En la actualidad, una organización que administra donaciones tiene dificultades para controlar el flujo de ingreso y salida de donativos, dificultando la trazabilidad de estos. En esta investigación se propone un sistema basado en blockchain que garantice la trazabilidad de los donativos desde su origen hasta su destino, utilizando un protocolo de consenso proof of work y un contrato inteligente (smart contract) con funciones específicas.
Georges Bell Bitjoka, Bouetou Thomas, Ferdinand Yves Mbarga
The study of cryptocurrencies doesn’t clearly propose different approaches that provide cryptocurrency development. The purpose of this paper is to determine approaches to cryptocurrency development, in which we select one to develop a national cryptocurrency that will be able to bring out Cameroun from CFA Franc. Developing a national cryptocurrency or bringing out Cameroun from CFA Franc is a monetary issue which is generalized in the problem of commodity exchange. This problem focuses on how to exchange goods and services while ensuring stakeholder satisfaction. To this end, after a brief literature review on the commodity exchange system, money and Bitcoin, we first explored possible approaches to the development of cryptocurrencies. The study in these approaches has enabled us to determine four different solutions: firstly by token development, secondly by hard fork development, thirdly by fork of source code development, and at last by fork of software development. For each approach, we make a summary presentation which lists its stages of development. The comparison of these approaches in terms of development time, development cost dependence on a blockchain platform and solution to exit from the CFA Franc led us to choose fork of software approach. The fork of software approach of cryptocurrencies development best solves our problem, since it offers us a cryptocurrency development solution, but also proprietary currency which is independent of blockchain platforms. Fork of software is a fork approach that observes behavior of existing software, in view to implementing it again and/or customizing it. We proposed an explorative development method which combines: the iterative and incremental method with evolutionary prototype, for application of the development approach retained above.
Money laundering accounts for approximately US$1 trillion each year. It is difficult to estimate how much of that amount includes cryptocurrencies such as bitcoin. Despite increased global regulation and enforcement, the use of cryptocurrencies in illicit trade and laundering activities grows each year. A corresponding growth in cybercrime, ransomware, identity fraud, and cryptocurrency theft from exchanges feeds the pool of illicit digital proceeds. Recent efforts to reduce cryptolaundering activities have been insufficient despite the global implications for terrorism funding and the cost to governments in continued anticrime enforcement and lost revenue.
The world experienced unprecedented growth in international trade in the past few decades. In this resulting environment of global competition, several new companies have spawned and are spawning. Sellers are often under immense pressure by the market players to accept open-account trade terms, shipping goods before receiving payment, leaving them exposed to increased risk. This creates working capital challenges for firms, especially small and medium enterprises. To mitigate this supply chain risk, several supplier-led and buyer-led supply chain finance solutions are facilitated by banks and financial technology companies. However, because of the new Basel III regulation framework for banks and several other Supply Chain Finance (SCF) adoption barriers, like fraudulent activities, many firms are unable to reap SCF’s full benefits. This study explains various SCF instruments, the key drivers in their growth and their adoption barriers. This study then focuses on the novel blockchain technology and smart contracts by delving deep into their history, components, limitations, risks and use cases. Using the knowledge gathered in the process, a proof-of-concept blockchain and smart contract is developed using the Ethereum platform, which can facilitate normal business, purchase order finance, reverse factoring and reverse securitization. To test the smart contract, four use cases for each SCF instrument mentioned are demonstrated. A JavaScript-based unit test is done to test the smart contract’s correct deployment and onboarding of actors along with their business and financing interactions – access controls to business documents, reverting malicious transactions and correct fund transfer. As a result of various assumptions taken in the development process, the smart contract works only as a basic proof-of-concept and lacks robustness on the ground of scalability and security. As a result, a future model is laid out which will use various software and hardware oracles for autonomous operations while using a complex system of a storage contract, a permanent contract which stores all the data, and logic contract, upgradable contract which can be changed any number of times, with a proxy contract making delegated “function” calls to logic contract to reduce the gas usage due to external function calls.
