The American corporate graveyard is littered with prior darlings of Wall Street and pillars of the New York Stock Exchange, such as Kodak and Polaroid (both photography pioneers). More recently, other businesses and entire industries that were once household names have similarly experienced plummeting demand: pay telephone manufacturers; travel agencies; wrist watch manufacturers; print news media such as newspapers and magazines; and many traditional brick and mortar retailers (replaced by Amazon). The common characteristic is that all of these businesses have become completely or substantially obsolete due to digitized technology.Now, the equivalent disruptive technological revolution in financial services is underway. During recent years, rapid technological advances have resulted in a sea change to the way most of the world conducts and regulates financial services. While the implications are vast and the ultimate ramifications are largely unknown at this time, this article: examines the brief but important history of virtual currencies in general; considers the impact of Bitcoin in particular; and explores the promise for widespread application of Bitcoin’s underlying blockchain technological platform to the financial services industry.This brief article proceeds in five parts, as follows. First, there is a discussion of disruptive changes taking place in financial services. Second, the article briefly explores virtual currencies and the genesis of Bitcoin. Third, there is an explanation of blockchain technology - what it is and why it is important. Fourth, the article discusses recent developments that provide a validation of blockchain application to financial services markets. Finally, there is a brief review of regulatory challenges to the adoption of this new technology. A purpose of this article is to enhance the reader’s understanding of the promises and challenges faced by financial service providers due to these rapid advances in technology.
Shi-Feng Sun, Dawu Gu, Joseph K. Liu, Udaya Parampalli · 5 authors
Non-malleability is an important and intensively studied security notion for many cryptographic primitives. In the context of public key encryption, this notion means it is infeasible for an adversary to transform an encryption of some message m into one of a related message m' under the given public key. Although it has provided a strong security property for many applications, it still does not suffice for some scenarios like the system where the users could issue keys on-the-fly. In such settings, the adversary may have the power to transform the given public key and the ciphertext. To withstand such attacks, Fischlin introduced a stronger notion, known as complete non-malleability, which requires that the non-malleability property be preserved even for the adversaries attempting to produce a ciphertext of some related message under the transformed public key. To date, many schemes satisfying this stronger security have been proposed, but they are either inefficient or proved secure in the random oracle model. In this work, we put forward a new encryption scheme in the common reference string model. Based on the standard DBDH assumption, the proposed scheme is proved completely non-malleable secure against adaptive chosen ciphertext attacks in the standard model. In our scheme, the well-formed public keys and ciphertexts could be publicly recognized without drawing support from unwieldy techniques like non-interactive zero knowledge proofs or one-time signatures, thus achieving a better performance.
Benoît Libert, Fabrice Mouhartem, Thomas Peters, Moti Yung
Digital signatures are perhaps the most important base for authentication and trust relationships in large scale systems. More specifically, various applications of signatures provide privacy and anonymity preserving mechanisms and protocols, and these, in turn, are becoming critical (due to the recently recognized need to protect individuals according to national rules and regulations). A specific type of signatures called "signatures with efficient protocols", as introduced by Camenisch and Lysyanskaya (CL), efficiently accommodates various basic protocols and extensions like zero-knowledge proofs, signing committed messages, or re-randomizability. These are, in fact, typical operations associated with signatures used in typical anonymity and privacy-preserving scenarios.
In Mobile Crowd Sensing (MCS), the power of the crowd, jointly with the sensing capabilities of the smartphones they wear, provides a new paradigm for data sensing. Scenarios involving user behavior or those that rely on user mobility are examples where standard sensor networks may not be suitable, and MCS provides an interesting solution. However, including human participation in sensing tasks presents numerous and unique research challenges. In this paper, we analyze three of the most important: user participation, data sensing quality and user anonymity. We tackle the three as a whole, since all of them are strongly correlated. As a result, we present PaySense, a general framework that incentivizes user participation and provides a mechanism to validate the quality of collected data based on the users' reputation. All such features are performed in a privacy-preserving way by using the Bitcoin cryptocurrency. Rather than a theoretical one, our framework has been implemented, and it is ready to be deployed and complement any existing MCS system.
