This is the first work to introduce the use of blockchain technology for the electronic traceability of wood from standing tree to final user. Infotracing integrates the information related to the product quality with those related to the traceability [physical and digital documents (Radio Frequency IDentification-RFID-architecture)] within an online information system whose steps (transactions) can be made safe to evidence of alteration through the blockchain. This is a decentralized and distributed ledger that keeps records of digital transactions in such a way that makes them accessible and visible to multiple participants in a network while keeping them secure without the need of a centralized certification organism. This work implements a blockchain architecture within the wood chain electronic traceability. The infotracing system is based on RFID sensors and open source technology. The entire forest wood supply chain was simulated from standing trees to the final product passing through tree cutting and sawmill process. Different kinds of Internet of Things (IoT) open source devices and tags were used, and a specific app aiming the forest operations was engineered to collect and store in a centralized database information (e.g., species, date, position, dendrometric and commercial information).
This research aims to find out the level of financial capacity of regional government in Indonesia before and after the proliferation of administrative region. The level of financial capacity is measured using analysis of local financial ratio consisting of regional financial independence ratio, degree of fiscal decentralization ratio, Local-Own Source Revenue (OSR) per capita growth analysis, and OSR effectiveness ratio. The number of sample used in this research is 15 districts in Indonesia which were split in 2008, 2012, and 2013 using purposive sampling method. Data used in this research is secondary data of Budget Realization Report of State Budget from Directorate General Suhairi 3 of Fiscal Balance of Ministry of Finance of Republic of Indonesia. Technique used to analyze data is analysis of local financial ratio and t-test (paired sample test). The result of t-test shows that there is significant difference between regional financial independence and degree of fiscal decentralization before and after the proliferation of administrative region. There is no significant difference between the OSR per capita growth and OSR effectiveness either before or after the proliferation of administrative region .
Airdrops are a popular method of distributing cryptocurrencies and tokens. While often considered risk-free from the point of view of recipients, their impact on privacy is easily overlooked. We examine the Clam airdrop of 2014, a forerunner to many of today's airdrops, that distributed a new cryptocurrency to every address with a non-dust balance on the Bitcoin, Litecoin and Dogecoin blockchains. Specifically, we use address clustering to try to construct the one-to-many mappings from entities to addresses on the blockchains, individually and in combination. We show that the sharing of addresses between the blockchains is a privacy risk. We identify instances where an entity has disclosed information about their address ownership on the Bitcoin, Litecoin and Dogecoin blockchains, exclusively via their activity on the Clam blockchain.
Para kavramı ihtiyaçlara ve teknolojideki gelişmelere bağlı olarak tarih boyunca değişim göstermiştir. Elektronik para kavramından sonra şimdi de kripto para kavramı küçük tasarruf sahiplerinden büyük devletlere varıncaya kadar hepimizin gündemine girmiş durumda. Kripto para kavram ve sistemi, bilişim ve ekonominin yanı sıra din ve hukuk tarafından da irdelenmeye muhtaçtır. Kripto para sistemine peşinen taraftar veya karşı olmak yerine, borsa, bankacılık, kredi gibi kavram ve sistemlerin geçirdiği dönüşümü dikkate alarak konuya dair çok boyutlu değerlendirmeler yapılması zaruret arz etmektedir. Bu çalışmada farklı yaklaşımlar arasında karşılaştırmalarda bulunarak İslam hukuku cephesinden konuya temas etmeye gayret göstereceğiz.
Over the past few decades, radio frequency identification (RFID) technology has been an important factor in securing products along the agri-food supply chain. However, there still exist security vulnerabilities when registering products to a specific RFID tag, particularly regarding the ease at which tags can be cloned. In this paper, a potential attack, labeled the "Hilt Shao attack", is identified which could occur during the initial phases of product registration, and demonstrate the type of attack using UID and CUID tags. Furthermore, a system is proposed using blockchain technology in order for the attacker to hide the cloned tag information. Results show that this attack, if carried out, can negate the profits of distributors along the supply chain, and negatively affect the consumer.