The field of post-quantum cryptography studies cryptographic systems that are secure against an adversary in possession of a quantum computer. In 2017, the National Institute of Standards and Technology (NIST) initiated a process to standardize quantum-resistant public-key cryptographic algorithms (NIST PQC Project). In this thesis we analyze the performance and security of the Bit-Flipping Key Encapsulation Mechanism (BIKE) -- one of the candidates in the NIST PQC project which advanced to the second round of the standardization process. BIKE is a code-based cryptographic system featuring three different variants of the protocol. In the first round of the NIST PQC project BIKE offered security only against chosen-plaintext attacks (CPA). In the second round, BIKE introduced three new variants that are claimed to be secure also against chosen-ciphertext attacks (CCA). Firstly, we build a secure implementation of the CCA protocol and show that its performance characteristics are only negligibly worse than the CPA variant. In the key decapsulation phase of the protocol BIKE uses a decoding algorithm which fails with some probability, called the Decoding Failure Rate (DFR). We analyze the DFR of two decoders used in BIKE, Back-Flip and Black-Gray, and propose a new decoder, called Black-Gray-Flip, that achieves the same DFR as the two previously used decoders while being almost twice as fast. Finally, we propose an algorithm for inversion of binary polynomials in a polynomial ring used in BIKE-2, the second variant of BIKE. Our implementation of the inversion significantly outperforms previously used algorithms. With this and the fact that the bandwidth requirement for BIKE-2 is the smallest among the three variants, BIKE-2 is positioned as the preferable variant of BIKE. The second part of this thesis studies the Legendre pseudorandom function (PRF) which is proposed to be used in the context of blockchains. We present a new algorithm for cryptanalysis of the Legendre PRF. The complexity of our algorithm is lower than the previous best known algorithm. Moreover, we show the results of breaking three Legendre PRF challenges posed by the Ethereum foundation. The most difficult challenge that we solved set the new record which is not broken so far.
Asuquo A. Okon, Ibrahim Elgendi, Olusegun Samuel Sholiyi, Jaafar M. H. Elmirghani · 6 authors
Whereas 4G LTE networks have brought about an increase in data rates of mobile networks, they are unable to meet the capacity demands of future networks. Specifically, the centralized nature of the evolved packet core (EPC) makes the network non-scalable to match the exponential increase in number of wireless devices in addition to the complexities of diverse service requirements. The SDN concept has recently attracted a lot of research interest as a viable proposition for bringing about programmability and ease of network management while also offering flexibility for innovative network designs. However, current SDN implementations are not adapted to support business agreements that foster interoperability among mobile network operators (MNOs). This paper is an extended version of our earlier work and we intend to present a unified SDN and blockchain architecture with enhanced spectrum management features for enabling seamless user roaming capabilities between MNOs. Our simulation results show that users can experience no disruption in service with very minimal delay as they traverse between operators.
Modern machine learning techniques have achieved surprisingly good standard test accuracy, yet classical machine learning theory has been unable to explain the underlying reason behind this success. The phenomenon of adversarial examples further complicates our understanding of what it means to have good generalization ability. Classifiers that generalize well to the test set are easily fooled by imperceptible image modifications, which can often be computed without knowledge of the classifier itself. The adversarial error of a classifier measures the error under which each test data point can be modified by an algorithm before it is given as input to the classifier. Followup work has showed that a tradeoff exists between optimizing for standard generalization error versus for adversarial error. This calls into question whether standard generalization error is the correct metric to measure. We try to understand the generalization capability of modern machine learning techniques through the lens of adversarial examples. To reconcile the apparent tradeoff between the two competing notions of error, we create new security definitions and classifier constructions which allow us to prove an upper bound on the adversarial error that decreases as standard test error decreases. We introduce a cryptographic proof technique by defining a security assumption in a simpler attack setting and proving a security reduction from a restricted black-box attack problem to this security assumption. We then investigate the double descent curve in the interpolation regime, where test error can continue to decrease even after training error has reached zero, to give a natural explanation for the observed tradeoff between adversarial error and standard generalization error. The second part of our work investigates further this notion of a black-box model by looking at the separation between being able to evaluate a function and being able to actually understand it. This is formalized through the notion of function obfuscation in cryptography. Given some concrete implementation of a function, the implementation is considered obfuscated if a user cannot produce the function output on a test input without querying the implementation itself. This means that a user cannot actually learn or understand the function even though all of the implementation details are presented in the clear. As expected this is a very strong requirement that does not exist for all functions one might be interested in. In our work we make progress on providing obfuscation schemes for simple, explicit function classes. The last part of our work investigates non-statistical biases and algorithms for nonconvex optimization problems. We show that the continuous-time limit of stochastic gradient descent does not converge directly to the local optimum, but rather has a bias term which grows with the step size. We also construct novel, non-statistical algorithms for two parametric learning problems by employing lattice basis reduction techniques from cryptography.
