Νικόλαος Αλεξόπουλος, Jörg Daubert, Max Mühlhäuser, Sheikh Mahbub Habib
Trust Management (TM) systems for authentication are vital to the security of online interactions, which are ubiquitous in our everyday lives. Various systems, like the Web PKI (X.509) and PGP's Web of Trust are used to manage trust in this setting. In recent years, blockchain technology has been introduced as a panacea to our security problems, including that of authentication, without sufficient reasoning, as to its merits.In this work, we investigate the merits of using open distributed ledgers (ODLs), such as the one implemented by blockchain technology, for securing TM systems for authentication. We formally model such systems, and explore how blockchain can help mitigate attacks against them. After formal argumentation, we conclude that in the context of Trust Management for authentication, blockchain technology, and ODLs in general, can offer considerable advantages compared to previous approaches. Our analysis is, to the best of our knowledge, the first to formally model and argue about the security of TM systems for authentication, based on blockchain technology. To achieve this result, we first provide an abstract model for TM systems for authentication. Then, we show how this model can be conceptually encoded in a blockchain, by expressing it as a series of state transitions. As a next step, we examine five prevalent attacks on TM systems, and provide evidence that blockchain-based solutions can be beneficial to the security of such systems, by mitigating, or completely negating such attacks.
Daniel Augot, Hervé Chabanne, Olivier Clémot, William R. George
The most fundamental purpose of blockchain technology is to enable persistent, consistent, distributed storage of information. Increasingly common are authentication systems that leverage this property to allow users to carry their personal data on a device while a hash of this data is signed by a trusted authority and then put on a blockchain to be compared against. For instance, in 2015, MIT introduced a schema for the publication of their academic certificates based on this principle. In this work, we propose a way for users to obtain assured identities based on face-to-face proofing that can then be validated against a record on a blockchain. Moreover, in order to provide anonymity, instead of storing a hash, we make use of a scheme of Brands to store a commitment against which one can perform zero-knowledge proofs of identity. We also enforce the confidentiality of the underlying data by letting users control a secret of their own. We show how our schema can be implemented on Bitcoin's blockchain and how to save bandwidth by grouping commitments using Merkle trees to minimize the number of Bitcoin transactions that need to be sent. Finally, we describe a system in which users can gain access to services thanks to the identity records of our proposal.
A developing field of interest for the distributed systems and applied cryptography community is that of smart contracts: self-executing financial instruments that synchronize their state, often through a blockchain. One such smart contract system that has seen widespread practical adoption is Ethereum, which has grown to secure approximately 30 billion USD of currency value and in excess of 300,000 daily transactions. \n \nUnfortunately, the rise of these technologies has been marred by a repeated series of security vulnerabilities and high pro file contract failures. To address these failures, the Ethereum community has turned to formal verification and program analysis which show great promise due to the computational simplicity and bounded-time execution inherent to smart contracts. Despite this, no fully formal, rigorous, comprehensive, and executable semantics of the EVM (Ethereum Virtual Machine) currently exists, leaving a lack of rigor on which to base such tools. \n \nIn this work, we present KEVM, the first fully executable formal semantics of the EVM, the bytecode language in which smart contracts are executed. We create this semantics in a framework for executable \nsemantics, the K framework. We show that our semantics not only passes the official 40,683-test stress test suite for EVM implementations, but also reveals ambiguities and potential sources of error in the existing \non-paper formalization of EVM semantics on which our work is based. \n These properties make KEVM an ideal formal reference implementation against which other implementations can be evaluated. \n \nWe proceed to argue for a semantics-first formal verification approach for EVM contracts, and demonstrate its practicality by using KEVM to verify practically important properties over the arithmetic operation of an \nexample smart contract and the correct operation of a token transfer function in a second contract. We show that our approach is feasible and not computationally restrictive. We hope that our work serves as the base for the development of a wide range of useful formally derived tools for Ethereum, including model checkers, certified compilers, and program equivalence checkers.
