Compact multisignature is vital for shrinking the signature size of decentralized blockchain. All practical compact multisignature schemes have been constructed from the discrete logarithm problem which is potentially vulnerable to quantum computing attacks. Lattice-based multisignature schemes are potential candidates for resisting quantum attacks. However, the existing lattice-based multisignature schemes suffer either loose signatures or large public key and signature sizes after compressing, which makes them unsuitable for blockchains. In this paper, we first present a practical lattice-based multisignature scheme with much smaller signature sizes than previous lattice-based multisignature schemes. Then, we extend our scheme to support public key aggregation with almost the same performance. Both of our multisignature schemes are provably secure in the random oracle model under the ring version of the short integer solution (Ring-SIS) assumption. They outperform the recent lattice-based multisignature scheme proposed by Bansarkhani and Sturm (BS) in terms of both signature size and communication overhead.
In order to deploy a secure WLAN mesh network, authentication of both users and APs is needed, and a secure authentication mechanism should be employed. However, some additional configurations of trusted third party agencies are still needed on-site to deploy a secure authentication system. This paper proposes a new block chain-based authentication protocol for WLAN mesh security access, to reduce the deployment costs and resolve the issues of requiring key delivery and central server during IEEE 802.11X authentication. This method takes the user’s authentication request as a transaction, considers all the authentication records in the mesh network as the public ledger and realizes the effective monitoring of the malicious attack. Finally, this paper analyzes the security of the protocol in detail, and proves that the new method can solve the dependence of the authentication node on PKI and CA.
Raheel Ahmed Memon, Jianping Li, Muhammad Irshad Nazeer, Ahmad Neyaz Khan · 5 authors
Integration of blockchain and Internet of Things (IoT) to build a secure, trusted and robust communication technology is currently of great interest for research communities and industries. But challenge is to identify the appropriate position of blockchain in current settings of IoT with minimal consequences. In this article we propose a blockchain-based DualFog-IoT architecture with three configuration filter of incoming requests at access level, namely: Real Time, Non-Real Time, and Delay Tolerant Blockchain applications. The DualFog-IoT segregate the Fog layer into two: Fog Cloud Cluster and Fog Mining Cluster. Fog Cloud Cluster and the main cloud datacenter work in a tandem similar to existing IoT architecture for real-time and non-real-time application requests, while the additional Fog Mining Cluster is dedicated to deal with only Delay Tolerant Blockchain application requests. The proposed DualFog-IoT is compared with existing centralized datacenter based IoT architecture. Along with the inherited features of blockchain, the proposed model decreases system drop rate, and further offload the cloud datacenter with minimal upgradation in existing IoT ecosystem. The reduced computing load from cloud datacenter doesn't only help in saving the capital and operational expenses, but it is also a huge contribution for saving energy resources and minimizing carbon emission in environment. Furthermore, the proposed DualFog-IoT is also being analyzed for optimization of computing resources at cloud level, the results presented shows the feasibility of proposed architecture under various ratios of incoming RT and NRT requests. However, the integration of blockchain has its footprints in terms of latent response for delay tolerant blockchain applications, but real-time and non-real-time requests are gracefully satisfying the service level agreement.
Abstract The implementation of a medical course in a city in the Brazilian northeastern region to expand and decentralize medical education as a result of the Project More Doctors for Brazil includes the institutionalization process that takes into consideration cultural and organizational aspects that facilitate or hinder the accomplishment of innovative practices. This study analyzed the implementation process according to key categories: pedagogical project, teaching-service integration, teacher development and infrastructure. The results showed facilitating elements and barriers that depend on the movement among the proposal’s instituted forces, instituting forces and the institutionalization process. A strategy for greater feasibility can be found in autonomous movements triggered by subjects who are committed to the objectives of the involved courses and institutions that work towards making legislations and intentions real.
Daniel Kales, Sebastian Ramacher, Christian Rechberger, Roman Walch · 5 authors
Post-quantum cryptography has received increased attention in recent years, in particular, due to the standardization effort by NIST. One of the second-round candidates in the NIST post-quantum standardization project is Picnic, a post-quantum secure signature scheme based on efficient zero-knowledge proofs of knowledge. In this work, we present the first FPGA implementation of Picnic. We show how to efficiently calculate LowMC, the block cipher used as a one-way function in Picnic, in hardware despite the large number of constants needed during computation. We then combine our LowMC implementation and efficient instantiations of Keccak to build the full Picnic algorithm. Additionally, we conform to recently proposed hardware interfaces for post-quantum schemes to enable easier comparisons with other designs. We provide evaluations of our Picnic implementation for both, the standalone design and a version wrapped with a PCIe interface, and compare them to the state-of-the-art software implementations of Picnic and similar hardware designs. Concretely, signing messages on our FPGA takes 0.25 ms for the L1 security level and 1.24 ms for the L5 security level, beating existing optimized software implementations by a factor of 4.
