We present a new Bitcoin coin selection algorithm, "coin selection with leverage", which aims to improve upon cost savings than that of standard knapsack like approaches. Parameters to the new algorithm are available to be tuned at the users discretion to address other goals of coin selection. Our approach naturally fits as a replacement for the standard knapsack ingredient of full coin selection procedures.
This report argues that including proof-of-stake cryptocurrency block rewards in gross income when the reward tokens are first created results in inequitable taxation and would discourage U.S. taxpayers from participating in this new technology. The better approach is to tax reward tokens when they are sold or exchanged.
In this two-part report, Sutherland proposes a single taxation policy for all public cryptocurrencies. Focusing on the mechanics of proof-of-stake networks and the economic incentives underlying their maintenance, Sutherland, in the first installment, begins to make the case that reward tokens should be taxed when they are sold or exchanged, not when they’re created.
In the second installment, Sutherland explores options for the equitable taxation of cryptocurrency reward tokens based on existing policies and principles. He concludes that for both proof-of-work and proof-of-stake cryptocurrencies, the best approach is to tax reward tokens only when they are sold or exchanged.
Although cryptocurrency would benefit from legislative and regulatory clarity and certainty, the report also argues that in the meantime no act of Congress or new Treasury regulation is required to ensure the proper taxation of block rewards.
Suyash Gupta, Jelle Hellings, Sajjad Rahnama, Mohammad Sadoghi
Multi-party data management and blockchain systems require data sharing among participants. To provide resilient and consistent data sharing, transactions engines rely on Byzantine FaultTolerant consensus (BFT), which enables operations during failures and malicious behavior. Unfortunately, existing BFT protocols are unsuitable for high-throughput applications due to their high computational costs, high communication costs, high client latencies, and/or reliance on twin-paths and non-faulty clients. In this paper, we present the Proof-of-Execution consensus protocol (PoE) that alleviates these challenges. At the core of PoE are out-of-order processing and speculative execution, which allow PoE to execute transactions before consensus is reached among the replicas. With these techniques, PoE manages to reduce the costs of BFT in normal cases, while guaranteeing reliable consensus for clients in all cases. We envision the use of PoE in high-throughput multi-party data-management and blockchain systems. To validate this vision, we implement PoE in our efficient ResilientDB fabric and extensively evaluate PoE against several state-of-the-art BFT protocols. Our evaluation showcases that PoE achieves up-to-80% higher throughputs than existing BFT protocols in the presence of failures.
Recently, we saw the emergence of consensus-based database systems that promise resilience against failures, strong data provenance, and federated data management. Typically, these fully-replicated systems are operated on top of a primary-backup consensus protocol, which limits the throughput of these systems to the capabilities of a single replica (the primary). To push throughput beyond this single-replica limit, we propose concurrent consensus. In concurrent consensus, replicas independently propose transactions, thereby reducing the influence of any single replica on performance. To put this idea in practice, we propose our RCC paradigm that can turn any primary-backup consensus protocol into a concurrent consensus protocol by running many consensus instances concurrently. RCC is designed with performance in mind and requires minimal coordination between instances. Furthermore, RCC also promises increased resilience against failures. We put the design of RCC to the test by implementing it in ResilientDB, our high-performance resilient blockchain fabric, and comparing it with state-of-the-art primary-backup consensus protocols. Our experiments show that RCC achieves up to 2.75x higher throughput than other consensus protocols and can be scaled to 91 replicas.
The recent surge in blockchain applications and database systems has renewed the interest in traditional Byzantine Fault Tolerant consensus protocols (BFT). Several such BFT protocols follow a primary-backup design, in which a primary} replica coordinates the consensus protocol. In primary-backup designs, the normal-case operations are rather simple. At the same time, primary-backup designs place an unreasonable burden on primaries and allows malicious primaries to affect the system throughput substantially, however. To resolve this situation, we propose the MultiBFT paradigm, a protocol-agnostic approach towards improving the performance of primary-backup consensus protocols. At the core of MultiBFT is an approach to continuously order the client-transactions by running several instances of the underlying BFT protocol in parallel. We bring forth our paradigm to two well-established BFT protocols and demonstrate that the rendered parallelized protocols are not only safe and live but also significantly outperform, up to $2\times$, their original non-parallelized forms. Further, we show that our MultiBFT paradigm reaches a throughput of up to $320$K transactions per second.
