In identity federations, users assigned to identity providers (IDPs) can access applications operated by service providers (SPs) without SP-specific credentials for authentication and authorization. While OpenID Connect and SAML are the two most widely adopted federation standards, using them inherently results in a trade-off between data quality guarantees and scalability, given how they handle the Metadata about the involved IDPs and SPs. This paper presents a novel approach for federation membership and federation Metadata management based on Distributed Ledger Technology. It applies the core idea of Certificate Transparency, as known from Global-PKI certificate authorities for X.509v3 server certificates, to SAML federation Metadata; therefore, it achieves OpenID Connect's federation building flexibility without losing the significant advantages of traditional SAML federations. An implementation based on Hyperledger Fabric is used to evaluate typical use cases by measuring impacts on Metadata distribution latency and Metadata size, and to discuss the feasibility of the presented approach.
Enabling search directly over encrypted data is a desirable technique to allow users to effectively utilize encrypted data outsourced to a remote server like cloud service provider. So far, most existing solutions focus on an honest-but-curious server, while security designs against a malicious server have not drawn enough attention. It is not until recently that a few works address the issue of verifiable designs that enable the data owner to verify the integrity of search results. Unfortunately, these verification mechanisms are highly dependent on the specific encrypted search index structures, and fail to support complex queries. There is a lack of a general verification mechanism that can be applied to all search schemes. Moreover, no effective countermeasures (e.g., punishing the cheater) are available when an unfaithful server is detected. In this work, we explore the potential of smart contract in Ethereum, an emerging blockchain-based decentralized technology that provides a new paradigm for trusted and transparent computing. By replacing the central server with a carefully-designed smart contract, we construct a decentralized privacy-preserving search scheme where the data owner can receive correct search results with assurance and without worrying about potential wrongdoings of a malicious server. To better support practical applications, we introduce fairness to our scheme by designing a new smart contract for a financially-fair search construction, in which every participant (especially in the multiuser setting) is treated equally and incentivized to conform to correct computations. In this way, an honest party can always gain what he deserves while a malicious one gets nothing. Finally, we implement a prototype of our construction and deploy it to a locally simulated network and an official Ethereum test network, respectively. The extensive experiments and evaluations demonstrate the practicability of our decentralized search scheme over encrypted data.
Alexander Yakubov, Wazen M. Shbair, Anders Wallbom, David Sanda · 5 authors
Public-Key Infrastructure (PKI) is the cornerstone technology that facilitates secure information exchange over the Internet. However, PKI is exposed to risks due to potential failures of Certificate Authorities (CAs) that may be used to issue unauthorized certificates for end-users. Many recent breaches show that if a CA is compromised, the security of the corresponding end-users will be in risk. As an emerging solution, Blockchain technology potentially resolves the problems of traditional PKI systems - in particular, elimination of single point-of-failure and rapid reaction to CAs shortcomings. Blockchain has the ability to store and manage digital certificates within a public and immutable ledger, resulting in a fully traceable history log. In this paper we designed and developed a blockchain-based PKI management framework for issuing, validating and revoking X.509 certificates. Evaluation and experimental results confirm that the proposed framework provides more reliable and robust PKI systems with modest maintenance costs.
Because of the popularity of the Internet, the integration services have gradually changed people daily life, such as e-commerce activities on transactions, transportation and so on. The E-auction, one of the popular e-commerce activities, allows bidders to directly bid the products over the Internet. As for sealed bid, the extra transaction cost is required for the intermediaries because the third-party is the important role between the buyers and the sellers help to trade both during the auction. In addition, it never guarantees whether the third-party is trust. To resolve the problems, the blockchain technology with low transaction cost is used to develop the smart contract of public bid and sealed bid. The smart contract, proposed in 1990 and implements via Ethereum platform, can ensure the bill secure, private, non-reputability and inalterability owing to all the transactions are recorded in the same but decentralized ledgers. The smart contract is composed of the address of Auctioneer, the start auction time, deadline, the address of current winner, the current highest price. In the experiments, the accounts are created through Ethereum wallet. In miner stage, the MinerGate is used in miner stage for obtaining money to pay the transaction fee. At recorder stage, the nodes of blockchain are synchronized to generate smart contract.