We present an architecture for peer-to-peer energy markets which can guarantee that operational constraints are respected and payments are fairly rendered, without relying on a centralized utility or microgrid aggregator. We demonstrate how to address trust, security, and transparency issues by using blockchains and smart contracts, two emerging technologies which can facilitate decentralized coordination between non-trusting agents. While blockchains are receiving considerable interest as a platform for distributed computation and data management, this is the first work to examine their use to facilitate distributed optimization and control. Using the Alternating Direction Method of Multipliers (ADMM), we pose a decentralized optimal power flow (OPF) model for scheduling a mix of batteries, shapable loads, and deferrable loads on an electricity distribution network. The DERs perform local optimization steps, and a smart contract on the blockchain serves as the ADMM coordinator, allowing the validity and optimality of the solution to be verified. The optimal schedule is securely stored on the blockchain, and payments can be automatically, securely, and trustlessly rendered without requiring a microgrid operator.
The Internet provided the world with interconnection. However, it did not provide it with trust. Trust is lacking everywhere in our society and is the reason for the existence of powerful intermediaries aggregating power. Trust is what prevents the digital world to take over. This has consequences for organisations: they are inefficient because time, energy, money and passion are wasted on verifying everything happens as decided. Managers play the role of intermediaries in such case: they connect experts with each others and instruct them of what to do. As a result, in our expert society, people’s engagement is low because no one is there to inspire and empower them. In other words, our society faces an unprecedented lack of leadership. Provided all those shortcomings, the study imagines the potential repercussions, especially in the context of management, of implementing a blockchain infrastructure in any type of organisation. Indeed, the blockchain technology seems to be able to remedy to those issues, for this distributed and immutable ledger provides security, decentralisation and transparency. In the context of a blockchain economy, the findings show that value creation will be rearranged, with experts directly collaborating with each others, and hierarchy being eliminated. This could, in turn, render managers obsolete, as a blockchain infrastructure will automate most of the tasks. As a result, only a strong, action-oriented, leadership would maintain the organisation together. This leadership-in-action would consist in igniting people to take action; coach members of the organisations so that their contribution makes sense in the greater context of life.
Cryptocurrencies — being digitally transmitted and embodied within peer-to-peer infrastructures — may mediate new forms of peer-driven interactions and collaborations among Internet users. In this paper, I performed in-depth interviews of cryptocurrencies’ emerging uses with 16 participants between September 2013 and March 2015. My analysis of how these users have used cryptocurrencies revealed a new feature, large-crowd, cost-effective transactions (trades involving massive numbers of participants), that can drive trades involving massive numbers of participants. Cryptocurrencies, having a peer-driven logical infrastructure, are already known to offer a freer alternate medium for users to customize or automate monetary processes. But the newly identified feature makes it possible for peer producers to organize work payment options involving a large crowd of contributors. This capacity suggests the emergence of many-to-many financial flows in small individual amounts. Taken together, I identify a cluster of temporal and spatial ways that cryptocurrencies remix and automate payment mechanisms and pathways.
Smart contracts are contracts essentially in form of Computer Codes, where the terms of the contract are enforced by the logic of the program’s execution. They do not require judgement or skill of any specialist. This allows us to form a vastly strong system of checks-and-balances, in a trust-less and decentralised manner. Smart contracts also gain the benefit of global transferability, without sacrificing any local knowledge. It’s both cost and time effective. Smart Contracts would dramatically reduce the costs of developing, maintain and securing our relationships. It’s very similar to an online Chessboard game, where the players would design the rules of the game before they are willing to play. And once the rules are agreed on, the Contract would act as a board manager, this allows the parties to move freely but within the rules of the game. Although, enforceability is a challenge to proper working of Smart Contracts, many international conventions can be used to govern the working of such contracts. There exists a clear lack of theoretical framework in this respect. This paper tries to draw out such a theoretical framework by identifying the different modes for regulating and enforcing smart contracts in multiple jurisdictions. Establishment of a legal framework regulating Smart Contracts would be a giant leap in the field of Contractual Laws.