German Abstract: Your legal concepts of property, expression, identity, movement, and context do not apply to us. They are all based on matter, and there is no matter here.“ Dies proklamierte einst der amerikanische Poet und Freigeist John Perry Barlow, der als Mitbegrunder der NGO Electronic Frontier Foundation fur Rechte im digitalen Zeitalter und eine moglichst weitgehende Deregulierung des Internets eintrat. Digitale Phanomene wie Kryptowahrungen sind nur schwer den bestehenden Konzepten einer ursprunglich durch korperliche Gegenstande gepragten Rechtsordnung zu unterwerfen. Dieser Aufsatz versucht am Beispiel von Bitcoins diese Erscheinungen in bestehende zivilrechtliche Strukturen einzuordnen und zu klaren, ob der Gesetzgeber regulierend einschreiten sollte. Hierzu werden nach einer Einleitung zu Kryptowahrungen (I.) ihre Rechtsnatur (II.) und Behandlung i.R.d. Schuldrechts (III.) erortert.
English Abstract: Your legal concepts of property, expression, identity, movement, and context do not apply to us. They are all based on matter, and there is no matter here. This was once proclaimed by the American poet and freethinker John Perry Barlow, who as co-founder of the NGO Electronic Frontier Foundation advocated rights in the digital age and the deregulation of the internet as far as possible. Digital phenomena such as cryptocurrencies are difficult to subordinate to existing concepts of a legal system originally shaped by physical objects. Using Bitcoins as an example, this article attempts to integrate these phenomena into existing civil law structures and to clarify whether the legislator should intervene to regulate them. After an introduction to cryptocurrencies (I.) their legal nature (II.) and treatment in the law of obligations (III.) are discussed.
The success of blockchain as the underlying technology for cryptocurrencies has opened up possibilities for its use in other application domains as well. The main advantages of blockchain for its potential use in other domains are its inherent security mechanisms and immunity to different attacks. A blockchain relies on a consensus method for agreeing on any new data. Most of the consensus methods which are currently used for the blockchain of different cryptocurrencies require high computational power and thus are not apt for resource constrained systems.
In this article, we discuss and survey the various blockchain based consensus methods that are applicable to resource constrained IoT devices and networks. A typical IoT network consists of several devices which have limited computational and communications capabilities. Most often, these devices cannot perform the intensive computations and are starved for bandwidth. Therefore, we discuss the possible measures that can be taken to reduce the computational power and convergence time for the underlying consensus methods. We also discuss some of the alternatives to the public blockchain like private blockchain and tangle, and their potential adoption for IoT networks. Furthermore, we discuss the existing consensus methods and blockchain implementations and explore the possibility of utilizing them to realize a blockchain based IoT network. Some of the open research challenges are also put forward.
The advent of Blockchain Technology allows us to develop a Decentralized Application called DApp on peer-to-peer network, which can harden changes of contracts in the DApp and denial of service (DoS) attacks to the DApp. We reengineer an App to a DApp allowing smart contracts, and compare the given legacy App and the target DApp. We conclude that DApp is not a separate application but a complementary application of the current App by comparing their architectures.
Internet of Things (IoT) devices present different security challenges that have not been addressed yet and there is no clear commitment from stakeholders to do so. Such problems have become evident and IoT devices are targets of malicious actors that employ them as instruments to fulfill their nefarious purposes. Recent attacks to major Internet services have shown the real damage vulnerable devices can make when compromised. Many of the endangered devices sit in home-based environments with users that are not familiar with security or network best practices, which make them easy targets for bad actors. Therefore, there exists the need to find practical solutions using existing technologies that have been, so far, proven to be efficient, such as the blockchain. This paper implements a proof of concept to secure consumer/home-based IoT devices and the networks around them using blockchain technology powered by Ethereum. The results obtained support the idea of a whitelisting application based on the Ethereum protocol.
Building a secure electronic voting system is a difficult task. The US Pentagon dropped their proposed online voting system which would have given overseas military personnel the opportunity to vote in the elections in 2005, citing the inability to ensure the legitimacy of votes as the reason. There is however a new cry in the wild to deploy a voting blockchain. The blockchain serves as a public ledger of transactions which cannot be reversed. The all-important consensus of transaction (i.e. legitimate votes) is achieved through 'miners' agreeing to validate new records being added. Whenever a new insertion is to be made e.g. votes, then a new transaction record is created by a voter adding details of their cast vote to the blockchain. Should it be deemed a valid transaction then the new vote is added to the end of the blockchain and remains there forever. What is neat about this solution is the fact that no centralized authority is needed to approve the votes but rather a majority consensus. Here everyone agrees on the final tally as they can count the votes themselves & because of the blockchain audit trail, anyone can verify that no votes were tampered with and no illegitimate votes were inserted. This paper discusses the application of blockchain to voting.
