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Sample records for black sigatoka attack

  1. Biological control of banana black Sigatoka disease with Trichoderma

    Directory of Open Access Journals (Sweden)

    Poholl Adan Sagratzki Cavero

    2015-06-01

    Full Text Available Black Sigatoka disease caused by Mycosphaerella fijiensis is the most severe banana disease worldwide. The pathogen is in an invasive phase in Brazil and is already present in most States of the country. The potential of 29 isolates of Trichoderma spp. was studied for the control of black Sigatoka disease under field conditions. Four isolates were able to significantly reduce disease severity and were further tested in a second field experiment. Isolate 2.047 showed the best results in both field experiments and was selected for fungicide sensitivity tests and mass production. This isolate was identified as Trichoderma atroviride by sequencing fragments of the ITS region of the rDNA and tef-1α of the RNA polymerase. Trichoderma atroviride was as effective as the fungicide Azoxystrobin, which is recommended for controlling black Sigatoka. This biocontrol agent has potential to control the disease and may be scaled-up for field applications on rice-based solid fermentation

  2. The Draft Genome Sequence of Mycosphaerella fijiensis, the Black Sigatoka Pathogen of Banana

    Science.gov (United States)

    Mycosphaerella fijiensis is a fungal pathogen of banana and the causal agent of the devastating Black Sigatoka or black leaf streak disease. Its control requires weekly fungicide applications when bananas are grown under disease-conducive conditions, which mostly represent precarious tropical enviro...

  3. Field Plot Techniques for Black Sigatoka Evaluation in East African Highland Bananas

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    Okoro, JU.

    1997-01-01

    Full Text Available Number of plants per experimental unit and number of replications for the efficient and precise assessment of black sigatoka leaf spot disease caused by Mycosphaerella fijiensis in East African Highland bananas were determined. Two representative cultivars were used. Host response to black sigatoka infection was measured by recording the youngest leaf with necrotic spots. The number of plants per experimental unit was determined, using the methods of maximum curvature and comparison of variances, while the number of replications was estimated by Hatheway's method. The optimum experimental plot size was 3 plants (18 m2 for the beer banana cultivar 'Igitsiri', and 30 plants (180 m2 for the cooking banana cultivar 'Igisahira Gisanzwe', using the comparison of variances method. However, the optimum plot size was 15 plants (90 m2 for both cultivars using the method of maximum curvature. The latter statistical method was preferred because of the low precision of the estimates in the former method. Unreplicated trials with plots of 15 plants could be adequate to assess black sigatoka response in East African bananas if uniform disease pressure exists.

  4. Molecular Characterization of Banana (AA Diploids with Contrasting Levels of Black and Yellow Sigatoka Resistance

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    Claudia F. Ferreira

    2004-01-01

    Full Text Available Most banana cultivars are susceptible to many diseases, whereas Sigatoka leads to greatest yield losses. One of the strategies to overcome this disease is thorough banana genetic breeding which consists in the obtainment of improved (AA diploids which are then crossed with triploids obtaining (AAAB tetraploid disease resistant bananas also presenting other important agronomic characteristics. The prior knowledge of the genetic diversity of (AA diploids, is therefore considered indispensable in order to direct the crosses being made. The objective of the present work was to analyze the genetic diversity of 20 (AA banana diploids with contrasting levels of reaction to yellow and black Sigatoka caused by Mycosphaerella musicola and M. fijensis, respectively, using molecular markers. From the dendrogram data it is shown that a great number of experimental hybrids can be obtained from the combination of genetically different diploids, therefore making the banana genetic breeding program more efficient regarding its objectives.

  5. The origin, versatility and distribution of azole fungicide resistance in the banana black Sigatoka pathogen Pseudocercospora fijiensis

    NARCIS (Netherlands)

    Chong Aguirre, Pablo A.

    2016-01-01

    Pseudocercospora fijiensis causes black Sigatoka disease of banana. It is one of the most damaging threats of the crop requiring excessive fungicide applications for disease control as the major export “Cavendish” clones are highly susceptible. The consequence of this practice is the red

  6. Plantio adensado não controla a sigatoka-negra da bananeira Dense plantation do not control banana black-sigatoka

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    Luadir Gasparotto

    2008-01-01

    Full Text Available Algumas publicações relatam que o adensamento populacional dos bananais reduz a severidade da sigatoka-negra (Mycosphaerella fijiensis. Instalou-se um ensaio com cinco tratamentos e quatro repetições. Os tratamentos 1.600, 2.000, 2.400, 2.800 e 3.200 plantas.ha-1 da cultivar D'Angola foram instalados em parcelas agrupadas de 2.000 m² cada. O tamanho das parcelas foi fixo e o número de plantas por parcela variou conforme o espaçamento adotado para cada população. A área de 2.000 m² foi dividida em quatro subáreas de 500 m², considerando-as como parcelas. Em cada subárea selecionaram-se 15 plantas centrais para serem avaliadas. Na época do florescimento registraram-se a severidade da doença na folha n.°10 e o número de folhas viáveis. Na colheita, a altura e o diâmetro do pseudocaule e o peso dos cachos, das pencas e dos frutos. A análise conjunta dos dados indica que todos os tratamentos foram semelhantes entre si e que o adensamento das plantas não controlou a sigatoka-negra.Many publications show that plantations of high density of bananas decrease the severity of black-sigatoka (Mycosphaerella fijiensis. To test this hypothesis it was instaled an experiment with five treatments and four repetitions. The treatments were density plant of 1.600, 2.000, 2.400, 2.800 e 3.200 plant.ha-1. The cultivar planted was D'Angola and each plot had fixed 2.000 m², the number of plants in each plot changed in accordance with the treatment tested. The plots were divided in four subplots of 500 m² where 15 plants located in the center were measured. The evaluation of severity was carried out in the leaf number ten during the flowering period. It was also evaluated the numbers of viable leaves, height, diameter and weight of production (banch, bunches and fruits. The analyses did not show effect of high density in the parameter measured and it was conclued that the treatments tested had not control black-sigatoka.

  7. Climatic Forcing on Black Sigatoka Disease of Banana Crops in Urabá, Colombia

    Science.gov (United States)

    Ochoa, A.; Álvarez, P.; Poveda, G.; Buriticá, P.; Mira, J.

    2012-12-01

    Bananas are widely the most consumed fruit in the world and Colombia is one of the major producers and exporters of bananas worldwide. We analyzed the climatic forcing agents on banana crops in the Urabá region, the largest banana producer in Colombia. Although this crop is harvested continuously throughout the entire year, it exhibits climate driven seasonality. Black Sigatoka Disease (BSD) has been the most important threat for banana production worldwide. BSD attacks plant leaves producing small spots of dead material. When BSD is not treated, it can grow enough to damage the entire leaf, reducing both growth and developmental rates which may result in the loss of the plant. BSD is caused by Mycosphaerella fijiensis. This fungus is dispersed by wind with its inoculation occurring when there is water on the leaf. Thus, climatic variables such as wind, relative humidity of air (RH) and leaf wetness duration (LWD) all affect phenological phases of the banana crop (suckering, growing, flowering and harvesting). This study was carried out at the Cenibanano Experimental Plot located in Carepa (Urabá, Colombia) during 2007-2012. We used phytopathologic and weather data from the Cenibanano database along with climatic data from the North American Regional Reanalysis (NARR). BSD was diagnosed using the Biological Forecasting method. Results show that rainfall drives both plant and disease development rate. During wet periods the Foliar Emission Rate exceeds rates measured during dry periods. Although wetness is a positive factor for fungal reproduction (and BSD), it also heightens the chance for the plant to create more foliar tissue to fight against BSD. Hence, during wet periods the Severity Index of BSD is reduced in relation to dry periods. This effect was also observed at the inter-annual scale of the El Niño - South Oscillation (ENSO) phenomenon. During the ENSO warm/cold phase (El Niño/La Niña) rainfall anomalies in Colombia were observed as negative