The implementation of good quality and equitable education is facing more complex challenges. Educational institutions which do not function properly and the low quality of human resources are the main factors besides other factors that need immediate attention in the world of Islamic education. The efficiency in education does require more decentralized management, as a matter of fact. The function of institutions in the implementation of autonomy in the area of Islamic education in particular should be able to manage and apply educational techniques autonomously either in the field of School-Based Management, organization, personnel, curriculum, facilities and infrastructure, studentship, cost and public relations as an opportunity or external environment as a challenge. The reposition of Islamic education in madrasah, modernization of boarding houses, and autonomy in higher education are the expectations of all sides in order to achieve good quality education which is managed by professional technical practitioners.
Bitcoin, a protocol for a new permissionless decentralized digital currency hailed the arrival of a new application domain for computer science. Following Bitcoin's arrival, a series of innovations derived from the state of the art in several fields has been applied to cryptocurrencies, and has been slowly reshaping monetary and financial instruments on public distributed ledgers. It was soon clear however that Bitcoin and similar cryptocurrencies still require additional improvements. This challenging domain presents researchers in the field with new and exciting questions. I provide examples from two main research threads, related to the scalability of the protocol and to its underlying incentives.
Viktor Dmytrovych Chernadchuk, Viktor Sukhonos, Inna Shkolnyk
The financial system of the advanced countries develops according to two basic models – a bank-based system and a market-based system, depending on the level of protection of the rights of owners, investors and lenders. A paradigm shift in functioning of global financial system and financial systems of all countries is based on financial law, which formalizes all financial relations. Reviewing the financial system of Ukraine, the researchers pay a special attention to public finance due to its substantial share in redistribution of Ukraine’s GDP. A comparative analysis of the concept “financial system” makes it possible to draw a certain analogy with the approaches of experts in financial law. From the economic point of view, a country’s financial system includes three key areas – state finance, household finance and corporate finance, which are closely interrelated. Matching these three spheres with the legal approach, state finance is defined as public finance, while household finance and corporate finance are referred as private finance. The financial market functions as a part of the financial system. In economic terms, the financial system is a dynamic and open environment, while it implies an intense movement of financial resources, a rapid emergence of new financial instruments and integration into the global financial market. From the legal point of view, the financial system is a static financial and legal phenomenon, which includes centralized and decentralized public funds, as well as funds of business entities and individuals.
BACKGROUND: Digital health technologies, including telemedicine, mobile health (mHealth), and remote monitoring, are playing a greater role in medical practice. Safe and accurate management of medical information leads to the advancement of digital health, which in turn results in a number of beneficial effects. Furthermore, mHealth can help lower costs by facilitating the delivery of care and connecting people to their health care providers. Mobile apps help empower patients and health care providers to proactively address medical conditions through near real-time monitoring and treatment, regardless of the location of the patient or the health care provider. Additionally, mHealth data are stored in servers, and consequently, data management that prevents all forms of manipulation is crucial for both medical practice and clinical trials. OBJECTIVE: The aim of this study was to develop and evaluate a tamper-resistant mHealth system using blockchain technology, which enables trusted and auditable computing using a decentralized network. METHODS: We developed an mHealth system for cognitive behavioral therapy for insomnia using a smartphone app. The volunteer data collected with the app were stored in JavaScript Object Notation format and sent to the blockchain network. Thereafter, we evaluated the tamper resistance of the data against the inconsistencies caused by artificial faults. RESULTS: Electronic medical records collected using smartphones were successfully sent to a private Hyperledger Fabric blockchain network. We verified the data update process under conditions where all the validating peers were running normally. The mHealth data were successfully updated under network faults. We further ensured that any electronic health record registered to the blockchain network was resistant to tampering and revision. The mHealth data update was compatible with tamper resistance in the blockchain network. CONCLUSIONS: Blockchain serves as a tamperproof system for mHealth. Combining mHealth with blockchain technology may provide a novel solution that enables both accessibility and data transparency without a third party such as a contract research organization.