The success of blockchain as the underlying technology for cryptocurrencies has opened up possibilities for its use in other application domains as well. The main advantages of blockchain for its potential use in other domains are its inherent security mechanisms and immunity to different attacks. A blockchain relies on a consensus method for agreeing on any new data. Most of the consensus methods which are currently used for the blockchain of different cryptocurrencies require high computational power and thus are not apt for resource-constrained systems. In this article, we discuss and survey the various blockchain based consensus methods that are applicable to resource constrained IoT devices and networks. A typical IoT network consists of several devices which have limited computational and communications capabilities. Most often, these devices cannot perform intensive computations and are starved for bandwidth. Therefore, we discuss the possible measures that can be taken to reduce the computational power and convergence time for the underlying consensus methods. We also talk about some of the alternatives to the public blockchain like private blockchain and tangle, along with their potential adoption for IoT networks. Furthermore, we review the existing consensus methods that have been implemented and explore the possibility of utilizing them to realize a blockchain based IoT network. Some of the open research challenges are also put forward.
This paper proposes a novel blockchain-based technique for creating an environment where individuals can be the custodians of their official education records and can easily share those records with others. A blockchain is a digitized, decentralized, open record of all cryptographic data exchanges. One key characteristic of the blockchain is its decentralized nature. Unlike records or accounts maintained by department, college, university, government agencies and other institutions, the blockchain does not require an intermediary to complete education records or alter records. Our solution incorporating the advanced features of blockchain allows education providers to issue official certificates that supply proof of completion or achievement. The proposed framework could also provide the corresponding functions for the after-college education and many other further usages.
Communities play a key role in educational development in many countries. In Cameroon, a number of legislations transfer certain educational responsibilities from the central government to local communities in line with the decentralized form of the state. Using the 2015/2016 academic year as the basis for assessment, this study examined the extent to which communities are responsive to the educational tasks assigned to them, and whether their contributions counts with regard to access to secondary education. Focus was on a sample of 65 randomly selected secondary schools in Fako Division of the South West Region of Cameroon. Principals from the schools responded to a questionnaire – the main instrument for data collection. Interviews were also held with parents, community leaders, councils and other stakeholders to complement questionnaire responses. Research data was analysed using the Statistical Package for Social Sciences (SPSS) and finding presented in the form of frequencies and proportions. Multinomial Logistic Regression Model was used to appraise the predictive power of community contributions on access to secondary education. The findings showed that community financing was little to inexistent and did not account for the relatively good access to secondary education reported. A major recommendation was for the government to effectively implement the process of decentralization by adequately empowering communities and other stakeholders at the decentralized level with finances and other resources needed to enhance the volume and quality of their participation in the achievement of state’s development concerns. Article visualizations:
It is believed that automated valet parking (AVP) system has great potential to mitigate the parking headache for the future smart city, as it can provide on-demand parking services, bringing immense benefits from energy saving for vehicles to time saving for drivers. For an AVP system, parking reservation is an indispensable part so that vehicles can accomplish automated parking in accordance with the reserved parking information. However, the reservation requests may not only reveal the driver identity, but also disclose his/her sensitive locations, e.g., the most visited places, which are of great concerns to users. To deal with this challenge, the anonymous techniques can be naturally applied during parking reservation, but directly applying the anonymous techniques in AVP will introduce a new security issue, i.e., the anonymous user may maliciously crash the AVP system by repetitively sending the reservation requests, which is called “double-reservation attack.” In this paper, we propose a new privacy-preserving reservation scheme for securing AVP system. Specifically, each anonymous user must have only one valid reservation token at any moment, and the token can only be used for booking one vacant parking space once. The proposed scheme does not only preserve the user's identity privacy and location privacy but also prevents the “double-reservation attack” based on several elegant building blocks, i.e., zero-knowledge proofs of knowledge and proxy resignature. Detailed security analysis confirms the security properties of our proposed scheme. In addition, extensive simulations are conducted to compare our proposed scheme with three previous schemes, and the experiment results demonstrate that our scheme is also much efficient in a WiFi-based testbed.
