Blockchain gaming is an emerging entertainment paradigm. However, blockchain games are still suffering from security issues, due to the immature blockchain technologies and its unsophisticated developers. In this work, we analyzed the blockchain game architecture and reveal the possible penetration methods of cracking. We scanned more than 600 commercial blockchain games to summarize a security overview from the perspective of the web server and smart contract, respectively. We also conducted three case studies for blockchain games to show detailed vulnerability detection.
With the growth in popularity for cryptocurrencies the need for privacy preserving blockchains is growing as well. Zcash is such a blockchain, providing transaction privacy through zero-knowledge proofs. In this paper we analyze transaction linkability in Zcash based on the currency minting transactions (mining). Using predictable usage patterns and clustering heuristics on mining transactions an attacker can link to publicly visible addresses over 84% of the volume of the transactions that use a ZK-proof. Since majority of Zcash transactions are not yet using ZK-proofs, we show that overall 95.5% of the total number of Zcash transactions are potentially linkable to public addresses by just observing the mining activity.
The following topics are dealt with: data privacy; security of data; cryptography; Internet of Things; Internet; computer network security; contracts; authorisation; cryptocurrencies; cloud computing.
The purpose of the research is to improve the methodological approach to assessing the financial security of the region in the context of decentralization, which, unlike the existing ones, makes it possible to determine the ways of ensuring the financial security of the regions through an integrated assessment of the contribution of individual factors and types of regulation to the final state of the financial security of the territories. Methodology. The methodological approach to the assessment of the financial security of the region under decentralization has been improved based on the application of normalization of the system of indicators and construction of integral indices by the type of impact indicator (exogenous or endogenous) and factors: decentralization, socio-economic status and fiscal policy of the regions. Individual time series have been identified and evaluated for each of these integrated indicators. Results. Based on the research, the methodological approach to the assessment of the financial security of the region under decentralization conditions has been improved, which makes it possible to determine the ways of ensuring the financial security of the regions by assessing the contribution of individual factors and types of regulation to the financial security. These individual contributions are grouped together to reflect the type of impact indicator (exogenous or endogenous) and factors such as decentralization, socio-economic status and fiscal policies of the regions. The categories of integrated indicators proposed in the article are useful for monitoring financial security drivers, making it clear what affects the financial security of a country under decentralization, how systemic events in the process of decentralization affect the financial security of regions over time. Practical meaning. The research identified three groups of regions of Ukraine in terms of their financial security: financially secure regions, which during the entire observation period were ascertained: a high integral financial security index (Dnipropetrovsk, Kyiv regions) and a sufficient integral financial security index (Lviv, Zaporizhzhya, Odesa, Poltava and Kharkiv regions); financially unstable regions where there is a potential for strengthening financial security (Vinnytsia, Donetsk, Kirovohrad, Mykolaiv, Cherkasy regions), but there is also a likelihood of aggravation of a negative financial situation (Ivano-Frankivsk, Zhytomyr, Sumy, Kherson, Khmelnytsky, Chernihiv regions); financially dangerous regions, which are dependent on state support, are not able to independently fulfill the majority of delegated to the local level of authority and to finance the economic development of the region (Volyn, Luhansk, Transcarpathian, Rivne, Ternopil, Chernivtsi regions). Therefore, the advantage of using this system of integrated indicators is that they give the developers of national regional policy and internal regional policy an up-to-date picture of the financial security situation in the region, wider than that provided only by some unsystematic indicators. Prospects for further research. The prospect for further research should be to improve methodological support for the financial security of Ukrainian regions.
Since their creation in 2009, crypto-assets have evolved from niche products into assets held and used much more widely. These assets pose challenges for policymakers and tax administrations, because, as pointed out by the OECD, they can be transferred and held without the participation of traditional financial intermediaries and without central administrators being aware of the transactions carried out or the location of crypto-assets holdings.