The incorporation of the territorial perspective into the Common Fisheries Policy (CFP), through the delimitation of fishing areas and the creation of Fishery Local Action Groups (FLAGs), has allowed the decentralized management Axis 4 of the European Fisheries Fund (EFF) through the application of the LEADER method in this sectoral policy. The present study brings together the research of five case study regions (including Portugal) and their FLAGs in the period 2007-2013. Based on the analysis of each participatory local development strategy (LDS) and measures financed, there are different responses to the experience: misalignment and lack of cohesion between projects, excessive dependence on local power, and, in contrast, very meritorious actions and impact both in the fisheries sector and in the sustainable development of the coastal communities.
With recent alarm and focus on Bitcoin , many researchers tried to come up with studies that are related to Bitcoin. This paper tries to do the same but with a focus on the area of Islamic finance. We try to relate Bitcoin and Islamic index to find if there is any relation between these two assets and to find which will stand out if they are put in one portfolio. Since both assets are deemed to be of high risk in nature, it is an interesting topic to be investigated especially if they are put together. This analysis was carried out using the standard time-series approach of cointegration, VECM and VDC. The empirical results evidenced that Bitcoin and Islamic index are theoretically related as they are cointegrated. Another interesting finding in this study unveiled that Islamic index will be more influential than Bitcoin if they are put in one portfolio.
Although Bitcoin has long been dominant in the crypto scene, it is certainly not alone. Ether is another cryptocurrency related project that has attracted an intensive attention because of its additional features. This study seeks to test whether these cryptocurrencies differ in terms of their volatile and speculative behaviors, hedge, safe haven and risk diversification properties. Using different econometric techniques, we show that a) Bitcoin and Ether are volatile and relatively more responsive to bad news, but the volatility of Ether is more persistent than that of Bitcoin; b) for both cryptocurrencies, the exuberance and the collapse of bubbles were identified, but Bitcoin appears more speculative than Ether; c) there is negative and significant correlation between Bitcoin/Ether and other assets (S\&P500 stocks, US bonds, oil), which would indicate that digital currencies can hedge against the price movements of these assets; d) there is negative tail independence between Bitcoin/Ether and other financial assets, implying that these cryptocurrencies exhibit the function of a weak safe haven; and e) The inclusion of Bitcoin/ Ether in a portfolio improve its efficiency in terms of higher reward-to-risk ratios. But investors who hold diversified portfolios made of stocks or bonds and Ether may face losses over bearish regime. In such situation, stock and bond investors may take a short position on Bitcoin.
At the heart of the Bitcoin is a blockchain protocol, a protocol for achieving consensus on a public ledger that records bitcoin transactions. To the extent that a blockchain protocol is used for applications such as contract signing and making certain transactions (such as house sales) public, we need to understand what guarantees the protocol gives us in terms of agents' knowledge. Here, we provide a complete characterization of agent's knowledge when running a blockchain protocol using a variant of common knowledge that takes into account the fact that agents can enter and leave the system, it is not known which agents are in fact following the protocol (some agents may want to deviate if they can gain by doing so), and the fact that the guarantees provided by blockchain protocols are probabilistic. We then consider some scenarios involving contracts and show that this level of knowledge suffices for some scenarios, but not others.
There is an exceptional character to the Canadian federation when it comes to dynamic de/centralization. Despite expectations that forces of modernization and globalization centralize federations, Canada’s overall “federal balance” has remained largely stable since 1867. Early in the federation’s life, there was decentralization in the fiscal realm and in a few policy fields (e.g., finance and securities as well as employment relations). The last several decades have witnessed decentralization in several policy fields, such as agriculture, citizenship, and immigration, and natural resource, but also centralization in such crucial ones as social welfare and language. The overall slight decentralist path of the Canadian federation occurred primarily through non-constitutional means. Court decisions played a significant role in shaping this path early on, but it is the territorial diversity of the country, primarily but not exclusively nationalism in Québec, along with the original centralized nature of the Canadian federation, that fundamentally accounts for why Canada has not centralized like so many other federations.
