroups of IoT devices form PoW blockchains, referred to as PoW sub-blockchains. Then, the connection among the PoW sub-blockchains employs a BFT inter-connector framework, such as Polkadot or Cosmos. In this paper, we focus on the PoW sub-blockchains formation, guided by a set of guidelines based on a set of dimensions, metrics and bounds. In order to prove the validity of the approach we carry on a performance and security evaluation.
Shi-Cho Cha, Jyun-Fu Chen, Chunhua Su, Kuo‐Hui Yeh
Recently, the popularity of the Internet of Things (IoT) has led to a rapid development and significant advancement of ubiquitous applications seamlessly integrated within our daily life. Owing to the accompanying growth of the importance of privacy, a great deal of attention has focused on the issues of secure management and robust access control of IoT devices. In this paper, we propose the design of a blockchain connected gateway which adaptively and securely maintains user privacy preferences for IoT devices in the blockchain network. Individual privacy leakage can be prevented because the gateway effectively protects users' sensitive data from being accessed without their consent. A robust digital signature mechanism is proposed for the purposes of authentication and secure management of privacy preferences. Furthermore, we adopt the blockchain network as the underlying architecture of data processing and maintenance to resolve privacy disputes.
Xiaohong Huang, Cheng Xu, Pengfei Wang, Hongzhe Liu
The Internet of Energy (IoE) provides an effective networking technology for distributed green energy, which allows the connection of energy anywhere at any time. As an important part of the IoE, electric vehicles (EVs), and charging pile management are of great significance to the development of the IoE industry. Previous work has mainly focused on network performance optimization for its management, and few studies have considered the security of the management between EVs and charging piles. Therefore, this paper proposes a decentralized security model based on the lightning network and smart contract in the blockchain ecosystem; this proposed model is called the lightning network and smart contract (LNSC). The overall model involves registration, scheduling, authentication, and charging phases. The new proposed security model can be easily integrated with current scheduling mechanisms to enhance the security of trading between EVs and charging piles. Experimental results according to a realistic infrastructure are presented in this paper. These experimental results demonstrate that our scheme can effectively enhance vehicle security. Different performances of LNSC-based scheduling strategies are also presented.
Carlos Molina-Jiménez, Ellis Solaiman, Ioannis Sfyrakis, Irene C. L. Ng · 5 authors
In this paper we discuss how conventional business contracts can be converted into smart contracts---their electronic equivalents that can be used to systematically monitor and enforce contractual rights, obligations and prohibitions at run time. We explain that emerging blockchain technology is certainly a promising platform for implementing smart contracts but argue that there is a large class of applications, where blockchain is inadequate due to performance, scalability, and consistency requirements, and also due to language expressiveness and cost issues that are hard to solve. We explain that in some situations a centralised approach that does not rely on blockchain is a better alternative due to its simplicity, scalability, and performance. We suggest that in applications where decentralisation and transparency are essential, developers can advantageously combine the two approaches into hybrid solutions where some operations are enforced by enforcers deployed on--blockchains and the rest by enforcers deployed on trusted third parties.
Interacting with Ethereum smart contracts can have potentially devastating financial consequences. In light of this, several regulatory bodies have called for a need to audit smart contracts for security and correctness guarantees. Unfortunately, auditing smart contracts that do not have readily available source code can be challenging, and there are currently few tools available that aid in this process. Such contracts remain opaque to auditors. To address this, we present Erays, a reverse engineering tool for smart contracts without the need for source code. Erays takes in smart contract from the Ethereum blockchain and produces high-level pseudocode suitable for manual analysis. We show how Erays can be used to provide insight into several contract properties, such as code complexity and code reuse in the ecosystem. We then leverage Erays to link contracts with no previously available source code to public source code, thus reducing the overall opacity in the ecosystem. Finally, we demonstrate how Erays can be used for reverse-engineering in four case studies: high-value multi-signature wallets, arbitrage bots, exchange accounts, and finally, a popular smart-contract game, Cryptokitties. We conclude with a discussion regarding the value of reverse engineering in the smart contract ecosystem, and how Erays can be leveraged to address the challenges that lie ahead.
Smart contracts, self-executing agreements based on blockchain technology, have the capacity to create trust in what we term no-trust contracting environments. We argue that using them in such environments is the path to unleash the full potential of smart contracts. Compared to the contract enforcement mechanisms characterized by traditional contract law or relational contracts, smart contracts can offer a superior solution for facilitating trade.