  8. Combating a Global Threat to a Clonal Crop: Banana Black Sigatoka Pathogen Pseudocercospora fijiensis (Synonym Mycosphaerella fijiensis) Genomes Reveal Clues for Disease Control

    NARCIS (Netherlands)

    Arango Isaza, Rafael E.; Diaz-Trujillo, Caucasella; Dhillon, Braham; Aerts, Andrea; Carlier, Jean; Crane, Charles F.; V. de Jong, Tristan; de Vries, Ineke; Dietrich, Robert; Farmer, Andrew D.; Fortes Fereira, Claudia; Garcia, Suzana; Guzman, Mauricio; Hamelin, Richard C.; Lindquist, Erika A.; Mehrabi, Rahim; Quiros, Olman; Schmutz, Jeremy; Shapiro, Harris; Reynolds, Elizabeth; Scalliet, Gabriel; Souza Manoel, Jr.; Stergiopoulos, Ioannis; Van der Lee, Theo A. J.; De Wit, Pierre J. G. M.; Zapater, Marie-Françoise; Zwiers, Lute-Harm; Grigoriev, Igor V.; Goodwin, Stephen B.; Kema, Gert H. J.

    2016-01-01

    Black Sigatoka or black leaf streak disease, caused by the ascomycete fungus Pseudocercospora fijiensis, inflicts huge costs on banana producers, due to crop losses and expenses for disease control. The global banana export trade relies on Cavendish clones that are highly susceptible to P. fijiensis

  9. Combating a Global Threat to a Clonal Crop : Banana Black Sigatoka Pathogen Pseudocercospora fijiensis (Synonym Mycosphaerella fijiensis) Genomes Reveal Clues for Disease Control

    NARCIS (Netherlands)

    Arango Isaza, Rafael E.; Diaz-Trujillo, Caucasella; Dhillon, Braham; Aerts, Andrea; Carlier, Jean; Crane, Charles F.; de Jong, Tristan V.; de Vries, Ineke; Dietrich, Robert; Farmer, Andrew D.; Fereira, Claudia Fortes; Garcia, Suzana; Guzman, Mauricio; Hamelin, Richard C.; Lindquist, Erika A.; Mehrabi, Rahim; Quiros, Olman; Schmutz, Jeremy; Shapiro, Harris; Reynolds, Elizabeth; Scalliet, Gabriel; Souza, Manoel; Stergiopoulos, Ioannis; Van der Lee, Theo A. J.; De Wit, Pierre J. G. M.; Zapater, Marie-Francoise; Zwiers, Lute-Harm; Grigoriev, Igor V.; Goodwin, Stephen B.; Kema, Gert H. J.

    2016-01-01

    Black Sigatoka or black leaf streak disease, caused by the Dothideomycete fungus Pseudocercospora fijiensis (previously: Mycosphaerella fijiensis), is the most significant foliar disease of banana worldwide. Due to the lack of effective host resistance, management of this disease requires frequent f

  10. Agrobacterium-mediated transformation of Mycosphaerella fijiensis, the devastating Black Sigatoka pathogen of bananas

    NARCIS (Netherlands)

    Díaz-Trujillo, C.; Adibon, H.; Kobayashi, K.; Zwiers, L.H.; Souza, M.T.; Kema, G.H.J.

    2010-01-01

    Mycosphaerella fijiensis, M. musicola en M. eumusae veroorzaken de Sigatoka-ziekte in banaan. Op dit moment is de toepassing van fungiciden de enige optie om deze ziekte te bestrijden. Het PRPB (Pesticide Reduction Program for Banana) investeert in de ontwikkeling van technieken voor de genotype- en

  11. Plantio irrigado de bananeiras resistentes à Sigatoka-negra consorciado com culturas anuais Irrigated banana resistant to black Sigatoka, with annual intercrops

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    Ildeu de Souza

    2010-03-01

    Full Text Available Com o objetivo de avaliar o plantio irrigado de bananeiras resistentes à Sigatoka-negra consorciado com cultura anuais, na região norte de Minas Gerais, um experimento foi instalado na Fazenda Experimental do Departamento de Ciências Agrárias da Universidade Estadual de Montes Claros, Câmpus de Janaúba-MG. O experimento foi conduzido no período de abril de 2006 a julho de 2007, delineado em blocos casualizados, segundo um esquema de parcelas subdivididas 3 x 5, tendo na parcela as três variedades de bananeiras: Pacovan Ken, Caipira e Thap Maeo, e na subparcela quatro culturas intercalares: Feijão-Pérola, Quiabo-Dardo, Melancia-Crimson-Sweet e Feijão-Caupi, e a testemunha (sem cultura intercalar, com três repetições. Ao todo, foram 756 bananeiras, em 45 parcelas, com 6 plantas úteis cada, constituindo a cultura principal. As culturas intercalares ocuparam as entrelinhas da bananeira, tanto aquelas com as linhas de irrigação como sem linha de irrigação. O plantio da bananeira e das culturas intercalares foi feito no mesmo período, utilizando-se do espaçamento de 3,0 m entre as linhas e 2,0 m entre as covas de bananeira, com microaspersores espaçados de 6 m. Avaliaram-se as características vegetativas e reprodutivas das variedades de bananeiras, no primeiro ciclo. Não foi observado efeito significativo dos cultivos intercalares sobre as variedades de bananeiras, com exceção do número de dias do plantio ao florescimento e do número de dias do plantio à colheita das variedades de bananeiras. O uso do feijão-caupi promoveu atraso no ciclo de produção das três variedades de bananeiras Pacovan Ken, Caipira e Thap Maeo.To assess the irrigated cultivation of banana resistant to black Sigatoka, intercropped with annual crops in the northern region of Minas Gerais, a trial was conducted on an experimental farm of the Universidade Estadual de Montes Claros, in Janaúba-MG. The experiment was carried out from April 2006 to

  12. Aceitação de cultivares de bananas resistentes à Sigatoka Negra junto ao consumidor da região Nordeste do Brasil Acceptance of banana cultivars resistant to Black Sigatoka by the consumer market of Northeast Brazilian region

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    Deborah dos Santos Garruti