Bitcoin is among the highest rated digital crypto-currency in financial investment markets. This technology relies on a backbone of distributed data architecture and peer-to-peer networking model called Blockchain. Unlike the current digital economy, which is governed centrally by financial institution or governments, Blockchain is fully autonomous without any third-party involvement. The exorbitant success of Bitcoin has attracted investors, scholars as well as organizations to peek into this lucrative technology for the possible application to other areas apart from crypto-currency. Blockchain can adopt Smart Contracts, which are digitally enabled contracts that can be executed and enforced fully or partially using pre-defined notions. The aim of this research is to investigate the synergy between Smart Contract and Blockchain to propose a digital framework for an academic paper publication model that has the capability to automate the entire process and challenge the existing system. It can also bring together all the stakeholders under the same system. The proposed model can further hold the stakeholders accountable for breach of contracts and/or reward them for executing the successes of terms pre-configured in the Smart Contract. The proposed model, called Digital Smart Publication or DSP (as referred in the document), is highly secure and ensures balance in distributing rewards to the involved stakeholders while keeping data integrity and security as paramount features.
Xiaolin Fu, Hong Wang, Zhi-Jie Wang, Zhong Shi · 6 authors
This paper aims to study the problems of surplus interaction, poor real-time performance, and excessive processing of information in the micro-grid scheduling and decision-making process. Firstly, the micro-grid dual-loop mobile topology structure is designed by using the method of block-chain and multi-agent fusion, realizing the real-time update of the decision-making body. Secondly, on the basis of optimizing the decision-making body, a two-layer model of intelligent decision-making under the decentralized mechanism is established. Aiming at the upper model, based on the theory of block-chain consensus mechanism, this paper proposes an improved evolutionary game algorithm. The maximum risk-benefit in the decision-making process is the objective function, which realizes the evaluation and optimization of decision tasks. For the lower layer model, based on the block-chain distributed ledger theory, this paper proposes an improved hybrid game reinforcement learning algorithm, with the maximum controllable load participation as the objective function, and realizes the optimal configuration of distributed energy in the micro-grid. This paper reveals the rules of group intelligent decision making in micro-grid under multi-task. Finally, the effectiveness of the proposed algorithm is verified by using Beijing Jin-feng Energy Internet Park data.
Bitcoin-NG, a scalable blockchain protocol, divides each block into a key block and many micro blocks to effectively improve the transaction processing capacity. Bitcoin-NG has a special incentive mechanism (i.e. splitting transaction fees to the current and the next leader) to maintain its security. However, this design of the incentive mechanism ignores the joint effect of transaction fees, mint coins and mining duration lengths on the expected mining reward. In this paper, we identify the advanced mining attack that deliberately ignores micro blocks to enlarge the mining duration length to increase the likelihood of winning the mining race. We first show that an advanced mining attacker can maximize its expected reward by optimizing its mining duration length. We then formulate a game-theoretical model in which multiple mining players perform advanced mining to compete with each other. We analyze the Nash equilibrium for the mining game. Our analytical and simulation results indicate that all mining players in the mining game converge to having advanced mining at the equilibrium and have no incentives for deviating from the equilibrium; the transaction processing capability of the Bitcoin-NG network at the equilibrium is decreased by advanced mining. Therefore, we conclude that the Bitcoin-NG blockchain protocol is vulnerable to advanced mining attack. We discuss how to reduce the negative impact of advanced mining for Bitcoin-NG.
Blockchain smart contracts are PC programs that can be adequately executed by an arrangement of ordinarily questioning center points, without the need of an external trusted in power. Since shrewd contracts handle and trade assets of huge regard, other than their correct execution it is also imperative that their use is secure against ambushes which go for taking or modifying the favorable circumstances. Ethereum, the most eminent and used structure for sharp contracts up to this point. It analyze the security vulnerabilities of Ethereum smart contracts, giving a logical order of customary programming traps which may incite vulnerabilities and exhibit a movement of attacks which misuse these vulnerabilities, empowering a foe to take money or cause other mischief
Blockchain is the technology that has attracted enormous interest recently as it provides security and privacy through immutable distributed ledger. It is the backbone of the most popular cryptocurrency, bitcoin. Due to its robust consensus mechanism and tamper proof data storage, it is widely adopted in the applications where trust is given utmost importance.Homomorphic Encryption algorithms can be used to operate on the data that is encrypted without the knowledge of private key. Operations can be performed on encrypted data without decrypting the data. Only client knows about the private key. These two technologies can be used to securely transfer and store data in the cloud systems.In this paper we propose how this blockchain technology and homomorphic encryption can be used to build reliable, tamper-proof and efficient electronic voting system. An electronic voting system should be secure, and itshould not allow duplicate votes and be fully tamper proof, while protecting the privacy of the voters. In this work, we have designed, implemented and tested an electronic voting application and providing hashing for votes and stored in blockchaincloud.If data in database is lost, then it can be retrieved from blockchain cloud.