An outdated Service Level Agreement (SLA) model, untrusted third parties with access to our data, unknown data location, and unwanted data movement continue to negatively affect trust in the cloud. The majority of current research into cloud trust focuses on ensuring a trustworthy hardware platform using attestations verified by some trusted third party(TTP). We are proposing an approach to improve cloud trust that leverages blockchain technology to help reduce the problem of depending on TTPs for policy evaluation and storage and help track our data. It provides consumers more control and expression of how they want their data handled and by whom. We propose to use Ethereum blockchain for storage and smart contracts as the vehicle for the policies. The main contributions presented in this research are: 1) storing policies in an authoritative source outside the cloud, 2) improving cloud trust by using decentralization, 3) providing a data movement policy model.
Many of today's crypto currencies use blockchains as decentralized ledgers and secure them with proof of work. In case of a fork of the chain, Bitcoin's rule for achieving consensus is selecting the longest chain and discarding the other chain as stale. It has been demonstrated that this consensus rule has a weakness against selfish mining in which the selfish miner exploits the variance in block generation by partially withholding blocks. In Ethereum, however, under certain conditions stale blocks don't have to be discarded but can be referenced from the main chain as uncle blocks yielding a partial reward. This concept limits the impact of network delays on the expected revenue for miners. But the concept also reduces the risk for a selfish miner to gain no rewards from withholding a freshly minted block. This paper uses a Monte Carlo simulation to quantify the effect of uncle blocks both to the profitability of selfish mining and the blockchain's security in Ethereum (ETH). A brief outlook about a recent Ethereum Classic (ETC) improvement proposal that weighs uncle blocks during the selection of the main chain will be given.
Being the largest blockchain with the capability of running smart contracts, Ethereum has attracted wide attention and its market capitalization has reached 20 billion USD. Ethereum not only supports its cryptocurrency named Ether but also provides a decentralized platform to execute smart contracts in the Ethereum virtual machine. Although Ether's price is approaching 200 USD and nearly 600K smart contracts have been deployed to Ethereum, little is known about the characteristics of its users, smart contracts, and the relationships among them. To fill in the gap, in this paper, we conduct the first systematic study on Ethereum by leveraging graph analysis to characterize three major activities on Ethereum, namely money transfer, smart contract creation, and smart contract invocation. We design a new approach to collect all transaction data, construct three graphs from the data to characterize major activities, and discover new observations and insights from these graphs. Moreover, we propose new approaches based on cross-graph analysis to address two security issues in Ethereum. The evaluation through real cases demonstrates the effectiveness of our new approaches.
Roben Castagna Lunardi, Regio A. Michelin, Charles V. Neu, Avelino F. Zorzo
Due to increased number of attacks on the Internet of Things (IoT) devices, the security of IoT networks became critical. Some recent researches proposed the adoption of blockchain in IoT networks without a thorough discussion on the impact of the solution on the devices performance. Furthermore, blockchain employment in the context of IoT can be challenging due to the devices hardware limitations. To fill this gap, this paper proposes an IoT ledger-based architecture to ensure access control on heterogeneous scenarios. This research applies conventional devices used on IoT networks, such as Arduino, Raspberry and Orange Pi boards. Finally, we perform performance evaluation focused on access control of IoT devices and on information propagation through peers on a private IoT network scenario.
Paul Dunphy, Luke Garratt, Fabien A. P. Petitcolas
Distributed Ledger Technology (DLT) has been proposed as a new way to incorporate decentralization into a wide range of digital infrastructures. Applications of DLT to digital identity are increasing in prevalence, with a recent survey reporting that 55% of DLT technologies in development track digital identity. However, while proofs of concept, open source software, and new ideas are readily available, it is still unclear the extent to which DLT can play a role to underpin new forms of digital identity. In this position paper, we situate this fast-moving application domain into the broader challenges faced in digital identity, with the aim to highlight the socio-technical nature of the challenge at hand, and to propose directions for future research.
In this paper, we propose IoTChain, a combination of the OSCAR architecture [1] and the ACE authorization framework [2] to provide an E2E solution for the secure authorized access to IoT resources. IoTChain consists of two components, an authorization blockchain based on the ACE framework and the OSCAR object security model, extended with a group key scheme. The blockchain provides a flexible and trustless way to handle authorization while OSCAR uses the public ledger to set up multicast groups for authorized clients. To evaluate the feasibility of our architecture, we have implemented the authorization blockchain on top of a private Ethereum network. We report on several experiments that assess the performance of different architecture components.