As a decentralized distributed technology, the data network built by blockchain technology is maintained by all nodes in the system, which has the characteristics of decentralization, untamperability, transparency, security and so on. In recent time, the rise of this technology has attracted much attention from finance, health care, education, public management, etc. The organic combination of this technology and supply chain network brings new changes to the industrial situation. This paper is an attempt to discuss the coupling of blockchain technology to automobile supply chain for problems such as the opacity of information and the difficulty of information interaction in the current information sharing level of automotive supply chain. This study aims to build a database of automobile product information from supply to recovery and proposes a system design concept of information sharing platform. This research will provide new ideas for visualizing product data and improving system efficiency in automotive supply chain.
The article is devoted to the analysis of the legal nature of the cryptocurrency as an object of financial and legal regulation from the point of view of Russian legislation. It includes the analysis of the qualification of the cryptocurrency described as money, electronic money, foreign currency, other property, as well as the possibility of assigning crypto-loans to obligations rights. The conclusion is made about the possibility of treating cryptocurrency as private money on a par with national currencies.
Lukas Christopher Eikeri, Sebastian Andresen Amundsen
Utilizing the generalized spillover index developed by Diebold and Yilmaz (2009,\n2012), we investigate the volatility connectedness between an index consisting of\nnine selected cryptocurrencies, S&P 500, Gold, and Copper. Furthermore, we\nstudy the connectedness and volatility spillover within the nine cryptocurrencies\nin the perspective of the categorization of the cryptocurrency market developed by\nCorbet et al. (2020b). To our knowledge, this is the first study investigating the\nconnectedness between these categories. Lastly, we analyze the initial effect of the\nCOVID-19 pandemic by using an extended set of data to June 2020 on the\nconnectedness within the cryptocurrency market. We also test the connectedness\nbetween the cryptocurrency market, S&P 500, and Gold during the same period.\nWe find that the cryptocurrency market has a weak connectedness with other\nfinancial markets, indicating that most of the volatility comes from within the\ncryptocurrency market. When studying the volatility spillover within the\ncryptocurrency market, in the perspective of categorizations, our results show that\nmost of the volatility is within the respective categories. Adding to this, there are\nsome key differences in the relationship of the categories. Finally, the COVID-19\npandemic increased the volatility and the spillovers across all markets. However,\nthe effects do not affect the results for the cryptocurrencies substantially.
Cloud Manufacturing is a manufacturing paradigm that focuses on collaboration and resource utilization. Until recently, little research has been done to combine the perspectives of cloud manufacturing and digital platform ecosystems. In the cloud manufacturing paradigm, the cloud coordinator takes up the dual role of a matchmaker and a platform owner, though, so it is interesting to research how any power dominance of the platform owner can be avoided. To do so, three dimensions of platform governance suggested by Tiwana 2014 – pricing policies, decision rights, and control – were considered in this contribution to recommend a fair value distribution mechanism for platform ecosystems in cloud manufacturing. Requirements for such a solution are formulated in this contribution and design patterns satisfying these requirements are derived. We propose using tokens administrated by distributed ledger technologies and smart contracts to enable a special split revenue scheme that satisfies the
There has been exponential growth in the use of digital technology around the globe in many businesses, due to the rapid technological advancement. The FinTech innovation like Machine learning, Artificial Intelligence and Distributed Ledger Technology (DLT) are revolutionizing the way business are being done today. One such industry that has been greatly influenced is the financial sector, with introduction of cryptocurrency as an instrument for buying and selling goods. This paper has objectives on implementation of DLT technology in a form of Proof of Concept for carrying out Anti-Money Laundering and Know Your Customer operation for the financial institution. As this from the first line of defence for the institution and the first point of user experience making it critical for the organisation. In the solution that user will be provide with control of the information and the organisation will be able to more transparent and auditable in line to the various financial regulation.
