Noureddine Lasla, Mohamed Younis, Wassim Znaïdi, Dhafer Ben Arbia
Cooperative Intelligent Transportation System (C- ITS) enables inter-networking of vehicles for alerts exchanging in order to improve road safety. While this technology is about to enter the market in the upcoming years, critical questions related to the communication security continue to be challenging research concerns. Current solutions to secure inter-vehicle communication depend mainly on the use of digital certificates for authentication. However, such an approach imposes significant overhead on vehicles since it is computationally demanding and requires validation of the certificate within a limited period. In addition, relying on a central node for deciding on issuing and revoking certificates introduces a single point of failure and could even risk the safety of motorists. In this paper, we propose the use of Blockchain to keep track of the certificate of each vehicle (valid or revoked) in distributed and immutable records. In essence we replace certificate verification with a lightweight blockchain-based authentication approach. In addition, we propose a fully distributed vehicle admission/revocation scheme. We show that our scheme could alleviate the computation overhead and enhance the response time while improving the overall system security.
Growing consumer awareness as well as manufacturers’ internal quality requirements lead to novel demands on supply chain traceability. Existing centralized solutions suffer from isolated data storage and lacking trust when multiple parties are involved. Decentralized blockchain-based approaches attempt to overcome these shortcomings by creating digital representations of physical goods to facilitate tracking across multiple entities. However, they currently do not capture the transformation of goods in manufacturing processes. Therefore, the relation between ingredients and product is lost, limiting the ability to trace a product’s provenance. We propose a blockchain-based supply chain traceability system using smart contracts. In such contracts, manufacturers define the composition of products in the form of recipes. Each ingredient of the recipe is a non- fungible token that corresponds to a batch of physical goods. When the recipe is applied, its ingredients are consumed and a new token is produced. This mechanism preserves the traceability of product transformations. The system is implemented for the Ethereum Virtual Machine and is applicable to any blockchain configuration that supports it. Our evaluation reveals that the gas costs scale linearly with the number of products considered in the system. This leads to the conclusion that the solution can handle complex use cases.
Research on Chinese civil society has tended to focus on the relationship between non-governmental organizations (NGOs) and the state. Such work has underestimated the complexity of the emerging institutional environment where Chinese NGOs are often caught between the state, the market, and a constrained civil society. How do civil society organizations and their respective nonprofit sectors emerge, what forms do they take? More specifically, how do organizational forms and strategies reflect political and market structures at the time? Chinese nonprofit sectors re-emerged in the late 1990s, and their relationships with the state have been contentious. The rapid transformation of the nonprofit sectors provides a unique opportunity to look at the emergence of a new organizational field. Using strategic action fields (SAFs) theory, I examine how organizations within the field of nonprofit organizations attempted to establish and defend their positions vis-à-vis the state and market. I conducted comparative case studies of two leading China's NGOs –Civil Society Center (CSC) in the city of Guangzhou and Excellence Promoter (EP) in the city of Shanghai. I traced the histories and current development of CSC and EP and their connected organizations and used ethnographic, interview, and survey data to triangulate the emerging urban nonprofit sectors in the context of an authoritarian state. I argue that, in different periods, the nonprofit organizational fields of Guangzhou and Shanghai reflected political and market structures at the time. In the early 2000s, Guangzhou’s nonprofit organizations were grassroots-driven, and a State Avoidance Autonomous field arose as large organizations decentralized into smaller organizations to decrease state scrutiny and intervention. In contrast, in Shanghai, where the state promoted nonprofit organizations as an extension of governmental programs, a State Alliance Social Market Field developed. This State Alliance Social Market Field prioritized business values and practices to guide organizational strategies rather than the ethical commitments that had been the center of the State Avoidance Autonomous field. By partnering with government, EP was able to rapidly expand while its Guangzhou counterpart, CSC, remained small and marginal. Powerful e-commerce companies such as Tencent, however, have been changing the rules and norms that used to govern the field. They entered the nonprofit field through the creation of a new fundraising platform that opened up alternative resources for Chinese NGOs. The involvement of the market through corporate foundations and new technologies has provided alternative funding for grassroots NGOs under the attack from the state. My study contributes to nonprofit studies and China studies by providing insight into how NGOs interact with different state and market players and the consequences of such interactions on organizational strategies.
Privacy in online applications has drawn tremendous attention in recent years. With the development of cloud-based applications, protecting users' privacy while guaranteeing the expected service from the server has become a significant issue. This paper surveyed the most popular cryptographic algorithms in privacy-preserving online applications to provide a tutorial-like introduction to researchers in this area. Specifically, this paper focuses on introduction to homomorphic encryption, secret sharing, secure multi-party computation and zero-knowledge proof.
