Mahmood A. Rashid, Krishneel Deo, Divnesh Prasad, K. Ranjith Singh · 6 authors
Blockchain is an emerging technology framework for creating and storing\ntransaction in distributed ledgers with a high degree of security and\nreliability. In this paper we present a blockchain-based platform to create and\nstore contracts in between students and their higher education sponsors. The\nsponsorship might be in any form, such as scholarship, donation or loan. The\nfund will be arranged and managed by a group of competitive agents\n(Fundraisers) who will hold the distributed ledgers and act as miners in the\nblockchain network.\n
When economy grows, and resident’s needs are diversifying, finance starts to become decentralization of power as a result. The offer of the public service by the centralized government is suitable to unify the citizen’s preference of the wide area, but what the local government where inhabitants are the nearest carries is desirable for the offer of the community service in a small range(Oates’s decentralization theorem). On the other hand, it becomes to cause the difference of various public services in each area in fiscal decentralization. Therefore, it is important how we measure progress of the financial decentralization in each area and the financial decentralization of power difference between each area. The purpose of this report analyzes economic and fiscal decentralization disparities in China from the measurement of the tile index based on the data of “the Chinese statistics summary (2000 through 2007)” before and after the western great development, at the same time it analyzes whether the relation between economy and financial decentralization is correlative, in other words, Oates’s decentralization theorem is concluded in Chinese economy. As a result of analysis, following three points were confirmed. 1. Expenditure decentralization disparities and difference of the district production per capita have positive correlation. Therefore, Oates’s decentralization theorem may be concluded. 2. However, when I consider population movement, Fiscal empowerment disparities and difference of the district production per capita have negative correlation. As a result, when I consider the side political, Oates’s decentralization theorem may not be concluded. 3. In the major cities of the coastal place such as Beijing and Shanghai, as for the growth rate of expenditure decentralization and the original expenditure decentralization, these coefficients of correlation were negative. Oates’s decentralization theorem is not concluded in these cities, and it is predicted that a factor except the finance strongly works for economic growth.The conclusion whether or not Oates’s decentralization theorem was concluded remains much more vague by the complicated political economic system in this way in China.
In today's blockchain system, designing a secure and high throughput blockchain on par with a centralized payment system is a difficult task. Sharding is one of the most worthwhile emerging technologies for improving the system throughput while maintain high-security level. However, previous sharding-related designs have two main limitations. First, the security and throughput of their random-based sharding system are not high enough as they did not leverage the heterogeneity among validators. Second, to design an incentive mechanism that promotes cooperation could incur a huge overhead on their system. In this article, we propose RepChain, a reputation-based secure and fast blockchain system via sharding, which also provides high incentive to stimulate node cooperation. RepChain utilizes reputation to explicitly characterize the heterogeneity among the validators and lay the foundation for the incentive mechanism. We propose a new double-chain architecture-a transaction chain and a reputation chain. For the transaction chain, an efficient Raft-based synchronous consensus has been presented. For the reputation chain, the synchronous Byzantine fault tolerance consensus that combines collective signing has been utilized to prevent the attack on both reputation score and the related transaction blocks. It supports a high throughput transaction chain with moderate generation speed. Moreover, we propose a reputation-based sharding and leader selection scheme. To analyze the security of RepChain, we propose a recursive formula to calculate the epoch security within only $\mathcal {O}(km^{2})$ time. Furthermore, we implement and evaluate RepChain on the Amazon Web Service platform. The results show our solution can enhance both throughout and security level of the existing sharding-based blockchain system.
While electronic signatures are widespread, there currently exists no viable signing solutions that can track amendments. We proposed VeriSign, a secure contract consensus platform where amendments to contracts can be tracked in a decentralized medium. We demonstrate a user-facing app where signatories can vote on original contracts and amendments, and incorporate a Blockchain where we store the transaction history of original contracts and amendments. This platform has possible applications in tracking the history of legislation, and amendments to legislation.