The Industrial Internet of Things (IIoT) plays an important role in the development of smart factories. However, the existing IIoT systems are prone to suffering from single points of failure and unable to provide stable service. Meanwhile, with the increase of node scale and network quantity, the maintenance cost presents to be higher. Such a disadvantage can be effectively compensated by the features such as security, privacy, non-tamperability and distributed deployment supported by the blockchain. In this paper, first, an intelligent manufacturing security model based on blockchain was proposed. Due to the high power consumption and low throughput of the traditional blockchain, IoT devices with limited power consumption can not work independently. Therefore, in this paper, a new Merkle Patricia tree (MPT) was adopted to extend the blockchain structure and provide fast query of node status. Second, since the MPT does not support concurrent operation and the data operation performance deteriorates with high data volume, a lock-free concurrent and cache-based Merkle Patricia tree was proposed (CMPT) to support lock-free concurrent data operation, which can improve the data operation efficiency in multi-core system. The experimental results indicate that, compared with the original MPT, the CMPT proposed in this paper effectively reduced the time complexity of data insertion and data query and improved the speed of block construction and data query.
Data tracking is of great significance and a central part in digital forensics. In today's complex network design, Internet of Things (IoT) devices communicate with each other and require strong security mechanisms. In maintaining an audit trail of IoT devices or provenance of IoT device data, it is important to know the origins of requests to ensure certain level of trust in IoT data. Blockchain can provide traceability of records generated from IoT devices in a sensitive environment. In this paper, we present an application layer data provenance model that works on execute-order architecture for cloud based IoT networks. It supports high throughput of transactions on the blockchain network with lightweight security overhead by using outsourced encryption on edge nodes. All communications among the IoT devices are connected to a blockchain network and stored on permissioned blockchain peers. The proposed system is evaluated to have less cryptographic load by offloading the IoT nodes with Edge nodes.
In recent years, the rapid development of blockchain technologies have attracted worldwide attention. Its application has been extended to many fields, such as digital finance, supply chain management, and digital asset transactions. For some enterprises and users, how to choose the most effective platform from many blockchains to control costs and share data is an important issue. To comprehensively evaluate the blockchain technologies, we first construct three-level evaluation indicators in terms of technical, market, and popularity indicators. Then, we propose an improved global DEA-Malmquist index without explicit inputs to assess the dynamic performance of blockchain technologies. Finally, we carry out an empirical analysis to evaluate 31 public blockchains' performance from May 2018 to April 2020. The results indicate that the overall performance of blockchain technologies is basically on the rise. Some blockchain technologies that have not yet received widespread attention have shown good dynamic performance.
Most people first encounter blockchain technology by way of cryptocurrencies like Bitcoin. Bitcoin came into existence during the start of the 2008 financial crisis and was first disclosed in October 2008.1Because of the timing and some clear indicators embedded into the first (genesis) block of Bitcoin, we know that a primary reason for developing cryptocurrency was a distrust of large institutions that control the world’s fiat currencies. However, what does currency have to do with media technology?
Roberta Bertagnoli Gasparo, Haroldo José José Torres da Silva
econômico: traz soluções para o mercado e estimula o debate frente ao "novo".Foi a partir do avanço do uso da internet de maneira global que os mercados eletrônicos alavancaram a tecnologia da informação para combinar compradores e vendedores de modo eficaz (Nian e Chuen, 2015).Soluções digitais para transações financeiras eliminam barreiras geográficas, estimulam o desenvolvimento tecnológico e reduzem a burocracia estatal sobre as transações comerciais, aliviando a carga