Lohkoketjuteknologia tuli tietoisuuteen vuonna 2008, kun sitä käytettiin maailman ensimmäisen kryptovaluutan, Bitcoinin taustalla. Lohkoketjun merkitys huomattiin heti, mikä näkyikin huomattavana määränä muiden kryptovaluuttojen syntymisenä. Lohkoketjuteknologiaa voidaan hyödyntää kryptovaluuttojen lisäksi myös muihin tarkoituksiin, ja esimerkiksi maailman isoimmat pankit tutkivat lohkoketjuteknologian mahdollisuuksia, mukaan lukien Yhdysvaltain keskuspankki sekä Euroopan keskuspankki. Tämän kirjallisuuskatsauksena toteutettavan tutkielman tarkoituksena on antaa pintapuolinen käsitys lohkoketjun toimintaperiaatteista, hyödyntämiskohteista sekä haasteista. Tutkielmassa perehdytään myöskin lohkoketjuteknologian keskiössä oleviin konsensusmekanismeihin, kuten Bitcoinissa käytettävään proof-of-work -mekanismiin. Lohkoketjuteknologian perimmäinen idea on, että verkon osapuolista jokainen pitää hallussaan täsmälleen samaa tietoa. Mikäli tietoja halutaan muuttaa, verkon osapuolien täytyy päästä asiasta yhteisymmärrykseen eli konsensukseen. Tämän vuoksi olemassa olevia tietoja on todella vaikea muuttaa, mikä on yksi lohkoketjuteknologian suurimmista hyödyistä. Konsensukseen voidaan päästä eri tavoilla riippuen valitusta konsensusmekanismista. Suurimmat kryptovaluutat käyttävät proof-of-work -mekanismia, eli todistetta tehdystä työstä, mutta esimerkiksi Ethereum on siirtymässä käyttämään proof-of-stake -mekanismia, eli todistetta panoksesta. Käytetty konsensusmekanismi on avainasemassa lohkoketjun toiminnassa, ja esimerkiksi Bitcoinin tapauksessa sen käyttämä konsensusmekanismi on syy sen globaalisti merkittävään virrankulutukseen.
The logical consequence of the concept of regional autonomy is the presence of fiscal decentralization. The independence of rural communities in the formulation of programs for the administration of governance and development at the village level becomes the space of urgency of village financial management, because substantially, through the enormous financial support Central Government, Provincial Government and Regency / City Government, the village is required to be able to organize governance and development implementation properly and correctly. Furthermore, increasing public demand for good governance has encouraged the central government and regional governments to implement public accountability. Krina describes accountability as a principle that guarantees that every administration activity can be accounted openly by the perpetrator to those affected by the implementation of the policy. Based on the problem, the paper builds on literature reviews covering various dimensions of Open Government and its applicability to village finance to build the empirical evidence and the frameworks. \nKeywords—Transparency, Village Finance system, Open \nGovernment Partnership
espanolLos contratos inteligentes o smart contracts, son una realidad que se viene aplicando desde hace tiempo, aunque han ganado relevancia con motivo del descubrimiento de la cadena de bloques. Tanto los smart contracts que se ejecutan de acuerdo con dicha tecnologia como los que tienen lugar fuera de ella responden esencialmente a un mismo esquema: son secuencias de codigo que expresan o implementan acuerdos existentes que pueden producir efectos juridicos cuya peculiaridad esencial es que se ejecutan de manera autonoma. Este articulo se dedica al estudio de los retos juridicos que suscitan los smart contracts con relevancia juridica ejecutados fuera de una cadena de bloques; en concreto, a si son o no contratos, a su proceso de formacion, a la incidencia que tiene en ellos el error, a su prueba en el proceso judicial, asi como a algunos aspectos relativos al pago. A fin de comprender de manera completa los contratos inteligentes, tambien se analiza su significado, su origen historico, su funcionamiento, sus ventajas y las dificultades que presentan. EnglishSmart contracts are a reality that has been applied for decades, although they have gained relevance due to the discovery of the blockchain. Both the smart contracts that are executed according to said technology and those which take place outside of it, respond essentially to the same scheme: they are code sequences which express or implement existing agreements that can produce legal effects whose essential feature is that they are self-executable autonomously. This paper is dedicated to the study of the legal challenges that arise from smart contracts executed outside the blockchain; in particular, to whether or not they are contracts, to their making process, to the incidence that the error has on them, to their proof in the judicial procedure, as well as to some aspects related to payment. In order to get a full understanding of smart contracts, their meaning, their historical origin, their operation, their advantages and their difficulties will be also analyzed.