Nicolas Gensollen, Vincent Gauthier, Monique Becker, Michel Marot
In the context of the smart grid, we propose in this paper an algorithm that forms coalitions of agents, called prosumers, that both produce and consume. It is designed to be used by aggregators that aim at selling aggregated surplus of production of the prosumers they control. We rely on real weather data sampled across stations of a given territory in order to simulate realistic production and consumption patterns for each prosumer. This enables us to capture geographical correlations among the agents while preserving the diversity due to different behaviors. As aggregators are bound to the market operator by a contract, they seek to maximize their offer while minimizing their risk. The proposed graph-based algorithm takes the underlying correlation structure of the agents into account and outputs coalitions with both high productivity and low variability. We show that the resulting diversified coalitions are able to generate higher benefits on a constrained energy market, and are more resilient to random failures of the agents.
Antonio Rizzi, Giovanni Romagnoli, Frédéric Thiesse
OBJECTIVE: This paper aims at proposing a new framework for the classification of RFID deployments in fashion and apparel retailing. The framework encompasses several different use cases (UCs) pursued by fashion and apparel retailers in the last decade, and updates, expands and goes beyond what has already been presented in the related literature. DESIGN, METHODOLOGY, APPROACH: We carried out a comprehensive literature review on RFID deployments in fashion and apparel retail. We searched different sources of information, that is, scientific papers, conferences and seminars proceedings, websites, magazines, newspapers etc., up to 160 papers that were carefully analysed and organised in a structured database. This data set also comprehends information from confidential projects. We analyse contents on the level of single RFID projects, that is, feasibility studies, proofs of concept, pilots or deployments. For each project, we determine what specific UCs were at stake. Eventually, the framework of all possible RFID UCs emerged from the analysis, and we set up a panel of industry partners to validate the framework using the Delphi method. FINDINGS: We structured the new framework along two levels: first, 6 categories were identified (i.e., level 1 use cases). Each category was then detailed, resulting in a total of 18 specific UCs (i.e., level 2 use cases). Each level 2 UC corresponds to a very specific objective pursued by an RFID implementation. For each UC, we propose a set of business metrics to evaluate deployment success as well as benefits achieved. PRACTICAL IMPLICATIONS: From a practitioner’s perspective, the framework offers a comprehensive and well-structured overview of the cost- and the revenue-related potentials of RFID implementations in the industry. Researchers, on the other hand, may use the framework to identify opportunities for further research regarding RFID deployments in retailing. ORIGINALITY/VALUE: Our framework is based on the current body of literature, and complements prior studies, which served as the starting point for our research.
The article explains the ongoing resilience of the Chinese Communist Party (CCP) regime as a dynamic process of continual institutional adaptation of the CCP’s threat-management system, which simultaneously must address vertical (popular) and horizontal (internal) challenges. The author finds that the CCP central leadership’s current top-down intervention into subnational governments, featuring Xi Jinping’s anti-corruption campaign, reform of local government financing platforms (LGFPs), and consolidation of personal power over the party-state, is the second of two major actions over the last thirty years designed to maintain the stability and survival of the single-party system. Notably, many of the contemporary challenges faced by the regime, such as a local government budgetary crisis and rampant official corruption within subnational governments, are in many respects the unforeseen consequences of an earlier intervention by the Center conducted in the mid-1990s under Jiang Zemin.
Bitcoin is the most popular cryptocurrency today. A bedrock of the Bitcoin framework is mining, a computation intensive process that is used to verify Bitcoin transactions for profit. We observe that mining is inherently error tolerant due to its embarrassingly parallel and probabilistic nature. We exploit this inherent tolerance to inaccuracy by proposing approximate mining circuits that trade off reliability with area and delay. These circuits can then be operated at Better Than Worst-Case (BTWC) to enable further gains. Our results show that approximation has the potential to increase mining profits by 30%.
Low-power high-performance VLSI design
Advancements in Semiconductor Devices and Circuit Design
Bitcoin is without a doubt the most successful cryptocurrency in circulation today, making it an extremely valuable target for attackers. Indeed, many studies have highlighted ways to compromise one or several Bitcoin nodes. In this paper, we take a different perspective and study the effect of large-scale network-level attacks such as the ones that may be launched by Autonomous Systems (ASes).
We show that attacks that are commonly believed to be hard, such as isolating 50% of the mining power, are actually within the reach of anyone with access to a BGP-enabled network and hijacking less than 900 prefixes. Once on path, AS-level adversaries can then partition the Bitcoin network or delay block propagation significantly. The key factors that enable these attacks are the extreme centralization of Bitcoin, both from a routing and a mining perspective, along with the fact that Bitcoin messages are sent unencrypted, without integrity guarantees.