 On the indirect taxation side, the VAT Committee discussed the issues relating to the VAT treatment of crypto-assets and, in particular, of cryptocurrencies, on several occasions. The discussion on the most recent of the working papers on this subject, No. 1037 on the VAT treatment of crypto-assets, resulted in the adoption of the Guidelines which aim at harmonising tax administrations’ practice regarding the VAT implications of the different transactions linked to crypto-assets.
 The article highlights the main challenges posed by cryptocurrencies in terms of VAT while focusing on the main supplies with the use of cryptocurrencies and their qualification for the VAT purposes. Those transactions range from the creation, verification, validation, and supply of cryptocurrencies through their modification, storage, transfer, to exchange. The article explains in this context the position of the VAT Committee reflected in the Guidelines.
We’ll see the same kind of Cambrian explosion we witnessed in the web world once we started using mutualized infrastructure in public clouds and frameworks. It took only three weeks to learn enough Ruby on Rails and Heroku to push out the first version of a management system for that brokerage. And that’s because I had to think only about the models, the views, and the controllers. The hardest part, of course, had to do with building a secure wallet.
Electronic transactions with cryptocurrency systems based on blockchain in our days have become very popular due to the good reputation of this technology. However, that good reputation cannot deny the serious anomalies and the risks that can cause these cryptocurrencies. In this work, we propose a new model for anomaly detection over bitcoin electronic transactions. We used in our proposal two machine learning algorithms, namely the One Class Support Vector Machines (OCSVM) algorithm to detect outliers and the K-Means algorithm in order to group the similar outliers with the same type of anomalies. We evaluated our work by generating detection results and we obtained high performance results on accuracy.
Kaihua Qin, Hadass, Henryk, Arthur Gervais, Joel Reardon
Lightweight Bitcoin clients execute a Simple Payment Verification (SPV) protocol to verify the validity of transactions related to a particular user. Currently, lightweight clients \nuse Bloom filters to significantly reduce the amount of bandwidth \nrequired to validate a particular transaction. This is despite the \nfact that research has shown that Bloom filters are insufficient \nat preserving the privacy of clients’ queries. \nIn this paper we describe our design of an SPV protocol \nthat leverages Private Information Retrieval (PIR) to create fully \nprivate and performant queries. We show that our protocol has \na low bandwidth and latency cost; properties that make our \nprotocol a viable alternative for lightweight Bitcoin clients and \nother cryptocurrencies with a similar SPV model. In contract \nto Bloom filters, our PIR-based approach offers deterministic \nprivacy to the user. \nAmong our results, we show that in the worst case, clients who \nwould like to verify 100 transactions occurring in the past week \nincurs a bandwidth cost of 33.54 MB with an associated latency \nof approximately 4.8 minutes, when using our protocol. The \nsame query executed using the Bloom-filter-based SPV protocol \nincurs a bandwidth cost of 12.85 MB; this is a modest overhead \nconsidering the privacy guarantees it provides.
Maximilian Tschuchnig, Dejan Radovanovic, Eduard Hirsch, Oberluggauer Anna-Maria · 5 authors
Conventional data storage methods like SQL and NoSQL offer a huge amount of possibilities with one major disadvantage, having to use a centralized authority. This authority may be in the form of a centralized or decentralized master server or a permissioned peer-to-peer setting. This paper looks at different technologies on how to persist data without using a central authority, mainly looking at permissionless peer-to-peer networks, primarily Distributed Ledger Technologies (DLTs) and a combination of DLTs with conventional databases. Afterwards it is shown how a system like this might be implemented in two prototypes which are then evaluated against conventional databases.
Tadas Limba, Andrius Stankevičius, Antanas Andrulevičius
Bitcoin, Cryptocurrencies and Blockchain technologies are widely discussed nowadays. The Bitcoin market value is discussed in top magazines, the names of people who earned money from cryptocurrencies are on the Richest People list. The Blockchain technology is said to be a one of disruption pioneers on the one hand, and cryptocurrency is said to be an illegal phenomenon on the other hand. The Fourth Industrial Revolution, which is based on digitalized industry is changing the power centres. Will cryptocurrency disrupt the financial sector? Or perhaps it will disrupt the retail market or global monetary policy. Disruptive technologies together with the Internet, Mobile Internet and Internet of Things are changing our world. While society has gained simple and reachable comfort for a cheaper price on the one hand, many people have lost their jobs on the other. Consequently, the authors presuppose discussion about the phenomenon of cryptocurrency through the context of social phenomena and legal regulation: divulge definitions, principles, relating to the topic; identify possible tendencies according to legal regulation and its practical realization.