According to the Taiwan Ministry of Education statistics, about one million graduates each year, some of them will go to countries, high schools or tertiary institutions to continue to attend, and some will be ready to enter the workplace employment. During the course of study, the students' all kinds of excellent performance certificates, score transcripts, diplomas, etc., will become an important reference for admitting new schools or new works. As schools make various awards or diplomas, only the names of the schools and the students are input. Due to the lack of effective anti-forge mechanism, events that cause the graduation certificate to be forged often get noticed. In order to solve the problem of counterfeiting certificates, the digital certificate system based on blockchain technology would be proposed. By the unmodifiable property of blockchain, the digital certificate with anti-counterfeit and verifiability could be made. The procedure of issuing the digital certificate in this system is as follows. First, generate the electronic file of a paper certificate accompanying other related data into the database, meanwhile calculate the electronic file for its hash value. Finally, 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. It will provide the demand unit to verify the authenticity of the paper certificate through mobile phone scanning or website inquiries. Through the unmodifiable properties of the blockchain, the system not only enhances the credibility of various paper-based certificates, but also electronically reduces the loss risks of various types of certificates.
Blockchain is at the center of attention recently and it is expected to have a huge impact on healthcare industry including dentistry as well. Blockchain is a fundamental technology behind Bitcoin and itis all about decentralization, security, reliability, and transparency. These characteristics of the technology empower it to disrupt the current healthcare industry in innumerable practices such as supply chain management in pharmaceuticals to prevent the counterfeited medicine, clinical trials to guarantee transparency, healthcare information exchanges or personal health record systems to ensure data integrity and interoperability, etc. It will surely revolutionize the way the current healthcare system works; from provider-oriented to patient-centered. Hence, it is time to seriously consider how we could be a part of this blockchain revolution in dentistry.
Bit coin is a type of crypto currency and worldwide payment system. It allows system to work without a central bank or single administrator and the first decentralized digital currency. Bit coin was invented by an unknown person or group of people under the name Satoshi Nakamoto. The network is peer-to-peer and transactions between the users are direct which are verified by network nodes through the use of cryptography and recorded in a public distributed ledger which is replicated, shared and synchronized digital data called a block chain. Block chain is used as the core technology for the transaction of bit currency, as block chain uses the concept of public and private key. People might think that the lack of control could mean chaos, but this is not true at all because the technology (block chain) behind bit coin is one of the most accurate and secured ever created.
This paper focuses on the results of the research carried out to determine the incidence of Fair Trade as a factor in reducing the poverty of small cocoa producers in the province of Los Rios, Ecuador. It also aimed to ascertain if there are guaranteed aid that will grant them a more direct access to the market for their products, under fairer and more equitable conditions. A mixed research design was used in the study. The qualitative activity was focused on observation, interviews, compilation of documents, registers, materials, and exchanges developed with cocoa producers to collect the information and know their criteria and opinions on the conditions and standard of living. This, however, was carried out from a quantitative point of view. The greatest amount of information was achieved through a structured survey with the application of a multivariate option questionnaire applied to a sample of 177 farmers. The main results obtained revealed that Fair Trade is a key element in reducing poverty levels as long as it is a fundamental part of the territorial development plans of Decentralized Autonomous Governments at all levels. Also, trade unions provide real support to farmers and they also assert their claims using a more continuous use of development premiums, adjustment of minimum guaranteed prices, and pre-financing.
Alan de Carvalho Dias Ferreira, Kassandra Pereria Vitor, Marcelo de Castro Haiachi, Alberto Reinaldo Reppold Filho
The financial support to the Elite Sports carried out historically through tax exemptions to the sports entities, in recent years has been added to a series of governmental actions, with emphasis on the agreements, the granting of scholarships to athletes and the Sports Incentive Law. This paper aims to describe the investment of federal public resources from agreements in paralympic sports, in addition to identifying their main beneficiaries and the types of expenses incurred. In order to do so, a descriptive research was carried out, using documentary research, in the National High-Performance Sport Secretariat of the Ministry of Sports (SNEAR), for the cataloging of agreements, onlending and decentralization agreements entered into by the federal public administration via SNEAR, to finance Paralympic sports from 2008 to 2016. It has been verified that Brazil has invested resources in the Paralympic sport with greater intensity between 2008 and 2014. However, it was evidenced that the Federal Government does not have systematized information or method to systematize the information on the transfer of financial resources through agreements, which was developed in this study. Other public entities, committees, confederations, leagues, federations, clubs and educational institutions are the destinations of the financial resources of the agreements, which can be applied in 12 different ways. Between 2008 and 2016 there was an increase in the amount of funds invested in Paralympic sports, mainly for the preparation of the Rio 2016 Games. The investments made through agreements are mainly in facilities and sports materials. It is concluded that financial resources of the Federal Government are spent without classification of the actions, entities or public to which such resources are destined. Thus, the systematization of this information, presented in this work, can substantially collaborate with the evaluation and formulation of government policies and actions.