We demonstrate the feasibility of large-scale attacks in practice against the deployed Bitcoin software and quantify their disruptive network-wide impact. The potential damage to Bitcoin is severe. By isolating a part of the network or delaying the propagation of blocks, network-level attackers can cause a significant amount of mining power to be wasted, leading to revenue losses and enabling a wide range of attacks such as double spending. We provide several suggestions on approaches to mitigate such attacks employing both short-term and long-term measures.
In this paper we describe a privacy-preserving method for commissioning an IoT device into a cloud ecosystem. The commissioning consists of the device proving its manufacturing provenance in an anonymous fashion without reliance on a trusted third party, and for the device to be anonymously registered through the use of a blockchain system. We introduce the ChainAnchor architecture that provides device commissioning in a privacy-preserving fashion. The goal of ChainAnchor is (i) to support anonymous device commissioning, (ii) to support device-owners being remunerated for selling their device sensor-data to service providers, and (iii) to incentivize device-owners and service providers to share sensor-data in a privacy-preserving manner.
As the most successful cryptocurrency to date, Bitcoin constitutes a target of choice for attackers. While many attack vectors have already been uncovered, one important vector has been left out though: attacking the currency via the Internet routing infrastructure itself. Indeed, by manipulating routing advertisements (BGP hijacks) or by naturally intercepting traffic, Autonomous Systems (ASes) can intercept and manipulate a large fraction of Bitcoin traffic. This paper presents the first taxonomy of routing attacks and their impact on Bitcoin, considering both small-scale attacks, targeting individual nodes, and large-scale attacks, targeting the network as a whole. While challenging, we show that two key properties make routing attacks practical: (i) the efficiency of routing manipulation; and (ii) the significant centralization of Bitcoin in terms of mining and routing. Specifically, we find that any network attacker can hijack few (<100) BGP prefixes to isolate ~50% of the mining power---even when considering that mining pools are heavily multi-homed. We also show that on-path network attackers can considerably slow down block propagation by interfering with few key Bitcoin messages. We demonstrate the feasibility of each attack against the deployed Bitcoin software. We also quantify their effectiveness on the current Bitcoin topology using data collected from a Bitcoin supernode combined with BGP routing data. The potential damage to Bitcoin is worrying. By isolating parts of the network or delaying block propagation, attackers can cause a significant amount of mining power to be wasted, leading to revenue losses and enabling a wide range of exploits such as double spending. To prevent such effects in practice, we provide both short and long-term countermeasures, some of which can be deployed immediately.
Bitcoin is the latest addition to the online payment transaction systems. It is a digital currency also known as cryptocurrency. Bitcoin system is the first transaction payment system that deviated from the conventional approach of processing and clearing transactions though the trusted third parties and allowed direct transactions between parties. Thus making the whole system decentralized. It is a pure peer to peer network system which facilitates every party on the network to keep track of all the transactions that are taking place on the network. It uses Cryptography for its implementation and to deal with the internet security threats. This papers aims to explore the need of the decentralized system, technology used for its implementation and also the key features of bitcoin system that makes it so unique as compared to the conventional currency. It also throws the light on the benefits of bitcoin system and its shortcomings.
Address clustering tries to construct the one-to-many mapping from entities to addresses in the Bitcoin system. Simple heuristics based on the micro-structure of transactions have proved very effective in practice. In this paper we describe the primary reasons behind this effectiveness: address reuse, avoidable merging, super-clusters with high centrality, and the incremental growth of address clusters. We quantify their impact during Bitcoin's first seven years of existence.
Ernest Mensah, Moses Aikins, Margaret Gyapong, Francis Anto · 6 authors
BACKGROUND: The global health system has a large arsenal of interventions, medical products and technologies to address current global health challenges. However, identifying the most effective and efficient strategies to deliver these resources to where they are most needed has been a challenge. Targeted and integrated interventions have been the main delivery strategies. However, the health system discourse increasingly favours integrated strategies in the context of functionally merging targeted interventions with multifunctional health care delivery systems with a focus on strengthening country health systems to deliver needed interventions. Neglected Tropical Diseases (NTD) have been identified to promote and perpetuate poverty hence there has been global effort to combat these diseases. The Neglected Tropical Diseases Programme (NTDP) in Ghana has a national programme team and office, however, it depends on the multifunctional health delivery system at the regional and district level to implement interventions. The NTDP seeks further health system integration to accelerate achievement of coverage targets. The study estimated the extent of integration of the NTDP at the national, regional and district levels to provide evidence to guide further integration. METHODOLOGY/PRINCIPAL FINDINGS: The research design was a descriptive case study that interviewed key persons involved in the programme at the three levels of the health system as well as extensive document review. Integration was assessed on two planes-across health system functions-stewardship and governance, financing, planning, service delivery, monitoring and evaluation and demand generation; and across three administrative levels of the health system-national, regional and district. A composite measure of integration designated Cumulative Integration Index (CII) with a range of 0.00-1.00 was used to estimate extent of integration at the three levels of the health system. Service delivery was most integrated while financing and planning were least integrated. Extent of integration was partial at all levels of the health system with a CII of 0.48-0.68; however it was higher at the district compared to the national and regional levels. CONCLUSIONS/SIGNIFICANCE: To ensure further integration of the NTDP, planning and finance management activities must be decentralized to involve regional and district levels of the health system. The study provides an empirical measure of extent of integration and indicators to guide further integration.