Several lawyers and economists have debated whether smart contracts might offer the prospect of cheaper, faster and better transactions. As we discuss below, contract law scholars caution that they neither replicate the relational context essential for the day-to-day practice of contracting nor offer a superior solution to problems addressed by traditional contract law, such as contract validity and legality. We clarify and systematize the current thinking on the legal nature and reliability of smart contracts, and address the concerns of contract law scholars. While doing that, we suggest a step forward in characterizing contracting environments, contract enforcement mechanisms and the trust relationship underlying contracts.
In this paper, we propose a novel blockchain‐based contractual routing (BCR) protocol for a network of untrusted IoT devices. In contrast to conventional secure routing protocols in which a central authority (CA) is required to facilitate the identification and authentication of each device, the BCR protocol operates in a distributed manner with no CA. The BCR protocol utilizes smart contracts to discover a route to a destination or data gateway within heterogeneous IoT networks. Any intermediary device can guarantee a route from a source IoT device to a destination device or gateway. We compare the performance of BCR with that of the Ad-hoc On‐Demand Distance Vector (AODV) routing protocol in a network of 14 devices. The results show that the routing overhead of the BCR protocol is 5 times lower compared to AODV at the cost of a slightly lower packet delivery ratio. BCR is fairly resistant to both Blackhole and Greyhole attacks. The results show that the BCR protocol enables distributed routing in heterogeneous IoT networks.
Current shareholder engagement systems face large classical inefficiencies. First, due to the large chains of intermediaries in the current securities models, transaction costs are high and shareholder votes and other information are not always correctly transmitted between shareholders and issuers. Recent cases including DNick Holding and T. Rowe Price show the ‘absurdness’ of the current systems. The Shareholder Rights Directive II addresses these problems and the Implementing Regulation already hints at modern technologies to increase the transparency and verifiability of shareholder engagement. Next, the current shareholder engagement system enables different opportunities for different types of shareholders, creating inequalities and hindering shareholder democracy. The solution to these substantial problems lies in a state-of-the-art technology: in this contribution we argue that blockchain technology can solve these current inefficiencies that shareholders and companies face. Using a permissioned blockchain, information can be stored in a verifiable and immutable way, with a consensus mechanism tailored to its purpose. The large amount of initiatives and prototypes of blockchain proxy voting and trading, including the legislative initiatives that were initiated in the past 2 years, show the merits of using this state-of-the-art technology. The Europe Union should incorporate this technology in its legislation, like the CSD regulation, for remaining technology-proof in this globalized market.
Balázs Bodó, Daniel J. Gervais, João Pedro Quintais
This article offers a normative analysis of key blockchain technology concepts from the perspective of copyright law. Some features of blockchain technologies—scarcity, trust, transparency, decentralized public records and smart contracts—seem to make this technology compatible with the fundamentals of copyright. Authors can publish works on blockchain creating a quasi-immutable record of initial ownership, and encode ‘smart’ contracts to license the use of works. Remuneration may happen on online distribution platforms where the smart contracts reside. In theory, such an automated setup allows for the private ordering of copyright. Blockchain technology, like Digital Rights Management 20 years ago, is thus presented as an opportunity to reduce market friction, and increase both licensing efficiency and the autonomy of creators. Yet, some of the old problems remain. The article examines the differences between new, smart-contract-based private ordering regime and the fundamental components of copyright law, such as exceptions and limitations, the doctrine of exhaustion, restrictions on formalities, the public domain and fair remuneration.
There is an immense need of a proof of delivery (PoD) of today's digital media and content, especially those that are subject to payment. Current PoD systems are mostly centralized and heavily dependent on a trusted third party (TTP) especially for payment. Such existing PoD systems often lack security, transparency, and visibility, and are not highly credible, as the TTP can be subject to failure, manipulation, corruption, compromise, and hacking. In this paper, we propose a decentralized PoD solution for PoD of digital assets. Our solution leverages key features of blockchain and Ethereum smart contracts to provide immutable and tamper-proof logs, accountability, and traceability. Ethereum smart contracts are used to orchestrate and govern all interactions and transactions including automatic payments in Ether cryptocurrency between customers, digital-content provider, and the file server hosting the digital content. All entities are incentivized to act honestly, and our solution has a mechanism to handle dispute if arisen among participants. The solution has an off-chain secure download phase involving the file server and customers. Moreover, our solution leverages the benefits of interplanetary file system to store the agreed upon terms and conditions between the smart contract actors. A security analysis of our proposed system has been provided. The full code of the smart contract has been publicly made available on Github.