    2012-05-01

    Full Text Available O Mal da Sigatoka Negra é devastador para as cultivares tradicionais de banana. No Brasil, cultivares resistentes estão sendo desenvolvidas, mas se a preferência do consumidor não for considerada, o programa de melhoramento pode falhar. Neste trabalho, a aceitabilidade de quatro cultivares resistentes foi acessada no Nordeste brasileiro e comparada a quatro variedades comerciais. Dois grupos de consumidores participaram: adultos jovens e donas de casa. Escala hedônica foi aplicada para aparência externa dos cachos, aceitação global e aceitação por atributos dos frutos (aparência sem a casca, aroma, sabor e textura, além de testes de preferência e intenção de compra. Os dados foram submetidos à ANOVA e Mapa de Preferência Interno. Mulheres e jovens mostraram opiniões semelhantes. As cultivares 'Preciosa' e 'Pacovan Ken' mostraram ser as mais promissoras, sendo que a primeira já pode substituir as cultivares comerciais 'Prata' e 'Pacovan' sem prejudicar a sua aceitabilidade, mas a 'Pacovan Ken' ainda precisa ser melhorada quanto à aparência.The Black Sigatoka Disease is devastating to traditional banana cultivars. In Brazil, resistant cultivars are being developed but if the consumer's preference is not taken into account, the breeding program may not succeed. In this research the acceptability of four resistant cultivars was accessed in the Northeastern Brazilian region and compared to four commercial varieties. Two groups of consumers participated: young adults and housewives. Hedonic scale was applied to external appearance of bunches, global acceptance and acceptance of fruits' attributes (appearance without peel, aroma, flavor and texture. Preference and purchase intent were also evaluated. Data were submitted to ANOVA and Preference Mapping. Women and young adults showed similar opinions. 'Preciosa' and 'Pacovan Ken' cultivars showed to be the most promising ones. 'Preciosa' can already substitute the commercial 'Prata

  13. Progresso da sigatoka-negra (Mycosphaerella fijiensis em bananeiras após a emissão do cacho no Município de Cáceres, Mato Grosso-Brasil Progress of black sigatoka (Mycosphaerella fijiensis in banana plants after the bunch emergence in the district of Cáceres, Mato-Grosso-Brazil

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    Márcia Benedita Martins

    2007-09-01

    Full Text Available A sigatoka-negra, causada pelo fungo Mycosphaerella fijiensis, pode causar 100% de perdas na produção das cultivares suscetíveis. O objetivo deste trabalho foi avaliar o progresso da sigatoka-negra em bananeiras após a emissão do cacho no Município de Cáceres, Mato Grosso. O experimento foi conduzido no período de fevereiro a dezembro de 2004 em plantios das cultivares Grande Naine, Maçã e Farta Velhaco, sendo esta última uma cultivar de plátano, do grupo Terra. As avaliações foram efetuadas a intervalos de 15 dias, quantificando-se, através de uma escala diagramática, a severidade da sigatoka-negra em todas as folhas de 5 plantas de cada cultivar, marcadas logo após a emissão das inflorescências. A partir dos dados coletados no campo, computaram-se: a severidade da doença na folha n.º 10 e o número de folhas viáveis. Considerou-se como folha viável as folhas sadias e aquelas com até 15% de área foliar lesionada. Os dados de temperatura e da umidade relativa foram registrados por um aparelho eletrônico instalado na área. A precipitação pluvial foi registrada na Estação meteorológica de Cáceres, distante 12 km do experimento. As condições climáticas foram favoráveis à sigatoka negra durante o ano todo e as plantas das cultivares Grande Naine, Maçã e Farta Velhaco após a emissão do cacho, perderam totalmente as folhas antes dos frutos atingirem o pleno desenvolvimento, cujos prejuízos no primeiro semestre atingiram 100% de perdas na produção comercializável.The black sigatoka, caused by Mycosphaerella fijiensis may cause 100% of yield losses in susceptible cultivars. The objective of this work was to evaluate the progress of the black sigatoka in banana plants after the bunch emergence, in the district of Cáceres, Mato Grosso State - Brazil. The experiment was carried out from February to December 2004, in banana cultivars "Grande Naine" and "Maçã", as well as plantain cultivar Farta Velhaco (Terra

  14. Combating a Global Threat to a Clonal Crop: Banana Black Sigatoka Pathogen Pseudocercospora fijiensis (Synonym Mycosphaerella fijiensis) Genomes Reveal Clues for Disease Control

    Science.gov (United States)

    Aerts, Andrea; Carlier, Jean; Crane, Charles F.; de Vries, Ineke; Dietrich, Robert; Farmer, Andrew D.; Fortes Fereira, Claudia; Garcia, Suzana; Guzman, Mauricio; Hamelin, Richard C.; Lindquist, Erika A.; Mehrabi, Rahim; Quiros, Olman; Schmutz, Jeremy; Reynolds, Elizabeth; Scalliet, Gabriel; Souza, Manoel; Stergiopoulos, Ioannis; Van der Lee, Theo A. J.; De Wit, Pierre J. G. M.; Zapater, Marie-Françoise; Zwiers, Lute-Harm; Grigoriev, Igor V.; Goodwin, Stephen B.; Kema, Gert H. J.

    2016-01-01

    Black Sigatoka or black leaf streak disease, caused by the Dothideomycete fungus Pseudocercospora fijiensis (previously: Mycosphaerella fijiensis), is the most significant foliar disease of banana worldwide. Due to the lack of effective host resistance, management of this disease requires frequent fungicide applications, which greatly increase the economic and environmental costs to produce banana. Weekly applications in most banana plantations lead to rapid evolution of fungicide-resistant strains within populations causing disease-control failures throughout the world. Given its extremely high economic importance, two strains of P. fijiensis were sequenced and assembled with the aid of a new genetic linkage map. The 74-Mb genome of P. fijiensis is massively expanded by LTR retrotransposons, making it the largest genome within the Dothideomycetes. Melting-curve assays suggest that the genomes of two closely related members of the Sigatoka disease complex, P. eumusae and P. musae, also are expanded. Electrophoretic karyotyping and analyses of molecular markers in P. fijiensis field populations showed chromosome-length polymorphisms and high genetic diversity. Genetic differentiation was also detected using neutral markers, suggesting strong selection with limited gene flow at the studied geographic scale. Frequencies of fungicide resistance in fungicide-treated plantations were much higher than those in untreated wild-type P. fijiensis populations. A homologue of the Cladosporium fulvum Avr4 effector, PfAvr4, was identified in the P. fijiensis genome. Infiltration of the purified PfAVR4 protein into leaves of the resistant banana variety Calcutta 4 resulted in a hypersensitive-like response. This result suggests that Calcutta 4 could carry an unknown resistance gene recognizing PfAVR4. Besides adding to our understanding of the overall Dothideomycete genome structures, the P. fijiensis genome will aid in developing fungicide treatment schedules to combat this

  15. Combating a Global Threat to a Clonal Crop: Banana Black Sigatoka Pathogen Pseudocercospora fijiensis (Synonym Mycosphaerella fijiensis) Genomes Reveal Clues for Disease Control.