The Intelligent vehicle (IV) is experiencing revolutionary growth in research and industry, but it still suffers from many security vulnerabilities. Traditional security methods are incapable to provide secure IV communication. The major issues in IV communication, are trust, data accuracy and reliability of communication data in the communication channel. Blockchain technology works for the crypto currency, Bit-coin, which is recently used to build trust and reliability in peer-to-peer networks having similar topologies as IV Communication. In this paper, we are proposing, Intelligent Vehicle-Trust Point (IV-TP) mechanism for IV communication among IVs using Blockchain technology. The IVs communicated data provides security and reliability using our proposed IV-TP. Our IV-TP mechanism provides trustworthiness for vehicles behavior, and vehicles legal and illegal action. Our proposal presents a reward based system, an exchange of some IV-TP among IVs, during successful communication. For the data management of the IV-TP, we are using blockchain technology in the intelligent transportation system (ITS), which stores all IV-TP details of every vehicle and is accessed ubiquitously by IVs. In this paper, we evaluate our proposal with the help of intersection use case scenario for intelligent vehicles communication.
Using 1-min returns of Bitcoin prices, we investigate statistical properties and multifractality of a Bitcoin time series. We find that the 1-min return distribution is fat-tailed, and kurtosis largely deviates from the Gaussian expectation. Although for large sampling periods, kurtosis is anticipated to approach the Gaussian expectation, we find that convergence to that is very slow. Skewness is found to be negative at time scales shorter than one day and becomes consistent with zero at time scales longer than about one week. We also investigate daily volatility-asymmetry by using GARCH, GJR, and RGARCH models, and find no evidence of it. On exploring multifractality using multifractal detrended fluctuation analysis, we find that the Bitcoin time series exhibits multifractality. The sources of multifractality are investigated, confirming that both temporal correlation and the fat-tailed distribution contribute to it. The influence of "Brexit" on June 23, 2016 to GBP--USD exchange rate and Bitcoin is examined in multifractal properties. We find that, while Brexit influenced the GBP--USD exchange rate, Bitcoin was robust to Brexit.
Rwanda is a good example of how a country can overcome challenges and obstacles to improve the socioeconomic well-being of citizens. With no reliable healthcare system in 1994, after the genocide against the Tutsi, the country has come a long way in building a decent healthcare system for its people. The purpose of this research is to analyze the changing PPP mixed in health care sector in Rwanda. The study was carried out to reflect/reveal or bring to light the perennial problems of the healthcare mixes within a period of six months. This work looked at the public-private sector mixes in healthcare system using Rwanda as a case study. In Rwanda, the ministry of health began health sector reforms in accordance with the Lusaka declaration in 1995. These reforms included decentralization of the health system, development of the primary healthcare system, and community participation in managing health service financing. Rwanda is one of the few African countries with 90% coverage in all Districts for immunization and access to critical health services including TB treatment and access to ARVs for HIV patients. Within a very short period of 23 years, Rwanda has built a working health system in which even the poor and disadvantaged have access to quality medical care through the Community Based Health Insurance.
Electronic voting presents many challenges due to its multiple security requirements. Some of the challenges are related to guaranteeing voters' privacy and system's transparency, which are hard to satisfy simultaneously. Electronic voting also presents other challenges such as usability, particularly from the voter's side. We study two particular problems of electronic voting. Cast-as-intended verifiability comprises those mechanisms which assure the voter that her cast ballot corresponds to her chosen voting options. Current proposals put the verification burden on the voter, something which is undesirable in real-world elections, where both technically skilled and non-skilled voters participate. In this thesis, we introduce the concept of universal cast-as-intended verifiability, which provides mechanisms which allow any entity to check that any ballot corresponds to the voter's selections - without revealing them. We formally define what universal cast-as-intended verifiability is and we give an electronic voting protocol satisfying this property. The other problem we have studied is the problem of invalid votes in electronic elections. Since a common selling point of electronic voting is that it avoids voters inadvertently spoiling