Economic preferences and personality traits are fundamental explanatory factors in understanding individual decision-making. They explain the heterogeneity within human behavior and are the reason why individuals differ in their actions although the preliminaries are the same. Labor market behavior, educational choices, investment decisions as well as fertility and health outcomes are only a few examples in which inherent characteristics play a key role. These findings rely on one joint assumption: preferences and personality traits do not change across the working age. The point in time when preferences are defined and measured is thus irrelevant. However, if this assumption is violated, theoretical models and empirical studies face the threat of endogeneity biases: preferences do not only affect life's outcomes, life's outcomes may also affect preferences. Testing the exogeneity assumption is thus obligatory. Herein, the present thesis makes its contribution and presents three different studies on the stability of economic preferences and personality traits. The first study in this thesis focuses on the stability of time preferences. So far, evidence on their stability is scarce and considerably restricted by very short time frames, very small sample sizes, or both. The Dutch Household Survey enables these obstacles to be circumvented and the long-term stability of time preferences within a representative sample to be analyzed. By relying on the `consideration of future consequences’ scale -- a behaviorally validated survey measure on time preferences -- this thesis finds that time preferences have, compared to other economic attitudes, a relatively low intra-individual stability. However, the analysis reveals that individuals' valuation of future utility neither varies with age nor changes persistently with past life experiences. Similar findings result from a replication of the analysis with the German Socio-Economic Panel and its ultra-short survey items on patience and impulsiveness. The thesis, therefore, comes to the conclusion that time preferences are stable in the long run but subjected to measurement issues. The second study focuses on the determinants of risk-taking. Using German panel data, we find that people become more risk-averse when losing work. The immediate income loss does not mediate this effect. Risk aversion also seems unrelated to the loss of non-monetary benefits of work. However, the study finds that risk aversion responds more strongly to losing work the more future income is at stake, and the effect manifests itself on the eve of job loss even when people have not yet suffered from the consequences of the event. Lower future income expectations and more uncertainty about future incomes may thus explain the effect of job loss on risk attitude. Nevertheless, the effect is not persistent. After some time, individuals turn back to their initial level of risk attitude. The last chapter of this thesis tests the stability of locus of control, a measure that depicts how much people believe in their ability to affect life outcomes. Using the German Socio-Economic Panel, we find that a job loss due to a plant closure has no long-lasting effect on locus of control. The common assumption of its stability is thus not rejected. However, during unemployment, control perception decreases significantly. The effect holds true independent from unemployment duration or socio-demographic characteristics and vanishes as soon as the unemployed find a new job. In conclusion, measurement of locus of control is affected by unemployment but not the trait itself. Using this trait as the explanatory variable can thus lead to biased estimations if this temporary deviation in measurement is not accounted for. In conclusion, the present thesis neither rejects the stability assumption nor claims that preferences or personality are perfectly stable. All measures analyzed change with time. But, interpreting this instability as proof of endogenous preferences or personality traits appears unjustified. Each of the studies proposes alternative, less controversial interpretations of instability.
Currently the search for a decentralized data model in companies for its big advantage in removing the middleman has been increasing. For that reason, DLT (Distributed Ledger Technology) technologies have gained a lot of visibility in the business world, the most well-known being Blockchain and its emerging Smart Contracts. The identified problem is the lack of knowledge and skill of companies in the domain of the rising Smart Contracts. In this paper, we propose a generic model that could increase the competence of companies in this field by creating a step-by-step tutorial on how to set up the development environment of Smart Contracts.
The success of various cryptocurrencies' systems has triggered a great interest in their functioning. The fluctuation of their values is very unpredictable, so the periods of growth are often abruptly interrupted by stagnation or a pronounced decline. Nevertheless, a large number of investors have been involved in the processes of mining and trading cryptocurrencies in recent years. When it comes to the negative aspects of cryptocurrencies, the focus is primarily on various forms of cybercrime. The number of hacker attacks using the blackmail software - ransomware, is on the increase. In such cases, cryptocurrencies are often used as a means of paying ransom. However, the energy efficiency of certain types of cryptocurrencies is a less common topic. The Proof-of-Work (PoW) algorithm used for mining in some systems is an energetically intensive and really expensive process, which after economic analysis no longer seems as profitable as it first appeared to be. Cryptocurrency trading could bring a great income to the investors, but also great losses, because it essentially represents a zero-sum game. The sudden increase in the number of miners led to the disturbance on the computer components market, causing the price increase and even the complete disappearance of certain graphics card models. Everything previously mentioned indicates that cryptocurrencies have brought many negative aspects and disturbances. The subject of this paper is the economic aspect of cryptocurrencies based on the PoW algorithm. The aim of the paper is to indicate the economic unsustainability of their current concept, due to the high costs borne directly by participants in the mining process and indirectly by participants in the computer components market.