Bitcoin is a virtual currency and a payment system based on cutting-edge innovations in cryptography and distributed systems. It has gained a wide range of popularity since its inception in 2009 and became the most successful crypto-currency in the financial market. It was devised by Satoshi NAKOMOTO and has been developed by many other experts before reaching maturity. Bitcoin security has been looked at by different experts in the past with different levels of analysis and it is still a hot research topic since new improvements are continuously being adopted by the community. Our study provides a high-overview of risks related to Bitcoin as a currency and as a payment system using EBIOS method.
The article presents the results of analysis of the distributed registry technology called blockchain. The analysis was performed for the possibility of using the blockchain technology in different spheres of human activity.
Authentication over insecure public networks or with untrusted servers raises more concerns in privacy and security.Modern algebra is one of the significantfields of mathematics. It is a combination of techniques used for a variety of applications including the process of the manipulation of the mathematical categories. In addition,modern algebra deals in depth with the study of abstractions such as groups, rings and fields,the main objective of this article is to provide a novel algebraic verification protocol using ring theory. The protocol is blind, meaning that it detects only the identity, and no additional information will be known anything about the prover (the biometric) to the authenticating server or vice-versa. More officially a blind authentication scheme is a cryptographic protocol that comprises of two parties, a user (the prover) that wants to achieve having signs on her messages, and a signer (the verifier) that is in ownership of his secret signing key. In this paper, we employ the algebraic structure called central Armendariz rings to design a neoteric algorithm for zero knowledge proof. The proposed protocol is established and illustrated through numerical example, and its soundness and completeness are proved.This method gave two important properties for the central Armendariz zero knowledge protocol compared with other known protocols.
A well-functioning financial sector in developing countries is extremely important for economic development. This requires local institutions, which originally were often state-controlled, but gradually non-state actors conquered the financial market. Recently the growing importance of alternative forms of finance in many African countries has become remarkable. Although often created by donors, their role changed when financial inclusion, economic liberalisation and decentralization became more important. Microfinance institutions started to compete with banks by also offering a broad range of services (loans, savings, transfers, accounts, insurance). This is a frugal innovation (less regulated financial institutions compete with regulated ones at a lower cost). Meanwhile, mobile payment revolution has been taking place in Africa and other developing regions. This article analyzes these developments and suggests that these new financial technologies contribute substantially to the 4th industrial revolution in the third world countries. Financial resources that become more available replaces development initiatives and allows developing countries finance industrial and agricultural revolutions with local money. We will deal in detail with one example â the role of M-Pesa in helping people to be 'financially included' and trying to learn from their experience with customer satisfaction for other countries.