Smart Sukuk structure is one of the most recent and significant structures for future sukuk
issuances. In the era of crowed funding and Financial Technology Enhancement, the Smart
Sukuk seems to be the future of Islamic fundraising for infrastructure and Business
developments. The equity wise Mudarabah contract of the Islamic Finance has proved to be
one of the most feasible contracts to govern the smart sukuk issuances. The conventional
Mudarabah Sukuk structure represents projects or business activities managed based on
Mudarabah contract. However, the unique features of smart sukuk and the proposed
Mudarabah smart contract is that, it has given rooms for more players to participate in sukuk
issuances, where as the conventional sukuk issuances has technically allowed mostly the
participations of big players such as government agencies, banks and large companies among
others. The revolutionary smart sukuk uses the block chain technology to boost the efficiency
and makes the process more transparent and reduces the issuance cost to secure the
involvements of small and medium enterprises SMEs, associations and social impact projects
owners to participate in the sukuk issuances. The paper studied the structure of the
conventional Mudarabah sukuk and proposed the newly smart Sukuk with its unique and
innovative features structured under the concept of Mudarabah smart contract.
The information age has dawned upon us through the comprehensive and boundless adoption of the internet; E-banking and smart-phones thus, causing a reliance on online transaction sys-tems reducing the need to handle tangible cash notes. The current monetary system is arguably on the cusp of an evolutionary moment through the adoption of virtualised currencies, this phe-nomenon potentially possesses the next metamorphic step in contemporary global economic money. Cryptocurrency is a radical new innovation, and has become a widely debated topic over the past few years despite this, the topic of the diffusion of innovation and the procedures which the phenomenon needs to overcome have had relatively small amounts of academic attention in comparison to other fields of research. Therefore, this study aims to identify how cryptocurrency is diffusing through the diffusion of innovation model with the intention of identifying the current location of diffusion; this in turn will create a more universalised understanding of the phenomenon in regards to other radical innovations. Due to the nature of the study, the conducted research utilised a qualitative method. Additional-ly, the focus on collecting data which will positively reflect an academic study with the purpose of uncovering information in alignment with the research questions of the study at hand lead to an ‘interpretivist’ methodology. Hence, 10 interviews were conducted of which the interviewees came from a range of different countries allowing the researcher to identify information rich da-ta. This approach allowed for two pathways of research to occur. Firstly, the non/potential in-vestors of which had basic cryptocurrency knowledge and secondly, current users/investors of which had an overall understanding of the cryptocurrency phenomenon. Furthermore, the pri-mary data alongside the utilisation of secondary survey questions and the literature allowed for a wider understanding of the phenomenon. The results of the study unveiled a range of trends and developments in the diffusion process. Accordingly, these findings advance the understanding of the micro, macro and psychological factors which are present in the diffusion of the cryptocurrency innovation. Thereby, the re-search draws attention to how a range of barriers synergistically working together requires a synergistic strategic approach from governments and individuals to surpass the current diffu-sion position and progress further, in turn increasing the chances of mainstream adoption.
Cryptocurrencies such as Bitcoin might revolutionize the economy through enabling peer-to-peer based transactions by abolishing the need for a trusted intermediary. As for now, Bitcoin remains to be the best recognized cryptocurrency, in particular in terms of market capitalization. However, as this paper shows, there are plenty of alternatives. This paper outlines the historical roots which have led to the creation of privately emitted, cryptography based digital currencies. Additionally, this paper discusses future possible hurdles of the development of cryptocurrencies and outlines features which might influence the success of a cryptocurrency. Insights into the beginning of cryptocurrency development are gained by analysis of the publicly available DOACC dataset. The paper does so by providing an overview of the techniques and mechanisms used by cryptocurrencies. It shows that newly created cryptocurrencies tend to be very similar in some properties in the early stages but new features and more diversity developed in more recent years. Additionally, newly created cryptocurrencies tend more and more to create a fixed number of coins before the initial announcement in order to sell these in Initial Coin Offerings. Even when the amount of premining increases over years, it remains at lower levels on the aggregate.
Digital currencies and cryptocurrencies have hesitantly started to penetrate the investors, and the next step will be the regulatory risk management framework. We examine the Value-at-Risk and Expected Shortfall properties for Bitcoin and Ethereum, using GARCH methodology and filtered historical simulation. We find the both Bitcoin and Ethereum are subject to a higher risk, therefore, to higher sufficient buffer and risk capital to cover potential losses.
Diese Arbeit untersucht die Möglichkeiten, einen exemplarischen kaufmännischen Prozess mit verschiedenen Akteuren auf der Ethereum-Plattform abzubilden. Das Wissen über die Funktionsweise der Blockchain-Technologie stellt die Grundlage für die Bearbeitung dar. Unter Berücksichtigung der Besonderheiten verteilter Systeme hinsichtlich der Datenhaltung sowie des Datenschutzes wird ein Konzept für die Abwicklung eines Warenan- bzw. Verkaufs entwickelt. Darin wird die Integration eines zusätzlichen Systems zur Speicherung von Daten vorgestellt, das sich kryptografischer Funktionen der Ethereum-Plattform bedient. Für wichtige Teile des Systems werden zudem Implementierungshinweise gegeben.