On considering the integrity of electronic evidence, in particular,we can see that such evidence needs to be protected from a number of undesirable outcomes namely, alteration or destruction. We need to guard against these events and others when trying to maintain system integrity and preserve the purity of evidence so that it could be acceptable in the court. Chain of Custody is nothing but the consecutive documentation of records. The Chain of Custody has all the necessary steps that a crime investigator must follow to make sure whether the information is honest. The Chain of Custody is significant because it cannot be proven that evidence was not altered during the time between collection and its usage in court. Then the collected evidence is not credible. Blockchain technology,a decentralized network currently used by Bitcoins and other Cryptocurrency networks, helps provide a secure database with the help of hashing the data and storing it in blocks.We propose to implement blockchain technology for the process of Chain of Custody, which helps in tracking the people whoaccess the data and assist in assuring the credibility of the data provided during the time of submission in court.
Open access
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
The monograph investigates the theoretical, methodological and practical aspects of thefunctioning of the financial system of the united territorial communities under the conditions of decentralization reform in Ukraine.In-depth analysis of the scientific concept of the development of local self-government has beencarried out. The peculiarities of the formation of revenues and expenditures of the united territorial communities in the conditions of reformation of the system of inter-budgetary relations have been highlighted.The peculiarities of the financial behaviour of the united territorial communities in the context ofthe priority of budget expenditures have been studied and determined. The monograph has determinedthe main directions of formation of the financial management system of the united territorial communities and carrying out of financial control over their activities in order to improve the financial capacityof the territorial communities.The monograph will be useful to specialists in finance, scholars, the teachers of higher educationalinstitutions, the students of economic specialties, as well as local self-government authorities.
Pericles Philippopoulos, Alessandro Ricottone, Carlos G. Oliver
We propose DIPS Difficulty-based Incentives for Problem Solving), a simple modification of the Bitcoin proof-of-work algorithm that rewards blockchain miners for solving optimization problems of scientific interest. The result is a blockchain which redirects some of the computational resources invested in hash-based mining towards scientific computation, effectively reducing the amount of energy `wasted' on mining. DIPS builds the solving incentive directly in the proof-of-work by providing a reduction in block hashing difficulty when optimization improvements are found. A key advantage of this scheme is that decentralization is preserved and no additional protocol layers are required on top of the standard blockchain. We study two incentivization schemes and provide simulation results showing that DIPS is able to reduce the amount of hash-power used in the network while generating solutions to optimization problems.
The characteristics of blockchain as decentralization, transparency, business activity undeniable proof mechanism etc. have achieved extensive attention from the academic circles and industrial circles. In view of the current deficiency of poor data sharing in G2B system, data authenticity, data security, and transaction subject identity's confidentiality cannot be effectively guaranteed, and the lack of authentication for government management departments (organization institutions) providing service or implementing management to enterprise businesses, this paper proposed to construct G2B system based on blockchain. Based on maintaining the architecture of traditional G2B system and the serviced or managed characteristics of enterprise businesses, was constructed respective G2B system based on blockchain for each section of enterprise business process. Each G2B system was based on blockchain correlated by the virtual links of enterprises and serviced or managed data for enterprises' business, and constituted blockchain interconnection network. The protocol was designed and the characteristics of G2B system analyzed based on blockchain. Application mode for G2B system was designed based on blockchain. A case based on blockchain was designed, including business operation principle, consensus mechanism, and supervision to government (organization).
Artificial intelligence (AI) and blockchain are likely to bring powerful economic and social effects. Blockchain's ability to cryptographically validate identities and transactions and create immutable records can enhance trust, transparency, and accountability. Part of the fascinating character of the AI stems from the fact that computers perform better than humans in repetitive tasks. Their judgment and intelligence are not affected by emotions, feelings, and needs. They have better memories and can process large amounts of information.1 AI, thus, enhances efficiency and provides new opportunities for cost savings and revenue generation. What is even more important is that AI and blockchain have strong complementary capabilities that can have dramatic effects on the performance of industries and markets. Each also has a potential to improve the performance and functioning of the other (see Figure 1).
Trung-Viet Nguyen, Lam-Son Lê, Bo Dao, Khuong Nguyen-An
A system for evaluating current services in the tourism industry is one of the sources of reference affecting tourists' decisions. However, such the system may not be trusted by users. The main reason may come from the evaluation result that has been tampered with via a third party or a network attack. Besides, the relationship between service providers and tourists is the service level agreements (SLAs), which is the provider's commitment. Nevertheless, the process of implementing the SLAs is manual, not automatic, so this leads to many disputes. In this study, we propose BlockSLA, an architecture for evaluating and enforcing agreements based on the blockchain. Our proposal uses the blockchain to ensure that the assessment process can be kept safe and reliable through the blockchain consensus processing mechanism. From these evaluations, smart contracts on the blockchain can automatically make compensation immediately and the parties (e.g., tourists, providers) can track these changes on their device. The architectural design is described in detail in this work.