In this paper, the German and Korean trade unions are investigated on their history, unionism and strategies. Through an international comparative study between the two countries, the author attempts to draw applicable implications from German-style unionism unique labor relations for Korean unions and their leaders. During the Weimar Republic, the German labor unions were divided along partisan lines, a situation that led to competition among the socialist, communist, Catholic, and liberal trade associations. After World War II, labor leaders wanted to break from the past, and to form a trade union federation independent of political parties. The result was the establishment of the Federation of German Trade Unions (Deutscher GewerkschaftsbundâDGB) in 1949. Four principles guided the founders of the DGB. First, the labor movement wanted representation through an organization that was unitary and autonomous, with no ties to particular religions or political parties. Second, labor leaders decided to organize the unions along with industrial lines so that all workers at one firm would belong to the same union irrespective of their individual occupations. This organizing principle provides unions with greater bargaining power when negotiating with employer associations, because one union represents the entire workforce of an industry. Third, a decentralized system of interest representation was created. Individual unions typically emulate the federal structure, with local, district, state, and national offices. Each level has some input into the shape of union policy. Fourth, the unions chose to rely on legislation for the protection of workers' rights, rather than on direct negotiations with business representatives. German Codetermination Act (Mitbestimmungsgesetz). The act implements the rule of parity (that is, equal representation of shareholders and employees on a supervisory board), especially for German stock corporations, German private limited liability companies and German limited liability partnerships with more than 2,000 employees. The German Codetermination Act was originally highly disputed, but has become an accepted part of corporate Germany in past decades due to attempts to balance the interests of shareholders and employees. âSocial partnershipâ has played a major role to integrate German society, and to alleviate labor disputes after the World War II in Germany. German unionism characterized by codetermination and âsocial partnershipâ between the labor and management can shed light on Koreaâs future industrial relations. Koreaâs union participation rate of 10.2 percent is less than half of what it was in 1989. Among OECD countries, Korean workersâ unionization ranks near bottom. That does not mean that unions do not wield considerable power. Critics accuse union leaders of serving their own interests before those of their workers and undue participation in politics, and say the current setup harms Koreaâs business competitiveness. To others, the unions are a necessary counterweight to the power of chaebol and to thank for gains in workersâ rights and working conditionsâmaking the idea of curbing their power ridiculous if not sinister. An important development in Korean unionism after 1987 was the emergence and rise of a movement independent of the officially recognized Federation of Korea Trade Unions. There were many attempts to organize a separate national center by union activists who did not follow FKTU policy lines although Korean law allowed only one national center until 1997. Non-recognized unions formed the Korea Confederation of Trade Unions and the KCTU was officially recognized by the government in 1999.
Purpose-The financial aspect of local government autonomy is considered a very important topic in the public finance literature especially for the developing countries. Fiscal autonomy empowers the local government units with the right means to provide better services for the community and to proper allocate the funds based on the citizens needs. The purpose of this paper is to study the level of financial autonomy in Albanian municipalities and compare the characteristics within different units of local government. Methodology-In this paper we analyze the financial autonomy of Albanian municipalities by proposing an index to compare the governmental units and classify them in four classes according to the degree of autonomy. Seven quantitative indicators are used in the index, with different importance coefficients. Findings-In Albania, while important progress has been made on advancing the decentralization reform in the last decade, autonomy of local government still remains a challenge. Local authorities do not have appropriate financial resources and they are depended on transfers from the central government budget.
This research aims to analyse the degree of fiscal dependence of local government upon the central government in the regency of Mimika, one of Indonesiaâs eastern regencies. The ratio of fiscal decentralization is used to calculate the local governmentâs ability to increase its regional revenue in order to support development initiatives in all sectors (Malmudi, 2010). Secondary data of locally-generated revenue and total revenue from the period 2010-2015 are used to measure the degree of fiscal decentralization. The results show that the degree of fiscal decentralization in the regency remained at a low level, reflected from the average value of 12.92 percent with the highest degree, of 25.09 percent in 2012. An analysis of fiscal decentralization in the period 2010 â 2015, indicates that the regency lacked sufficient fiscal capacity, showing heavy dependence upon financing from the central government. The local government is expected to develop the regionâs potentiality through creative efforts within their governmental apparatus to increase local revenues. The funds from the central government could provide a positive contribution if used in the consumption of goods and services that potentially support economic activities.
Umut Can Ăabuk, EylĂŒl AdıgĂŒzel, Enis Karaarslan
In the second decade of the 21st century, blockchain definitely became one of the most trending computational technologies. This research aims to question the feasibility and suitability of using blockchain technology within e-voting systems, regarding both technical and non-technical aspects. In today's world, although the course of this spreading is considerably slow, several countries already use means of e-voting due to many social and economic reasons, which we further investigated. Nevertheless, the number of countries offering various e-government solutions, apart from e-voting, is significantly high. E-voting systems, naturally, require much more attention and assurance regarding potential security and anonymity issues, since voting is one of the few extremely critical governmental processes. Nevertheless, e-voting is not purely a governmental service, but many companies and nonprofit organizations would benefit the cost-efficiency, scalability, remote accessibility, and ease of use that it provides. Blockchain technology is claimed to be able to address some, obviously not all, important security concerns, including anonymity, confidentiality, integrity, and non-repudiation. The analysis results presented in this article mostly confirm these claims.