    Science.gov (United States)

    Arango Isaza, Rafael E; Diaz-Trujillo, Caucasella; Dhillon, Braham; Aerts, Andrea; Carlier, Jean; Crane, Charles F; V de Jong, Tristan; de Vries, Ineke; Dietrich, Robert; Farmer, Andrew D; Fortes Fereira, Claudia; Garcia, Suzana; Guzman, Mauricio; Hamelin, Richard C; Lindquist, Erika A; Mehrabi, Rahim; Quiros, Olman; Schmutz, Jeremy; Shapiro, Harris; Reynolds, Elizabeth; Scalliet, Gabriel; Souza, Manoel; Stergiopoulos, Ioannis; Van der Lee, Theo A J; De Wit, Pierre J G M; Zapater, Marie-Françoise; Zwiers, Lute-Harm; Grigoriev, Igor V; Goodwin, Stephen B; Kema, Gert H J

    2016-08-01

    Black Sigatoka or black leaf streak disease, caused by the Dothideomycete fungus Pseudocercospora fijiensis (previously: Mycosphaerella fijiensis), is the most significant foliar disease of banana worldwide. Due to the lack of effective host resistance, management of this disease requires frequent fungicide applications, which greatly increase the economic and environmental costs to produce banana. Weekly applications in most banana plantations lead to rapid evolution of fungicide-resistant strains within populations causing disease-control failures throughout the world. Given its extremely high economic importance, two strains of P. fijiensis were sequenced and assembled with the aid of a new genetic linkage map. The 74-Mb genome of P. fijiensis is massively expanded by LTR retrotransposons, making it the largest genome within the Dothideomycetes. Melting-curve assays suggest that the genomes of two closely related members of the Sigatoka disease complex, P. eumusae and P. musae, also are expanded. Electrophoretic karyotyping and analyses of molecular markers in P. fijiensis field populations showed chromosome-length polymorphisms and high genetic diversity. Genetic differentiation was also detected using neutral markers, suggesting strong selection with limited gene flow at the studied geographic scale. Frequencies of fungicide resistance in fungicide-treated plantations were much higher than those in untreated wild-type P. fijiensis populations. A homologue of the Cladosporium fulvum Avr4 effector, PfAvr4, was identified in the P. fijiensis genome. Infiltration of the purified PfAVR4 protein into leaves of the resistant banana variety Calcutta 4 resulted in a hypersensitive-like response. This result suggests that Calcutta 4 could carry an unknown resistance gene recognizing PfAVR4. Besides adding to our understanding of the overall Dothideomycete genome structures, the P. fijiensis genome will aid in developing fungicide treatment schedules to combat this

  16. Construction and characterization of a plant transformation-competent BIBAC library of the black Sigatoka-resistant banana Musa acuminata cv. Tuu Gia (AA).

    Science.gov (United States)

    Ortiz-Vázquez, E; Kaemmer, D; Zhang, H-B; Muth, J; Rodríguez-Mendiola, M; Arias-Castro, C; James, Andrew

    2005-02-01

    A plant transformation-competent binary bacterial artificial chromosome (BIBAC) library was constructed from Musa acuminata cv. Tuu Gia (AA), a black Sigatoka-resistant diploid banana. After digestion of high-molecular-weight banana DNA by HindIII, several methods of DNA size selection were tested, followed by ligation, using a vector/insert molar ratio of 4:1. The library consists of 30,700 clones stored in 80 384-well microtiter plates. The mean insert size was estimated to be 100 kb, and the frequency of inserts with internal NotI sites was 61%. The majority of insert sizes fell into the range of 100+/-20 kb, making them suitable for Agrobacterium-mediated transformation. Only 1% and 0.9% of the clones contain chloroplast and mitochondrial DNA, respectively. This is the first BIBAC library for banana, estimated to represent five times its haploid genome (600 Mbp). It was demonstrated by hybridization that the library contains typical members of resistance gene and defense gene families that can be used for transformation of disease susceptible banana cultivars for banana genetic improvement.

  17. Worldwide geographical distribution of Black Sigatoka for banana: predictions based on climate change models Distribuição geográfica da Sigatoka Negra da bananeira estimada por modelos de mudanças climáticas globais

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    Waldir Cintra de Jesus Júnior

    2008-12-01

    Full Text Available As mudanças climáticas poderão alterar as doenças de plantas e afetar a eficácia das medidas de manejo. Um dos prováveis impactos será na distribuição geográfica das doenças. A Sigatoka Negra é considerada a principal doença da cultura da banana em decorrência dos danos causados e aumento do custo de manejo. O impacto sócio-econômico da doença continua aumentando, uma vez que a doença tem atingido novas áreas de plantio, tornando o manejo mais difícil. Este trabalho tem por objetivos comparar a distribuição geográfica da doença por meio da elaboração de mapas nas seguintes situações: a clima atual e futuro (2020, 2050 e 2080, b cenários A2 e B2 do Painel Intergovernamental de Mudanças Climáticas, c predito por seis diferentes modelos de mudanças climáticas e pela média dos mesmos e, d entre meses. Haverá redução das áreas favoráveis à doença no futuro, sendo que tal redução será mais acentuada no cenário A2 do que no B2 e gradativa para as décadas de 2020, 2050 e 2080. Predições efetuadas com o uso da média dos dados estimados pelos modelos permitiram redução na variabilidade da simulação em comparação com a predição gerada por cada modelo individualmente. Alterações na distribuição geográfica da doença ocorrerão entre meses, de modo que áreas consideradas desfavoráveis tornar-se-ão favoráveis e vice-versa. Apesar disso, extensas áreas continuarão favoráveis ao desenvolvimento da Sigatoka Negra.Global climatic changes will potentially influence plant diseases and the efficacy of their management options. One of the most likely impacts of climate change will be felt by the geographical distribution of plant diseases. Black Sigatoka is considered the most damaging and costly disease of banana. The socio-economic impact of this disease has continued to increase as the pathogen reaches new areas and the disease becomes more difficult to be controled. The objectives of this

  18. To mitigate Black-hole attack with CBDS in MANET

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    Navjot

    2015-06-01

    Full Text Available Mobile ad-hoc network is self configured network that consist of mobile nodes which communicate with each other. Distributed self-organized nature of this network makes it venerable to various attacks likes DOS attack, Black hole attack, wormhole attack and jamming attack etc. Blackhole attack is one of the serious attack in network in which information loss occur which degrades the performance of network. In this work black hole attack is detected with the help of CBDS (cooperative Bait Detection Algorithm and MD5 is used for the security purpose. This work is implemented in Network simulator and performance is checked on the bases of network parameters.

  19. Singlet molecular oxygen generation by light-activated DHN-melanin of the fungal pathogen Mycosphaerella fijiensis in black Sigatoka disease of bananas.

    Science.gov (United States)

    Beltrán-García, Miguel J; Prado, Fernanda M; Oliveira, Marilene S; Ortiz-Mendoza, David; Scalfo, Alexsandra C; Pessoa, Adalberto; Medeiros, Marisa H G; White, James F; Di Mascio, Paolo

    2014-01-01

    In pathogenic fungi, melanin contributes to virulence, allowing tissue invasion and inactivation of the plant defence system, but has never been implicated as a factor for host cell death, or as a light-activated phytotoxin. Our research shows that melanin synthesized by the fungal banana pathogen Mycosphaerella fijiensis acts as a virulence factor through the photogeneration of singlet molecular oxygen O2 (1Δg). Using analytical tools, including elemental analysis, ultraviolet/infrared absorption spectrophometry and MALDI-TOF mass spectrometry analysis, we characterized both pigment content in mycelia and secreted to the culture media as 1,8-dihydroxynaphthalene (DHN)-melanin type compound. This is sole melanin-type in M. fijiensis. Isolated melanins irradiated with a Nd:YAG laser at 532 nm produced monomol light emission at 1270 nm, confirming generation of O2 (1Δg), a highly reactive oxygen specie (ROS) that causes cellular death by reacting with all cellular macromolecules. Intermediary polyketides accumulated in culture media by using tricyclazole and pyroquilon (two inhibitors of DHN-melanin synthesis) were identified by ESI-HPLC-MS/MS. Additionally, irradiation at 532 nm of that mixture of compounds and whole melanized mycelium also generated O2 (1Δg). A pigmented-strain generated more O2 (1Δg) than a strain with low melanin content. Banana leaves of cultivar Cavendish, naturally infected with different stages of black Sigatoka disease, were collected from field. Direct staining of the naturally infected leaf tissues showed the presence of melanin that was positively correlated to the disease stage. We also found hydrogen peroxide (H2O2) but we cannot distinguish the source. Our results suggest that O2 (1Δg) photogenerated by DHN-melanin may be involved in the destructive effects of Mycosphaerella fijiensis on banana leaf tissues. Further studies are needed to fully evaluate contributions of melanin-mediated ROS to microbial pathogenesis.