Open access
Blockchain Technology Applications and Security
FinTech, Crowdfunding, Digital Finance
Advanced Steganography and Watermarking Techniques
Blockchain-based smart contracts are emerging as a disruptive force that may change the way financial statement audits are performed and delivered. With their potential ability to autonomously execute audit procedures on behalf of the auditor and disclose the results of these audit procedures, blockchain-based smart contracts have the potential to improve audit quality and meet the information demands of various vested parties for more timely and transparent audit reporting. This paper proposes the application of smart contracts to auditing as an enabler for improved audit data analytics and close to real-time audit reporting.
The role-based access control (RBAC) framework is a mechanism that describes the access control principle. As a common interaction, an organization provides a service to a user who owns a certain role that was issued by a different organization. Such trans-organizational RBAC is common in face-toface communication but not in a computer network, because it is difficult to establish both the security that prohibits the malicious impersonation of roles and the flexibility that allows small organizations to participate and users to fully control their own roles. In this paper, we present an RBAC using smart contract (RBAC-SC), a platform that makes use of Ethereum's smart contract technology to realize a trans organizational utilization of roles. Ethereum is an open blockchain platform that is designed to be secure, adaptable, and flexible. It pioneered smart contracts, which are decentralized applications that serve as “autonomous agents”running exactly as programmed and are deployed on a blockchain. The RBAC-SC uses smart contracts and blockchain technology as versatile infrastructures to represent the trust and endorsement relationship that are essential in the RBAC and to realize a challenge-response authentication protocol that verifies a user's ownership of roles. We describe the RBAC-SC framework, which is composed of two main parts, namely, the smart contract and the challenge-response protocol, and present a performance analysis. A prototype of the smart contract is created and deployed on Ethereum's Testnet blockchain, and the source code is publicly available.
A smart contract is hard to patch for bugs once it is deployed, irrespective of the money it holds. A recent bug caused losses worth around $50 million of cryptocurrency. We present ZEUS-a framework to verify the correctness and validate the fairness of smart contracts. We consider correctness as adherence to safe programming practices, while fairness is adherence to agreed upon higher-level business logic. ZEUS leverages both abstract interpretation and symbolic model checking, along with the power of constrained horn clauses to quickly verify contracts for safety. We have built a prototype of ZEUS for Ethereum and Fabric blockchain platforms, and evaluated it with over 22.4K smart contracts. Our evaluation indicates that about 94.6% of contracts (containing cryptocurrency worth more than $0.5 billion) are vulnerable. ZEUS is sound with zero false negatives and has a low false positive rate, with an order of magnitude improvement in analysis time as compared to prior art.
The question of regulation in the domain of cryptocurrencies has been tackled in various ways, exhibiting therein a desire to strike a balance between fostering innovation and promoting oversight. This chapter examines the case of BitLicense, issued by the New York Department of Financial Services (DFS), with the aim of contextualizing the relative merits of regulatory and oversight initiatives in the domain of cryptocurrencies. This includes an examination of the impact and critiques regarding BitLicense since its promulgation, along with the use of perspectives from public value theory (PVT) to contextualize the value creation efforts of the DFS using BitLicense as a regulatory instrument. The findings of the chapter suggest that contrasting views exist on the value creation of cryptocurrency regulations, and this is reflected both in a PVT approach as well as the evolving praxis of virtual currency regulatory and oversight efforts.
Shaen Corbet, Charles Larkin, Brian M. Lucey, Larisa Yarovaya
Eastman Kodak is an American technology company that produces imaging products. In 2018, it announced its intentions to enter the crytpocurrency market, raising concerns that it could be taking advantage of a potential cryptocurrency bubble for short-term gains. We analyse the relationships between Kodak, crytocurrency and stock market index returns. We find evidence of a significant, sustained increase in both the share price and price volatility of Kodak after the KODAKCoin announcement, with an increased correlation between the price of Kodak shares and Bitcoin.