Most popular blockchain solutions, like Bitcoin, rely on proof-of-work, guaranteeing that the output of the consensus is agreed upon with high probability. However, this probability depends on the delivery of messages and that the computational power of the system is sufficiently scattered among pools of nodes in the network so that no pool can mine more blocks faster than the crowd. New approaches, like Ethereum, generalise the proof-of-work approach by letting individuals deploy their own private blockchain with high transaction throughput. As companies are starting to deploy private chains, it has become crucial to better understand the guarantees blockchains offer in such a small and controlled environment. In this paper, we present the \emph{Blockchain Anomaly}, an execution that we experienced when building our private chain at NICTA/Data61. Even though this anomaly has never been acknowledged before, it may translate into dramatic consequences for the user of blockchains. Named after the infamous Paxos anomaly, this anomaly makes dependent transactions, like "Bob sends money to Carole after he received money from Alice" impossible. This anomaly relies on the fact that existing blockchains do not ensure consensus safety deterministically: there is no way for Bob to make sure that Alice actually sent him coins without Bob using an external mechanism, like converting these coins into a fiat currency that allows him to withdraw. We also explore smart contracts as a potential alternative to transactions in order to freeze coins, and show implementations of smart contract that can suffer from the Blockchain anomaly and others that may cope with it.
This paper analyses the heterogeneity of household consumer preferences for electricity service contracts in a smart grid context. Platform pricing strategies that could incentivise consumers to participate in a two-sided electricity platform market are discussed. The research is based on original data from a discrete choice experiment on electricity service contracts that was conducted with 1,892 electricity consumers in Great Britain in 2015. We estimate a flexible mixed logit model in willingness to pay space and exploit the results in posterior analysis. The findings suggest that while consumers are willing to pay for technical support services, they are likely to demand significant compensation to share their usage and personally identifying data and to participate in automated demand response programs involving remote monitoring and control of electricity usage. Cross-subsidisation of consumers combining appropriate participation payments with sharing of bill savings could incentivise participation of the number of consumers required to provide the optimal level of demand response. We also examine the preference heterogeneity to suggest how, by targeting customers with specific characteristics, smart electricity service providers could significantly reduce their customer acquisition costs.
We examine a protocol $\pi_{\text{beacon}}$ that outputs unpredictable and publicly verifiable randomness, meaning that the output is unknown at the time that $\pi_{\text{beacon}}$ starts, yet everyone can verify that the output is close to uniform after $\pi_{\text{beacon}}$ terminates. We show that $\pi_{\text{beacon}}$ can be instantiated via Bitcoin under sensible assumptions; in particular we consider an adversary with an arbitrarily large initial budget who may not operate at a loss indefinitely. In case the adversary has an infinite budget, we provide an impossibility result that stems from the similarity between the Bitcoin model and Santha-Vazirani sources. We also give a hybrid protocol that combines trusted parties and a Bitcoin-based beacon.
The Indonesian government imposed a policy of regional autonomy with the aim to facilitate local governments regulate local affairs independently. Tangerang City is one of the areas that implement decentralization policy and requires a lot of funds to finance regional development. The biggest potential possessed Tangerang City in the financing of regional expenditures derived from local taxes and are expected to provide the largest contribution in PAD. This study aims to determine the effectiveness of tax collection hotels, restaurants, billboards and parking, and its contribution to the PAD Tangerang City. Methods of data analysis in this research is descriptive analysis. The variables in this study are the ratio of the effectiveness and contribution analysis. Data analysis technique in this study is a quantitative analysis. Based on the analysis, the average effective tax collection hotel, restaurant tax, advertisement tax and parking tax years 2010-2014 is very effective and the average contribution collection hotel, restaurant tax, advertisement tax and Tangerang city parking tax years 2010-2014 is lack.