  20. Singlet molecular oxygen generation by light-activated DHN-melanin of the fungal pathogen Mycosphaerella fijiensis in black Sigatoka disease of bananas.

    Directory of Open Access Journals (Sweden)

    Miguel J Beltrán-García

    Full Text Available In pathogenic fungi, melanin contributes to virulence, allowing tissue invasion and inactivation of the plant defence system, but has never been implicated as a factor for host cell death, or as a light-activated phytotoxin. Our research shows that melanin synthesized by the fungal banana pathogen Mycosphaerella fijiensis acts as a virulence factor through the photogeneration of singlet molecular oxygen O2 (1Δg. Using analytical tools, including elemental analysis, ultraviolet/infrared absorption spectrophometry and MALDI-TOF mass spectrometry analysis, we characterized both pigment content in mycelia and secreted to the culture media as 1,8-dihydroxynaphthalene (DHN-melanin type compound. This is sole melanin-type in M. fijiensis. Isolated melanins irradiated with a Nd:YAG laser at 532 nm produced monomol light emission at 1270 nm, confirming generation of O2 (1Δg, a highly reactive oxygen specie (ROS that causes cellular death by reacting with all cellular macromolecules. Intermediary polyketides accumulated in culture media by using tricyclazole and pyroquilon (two inhibitors of DHN-melanin synthesis were identified by ESI-HPLC-MS/MS. Additionally, irradiation at 532 nm of that mixture of compounds and whole melanized mycelium also generated O2 (1Δg. A pigmented-strain generated more O2 (1Δg than a strain with low melanin content. Banana leaves of cultivar Cavendish, naturally infected with different stages of black Sigatoka disease, were collected from field. Direct staining of the naturally infected leaf tissues showed the presence of melanin that was positively correlated to the disease stage. We also found hydrogen peroxide (H2O2 but we cannot distinguish the source. Our results suggest that O2 (1Δg photogenerated by DHN-melanin may be involved in the destructive effects of Mycosphaerella fijiensis on banana leaf tissues. Further studies are needed to fully evaluate contributions of melanin-mediated ROS to microbial pathogenesis.

  1. Caracterização morfológica e avaliação de cultivares de bananeira resistentes a Sigatoka Negra (Mycosphaerella fijiensis Morelet no sudoeste goiano Morphologic characterization and evaluation of banana cultivars resistant to the Black Sigatoka disease (Mycosphaerella fijiensis Morelet in the Southwest of the State of Goiás, Brazil

    Directory of Open Access Journals (Sweden)

    Silvia Correa Santos

    2006-12-01

    Full Text Available Cinco cultivares de bananeira resistentes a Sigatoka Negra foram cultivadas na área experimental da Universidade Federal de Goiás, no município de Jataí, localizado na região Sudoeste do Estado. O objetivo foi introduzir genótipos resistentes a Sigatoka Negra no Estado, bem como fazer a caracterização morfológica desses materiais nessas condições climáticas. O trabalho foi realizado por meio da avaliação, em três ciclos produtivos, dos seguintes componentes de produção: intervalo em dias entre o plantio e o florescimento, número de folhas no florescimento e na colheita, número de pencas por cacho, frutos por cacho e frutos por penca, comprimento do cacho e dos frutos e peso do engaço, das pencas e do cacho. As cultivares falsa FHIA-18 e Caipira produziram em média aos 393 dias, apresentando maior precocidade em relação às demais cultivares. Como era esperado, a FHIA-21, que é uma bananeira tipo Terra, apresentou um ciclo maior (488 dias. O clima e a altitude de Jataí-GO podem ter contribuído para o aumento do ciclo das cinco cultivares quando comparado com outras regiões. Para as características de produção, a FHIA-01 e a falsa FHIA-18 se destacaram das demais. Para o número de pencas, a Thap Maeo se destacou nos três ciclos, mostrando a característica deste genótipo. As maiores alturas na floração foram observadas nas cultivares FHIA-21 e Thap Maeo, que também foram as que mais sofreram com os efeitos do vento.Five banana cultivars resistant to the Black Sigatoka Disease were grown at the experimental field of the Universidade Federal de Goiás (UFG, located in the Southwest region of the State of Goiás (Brazil. This work aimed the introduction of Black Sigatoka resistant cultivars as well as the characterization of the morphological aspects of such cultivars at that climatic region. The following characteristics were evaluated, in the first three cycles: days between planting and flowering, leaf number at

  2. Black Hole and Greyhole Attack in Wireless Mesh Network

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    Rupinder Kaur

    2014-10-01

    Full Text Available Security is an important need in wireless mesh networks to give safe and shared information between wireless non-static nodes. In wireless network nodes has ability to act correctly and route the packets. Wireless mesh networks unusual method of producing,keeping and sharing information ability of mobile objects to show spontaneous and cheap adjusting arrangement itself.There are different types of communication devices in technology by which performance is measured.There is a major issue which take part in network and provide security from various kinds of malicious attacks.There are various attacks such as black hole attack,wormhole attack,Greyhole attack, and evesdropping attack.Black hole and Greyhole attacks are network layer attacks that spoils the performance by falling the packets.The black hole and Grey hole are the problem of security that consider in wireless networks.Black hole and Greyhole attack is one type of way of interrupting attack and can cause large amount of damage to network.Black hole attack is act like ad-hoc network; which create network and attack on packets.In black hole attack where a false node not make correct paths in public to receiver node during the direction finding process. Theattacker achieves this attack when all the similar kinds of nodes communicate and make network to each other. It is very important to protectthe network layer from these attack which is also a great issues in wireless mesh network. Greyhole attack is very difficult to detect in wireless mesh network.In this paper,its an overview about black hole attack and grey hole in wireless mesh network and define problem statement about them. Secondly, its take study about related work in which many authors perform on these attacks and then its discuss about proposed method.Thirdly,the results are simulated carried out in OPNET simulator where black hole attack and grey hole attack shows the performance and Its analysis the throughput in network.

  3. Performance analysis of black hole attacks in geographical routing MANET

    Directory of Open Access Journals (Sweden)

    H.J Shanthi

    2014-10-01

    Full Text Available The MANET (Mobile Adhoc Network is vulnerable to several types of attacks. The most commonly classified attack is black hole attack, which is carried by single or multiple attackers, advertising itself of having a short fresh route to transmit data. The aim is to ensure security against the black hole attack and analyze the performance in geographical routing. The simple method is to send data as small blocks instead of entire data. The traffic is monitored independently in its neighborhood. The mechanism uses geographic information to detect variance in neighbor relations and node movements. We analyze the black hole attack in two popular location based protocol LAR and DREAM. It provides the stimulation study of black hole attack with the minimum attacker and also provides analysis on the parameters such as throughput, packet delivery and delay done with OMNET++ simulator. The simulation results show that packet loss increases and throughput decreases in the network with a black hole node in geographical routing. The proposed mechanism can be combined with existent routing protocols to defend against black hole attacks.