Despite growing adoption of cryptocurrencies, making fast payments at scale remains a challenge. Payment channel networks (PCNs) such as the Lightning Network have emerged as a viable scaling solution. However, completing payments on PCNs is challenging: payments must be routed on paths with sufficient funds. As payments flow over a single channel (link) in the same direction, the channel eventually becomes depleted and cannot support further payments in that direction; hence, naive routing schemes like shortest-path routing can deplete key payment channels and paralyze the system. Today's PCNs also route payments atomically, worsening the problem. In this paper, we present Spider, a routing solution that "packetizes" transactions and uses a multi-path transport protocol to achieve high-throughput routing in PCNs. Packetization allows Spider to complete even large transactions on low-capacity payment channels over time, while the multi-path congestion control protocol ensures balanced utilization of channels and fairness across flows. Extensive simulations comparing Spider with state-of-the-art approaches shows that Spider requires less than 25% of the funds to successfully route over 95% of transactions on balanced traffic demands, and offloads 4x more transactions onto the PCN on imbalanced demands.
Paolo Chiades, Luciano Greco, Vanni Mengotto, Luigi Moretti · 5 authors
For the period 2003–2014, we investigate unexplored effects of fiscal consolidation in decentralized public finance on a large dataset of Italian municipalities. Based on a simple, realistic theoretical model, we show that municipalities increase arrears on committed investment expenditure as a response to intergovernmental transfer cuts. Then, we test our predictions controlling for potential sources of endogeneity, and find that a reduction in intergovernmental transfers causes a significant increase in arrears, in addition to other common adjustments to local fiscal policies (e.g., tax revenues). Our results highlight a perverse effect of fiscal consolidation packages implemented by centrally imposed fiscal restraints.
With the rapid development of distributed renewable energy (DRE), demand response (DR) programs, and the proposal of the energy internet, the current centralized trading of the electricity market model is unable to meet the trading needs of distributed energy. As a decentralized and distributed accounting mode, blockchain technology fits the requirements of distributed energy to participate in the energy market. Corresponding to the transaction principle, a blockchain-based integrated energy transaction mechanism is proposed, which divides the trading process into two stages: the call auction stage and the continues auction stage. The transactions among the electricity and heat market participants were used as examples to explain the details of the trading process. Finally, the smart contracts of the transactions were designed and deployed on the Ethereum private blockchain site to demonstrate the validity of the proposed transaction scheme.
In recent years, there have been many significant changes in commercial transactions. Not only e-commerce continues to grow, but also the form of payment services and service providers are consistently growing, such as virtual currency. One of virtual currency that quite popular is cryptocurrency especially Bitcoin. China became the country with the largest Bitcoin market in the world in the past few years. However, due to the concerns about money laundering and threats to China's financial stability and affecting the domestic currency, the Chinese government has formed a strict policy on Bitcoin. Therefore, nowadays, China is no longer the largest Bitcoin market in the world. Regarding the recently implemented policy, this study aims to analyze whether Bitcoin does affect China's exchange rate. The main independent variables in this research are specified to Bitcoin price volatility from BTCE, and controlled with the variable of the current account, inflation, and money supply. Monthly time series data from November 2012 until July 2017 is analyzed using autoregressive distributed lag (ARDL). The estimation results show that Bitcoin price volatility significantly affects the exchange rate in the long run. The higher of Bitcoin price volatility implies higher risk. The negative sign in the coefficient suggests that when Bitcoin's price volatility increases, investors tend to switch their investments on real currency will be preferable so that the exchange rate will be appreciated.
We initiate the study of quantum races, games where two or more quantum computers compete to solve a computational problem. While the problem of dueling algorithms has been studied for classical deterministic algorithms, the quantum case presents additional sources of uncertainty for the players. The foremost among these is that players do not know if they have solved the problem until they measure their quantum state. This question of `when to measure?' presents a very interesting strategic problem. We develop a game-theoretic model of a multiplayer quantum race, and find an approximate Nash equilibrium where all players play the same strategy. In the two-party case, we further show that this strategy is nearly optimal in terms of payoff among all symmetric Nash equilibria. A key role in our analysis of quantum races is played by a more tractable version of the game where there is no payout on a tie; for such races we completely characterize the Nash equilibria in the two-party case. One application of our results is to the stability of the Bitcoin protocol when mining is done by quantum computers. Bitcoin mining is a race to solve a computational search problem, with the winner gaining the right to create a new block. Our results inform the strategies that eventual quantum miners should use, and also indicate that the collision probability---the probability that two miners find a new block at the same time---would not be too high in the case of quantum miners. Such collisions are undesirable as they lead to forking of the Bitcoin blockchain.