Analyzing the Bitcoin Ponzi Scheme Ecosystem

This paper analyzes the supply and demand for Bitcoinbased Ponzi schemes. There are a variety of these types of scams: from long cons such as Bitcoin Savings & Trust to overnight doubling schemes that do not take off. We investigate what makes some Ponzi schemes successful and others less so. By scouring 11 424 threads on bitcointalk.org, we identify 1 780 distinct scams. Of these, half lasted a week or less. Using survival analysis, we identify factors that affect scam persistence. One approach that appears to elongate the life of the scam is when the scammer interacts a lot with their victims, such as by posting more than a quarter of the comments in the related thread. By contrast, we also find that scams are shorter-lived when the scammers register their account on the same day that they post about their scam. Surprisingly, more daily posts by victims is associated with the scam ending sooner

Do Malware Reports Expedite Cleanup? An Experimental Study

Web-based malware is pervasive. Miscreants compromise insecure hosts or even set up dedicated servers to distribute malware to unsuspecting users. This scourge is mainly fought by the voluntary action of private actors who detect and report infections to affected site owners, hosting providers and registrars. In this paper we describe an experiment to assess whether sending reports to affected parties makes a measurable difference in cleaning up malware. Using community reports of malware submitted to StopBadware over two months in Fall 2011, we find evidence that detailed notices are immediately effective: 32% of malware-distributing websites are cleaned within one day of sending a notice, compared to just 13% of sites not receiving a notice. The improved cleanup rate holds for longer periods, too – 62% of websites receiving a detailed notice were cleaned up after 16 days, compared to 45% of websites not receiving a notice. It turns out that including details describing the compromise is essential for the notice to work – sending reports with minimal descriptions of the malware was found to be roughly as effective as not sending reports at all. Furthermore, we present evidence that sending multiple notices from two sources is not helpful. Instead, only the first transmitted notice makes a difference

Investigating the concentration of High Yield Investment Programs in the United Kingdom

Ponzi schemes that offer absurdly high rates of return by relying on more and more people paying into the scheme have been documented since at least the mid-1800s. Ponzi schemes have shifted online in the Internet age, and some are re-branded as HYIPs or High Yield Investment Programs. This paper focuses on understanding HYIPs' continuous presence and presents various possible reasons behind their existence in today's world. A look into the countries where these schemes purport to exist, we find that 62.89% of all collected HYIPs claim to be in the United Kingdom (UK), and a further 55.56% are officially registered in the UK as a 'limited company' with a registration number provided by the UK Companies House, a UK agency that registers companies. We investigate other factors influencing these schemes, including the HYIPs' social media platforms and payment processors. The lifetime of the HYIPs helps to understand the success/failure of the investment schemes and helps indicate the schemes that could attract more investors. Using Cox proportional regression analysis, we find that having a valid UK address significantly affects the lifetime of an HYIP

Detecting Text Reuse in Cryptocurrency Whitepapers

Thousands of new cryptocurrencies have been introduced in recent years. Most are introduced with a so-called "whitepaper" containing a mix of technical documentation, legal boilerplate and marketing material. Notably, many proposed currencies reuse text from previous established cryptocurrencies. We analyze the whitepapers from 1 260 actively traded cryptocurrencies and 2 039 ICOs. We develop two measures of similarity. Moderately similar papers reuse text in a portion of the paper, often the legal disclaimers. By contrast, some highly similar whitepapers appear to copy most of the text. 4% of coin and 19% of ICO whitepapers are highly similar to those of traded coins. The fraction rises to 64% for coins and 67% for ICOs when we consider moderate text reuse

Short Paper: An Exploration of Code Diversity in the Cryptocurrency Landscape

Interest in cryptocurrencies has skyrocketed since their introduction a decade ago, with hundreds of billions of dollars now invested across a landscape of thousands of different cryptocurrencies. While there is significant diversity, there is also a significant number of scams as people seek to exploit the current popularity. In this paper, we seek to identify the extent of innovation in the cryptocurrency landscape using the open-source repositories associated with each one. Among other findings, we observe that while many cryptocurrencies are largely unchanged copies of Bitcoin, the use of Ethereum as a platform has enabled the deployment of cryptocurrencies with more diverse functionalities

The rise and fall of cryptocurrency coins and tokens

Since Bitcoin’s introduction in 2009, interest in cryptocurrencies has soared. One manifestation of this interest has been the explosion of newly created coins and tokens. In this paper, we analyze the dynamics of this burgeoning industry. We consider both cryptocurrency coins and tokens. The paper examines the dynamics of coin and token creation, competition and destruction in the cryptocurrency industry. In order to conduct the analysis, we develop a methodology to identify peaks in prices and trade volume, as well as when coins and tokens are abandoned and subsequently “resurrected”. We also study trading activity. Our data spans more than 4 years: there are 1082 coins and 725 tokens in the data. While there are some similarities between coins and tokens regarding dynamics, there are some striking differences as well. Overall, we find that 44% of publicly-traded coins are abandoned, at least temporarily. 71% of abandoned coins are later resurrected, leaving 18% of coins to fail permanently. Tokens experience abandonment less frequently, with only 7% abandonment and 5% permanent token abandonment at the end of the data. Using linear regressions, we find that market variables such as the bitcoin price are not associated with the rate of introducing new coins, though they are positively associated with issuing new tokens. We find that for both coins and tokens, market variables are positively associated with resurrection. We then examine the effect that the bursting of the Bitcoin bubble in December 2017 had on the dynamics in the industry. Unlike the end of the 2013 bubble, some alternative cryptocurrencies continue to flourish after the bursting of this bubble