  4. Effect of Black Hole Attack on MANET Routing Protocols

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    Jaspal Kumar

    2013-04-01

    Full Text Available Due to the massive existing vulnerabilities in mobile ad-hoc networks, they may be insecure against attacks by the malicious nodes. In this paper we have analyzed the effects of Black hole attack on mobile ad hoc routing protocols. Mainly two protocols AODV and Improved AODV have been considered. Simulation has been performed on the basis of performance parameters and effect has been analyzed after adding Black-hole nodes in the network. Finally the results have been computed and compared to stumble on which protocol is least affected by these attacks.

  5. Variable Number of Tandem Repeat Markers in the Genome Sequence of Mycosphaerella Fijiensis, the Causal Agent of Black Leaf Streak Disease of Banana (Musa spp.)

    Science.gov (United States)

    Mycosphaerella fijiensis, the causal agent of banana leaf streak disease (commonly known as black Sigatoka), is the most devastating pathogen attacking bananas (Musa spp). Recently the whole genome sequence of M. fijiensis became available. This sequence was screened for the presence of Variable Num...

  6. Performance Analysis of Black Hole Attack in Vanet

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    Vimal Bibhu

    2012-10-01

    Full Text Available Black hole attack in Vehicular Ad Hoc Network is major problem related with the field of computer networking. In this paper we present the performance analysis of the black hole attack in Vehicular Ad Hoc Network. We elaborate the different types of attacks and their depth in ad hoc network. The performance metric is taken for the evaluation of attack which depends on a packet end to end delay, network throughput and network load. The delay, throughput and load are simulated by the help of OPNET 14.5 modeler. The simulation setup comprises of 30 Vehicular nodes moving with constant speed of 10 meter per second. The data rate of Vehicular nodes is 11 Mbps with default transmitting power of 0.005 watts. With On Demand Distance Vector Routing and Optimized Link State Routing the malicious node buffer size is lowered to a level which increase packet drops.

  7. Preventing AODV Routing Protocol from Black Hole Attack

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    Lalit Himral,

    2011-05-01

    Full Text Available Ad-hoc networks, due to their improvised nature, are frequently established insecure environments, which makes them susceptible to attacks. These attacks are launched by participating malicious nodes against different network services. Routing protocols, which act as the binding force in these networks, are a common target of these nodes. Ad hoc On-demand Distance Vector routing (AODVis a widely adopted network routing protocol for Mobile Ad hoc Network (MANET. Black hole attack is one of the severe security threats in ad-hoc networks which can be easily employed by exploitingvulnerability of on-demand routing protocols such as AODV. In this paper we proposed a solution for identifying the malicious node in AODV protocol suffering from black hole attack.

  8. Prevention of Co-operative Black Hole Attack in MANET

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    Latha Tamilselvan

    2008-05-01

    Full Text Available A mobile ad hoc network (MANET is an autonomous network that consists of mobile nodes that communicate with each other over wireless links. In the absence of a fixed infrastructure, nodes have to cooperate in order to provide the necessary network functionality. One of the principal routing protocols used in Ad hoc networks is AODV (Ad hoc On demand Distance Vector protocol. The security of the AODV protocol is compromised by a particular type of attack called ‘Black Hole’ attack In this attack a malicious node advertises itself as having the shortest path to the node whose packets it wants to intercept. To reduce the probability it is proposed to wait and check the replies from all the neighboring nodes to find a safe route. Our approach to combat the Black hole attack is to make use of a ‘Fidelity Table’ wherein every participating node will be assigned a fidelity level that acts as a measure of reliability of that node. In case the level of any node drops to 0, it is considered to be a malicious node, termed as a ‘Black hole’ and is eliminated. Computer simulation using GLOMOSIM shows that our protocol provides better security and also better performance in terms of packet delivery than the conventional AODV in the presence of Black holes with minimal additional delay and Overhead.

  9. A Study of Black Hole Attack on MANET Performance

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    C. K. Nagpal

    2012-08-01

    Full Text Available Mobile Ad hoc Network (MANET is a self-organized wireless network, consisting of nodes (mobile devices responsible for its creation, operation and maintenance. The communication in the MANET is of multihop in nature due to absence of any fixed infrastructure. An attacker may intrude easily into MANET by posing as legitimate intermediate node and present various types of security attacks on data exchanges taking place between source and destination. In this paper we study the impact of presence of black hole node on MANET performance on the basis of reachability, hop count, neighbor node density and path optimality. We observe that as the percentage of black hole nodes increases, the MANET performance degrades significantly.

  10. Indirect Speculative Attacks and the Black Market for Foreing Exchange: The Example of Sudan Indirect Speculative Attacks and the Black Market for Foreing Exchange: The Example of Sudan

    OpenAIRE

    1993-01-01

    Indirect Speculative Attacks and the Black Market for Foreing Exchange: The Example of Sudan The paper extends the recent literature on collapsing exchange roles and balance of payment crises to the case when currency inconvertibility gives rise to the emergence of an "illegal" black market. The presence of the black market generates indirect speculative attacks on the official reserves because, due to inconvertibility, agents cannot directly buy official reserves. The paper derives several c...

  11. Indirect Speculative Attacks and the Black Market for Foreing Exchange: The Example of Sudan Indirect Speculative Attacks and the Black Market for Foreing Exchange: The Example of Sudan

    Directory of Open Access Journals (Sweden)

    Ibrahim A. Elbadawi

    1993-03-01

    Full Text Available Indirect Speculative Attacks and the Black Market for Foreing Exchange: The Example of Sudan The paper extends the recent literature on collapsing exchange roles and balance of payment crises to the case when currency inconvertibility gives rise to the emergence of an "illegal" black market. The presence of the black market generates indirect speculative attacks on the official reserves because, due to inconvertibility, agents cannot directly buy official reserves. The paper derives several conditional probability statements regarding the likelihood of successful devaluation as a way to unify the official and black market exchange rates and achieve economic stabilization.

  12. Performance Analysis of AODV under Black Hole Attack through Use of OPNET Simulator

    CERN Document Server

    Esmaili, H A; gharaee, Hossein

    2011-01-01

    Mobile ad hoc networks (MANETs) are dynamic wireless networks without any infrastructure. These networks are weak against many types of attacks. One of these attacks is the black hole. In this attack, a malicious node advertises itself as having freshest or shortest path to specific node to absorb packets to itself. The effect of black hole attack on ad hoc network using AODV as a routing protocol will be examined in this research. Furthermore, we investigate solution for increasing security in these networks. Simulation results using OPNET simulator depict that packet delivery ratio in the presence of malicious nodes, reduces notably.

  13. The Impact of Black-Hole Attack on ZRP Protocol

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    CHAHIDI Badr

    2016-07-01

    Full Text Available lack of infrastructure in ad hoc networks makes their deployment easier. Each node in an ad hoc network can route data using a routing protocol, which decreases the level of security. Ad hoc networks are exposed to several attacks such as the blackhole attack. In this article, a study has been made on the impact of the attack on the hybrid routing protocol ZRP (Zone Routing Protocol. In this attack a malicious node is placed between two or more nodes in order to drop data. The trick of the attack is simple, the malicious node declares to have the most reliable way to the destination so that the wife destination chooses this path. In this study, NS2 is used to assess the impact of the attack on ZRP. Two metrics measure, namely the packet delivered ratio and end to end delay.