Undeniably one of the most anticipated and potentially revolutionary technologies since the invention of the internet, blockchain promises to usher in a new era of how we do business and handle information. Although a cryptographically secured chain of digital files was described in work* dated as early as 1991, the invention of blockchain in its current, most popular form, as a distributed ledger for transactions on a network, is credited to the pseudonymous Satoshi Nakamoto, the inventor(s) of Bitcoin, in 2008. Cryptography has been around for centuries, but the cryptocurrency & blockchain community as a whole largely considers Satoshi Nakamoto’s Bitcoin as the first blockchain. Although initially intended as the supporting technology behind a digital form of money, blockchain is beginning to show it’s potential to expand to numerous applications with real world use-cases in preexisting industries.
Atomic swaps enable the transfer of value between the cryptocurrencies of various blockchains without the need to trust an intermediary. In this paper, we propose the concept of atomic loans, which utilize atomic swap technology to allow market participants to create overcollateralized debt instruments in a trustless and disintermediated manner. The primary use cases for atomic loans include enabling fiat/stablecoin access for cryptocurrency holders to participate within legacy systems, as well as enabling leverage for margin trading. We also introduce a bidding process for liquidating collateral in the case of default which provides the ability for a more fair distribution of collateral.
István András Seres, László Gulyás, Dániel Nagy, Péter Burcsi
Bitcoin's Lightning Network (LN) is a scalability solution for Bitcoin allowing transactions to be issued with negligible fees and settled instantly at scale. In order to use LN, funds need to be locked in payment channels on the Bitcoin blockchain (Layer-1) for subsequent use in LN (Layer-2). LN is comprised of many payment channels forming a payment channel network. LN's promise is that relatively few payment channels already enable anyone to efficiently, securely and privately route payments across the whole network. In this paper, we quantify the structural properties of LN and argue that LN's current topological properties can be ameliorated in order to improve the security of LN, enabling it to reach its true potential.
In this paper, we will describe a concept of a cryptocurrency issuance protocol which supports digital currencies in a Proof-of-Work ( ) like manner. However, the methods assume alternative utilization of assets used for cryptocurrency creation (rather than purchasing electricity necessary for ).
In this paper, we will describe a concept of a cryptocurrency issuance\nprotocol which supports digital currencies in a Proof-of-Work (< PoW >) like\nmanner. However, the methods assume alternative utilization of assets used for\ncryptocurrency creation (rather than purchasing electricity necessary for <\nmining >).\n
Gianluca Miscione, Tobias Goerke, Stefan Klein, Gerhard Schwabe · 5 authors
Blockchain technology provides a distributed ledger and is based on a logic of peer to peer authentication. It gained prominence with the rise of cryptocurrencies but provides a much broader field of possible application, including – but not limited to – land and other registries, global trade systems. While it has been originally closely linked to a libertarian, anarchic agenda, recent developments of commercial applications have illustrated that it can been dissociated from a particular ideological framing. The purpose of our paper is to identify and classify core properties of blockchain as an organizational technology and related modes of blockchain governance. We do this by looking at a number of case studies which highlight a number of governance design issues as well as unintended effects of the technology and related design choices. We are exploring the linkages between blockchain application properties and related design options and choices.
Constant technological innovation is the current reality for businesses and people. Most of the technologies have great potential beyond what they are designed for. Blockchain, the underlying distributed ledger technology of Bitcoin, has only recently begun to be tested for other uses. This paper studies Blockchain technology and its applications to supply chains. The concept of Blockchain technology will be scrutinized and its implementation benefits and limitations presented. Furthermore, the use cases and benefits of Blockchain technology for supply chains will be analyzed. The paper is complemented with examples and achievements of organizations testing the technology and experts opinions on the technology and its future.
Mozhdeh Farhadi, Daniele Miorandi, Guillaume Pierre
IoT provides services by connecting smart devices to the Internet, and exploiting data generated by said devices to enable value-added services to individuals and businesses. In such cases, if data is exposed, tampered or lost, the service would not behave correctly. In this article, we discuss data security in IoT applications across five dimensions: confidentiality, integrity, authenticity, non-repudiation and availability. We discuss how distributed ledger technology could be used to overcome these issues and propose to use a fog computing architecture as decentralized computational support to deploy the ledger.