their votes, deliberately spoiled ballots appearing in the tallying phase of an electronic election can cause mistrust on the system. Indeed, election stakeholders might think that the system is flawed or that it was exploited somehow. To avoid this situation, we define the concept of vote validatability, which states the electronic voting system should be able to detect spoiled ballots before they are successfully cast. In addition to formally defining this notion, we design an electronic voting protocol satisfying this property. All these security requirements of electronic voting systems are implemented with cryptographic tools. In addition to encryption and signature schemes, another essential primitive for building electronic voting protocols is zero-knowledge proofs. Zero-knowledge proofs allow a prover to convince a verifier that a statement is true without leaking any other information. These zero-knowledge proofs can be used to, for example, prove that the tally of the election was done properly. Recently, Groth and Sahai constructed efficient non-interactive zero-knowledge proofs for a wide range of statements including, among others, statements appearing in electronic voting. In this thesis we give two contributions on Groth-Sahai proofs. On the one hand, we give a framework for deriving cryptographic assumptions from which to build secure cryptographic protocols. In particular, we build new Groth-Sahai proofs improving the efficiency of currently known constructions. Independently, we show how the original Groth-Sahai proofs can be extended to be compatible with even more statements, how to improve their out-of-the-box efficiency for many of these statements and how to improve their re-usability efficiency among multiple statements. Els sistemes de vot electrònic presenten molts reptes a causa dels seus múltiples requeriments. Alguns d'aquests reptes estan relacionats amb garantir la privacitat del votant i la transparència del sistema, requisits que són difícils de satisfer al mateix temps. D'altra banda, els sistemes de vot electrònic presenten altres reptes com la usabilitat, sobretot de cara als votants. En aquesta tesi estudiem dos problemes del vot electrònic. La verificabilitat "cast-as-intended" tracta d'obtenir mecanismes que garanteixin al votant que el seu vot correspon a les seves preferències. Les propostes actuals posen la càrrega de la verificació en el votant, cosa que no és desitjable en eleccions del món real, on participen votants amb diferents graus de coneixements tècnics. Nosaltres introduïm el concepte de "universal cast-as-intended verifiability", que proporciona mecanismes per a que qualsevol entitat de l'elecció pugui comprovar que qualsevol vot conté les preferències del votant que l'ha emès - sense revelar el contingut del vot. A banda de definir formalment el concepte de "universal cast-as-intended verifiability" també proposem un protocol de vot electrònic que satisfà aquesta propietat. L'altre problema que hem estudiat és el problema dels vots invàlids en eleccions electròniques. Un dels avantatges del vot electrònic és que permet evitar que els votants emetin vots nuls sense voler. Per això, si durant el recompte de l'elecció apareixen vots nuls construïts intencionadament es pot crear desconfiança en el sistema de vot. Els usuaris del sistema de vot poden pensar que el sistema té forats de seguretat o que ha estat atacat. Per evitar aquesta situació, definim el concepte de "vote validatability", una propietat dels sistemes de vot electrònic que garanteix que els vots nuls es poden identificar en el moment que s'emeten. En aquesta tesi hem definit formalment aquesta propietat i hem dissenyat un protocol que la satisfà. Tots aquests requisits de seguretat dels protocols de vot electrònic s'implementen amb eines criptogràfiques. Les principals eines que s'utilitzen són esquemes de xifrat, esquemes de firma i proves de coneixement zero. Una prova de coneixement zero permet a una entitat convèncer una altra entitat que una sentència és certa sense donar cap altra informació que la certesa de la sentència. Aquestes proves de coneixement zero es poden fer servir, per exemple, per demostrar que el recompte de l'elecció s'ha fet correctament. Recentment, Groth i Sahai han construït proves de coneixement zero que es poden fer servir per un ampli ventall de sentències com per exemple sentències que apareixen en protocols de vot electrònic. En aquesta tesi hem fet dos contribucions sobre les proves de Groth i Sahai. Per una banda donem un marc teòric que permet derivar hipòtesis criptogràfiques per construir protocols criptogràfics. En particular, construïm noves proves de Groth i Sahai millorant l'eficiència de les construccions existents. De manera independent, indiquem com les proves de Groth i Sahai es poden estendre per fer-les compatibles amb un ventall més ampli de sentències, millorem l'eficiència de les proves de Groth i Sahai per moltes d'aquestes sentències i, en particular, quan es fan servir per demostrar múltiples sentències.