Aleš Zamuda, Vincenzo Crescimanna, Juan C. Burguillo, Joana Dias · 12 authors
This chapter surveys the state-of-the-art in forecasting cryptocurrency value by Sentiment Analysis. Key compounding perspectives of current challenges are addressed, including blockchains, data collection, annotation, and filtering, and sentiment analysis metrics using data streams and cloud platforms. We have explored the domain based on this problem-solving metric perspective, i.e., as technical analysis, forecasting, and estimation using a standardized ledger-based technology. The envisioned tools based on forecasting are then suggested, i.e., ranking Initial Coin Offering (ICO) values for incoming cryptocurrencies, trading strategies employing the new Sentiment Analysis metrics, and risk aversion in cryptocurrencies trading through a multi-objective portfolio selection. Our perspective is rationalized on the perspective on elastic demand of computational resources for cloud infrastructures.
This project uses software development to investigate the link between software and finance. The focus of the work is developing and implementing a trading algorithm which seeks to make profit by making trades based on arbitrage opportunities between currencies. Specifically, the sets of currencies examined are two fiat currencies and one cryptocurrency. Trades are made by combining a blockchain system, which maintains the cryptocurrency, and the live foreign exchange market, which enables fiat currency exchange. The main methodologies for carrying out the research are test-driven development and the use of a simulation to facilitate trades. By passing all of the unit tests, the software is verified. In addition, data gathered during runs of the simulation show that the algorithm successfully identifies arbitrage opportunities and turns a profit on average over many runs. This project proposes an interesting topic for further research in the field of blockchain technology used for financial trading.
Cryptocurrencies are gaining significant attention and financial investment. Among the wave of new cryptocurrencies, the first cryptocurrency introduced, Bitcoin, remains the most notable and most heavily used.\nWhile Bitcoin is often perceived as an anonymous system, it is in fact only pseudonymous and a variety of methods are known to reidentify the holders of Bitcoin wallets. As a result, services have emerged which ``anonymize" Bitcoin by making it difficult to trace the origin of Bitcoin funds. These services are referred to as ``mixers" or ``tumblers," but are more generally methods of laundering Bitcoin funds.\nIn the United States, a system of anti-money-laundering (AML) regulations developed since the 1970s requires financial services organizations to take positive steps to identify their customers, prevent use of their services for money laundering, and detect and report customers which appear to be engaged in money laundering.\nThese AML regulations have been interpreted by the primary regulator, FinCEN, as fully applicable to Bitcoin. This creates a clear conflict with laundering services which are directly intended to prevent organizations identifying the possessor of funds.\nThis thesis explores the advancing state of both Bitcoin laundering services and Bitcoin anti-laundering services intended to assist in compliance with AML regulations. The current state of the art in both laundering and anti-laundering services is explored. Later, current research and avenues for improvement in these services are discussed.\nUltimately, the way forward for Bitcoin AML regulation is discussed. The current regulatory approach to Bitcoin is insufficient to mitigate laundering with Bitcoin and should be refocused.
Although many people equate blockchain with bitcoin, cryptocurrency, and smart contracts, the technology also has the potential to transform the way companies look at governance and enterprise risk management, and to assist governments and businesses in mitigating human rights impacts. This Article will discuss how state and non-state actors use the technology outside of the realm of cryptocurrency. Part I will provide an overview of blockchain technology. Part II will briefly describe how public and private actors use blockchain today to track food, address land grabs, protect refugee identity rights, combat bribery and corruption, eliminate voter fraud, and facilitate financial transactions for those without access to banks. Part III will discuss key corporate governance, compliance, and social responsibility initiatives that currently utilize blockchain or are exploring the possibilities for shareholder communications, internal audit, and cyber security. Part IV will delve into the business and human rights landscape and examine how blockchain can facilitate compliance.
Specifically, we will focus on one of the more promising uses of distributed ledger technology – eliminating barriers to transparency in the human rights arena thereby satisfying various mandatory disclosure regimes and shareholder requests. Part V will pose questions that board members should ask when considering adopting the technology and will recommend that governments, rating agencies, sustainable stock exchanges, and institutional investors provide incentives for companies to invest in the technology, when appropriate. Given the increasing widespread use of the technology by both state and non-state actors and the potential disruptive capabilities, we conclude that firms that do not explore blockchain’s impact risk obsolescence or increased regulation.