Magnetotransport in graphene on silicon side of SiC

We have studied the transport properties of graphene grown on silicon side of SiC. Samples under study have been prepared by two different growth methods in two different laboratories. Magnetoresistance and Hall resistance have been measured at temperatures between 4 and 100 K in resistive magnet in magnetic fields up to 22 T. In spite of differences in sample preparation, the field dependence of resistances measured on both sets of samples exhibits two periods of magneto-oscillations indicating two different parallel conducting channels with different concentrations of carriers. The semi-quantitative agreement with the model calculation allows for conclusion that channels are formed by high-density and low-density Dirac carriers. The coexistence of two different groups of carriers on the silicon side of SiC was not reported before.Comment: 5 pages, 6 figures, accepted for publication in the "IOP Journal of Physics: Conference series" as a contribution to the proceedings of the 20th International Conference on "High Magnetic Fields in Semiconductor Physics", HMF 2

Biodiversity of wild Lactococcus lactis and their geo-spatial relationship with the environment

Lactic acid bacteria are distributed in nature, isolating themselves from diverse ecosystems and presenting a wide metabolic biodiversity. In Corrientes (Argentina), artisanal cheeses and their specific environment are an important source of autochthonous lactic acid bacteria. The objective of this work was to establish associations between the phenotypic characteristics of strains of Lactococcus lactis subsp. lactis native from Corrientes with climatological data of the Province and the characteristics of the soil and the landscapes. Physiological and biochemical characterization data of Lactococcus lactis subsp. lactis isolated from the dairy environment and from different localities of Corrientes will be used. The strains were space-located through Google Earth, flood and drought events were evaluated using Standardized Precipitation Evapotranspiration Index, and soil composition data (A and Bt horizons) in the study areas were obtained from the experimental station National Institute of Agricultural Technology-Corrientes. A statistical analysis was applied to these results (Infostat Software, Di Rienzo et al. 2008). The resulting consists in three conglomerates, differentiating strains from soils coming from “flooded landscapes” and those from “sandy hills landscape”. The analysis by main components highlighted the preference of strains from flooded landscapes by a saline-alkaline environment, affecting during periods of drought, and strains from sandy hills landscape by a low medium in salts and acid soil, directly during period of high humidity resulting from previous floods.Fil: Maidana, Mario Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; ArgentinaFil: Contreras, Félix Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Vasek, Olga M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; Argentin

Analyzing Target-Based Cryptocurrency Pump and Dump Schemes

As the number of cryptocurrencies has exploded in recent years, so too has the fraud. One popular strategy is when actors promote coordinated purchases of coins in hopes of temporarily driving up prices. Prior work investigating such pump and dump schemes has focused on the immediate impact to prices following pump signals, which were largely interpreted as following the same strategy. The reality, as with most cybercrimes, is that the operators of the schemes try out a much more heterogeneous mix of tactics. From a population of 12,252 pump signals observed between July 2017 and January 2019, we identify and examine 3,683 so-called target-based pump signals that announce promoted coins alongside buy and sell targets, but without a coordinated purchase time. We develop a strategy to measure the success of target pumps over longer time horizons. We find that around half of these pumps reach at least one of their sell targets, and that reaching their peak price often takes days, as opposed to the seconds or minutes required in pumps studied previously. We also examine the various groups promoting coins and present evidence that groups try a variety of distinct strategies and experience varying success. We find that the most successful groups promote many coins and issue many pumps, but not for the same coins. As decentralized finance becomes more popular, a deeper understanding of price manipulation techniques like target pumps is needed to combat fraud

Quesos artesanales de Corrientes. Riesgo de enfermedades transmitidas por alimentos: Encefalopatia espongiforme Bovina. Review.

Las Enfermedades Transmitidas por Alimentos (ETAs) constituyen un problema de Salud Pública, de donde deriva la importancia de conocer la "trazabilidad" de los alimentos para ofrecer productos seguros e inocuos. Entre los casos preocupantes se destaca la Encefalopatía Espongiforme Bovina (EEB), ya que actualmente se conoce que el agente etiológico puede atravesar la barrera de especie y desarrollar su variante humana, la enfermedad de Creutzfeldt-Jakob (vECJ). Es preciso considerar el potencial ingreso del agente infectivo en la cadena alimentaria humana durante la alimentación del ganado empleado para la elaboración de derivados de este origen, debido a que el prin1er brote de la enfermedad, surgió a partir de los piensos contaminados, enfatizándose la necesidad de reforzar los controles desde el inicio de la cadena alin1entaria. En el presente trabajo se otorga especial atención a la posibilidad de contaminación por priones durante la elaboración del Queso Artesanal de Corrientes, a través de dos materias primas: el agente coagulante artesanal bovino y la leche