O.S. Bolotaeva, Алла Степанова, Світлана Алексеева
This article examines the legal nature of cryptocurrency. Comprehensive analysis is conducted on the legal nature of digital currency; its correlation with the traditional money and e-money is determined. The author summarizes and systematizes the opinions of the scholars on these issues, as well as the existing legislation. The object of this research is the public relations arising process of functionality of crypto technologies and with regards to such the phenomenon of cryptocurrency in Russia. The subject of this research is the Constitution of the Russian Federation, normative legal acts that comprise the current legislation of the Russian Federation, as well as scientific works dedicated to the public relations in this sphere. The goal lies in examination and revelation of the financial legal essence of cryptocurrency, its legal nature and role among the objects of civil rights. The conclusion is made that the states will act towards the implementation of cryptocurrency into the economy. Digital currency is a promising trends of development and investment. The question of legal regulation and consolidation of the status of cryptocurrency remains important and relevant for not only Russia or any country, but the entire world community. The economy that is based on cryptocurrency has good chances to become a reality on the global scale.
The paper proposes the link between cryptocurrency implementation in the financial sector and energy consumption worldwide. The underlying mechanism of this blockchain infrastructure is described, practical cases of its adoption in various segments of the financial sector are provided. This paper tries to explain the power consumption of the cryptocurrency mining at the case of Bitcoin, Ethereum, Monero, Litecoin. Since mining is not regulated by the state, and even banned in some countries, it is difficult to find accurate data on how much electricity is spent on it. Method of Herfindahl–Hirschman is used for efficiency estimate of crypto market.Keywords: energy consumption, mining pools, bitcoin, blockchain, cryptocurrency, cloud mining.JEL Classifications: G32, G34, O33.DOI: https://doi.org/10.32479/ijeep.7685
A blockchain is a tamper-proof distributed transaction registry; first popularized by Bitcoin [1], it has now been extended to support storage of arbitrary state and computations in-ledger. Ethereum [2] and its smart contract model have proven to be a very popular choice for this task, routinely managing assets valued in the billions. However, development of such contracts has been anything but easy. While formally specified, the Ethereum execution platform is based on a low-level machine, quite similar to assembly; semantics for contract operations such as call are quite complex, and the need for resource management creates unanticipated modes of failure. The dominant day-to-day programming platform for Ethereum is Solidity [3], an Object-Oriented language that identifies contracts with objects. While reasoning about Solidity programs is much easier than for their bytecode counterparts, it is not extent of challenges either, and moreover, Solidity lacks a source-level semantics, which forces developers to reason over output bytecode again. In this short paper we explore the main barriers to lift in order to achieve a principled compilation strategy for Solidity. We will review the standard concepts on verified and secure compilation, and frame them in the context of the Ethereum platform.
We develop a strong diagnostic for bubbles and crashes in Bitcoin, by analysing the coincidence (and its absence) of fundamental and technical indicators. Using a generalized Metcalfe's Law based on network properties, a fundamental value is quantified and shown to be heavily exceeded, on at least four occasions, by bubbles that grow and burst. In these bubbles, we detect a universal super-exponential unsustainable growth. We model this universal pattern with the Log-Periodic Power Law Singularity (LPPLS) model, which parsimoniously captures diverse positive feedback phenomena, such as herding and imitation. The LPPLS model is shown to provide an ex ante warning of market instabilities, quantifying a high crash hazard and probabilistic bracket of the crash time consistent with the actual corrections; although, as always, the precise time and trigger (which straw breaks the camel's back) is exogenous and unpredictable. Looking forward, our analysis identifies a substantial but not unprecedented overvaluation in the price of Bitcoin, suggesting many months of volatile sideways Bitcoin prices ahead (from the time of writing, March 2018).