We study selfish mining in Ethereum. The problem is combinato-rially more complex than in Bitcoin because of major differences in the reward system and a different difficulty adjustment formula. Equivalent strategies in Bitcoin do have different profitabilities in Ethereum. The attacker can either broadcast his fork one block by one, or keep them secret as long as possible and publish them all at once at the end of an attack cycle. The first strategy is damaging for substantial hashrates, and we show that the second strategy is even worse. This confirms what we already proved for Bitcoin: Selfish mining is most of all an attack on the difficulty adjustment formula. We show that the current reward for signaling uncle blocks is a weak incentive for the attacker to signal blocks. We compute the profitabilities of different strategies and find out that for a large parameter space values, strategies that do not signal blocks are the best ones. We compute closed-form formulas for the apparent hashrates for these strategies and compare them. We use a direct combinatorics analysis with Dyck words to find these closed-form formulas.
Medical care has become one of the most indispensable parts of human lives, leading to a dramatic increase in medical big data. To streamline the diagnosis and treatment process, healthcare professionals are now adopting Internet of Things (IoT)-based wearable technology. Recent years have witnessed billions of sensors, devices, and vehicles being connected through the Internet. One such technology-remote patient monitoring-is common nowadays for the treatment and care of patients. However, these technologies also pose grave privacy risks and security concerns about the data transfer and the logging of data transactions. These security and privacy problems of medical data could result from a delay in treatment progress, even endangering the patient's life. We propose the use of a blockchain to provide secure management and analysis of healthcare big data. However, blockchains are computationally expensive, demand high bandwidth and extra computational power, and are therefore not completely suitable for most resource-constrained IoT devices meant for smart cities. In this work, we try to resolve the above-mentioned issues of using blockchain with IoT devices. We propose a novel framework of modified blockchain models suitable for IoT devices that rely on their distributed nature and other additional privacy and security properties of the network. These additional privacy and security properties in our model are based on advanced cryptographic primitives. The solutions given here make IoT application data and transactions more secure and anonymous over a blockchain-based network.
Albert Galiev, Shamil Ishmukhametov, Rustam Latypov, Nikolai Prokopyev · 6 authors
In this paper, we propose a novel archival system called ARCHAIN, developed for the State archive-keeping committee of the Republic of Tatarstan (Russia). The blockchain is the primary part of the system, which stores transactions (facts of transfer of documents to the archive) in a protected form.
The purpose of this study is to analyze possible problems in issuing digital diplomas, using the blockchain technology, and to promote solving these problems as well as to show the possibility of practical implementation of the blockchain technology, using a test example. Materials and methods. The study included a review of bibliographic sources on the use of blockchain technologies in the education system, as well as computer modeling of the task of registering and verifying a digital diploma in the blockchain. Results. In the course of the work, a model of the process of issuing and verifying digital diplomas was built, and a number of problems related to the practical implementation of this model were also considered. At the same time, the following groups of problems that restrain the spread of blockchain in the education sector of the Russian Federation were identified: technical and technological problems (lack of a national blockchain platform); legal issues (lack of legal force of digital diplomas); organizational problems (lack of a centralized management structure that coordinates the “educational” blockchain as a single digital information space). An example was also realized, showing the hardware and technological capabilities of the implementation of the task under consideration using the currently open (freely available) platforms. To implement the proposed test case, the Ethereum blockchain network was used, in particular, its RinkeBy test network. The project implementation consisted of the following stages: creating a digital diploma file and placing it in the open file-sharing network in order to obtain the corresponding document hash; obtaining blockchain address (an electronic wallet was created using the MetaMask browser plugin, which allows for the transfer of data on a digital diploma to the blockchain); preparing data to be sent to the blockchain, where the data was a hexadecimal code, containing brief information about a digital diploma, including its hash; transferring data to the Ethereum blockchain (making a transaction); verification of transaction results in Etherscan. Conclusion. The blockchain technology provides great opportunities in improving the concept of e-learning, taking into account the current requirements of the digital economy. This technology can conceptually change the data archiving system, increase the reliability of information protection against falsification, and significantly speed up the execution of requests for information and data processing. The problems that arise can be successfully resolved, as long as that the blockchain becomes one of the principles of the unified information educational space. At the same time, the blockchain gives the following new opportunities: transparency and verifiability of the system of certification of graduates of educational institutions; the possibility of liquidation of intermediary organizations that implement a variety of support monitoring and certifying functions, associated with the “paper” requests for confirmation of diplomas; the overall reduction in paper workflow, the transfer of the classic “paper” business-processes into the information space, and as a result of all this – the practical implementation and example of the realization of the concept of digitalization of the knowledge economy.
