A Digital Cash Paradigm with Valued and No-Valued e-Coins

Digital cash is a form of money that is stored digitally. Its main advantage when compared to traditional credit or debit cards is the possibility of carrying out anonymous transactions. Diverse digital cash paradigms have been proposed during the last decades, providing different approaches to avoid the double-spending fraud, or features like divisibility or transferability. This paper presents a new digital cash paradigm that includes the so-called no-valued e-coins, which are e-coins that can be generated free of charge by customers. A vendor receiving a payment cannot distinguish whether the received e-coin is valued or not, but the customer will receive the requested digital item only in the former case. A straightforward application of bogus transactions involving no-valued e-coins is the masking of consumption patterns. This new paradigm has also proven its validity in the scope of privacy-preserving pay-by-phone parking systems, and we believe it can become a very versatile building block in the design of privacy-preserving protocols in other areas of research. This paper provides a formal description of the new paradigm, including the features required for each of its components together with a formal analysis of its security.This research was funded by the Spanish Ministry of Science, Innovation and Universities grant number MTM2017-83271-R

Anonymous, authentic, and accountable resource management based on the E-cash paradigm

The prevalence of digital information management in an open network has driven the need to maintain balance between anonymity, authenticity and accountability (AAA). Anonymity allows a principal to hide its identity from strangers before trust relationship is established. Authenticity ensures the correct identity is engaged in the transaction even though it is hidden. Accountability uncovers the hidden identity when misbehavior of the principal is detected. The objective of this research is to develop an AAA management framework for secure resource allocations. Most existing resource management schemes are designed to manage one or two of the AAA attributes. How to provide high strength protection to all attributes is an extremely challenging undertaking. Our study shows that the electronic cash (E-cash) paradigm provides some important knowledge bases for this purpose. Based on Chaum-Pederson’s general transferable E-cash model, we propose a timed-zero-knowledge proof (TZKP) protocol, which greatly reduces storage spaces and communication overheads for resource transfers, without compromising anonymity and accountability. Based on Eng-Okamoto’s general divisible E-cash model, we propose a hypercube-based divisibility framework, which provides a sophisticated and flexible way to partition a chunk of resources, with different trade-offs in anonymity protection and computational costs, when it is integrated with different sub-cube allocation schemes. Based on the E-cash based resource management framework, we propose a privacy preserving service oriented architecture (SOA), which allows the service providers and consumers to exchange services without leaking their sensitive data. Simulation results show that the secure resource management framework is highly practical for missioncritical applications in large scale distributed information systems

SECURITY, PRIVACY AND APPLICATIONS IN VEHICULAR AD HOC NETWORKS

With wireless vehicular communications, Vehicular Ad Hoc Networks (VANETs) enable numerous applications to enhance traffic safety, traffic efficiency, and driving experience. However, VANETs also impose severe security and privacy challenges which need to be thoroughly investigated. In this dissertation, we enhance the security, privacy, and applications of VANETs, by 1) designing application-driven security and privacy solutions for VANETs, and 2) designing appealing VANET applications with proper security and privacy assurance. First, the security and privacy challenges of VANETs with most application significance are identified and thoroughly investigated. With both theoretical novelty and realistic considerations, these security and privacy schemes are especially appealing to VANETs. Specifically, multi-hop communications in VANETs suffer from packet dropping, packet tampering, and communication failures which have not been satisfyingly tackled in literature. Thus, a lightweight reliable and faithful data packet relaying framework (LEAPER) is proposed to ensure reliable and trustworthy multi-hop communications by enhancing the cooperation of neighboring nodes. Message verification, including both content and signature verification, generally is computation-extensive and incurs severe scalability issues to each node. The resource-aware message verification (RAMV) scheme is proposed to ensure resource-aware, secure, and application-friendly message verification in VANETs. On the other hand, to make VANETs acceptable to the privacy-sensitive users, the identity and location privacy of each node should be properly protected. To this end, a joint privacy and reputation assurance (JPRA) scheme is proposed to synergistically support privacy protection and reputation management by reconciling their inherent conflicting requirements. Besides, the privacy implications of short-time certificates are thoroughly investigated in a short-time certificates-based privacy protection (STCP2) scheme, to make privacy protection in VANETs feasible with short-time certificates. Secondly, three novel solutions, namely VANET-based ambient ad dissemination (VAAD), general-purpose automatic survey (GPAS), and VehicleView, are proposed to support the appealing value-added applications based on VANETs. These solutions all follow practical application models, and an incentive-centered architecture is proposed for each solution to balance the conflicting requirements of the involved entities. Besides, the critical security and privacy challenges of these applications are investigated and addressed with novel solutions. Thus, with proper security and privacy assurance, these solutions show great application significance and economic potentials to VANETs. Thus, by enhancing the security, privacy, and applications of VANETs, this dissertation fills the gap between the existing theoretic research and the realistic implementation of VANETs, facilitating the realistic deployment of VANETs

Cryptography and Its Applications in Information Security

Nowadays, mankind is living in a cyber world. Modern technologies involve fast communication links between potentially billions of devices through complex networks (satellite, mobile phone, Internet, Internet of Things (IoT), etc.). The main concern posed by these entangled complex networks is their protection against passive and active attacks that could compromise public security (sabotage, espionage, cyber-terrorism) and privacy. This Special Issue “Cryptography and Its Applications in Information Security” addresses the range of problems related to the security of information in networks and multimedia communications and to bring together researchers, practitioners, and industrials interested by such questions. It consists of eight peer-reviewed papers, however easily understandable, that cover a range of subjects and applications related security of information