C. Furlanello, M. De Domenico, G. Jurman, N. Bussola
Publishing reproducible analyses is a long-standing and widespread challenge for the scientific community, funding bodies and publishers. Although a definitive solution is still elusive, the problem is recognized to affect all disciplines and lead to a critical system inefficiency. Here, we propose a blockchain-based approach to enhance scientific reproducibility, with a focus on life science studies and precision medicine. While the interest of encoding permanently into an immutable ledger all the study key information-including endpoints, data and metadata, protocols, analytical methods and all findings-has been already highlighted, here we apply the blockchain approach to solve the issue of rewarding time and expertise of scientists that commit to verify reproducibility. Our mechanism builds a trustless ecosystem of researchers, funding bodies and publishers cooperating to guarantee digital and permanent access to information and reproducible results. As a natural byproduct, a procedure to quantify scientists' and institutions' reputation for ranking purposes is obtained.
The Intelligent vehicle (IV) is experiencing revolutionary growth in research and industry, but it still suffers from many security vulnerabilities. Traditional security methods are incapable to provide secure IV data sharing. The major issues in IV data sharing are trust, data accuracy and reliability of data sharing data in the communication channel. Blockchain technology works for the crypto currency, Bit-coin, which is recently used to build trust and reliability in peer-to-peer networks having similar topologies as IV Data sharing. In this paper, we have proposed Intelligent Vehicle data sharing we are proposing a trust environment based Intelligent Vehicle framework. In proposed framework, we have use the blockchain technology as backbone of the IV data-sharing environment. The blockchain technology is provide the trust environment between the vehicles with the based on proof of driving.
Reproducibility, data sharing, personal data privacy concerns and patient enrolment in clinical trials are huge medical challenges for contemporary clinical research. A new technology, Blockchain, may be a key to addressing these challenges and should draw the attention of the whole clinical research community.Blockchain brings the Internet to its definitive decentralisation goal. The core principle of Blockchain is that any service relying on trusted third parties can be built in a transparent, decentralised, secure "trustless" manner at the top of the Blockchain (in fact, there is trust, but it is hardcoded in the Blockchain protocol via a complex cryptographic algorithm). Therefore, users have a high degree of control over and autonomy and trust of the data and its integrity. Blockchain allows for reaching a substantial level of historicity and inviolability of data for the whole document flow in a clinical trial. Hence, it ensures traceability, prevents a posteriori reconstruction and allows for securely automating the clinical trial through what are called Smart Contracts. At the same time, the technology ensures fine-grained control of the data, its security and its shareable parameters, for a single patient or group of patients or clinical trial stakeholders.In this commentary article, we explore the core functionalities of Blockchain applied to clinical trials and we illustrate concretely its general principle in the context of consent to a trial protocol. Trying to figure out the potential impact of Blockchain implementations in the setting of clinical trials will shed new light on how modern clinical trial methods could evolve and benefit from Blockchain technologies in order to tackle the aforementioned challenges.
Open access
Ethics in Clinical Research
Artificial Intelligence in Healthcare and Education
Blockchains such as Bitcoin and Ethereum execute payment transactions securely, but their performance is limited by the need for global consensus. Payment networks overcome this limitation through off-chain transactions. Instead of writing to the blockchain for each transaction, they only settle the final payment balances with the underlying blockchain. When executing off-chain transactions in current payment networks, parties must access the blockchain within bounded time to detect misbehaving parties that deviate from the protocol. This opens a window for attacks in which a malicious party can steal funds by deliberately delaying other parties' blockchain access and prevents parties from using payment networks when disconnected from the blockchain. We present Teechain, the first layer-two payment network that executes off-chain transactions asynchronously with respect to the underlying blockchain. To prevent parties from misbehaving, Teechain uses treasuries, protected by hardware trusted execution environments (TEEs), to establish off-chain payment channels between parties. Treasuries maintain collateral funds and can exchange transactions efficiently and securely, without interacting with the underlying blockchain. To mitigate against treasury failures and to avoid having to trust all TEEs, Teechain replicates the state of treasuries using committee chains, a new variant of chain replication with threshold secret sharing. Teechain achieves at least a 33x higher transaction throughput than the state-of-the-art Lightning payment network. A 30-machine Teechain deployment can handle over 1 million Bitcoin transactions per second.