Gourang Aggarwal, Vimal Patel, Gaurav Varshney, Kimberly R. Oostman
Blockchain and its application on cryptocurrency transactions have gathered a lot of attention and popularity since the birth of the pioneer Bitcoin in 2009. More than 1500 cryptocurrencies are currently circulated in the market. The technology underpinning Bitcoin and other cryptocurrencies is Blockchain and is a rapidly growing decentralized distributed ledger technology which find its major involvement in cryptocurrencies. But cryptocurrencies are of extremely volatile and fragile nature which makes it difficult to be used as a stable currency for transactions and devoid this market of human trust. Cryptocurrency market is controlled by various social and government factors which keeps it fluctuating. This paper identifies and discusses the important factors that govern the cryptocurrency market and analyzes the impact of these factors. A pilot user survey has also been presented at the end of this paper to understand and demonstrate the societal view of the acceptance of cryptocurrencies.
E-government provides access to services anytime anywhere. There are many e-Government frameworks already exist to integrate e-government services, but efficient full interoperability still a challenge. Interoperability per se can be modeled via four maturity stages, in which the interoperability zone is the holy grail of full interoperability to be reached ultimately with strategy alignment. As e-government services shift in the same way as e-commerce with value chain, this implicitly implies the possibility of benefiting from blockchain with e-government. Blockchain is a nascent promising architecture, whose transactions are permanent, verifiable, and recorded in a distributed ledger. This research article suggests applying blockchain in achieving e- government interoperability. Forms are juxtaposed on the outer borders of the system. These forms adopt those used by UK government, because they are standard as well as they are available for Python developers. Once a form has been completed, PySOA calls the requested service, before storing the data in Ontology Blockchain. After the service is performed, the policies are analyzed in batch processing using quantgov. A report is submitted to the central government periodically. Ontology Blockchain has a dual effect. On the one hand, it works as a secure data storage. On the other hand, it cooperates with PySOA in supporting both technology and semantic interoperability . The most important feature of the proposed method is the presence of (Government Interoperability Zone Alignment; GIZA), which acts as a backbone that coherently connects the internal subcomponents. This linkage is possible, because each form has an title, that corresponds to the appropriate service name. Each service in turn has a counterpart in the wallets stored in Ontology blockchain. To measure interoperability empirically, there is a need for metrics. This study adopts and quantizes a standard interoperability matrix along three dimensions of interoperability of Conceptual (Syntax& Semantics), Organizational (Responsibilities& Organization per se), and Technology (Platform& Communication). While concerns are : data, business, service, and process. Any deviation from the standard could contributes to the interoperability score (counting mismatches) or interoperability grade (counting absolute differences). An estimation is performed, for 1000 total random cases. It is estimated that the probability of getting a conceptual/technical interoperability score as large as the standard strategy score is (713 /1000 = 0.713 (2 in 3). It is estimated too that the probability of getting a organizational interoperability score as large as the standard strategy score is (712 /1000 = 0.712 (2 in 3). Then, Markov model is proposed to provide an accurate representation of the evolution of the strategies over time.
The use of cryptocurrencies such as Bitcoin and Ethereum in performing online transactions has been on the rise in the world. Africa as a continent is not left out in the adoption of blockchain and cryptocurrencies. This paper explores the prospects and challenges of developing a cryptocurrency in Rwanda which we denote Rwandacoin. In addition, the paper discusses the potentials of Rwandacoin easing intercountry trading in East Africa.