Bitcoin, introduced in 2008 and launched in 2009, is the first digital currency to solve the double spending problem without relying on a trusted third party. Bitcoin provides a way to transact without any trusted intermediary, but its privacy guarantees are questionable. Despite the fact that Bitcoin addresses are not linked to any identity, multiple deanonymization attacks have been proposed. Alternative cryptocurrencies such as Dash, Monero, and Zcash aim to provide stronger privacy by using sophisticated cryptographic techniques to obfuscate transaction data. Previous work in cryptocurrency privacy mostly focused on applying data mining algorithms to the transaction graph extracted from the blockchain. We focus on a less well researched vector for privacy attacks: network analysis. We argue that timings of transaction messages leak information about their origin, which can be exploited by a well connected adversarial node. For the first time, network level attacks on Bitcoin and the three major privacy-focused cryptocurrencies have been examined. We describe the message propagation mechanics and privacy guarantees in Bitcoin, Dash, Monero, and Zcash. We propose a novel technique for linking transactions based on transaction propagation analysis. We also unpack address advertisement messages (ADDR), which under certain assumptions may help in linking transaction clusters to IP addresses of nodes. We implement and evaluate our method, deanonymizing our own transactions in Bitcoin and Zcash with a high level of accuracy. We also show that our technique is applicable to Dash and Monero. We estimate the cost of a full-scale attack on the Bitcoin mainnet at hundreds of US dollars, feasible even for a low budget adversary.
Sebastian Henningsen, Daniel Teunis, Martin Florian, Björn Scheuermann
Ethereum is a decentralized Blockchain system that supports the execution of Turing-complete smart contracts. Although the security of the Ethereum ecosystem has been studied in the past, the network layer has been mostly neglected. We show that Go Ethereum (Geth), the most widely used Ethereum implementation, is vulnerable to eclipse attacks, effectively circumventing recently introduced (Geth v1.8.0) security enhancements. We responsibly disclosed the vulnerability to core Ethereum developers; the corresponding countermeasures to our attack where incorporated into the v1.9.0 release of Geth. Our false friends attack exploits the Kademlia-inspired peer discovery logic used by Geth and enables a low-resource eclipsing of long-running, remote victim nodes. An adversary only needs two hosts in distinct /24 subnets to launch the eclipse, which can then be leveraged to filter the victim's view of the Blockchain. We discuss fundamental properties of Geth's node discovery logic that enable the false friends attack, as well as proposed and implemented countermeasures.
Open access
3 source records
Peer-to-Peer Network Technologies
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Blockchain technology, and more specifically Bitcoin (one of its foremost applications), have been receiving increasing attention in the scientific community. The first publications with Bitcoin as a topic, can be traced back to 2012. In spite of this short time span, the production magnitude (1162 papers) makes it necessary to make a bibliometric study in order to observe research clusters, emerging topics, and leading scholars. Our paper is aimed at studying the scientific production only around bitcoin, excluding other blockchain applications. Thus, we restricted our search to papers indexed in the Web of Science Core Collection, whose topic is "bitcoin". This database is suitable for such diverse disciplines such as economics, engineering, mathematics, and computer science. This bibliometric study draws the landscape of the current state and trends of Bitcoin-related research in different scientific disciplines.
istributed ledger technology (DLT) and blockchain, and their headline-catching applications in cryptoassets and initial coin offerings (ICOs), have attracted extraordinary global attention. Alongside Bitcoin's spectacular rise and fall in the past few years, there has been an explosion of ICOs, a tokenization of assets, and fund-raising projects utilizing digital tokens issued and operated on blockchains.
This paper examines the way in which blockchain technology can be used to improve the verification of integrity of evidence in digital forensics. Some background into digital forensic practices and blockchain technology are discussed to provide necessary context. A particular scalable method of verifying point-in-time existence of a piece of digital evidence, using the OpenTimestamps (OTS) service, is described, and tests are carried out to independently validate the claims made by the service. The results demonstrate that the OTS service is highly reliable with a zero false positive and false negative error rate for timestamp attestations, but that it is not suitable for timesensitive timestamping due to the variance of the accuracy of timestamps induced by block confirmation times in the Bitcoin blockchain.