João Pedro Quintais, Balázs Bodó, Αλεξάνδρα Γιαννοπούλου, Valeria Ferrari
It is a high-risk, high-reward enterprise to write a scholarly monograph on an emerging technology when its societal use, economic worth, and even its technical design are still in flux. With little empirical material with which to work, one often has to resort to extrapolating the future developments from the myriad seed of possibilities of the present. Yet, there are moments in time when undertaking such an enterprise seems inevitable, because there is a rough consensus that the emerging technology represents more than just an incremental improvement of already existing routines, and promises—or threatens—a disruption of the status quo. Such is the case of blockchain or distributed ledger technologies. In that light, Primavera De Filippi’s and Aaron Wright’s Blockchain and the Law is a timely and valuable contribution.
Healthcare record sharing among various medical roles is a critical and challenging research problem especially in today’s everchanging global IT solutions. The emergence of blockchain as a new enabling technology brought radical changes to numerous business applications, including healthcare. Blockchain is a trusted distributed ledger that forms a decentral-ized infrastructure. There have been several proposals regarding the sharing of critical healthcare records over blockchain infras-tructure without requiring prior knowledge/trust of the parties involved (patients, service providers, and insurance companies). Another yet important issue is to securely share medical records across various countries for travelling patients to ensure an integrated and ubiquitous healthcare service. In this paper, we present a globally integrated healthcare record sharing architec-ture based on blockchain and HL7 client. Healthcare records are stored at the hosting country and are not stored on the blockchain. This architecture avails medical records of travelling patients temporarily and after performing necessary authentication. The actual authorisation process is performed on a federated identity management system, such as, the Shibboleth. Though there are similarities with identity management systems, our system is unique as it involves the patient in the permission process and discloses to them the identities of entities accessed their health records. Our solution also improves performance and guarantees privacy and security through the use of blockchain and identity management system.
Jan 1, 2019·Proceedings of the ... Annual Hawaii International Conference on System Sciences/Proceedings of the Annual Hawaii International Conference on System Sciences
Benedikt Notheisen, Sven Willrich, Maximilian Diez, Christof Weinhardt
In recent years, blockchain and distributed ledger technology (DLT) and its disruptive potential has been one of the most discussed topics in the field of information systems. Driven by the prospect of cost savings and efficiency gains, financial markets are at the core of these discussions. However, in the increasingly convoluted and constantly evolving market of technology providers and platforms, organizations struggle to find a solution that fulfills the specific requirements of their application scenario. To evaluate the suitability of different blockchain-based platforms for securities post-trading, we develop a new methodology to create a technology classification that takes the demands of a specific application context into account. The resulting requirement-based taxonomy sheds light on factors that impede the adoption of blockchain- and DLT-based post-trading, highlights future research challenges, and offers a valuable tool to induce communication between involved stakeholders.
Antonio Clim, Răzvan Daniel Zota, Radu Constantinescu
The most important aspect of handling data in the healthcare industry is its seamless and secure transition across intercepting nodes. Effective elimination of third-party entities and ensuring direct links between patient and healthcare provider can result in the transmission of error-free, unduplicated data. The use of blockchains can open up opportunities to counter the current requirements due to their ability to safely share information across nodes and networks from the access point and secure the safety of transactions. Currently, sharing medical data is observed to be slow, incomplete, insecure, and provider-centric. These shortcomings prevent data interoperability and are a consequence of lack of foundational, structural, and semantic inoperability. By applying the blockchain technologies with appropriate markers, the safety of patient data can be ensured during data transmission. This paper evaluates the potential use of blockchain technology in association with mobile-based healthcare applications.
Pharmaceutical companies that manufacture, ship and supply products face difficulties in tracking their products, allowing counterfeiters to inject counterfeit drugs into the system. This situation is observed, in particular, in the Russian market of turnover of pharmaceutical products, although the problem has long been global. The ability of blockchain systems to pinpoint the origin of data makes them particularly suitable for pharmaceutical supply chain applications. The data stored in the blockchain distributed register on the identification of drugs produced by the plant, as well as records of their movements throughout the supply chain, can accurately determine the authenticity of pharmaceutical products lying on the shelves of pharmacies. The development and implementation of such a system can be a big step towards winning the exhausting fight against the easy availability of counterfeit drugs and medical products. In the first part of this work, the main characteristics and features of the functioning of blockchain systems will be studied. In the second and final part, the designed concept of the pharmaceutical turnover control system based on the blockchain technology Hyperledger Fabric using the Hyperledger Composer development environment will be investigated.