Abstract The article presents the results of the study of the blockchain technology. The main barriers of technology implementation were identified and ways for their elimination were suggested. Advantages and disadvantages of the technology were identified. It allowed for studies of feasibility of technology implementation for performing social and economic infrastructure tasks. The issue of effective application of this technology was studied. In Russia, the blockchain technology has been discussed by the Government of the Russian Federation and the State Duma. Despite some advantages, only in some countries, the blockchain technology is used in business processes. The blockchain technology can be used to solve logistics problems, data security tasks, political, economic and medical problems.
Abstract This paper aims to identify, and analyze how the use of blockchains technology can support sustainable supply chain management strategies. This support is seen from environmental, economic, and social aspects. In addition, it explains the various advantages of using Blokchain technology to reduce the use of transportation and other resources that have the potential to damage the environment. From an economic aspect, this technology has the potential to increase the efficiency of cost and time. Blockchain technology also has the potential to provide social benefits for the companies involved because of the increasingly good reputation of the organization. Three examples of implementation of the blockchain in three different industries are also provided in this paper. This paper also points out the potential disadvantages of using this technology for supply chains that can threaten supply chain sustainability.
Zusammenfassung Dieser Beitrag stellt die Grundsätze von auf Smart Contracts und der Blockchain-Technologie basierenden Rating-Verfahren zur Bonitätsbewertung vor. Es werden die technologischen Grundlagen von Blockchain und Smart Contracts erläutert und diskutiert, inwieweit die Finanzbranche im Bereich des Ratings von dieser Technologie profitieren kann. Zunächst werden die Probleme traditioneller Ratingverfahren und deren Akteure thematisiert und anschließend Lösungsansätze aufgezeigt, um diese zu überwinden. Damit zeigt dieser außerhalb der traditionellen Bankdienstleistungen befindliche Anwendungsfall, dass mit der Blockchain-Technologie neue Potenziale für Geschäftsmodelle entstehen, die etablierte Prozesse grundlegend verändern und damit ein weiteres Mosaik zur Disruption der Finanzbranche darstellen können.
There has been a massive growth of Internet of Things (IoT) applications recently for both personal and organization use cases. But an IoT network is vulnerable to many privacy and security concerns. While some researchers have tried to define different access control models for IoT and tried to use blockchain in some cases, the solutions presented to date lacks a flexible and robust access control model that can be used for complex organization and cross-organization resource access scenarios and lacks the scalability and performance needed for IoT. This paper introduces a novel entitlement-based access control model that provides an efficient and secure way to delegate resource access rights to any entity. The solution uses service-oriented approach and a combination of public blockchain (with smart contracts) and local off-chain data for entitlements management and control. To analyze the proposed architecture, a large-scale cross-organization IoT scenario is taken into consideration and some qualitative evaluations are presented while implementation with Ethereum blockchain and smart contracts are currently in progress.
Recently, crowd sensing has been intensively researched, due to the rapid growth of sensor-integrated mobile devices. Crowd sensing is a participatory sensing service where a server gathers and analyzes sensing data submitted from mobile devices of lots of users. In crowd sensing, the user's anonymity is desired, since the server gathers sensitive data from the participants including their GPS locations and moving path. However, the anonymous data submission may compromise the trust of the sensing data, because anonymous users may submit inappropriate sensing data, but they cannot be traced. Therefore, as the system to achieve both anonymity and trust in crowd sensing, ARTSense has been proposed. In the system, the trust of the sensing data is assessed on the sensed environment, other users' sensing, and the reputation of the user, and furthermore the reputation of the user is anonymously managed on the feedback from the trust assessment for the data. However, the anonymous reputation system of ARTSense has the efficiency problem, i.e., the user needs to wait a random time after the data submission phase before requesting the reputation update, which causes the communication delay. In this paper, we propose an efficient anonymous reputation system for crowd sensing, which can be integrated to the trust assessment in ARTSense. In the proposed system, during the data submission, the reputation update is anonymously completed. This is because the server does not manage the reputation of each user, but each user manages his/her reputation in the user side, where the the validity of the reputation is ensured by a certificate and anonymously checked by zero-knowledge proofs. Therefore, the proposed system achieves the better efficiency with no delay.
Abstract The purpose of this study to identify of trading cryptocurrency on Marketplace with the intention that users can understand the trading marketplace easily and quickly based on the stages of trading that are recommended in the system in this study. The method that used in this research was a descriptive method to find out a complete description of the variables with related situations. The result of this research is to find out about the implementation of trading on the marketplace, profits, risks, security and using features in the marketplace. This research will discuss how to trade cryptocurrency on the x marketplace, profit, risk, security and use the tools in the marketplace. The conclusion in this study is the existence of a system that has such completeness Interface, website simplicity, security features, clear office and team, regulation of legal entities, responsive customer service, speed of deposit or withdrawal of a Marketplace affects Trader to trade in the marketplace.