With data intensive computing helping advance state-of-the-art in varied fields, data provenance and lineage continue to remain formidable challenges in assisting with integrity and reproducibility in research and applications. This is particularly challenging for distributed scenarios, where data may be originating from decentralized sources without any centralized control by a single trusted entity. To date most of the data provenance systems are specific to particular domains, and are often centralized. Distributed ledgers such as blockchains have proved quite popular and effective in addressing trust and consensus without central control. There are a few recent proposals to employ blockchains for data provenance, however, they rely on currency in order to propose transactions using public blockchains.\n\nWe present HyperProv, a general framework for data provenance based on the permissioned blockchain Hyperledger Fabric (HLF), and to the best of our knowledge, the first provenance system that is ported to ARM based devices such as Raspberry Pi (RPi). HyperProv records the operation history and data lineage by tracking checksums, editors, timestamps, data pointers, dependencies, and more. Provenance data is retrieved and stored through a NodeJS client library to simplify interactions with the blockchain. HyperProv has a set of built-in queries using smart contracts that enable lightweight retrieval of large collections of provenance data. We evaluate the throughput, latency and resource consumption of HyperProv on x86-64 desktop machines, as well as RPi, demonstrating the feasibility of using HyperProv on RPi for tamperproof data provenance, useful in particular for Internet of Things use cases.
Block Chain is mainly used for Cryptocurrency i.e Digital Currency which is used in verification and currency units of Fund transfer are independently operated without a central bank. Characteristics of block chain are explained in this paper. There are 4 types of characteristics such as Decentralization, Persistency, Anonymity, and Audit ability. A Consensus algorithm is used in blockchain. Key factors of blockchain are introduced such as Decentralized & distributed, Secure, Next smart contract, consensus & immutable. Here block structure and hierarchical layer explained in blockchain example: Data Layer, Network Layer, Consensus Layer, and Incentive Layer, contract Layer & application Layer. , Also some features of blockchain are explained which are Public Distributed Ledger, mining, Proof of work and hash encryption. We have explained the types of blockchain viz. Public Blockchain, Private Block Chain & consortium. we have explained the applications of block chain.
This article discusses current developments in East Asia to more effectively use mediation with international commercial arbitration, supported by the 2019 United Nations Convention on International Settlement Agreements Resulting from Mediation (the “Singapore Convention”) and the UNCITRAL Model Law on International Commercial Mediation (the “UNCITRAL Model Mediation Law”), and by online dispute resolution using innovative technology (including artificial intelligence, machine learning, the internet of things, blockchain, distributed ledger technology and smart contracts). It discusses the background to the changing approach including the increasing pressure for arbitration to become a mechanism of last resort in international dispute resolution prompted by policy makers’ and users’ demands for cheaper , quicker and culturally more international dispute resolution and the changing sources of international investment, developments in international relations including the Belt and Road Initiative announced by China, and the initiatives being undertaken by various investment and trade communities including APEC, particularly focusing on micro, small and medium sized enterprises (each a “MSME”). This article briefly refers to the current status of online dispute resolution utilizing innovative technology, and the legal opportunities and challenges posed by it. Finally, it briefly refers to some neuroscience research relevant to dispute resolution.
The graduation certificate forgery has become a major problem in now a days and the lack of effective anti-forge mechanism, In order to solve the problem of counterfeiting certificates, the digital certificate system based on blockchain technology would be introduced. The system generate the electronic file of a paper certificate accompanying other related data into the database and calculates its hash value. It then store the hash value into the block in the chain system. The system will create a related QR-code and inquiry string code to affix to the paper certificate, this will verify the authenticity of the paper certificate through mobile phone scanning or website inquiries. By integrating the features of blockchain, the system improves the efficiency operations at each stage.