Volatility Modeling Using High Frequency Trade Data to Identify Cryptocurrency Bubbles

In the light of sudden interest in Bitcoin during 2017, which saw Bitcoin growing multifold in market price, I study blockchain, Bitcoin and few other top cryptocurrencies, and examine whether Bitcoin was in a financial bubble during late 2017 and early 2018, when Bitcoin price had a sudden and dramatic run up. I conduct statistical analysis on the High Frequency Trade (HFT) data, sourced from Bloomberg and other crypto exchanges. The statistical analysis includes filtering in price data using 5%, 7% and 10% daily price jump rules (considered separately), interpolating price points between low and high prices in the time series, estimating price volatility at discrete price points, analyzing the volatility behavior and concluding whether or not price process is a strict local martingale. A bubble is confirmed if the price process is a strict local martingale, and not a true martingale. I run the test for Bitcoin, and find that Bitcoin was in intermittently in a bubble during the years 2017 and 2018. I repeat the test for Ethereum, another top trading cryptocurrency, and find that Ethereum was in a bubble during Nov 2017 - Feb 2018, but infrequently and for lower duration of days as compared to Bitcoin. Though Bitcoin price dramatically increased during 2017, the number of transactions and transactions volume rather fell. I develop a statistical test that can be applied on the High Frequency Trade (HFT) data of any highly traded asset to identify whether or not that asset has been in a bubble during the period of consideration. I also find that Bitcoin has positive correlation with other top cryptocurrencies and almost zero correlation with S&P 500, gold, and the crude oil

LAND AND AGRARIAN REFORM IN THE KYRGYZ REPUBLIC

This report presents LTC's findings and recommendations on the land tenure transition. The information contained in this report has been used to prepare a second document, Land and Agrarian Reform in the Kyrgyz Republic: Consolidation Plan, that proposes a set of actions to ensure that the reforms are completed and produce a viable, market-oriented, agricultural sector. Chapter 1 offers baseline geographic information on the KR, an account of the macroeconomic environment in which reforms are taking place, a brief project history, and a description of the research methods. Chapter 2 chronicles the legal and regulatory changes that have driven land and agrarian reform in the KR since 1991 and evaluates this legislation for its legal consistency, underlying economic assumptions, and broad policy implications. Chapter 3 employs national land statistics to describe changes in the agrarian structure that have resulted from the legal and regulatory evolution during 1991-1995, including the number and size of farms, land use, and related indicators of land tenure change and agrarian reform. Chapter 4 reviews the structure, function, and efficacy of administrative bodies that set and enforce land and land reform policy, recommends administrative adjustments, and identifies land administration tasks the state can eliminate-and others it will need to bolster-as the KR completes its transition from command structures to market principles in agriculture. Finally, Chapter 5 uses data obtained in structured surveys and case studies conducted by LTC on a 10 percent sample of former state and collective farms to describe at the farm level the successes and shortcomings of reform measures to date; the chapter also makes recommendations for new or altered land reform policies and procedures.Agrarian structure--Kyrgyzstan, Land administration--Kyrgyzstan, Land reform--Kyrgyzstan, Land tenure--Government policy--Kyrgyzstan, Land tenure--Kyrgyzstan, Land titles--Registration and transfer--Kyrgyzstan, International Development, Land Economics/Use,

Mobile Edge Computing

This is an open access book. It offers comprehensive, self-contained knowledge on Mobile Edge Computing (MEC), which is a very promising technology for achieving intelligence in the next-generation wireless communications and computing networks. The book starts with the basic concepts, key techniques and network architectures of MEC. Then, we present the wide applications of MEC, including edge caching, 6G networks, Internet of Vehicles, and UAVs. In the last part, we present new opportunities when MEC meets blockchain, Artificial Intelligence, and distributed machine learning (e.g., federated learning). We also identify the emerging applications of MEC in pandemic, industrial Internet of Things and disaster management. The book allows an easy cross-reference owing to the broad coverage on both the principle and applications of MEC. The book is written for people interested in communications and computer networks at all levels. The primary audience includes senior undergraduates, postgraduates, educators, scientists, researchers, developers, engineers, innovators and research strategists

Blockchain and Crypto Currency

This open access book contributes to the creation of a cyber ecosystem supported by blockchain technology in which technology and people can coexist in harmony. Blockchains have shown that trusted records, or ledgers, of permanent data can be stored on the Internet in a decentralized manner. The decentralization of the recording process is expected to significantly economize the cost of transactions. Creating a ledger on data, a blockchain makes it possible to designate the owner of each piece of data, to trade data pieces, and to market them. This book examines the formation of markets for various types of data from the theory of market quality proposed and developed by M. Yano. Blockchains are expected to give data itself the status of a new production factor. Bringing ownership of data to the hands of data producers, blockchains can reduce the possibility of information leakage, enhance the sharing and use of IoT data, and prevent data monopoly and misuse. The industry will have a bright future as soon as better technology is developed and when a healthy infrastructure is created to support the blockchain market