  14. COMPARING THE IMPACT OF BLACK HOLE AND GRAY HOLE ATTACKS IN MOBILE ADHOC NETWORKS

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    Bose

    2012-01-01

    Full Text Available Mobile Adhoc Networks (MANETs are dynamic in nature. Any nodes can join and leave the network at any time. Hence any type of intruders can attack the communication at any time, especially the routing mechanism between the nodes. In this study, we study and understand two types of attacks which cause more damage to the routing performance of MANET; the attacks are Black Hole attacks and Gray Hole attacks and compare the impact of these attacks on MANET. “Send Fake Route Reply to the nodes” type of attack is used to understand the behavior of these two types of attacks. Existing AODV protocol is modified in order to study these types of attacks in MANET. Performance evaluation of the proposed method is carried out using NS-2. In the presence of these attacks the network performance degrades for various network attributes. The performance of MANET under attack is thoroughly investigated, by applying it on various network parameters with various node densities. Not only had that which attack causes more damage to the environment also studied.

  15. Prevention of Co-operative Black Hole attack in Manet on DSR protocol using Cryptographic Algorithm

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    G.Vennila

    2014-10-01

    Full Text Available The Mobile ad-hoc network (MANET is a collection of wireless mobile node in which each node can communicate with other node without use of predefined infrastructure. Currently, a lot of efficient protocols have been proposed for MANET. All of these efficient Routing protocols are depends only conviction and supportive environment. Conversely, the networks are more vulnerable to various kinds of routing attacks with the presence of malicious nodes. Black hole attack is one of network layer attack. In this attack, A malicious node make use of routing protocol to advertise itself that has a shortest path to reach destination, drops at the cost of original routing packets. In our work, the proposed algorithm is used to secure the DSR protocol. This will help to improve the performance of Mobile Ad hoc network due to the attack. There are several prevention mechanisms to eliminate the Black Hole attack in MANET. The aim of the paper is to provide better prevention of Co-operative Black hole attack in MANET and how it affects the performance metrics in terms of throughput and delay of the network by comparing the network performance with and without black hole nodes.

  16. Guard against cooperative black hole attack in Mobile Ad-Hoc Network

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    Harsh Pratap Singh

    2011-07-01

    Full Text Available A mobile ad-hoc network is an autonomous network that consists of nodes which communicate with each other with wireless channel. Due to its dynamic nature and mobility of nodes, mobile ad hoc networks are more vulnerable to security attack than conventional wired and wireless networks. One of the principal routing protocols AODV used in MANETs. The security of AODV protocol is influence by the particular type of attack called Black Hole attack. In a black hole attack, a malicious node injects a faked route reply claiming to havethe shortest and freshest route to the destination. However, when the data packets arrive, the malicious node discards them. To preventing black hole attack, this paper presents RBS (Reference Broadcast Synchronization & Relative velocity distance method for clock synchronization process in Mobile ad-hoc Network for removal of cooperative black hole node. This paper evaluates the performance in NS2 network simulator and our analysis indicates that this method is very suitable to remove black hole attack.

  17. Detection and Removal of Gray, Black and Cooperative Black Hole Attacks in AODV Technique

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    Hosny M. Ibrahim

    2015-05-01

    Full Text Available Mobile ad hoc network (MANET is an autonomous self-configuring infrastructure-less wireless network. MANET is vulnerable to a lot of routing security threats due to unreliability of its nodes that are highly involved in the routing process. In this paper, a new technique is proposed to enhance the security of one of the most popular MANET routing protocols that is called Ad hoc on Demand Distance Vector (AODV with minimum routing overhead and high packet delivery ratio. The proposed technique intends to detect and remove black, gray, and cooperative black hole AODV attacks depending on a mobile backbone network constructed from randomly moving regular MANET nodes based on their trust value, location, and power. The backbone network monitors regular nodes as well as each other to periodically estimate monitoring trust values which represent the reliability of each node in the network. The drop in the monitoring trust value of any node is used as a clue to its malicious behavior. The backbone network also tries to bait the malicious nodes to reply to a request for a route to fake destination address. The proposed technique uses the control packets of the AODV to exchange its control information which highly reduces the overhead. The simulation results show that the performance of the proposed technique is more secure than AODV and the other recently introduced techniques.

  18. On Protocols to Prevent Black Hole Attacks in Mobile Ad Hoc Networks

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    Umesh Kumar Singh

    2015-01-01

    Full Text Available Wireless or Mobile Networks emerged to replace the wired networks. The new generation of wireless network is relatively different than the comparisons of traditional wired network in many aspects like resource sharing, power usage, reliability, efficient, ease to handle, network infrastructure and routing protocols, etc. Mobile Ad-Hoc Networks (MANETs are autonomous and decentralized wireless systems. MANETs consist of mobile nodes that are free in moving in and out in the network. There is an increasing threat of attacks on the MANET. Thus, in MANET black hole attack are mostly serious security attacks. In this paper, we have examined certain black hole attacks prevention routing protocols. Finally, we have compared some routing protocols using some important parameters and then addressed major issues related to this.

  19. Simulation and Analysis of AODV and DSR Routing Protocol under Black Hole Attack

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    Amin Mohebi

    2013-11-01

    Full Text Available In this paper, two routing protocols (AODV and DSR are simulated under regular operation, single and cooperative black hole attack. This work has been performed by simulator to show consequence of black hole attacks in MANET by using various graphs which are used to collect data in term of several metrics. One common method to perform most of researches in the MANET security field is to simulate and analyze the routing protocols in various scenarios. This work has been based on the implementation and experiments in the OPNET modeler version 14.5. Finally the results have been computed and compared to stumble on which protocol is least affected by these attacks.

  20. MITIGATING BLACK HOLE ATTACK IN MANET BY EXTENDING NETWORK KNOWLEDGE

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    Hicham Zougagh

    2013-11-01

    Full Text Available The Optimized Link State Routing Protocol is developed for Mobile Ad Hoc Network. It operates as a table driven, proactive protocol. The core of the OLSR protocol is the selection of Multipoint Relays (MPRs, used as a flooding mechanism for distributing control traffic messages in the network, and reducing the redundancy in the flooding process. A node in an OLSR network selects its MPR set so that all two hop neighbor are reachable by the minimum number of MPR. However, if an MPR misbehaves during the execution of the protocol, the connectivity of the network is compromised. This paper introduces a new algorithm for the selection of Multipoint Relays (MPR with additional coverage whose aims is to provide each node to selects alternative paths to reach any destination two hops away. This technique helps avoid the effect of malicious attacks and its easily to implement the corresponding algorithm.

  1. Using Apriori algorithm to prevent black hole attack in mobile Ad hoc networks

    Directory of Open Access Journals (Sweden)

    Seyed Javad Mirabedini

    2013-01-01

    Full Text Available A mobile ad hoc network (MANET is considered as an autonomous network, which consists of mobile nodes, which communicate with each other over wireless links. When there is no fixed infrastructure, nodes have to cooperate in order to incorporate the necessary network functionality. Ad hoc on Demand Distance Vector (AODV protocol is one of the primary principal routing protocols implemented in Ad hoc networks. The security of the AODV protocol is threaded by a specific kind of attack called ‘Black Hole’ attack. This paper presents a technique to prevent the Black hole attack by implementing negotiation with neighbors who claim to maintain a route to destination. Negotiation process is strengthen by apriori method to judge about suspicious node. Apriori algorithm is an effective association rule mining method with relatively low complexity, which is proper for MANETs. To achieve more improvement, fuzzy version of ADOV is used. The simulation results indicate that the proposed protocol provides more securable routing and also more efficiency in terms of packet delivery, overhead and detection rate than the conventional AODV and fuzzy AODV in the presence of Black hole attacks.