This letter proposes a novel demurrage mechanism for blockchain electricity marketplaces, whereby the redemptive value of energy-backed tokens declines with time. This mechanism is intended to reward organic price-responsive load shifting by incentivising the consumption of electricity when it is locally abundant. To demonstrate how such a demurrage mechanism might function in practice, this letter describes a mixed complementarity model of a notional token marketplace. These market simulations indicate that, in equilibrium and with rational actors, the demurrage mechanism creates price signals that temporally align the production and consumption of electricity.
Blockchains have recently gained popularity thanks to their ability to record "digital truth". They are designed to keep persistence, security, and avoid attacks which is useful for many applications. However, they are still problematic in their energy consumption, governance, and scalability Current solutions either require vast computing power via Proof-of-Work (PoW) or cannot directly utilize computing power as a resource in virtual mining. Here, we propose incentive-based protocols that use competitions to integrate computing power into blockchains. We introduce Proof-of-Accumulated-Work (PoAW): miners compete in costumer-submitted jobs, accumulate recorded work whenever they are successful, and, over time, are remunerated. The underlying competition replaces the standard hash puzzle-based competitions of PoW. A competition is managed by a dynamically-created small masternode network (dTMN) of invested miners. dTMNs allow for scalability as we do not need the entire network to manage the competition. Using careful design on incentives, our system preserves security, avoids attacks, and offers new markets to miners. When there are no costumers the system converges into a standard protocol. Our proposed solution improves the way by which the blockchain infrastructure works and makes use of its computing power. We also discuss how the protocol can be used by fields that require solving difficult optimization problems, such as Artificial Intelligence and Pattern Recognition in Big Data.
Dominic Deuber, Bernardo Magri, Sri Aravinda Krishnan Thyagarajan
Bitcoin is an immutable permissionless blockchain system that has been extensively used as a public bulletin board by many different applications that heavily relies on its immutability. However, Bitcoin's immutability is not without its fair share of demerits. Interpol exposed the existence of harmful and potentially illegal documents, images and links in the Bitcoin blockchain, and since then there have been several qualitative and quantitative analysis on the types of data currently residing in the Bitcoin blockchain. Although there is a lot of attention on blockchains, surprisingly the previous solutions proposed for data redaction in the permissionless setting are far from feasible, and require additional trust assumptions. Hence, the problem of harmful data still poses a huge challenge for law enforcement agencies like Interpol (Tziakouris, IEEE S&P'18). We propose the first efficient redactable blockchain for the permissionless setting that is easily integrable into Bitcoin, and that does not rely on heavy cryptographic tools or trust assumptions. Our protocol uses a consensus-based voting and is parameterised by a policy that dictates the requirements and constraints for the redactions; if a redaction gathers enough votes the operation is performed on the chain. As an extra feature, our protocol offers public verifiability and accountability for the redacted chain. Moreover, we provide formal security definitions and proofs showing that our protocol is secure against redactions that were not agreed by consensus. Additionally, we show the viability of our approach with a proof-of-concept implementation that shows only a tiny overhead in the chain validation of our protocol when compared to an immutable one.
A new type of watermarks for handwritten black-white documents is suggested. Insertion of the watermark in a document minimizes distortion of the latter. The method is intended for validation of handwritten records placed in blockchain database.
Blockchains are distributed secure ledgers to which transactions are issued
continuously and each block is tightly coupled to its predecessors.
Permissioned blockchains place special emphasis on transactions throughput. In
this paper we present TOY, which leverages the iterative nature of blockchains
in order to improve their throughput in optimistic execution scenarios. TOY
trades latency for throughput in the sense that in TOY the last f+1 blocks of
each node's blockchain are considered tentative, i.e., they may be rescinded in
case one of the last f+1 blocks proposers was Byzantine. Yet, when optimistic
assumptions are met, a new block is decided in each communication step, which
consists of a proposer that sends only its proposal and all other participants
are sending a single bit each. Our performance study demonstrates that in a
single Amazon data-center, TOY running on 10 mid-range Amazon nodes obtains a
throughput of up to 160K transactions per second for (typical Bitcoin size) 512
bytes transactions. In a 10 nodes Amazon geo-distributed setting with 512 bytes
transactions, TOY obtains a throughput of 30K transactions per second.