  2. Performance Evaluation of Mesh based Multicast Reactive Routing Protocol under Black Hole Attack

    CERN Document Server

    Anita, E A Mary

    2009-01-01

    A mobile ad-hoc network is an autonomous system of mobile nodes connected by wireless links in which nodes cooperate by forwarding packets for each other thereby enabling communication beyond direct wireless transmission range. The wireless and dynamic nature of ad-hoc networks makes them vulnerable to attacks especially in routing protocols. Providing security in mobile ad-hoc networks has been a major issue over the recent years. One of the prominent mesh base reactive multicast routing protocols used in ad-hoc networks is On Demand Multicast Routing protocol (ODMRP). The security of ODMRP is compromised by a primary routing attack called black hole attack. In this attack a malicious node advertises itself as having the shortest path to the node whose packets it wants to intercept. This paper discusses the impact of black hole attack on ODMRP under various scenarios. The performance is evaluated using metrics such as packet delivery ratio and end to end delay for various numbers of senders and receivers via...

  3. A Cluster based Technique for Securing Routing Protocol AODV against Black-hole Attack in MANET

    Directory of Open Access Journals (Sweden)

    Sonam Yadav

    2013-04-01

    Full Text Available Mobile ad-hocnetworks areprone tovarioussecurity vulnerabilitiesbecause of its characteristicsmainlyhigh mobility of nodes,and no well defined architecture.Security measuresare difficult to implement asthere is nocentral administration. Several attackson Mobile ad-hoc networkhavebeen identified so farand Black hole attack is oneof them. In this paper we discussblack hole attackon Ad-hoc network andpropose a solution to the hijacked node behaving as black hole node. A scenario has been consideredwhere anode inside network has been intruded andcompromised tocause blackholeattack. The proposedsecuritysolutionmodifies original AODV using a hierarchical basedintrusion detectionmethod toidentifyhijacked nodeand exclude the particular node from network

  4. Proactive Alleviation Procedure to Handle Black Hole Attack and Its Version

    Directory of Open Access Journals (Sweden)

    M. Rajesh Babu

    2015-01-01

    Full Text Available The world is moving towards a new realm of computing such as Internet of Things. The Internet of Things, however, envisions connecting almost all objects within the world to the Internet by recognizing them as smart objects. In doing so, the existing networks which include wired, wireless, and ad hoc networks should be utilized. Moreover, apart from other networks, the ad hoc network is full of security challenges. For instance, the MANET (mobile ad hoc network is susceptible to various attacks in which the black hole attacks and its versions do serious damage to the entire MANET infrastructure. The severity of this attack increases, when the compromised MANET nodes work in cooperation with each other to make a cooperative black hole attack. Therefore this paper proposes an alleviation procedure which consists of timely mandate procedure, hole detection algorithm, and sensitive guard procedure to detect the maliciously behaving nodes. It has been observed that the proposed procedure is cost-effective and ensures QoS guarantee by assuring resource availability thus making the MANET appropriate for Internet of Things.

  5. Proactive Alleviation Procedure to Handle Black Hole Attack and Its Version.

    Science.gov (United States)

    Babu, M Rajesh; Dian, S Moses; Chelladurai, Siva; Palaniappan, Mathiyalagan

    2015-01-01

    The world is moving towards a new realm of computing such as Internet of Things. The Internet of Things, however, envisions connecting almost all objects within the world to the Internet by recognizing them as smart objects. In doing so, the existing networks which include wired, wireless, and ad hoc networks should be utilized. Moreover, apart from other networks, the ad hoc network is full of security challenges. For instance, the MANET (mobile ad hoc network) is susceptible to various attacks in which the black hole attacks and its versions do serious damage to the entire MANET infrastructure. The severity of this attack increases, when the compromised MANET nodes work in cooperation with each other to make a cooperative black hole attack. Therefore this paper proposes an alleviation procedure which consists of timely mandate procedure, hole detection algorithm, and sensitive guard procedure to detect the maliciously behaving nodes. It has been observed that the proposed procedure is cost-effective and ensures QoS guarantee by assuring resource availability thus making the MANET appropriate for Internet of Things.

  6. A Mechanism for Detection of Cooperative Black Hole Attack in Mobile Ad Hoc Networks

    CERN Document Server

    Sen, Jaydip; Ukil, Arijit

    2011-01-01

    A mobile ad hoc network (MANET) is a collection of autonomous nodes that communicate with each other by forming a multi-hop radio network and maintaining connections in a decentralized manner. Security remains a major challenge for these networks due to their features of open medium, dynamically changing topologies, reliance on cooperative algorithms,absence of centralized monitoring points, and lack of clear lines of defense. Most of the routing protocols for MANETs are thus vulnerable to various types of attacks. Ad hoc on-demand distance vector routing (AODV) is a very popular routing algorithm. However, it is vulnerable to the well-known black hole attack, where a malicious node falsely advertises good paths to a destination node during the route discovery process. This attack becomes more sever when a group of malicious nodes cooperate each other. In this paper, a defense mechanism is presented against a coordinated attack by multiple black hole nodes in a MANET. The simulation carried out on the propose...

  7. Detection of Multiple Black hole nodes attack in MANET by modifying AODV protocol

    Directory of Open Access Journals (Sweden)

    Nishu Kalia

    2016-05-01

    Full Text Available Ad hoc Networks (MANET is a self-configuring, infrastructure less network consists of independent mobile nodes that can communicate via wireless medium. Each mobile node can move freely in any direction, and changes their links to other devices frequently. Security is an essential part of ad hoc networks. Due to its dynamic topology, resource constraints, no centralized infrastructure and limited security, it is vulnerable to various attacks and black hole attack is one of them. In this attack, the malicious node advertises itself as having the shortest path to the destination and falsely replies to the route requests, and drops all receiving packets. There can be more than one black hole nodes present in the network which can work individually or in a group. In this thesis, the fake routing information is used by the source node in order to detect the multiple black hole nodes present in the wireless adhoc networks. The proposed mechanism is implemented in NS-2.34.

  8. Molecular diagnostics for the Sigatoka disease complex of banana

    NARCIS (Netherlands)

    Arzanlou, M.; Abeln, E.C.A.; Kema, G.H.J.; Waalwijk, C.; Carlier, J.; Crous, P.W.

    2007-01-01

    The Sigatoka disease complex of banana involves three related ascomycetous fungi, Mycosphaerella fijiensis, M. musicola, and M. eumusae. The exact distribution of these three species and their disease epidemiology remain unclear, because their symptoms and life cycles are rather similar. Disease dia

  9. A Cross Layer for Detection and Ignoring Black Hole Attack in MANET

    Directory of Open Access Journals (Sweden)

    Azza Mohammed

    2015-09-01

    Full Text Available MANET Mobile Ad hoc Network are evolved through various characteristics such as shared media, this property make a routing protocols vulnerable. AODV is a reactive routing where each intermediate node cooperates in the process of route discovery. In this case, the node that behaves as malicious exploit the malfunction of specified service. The black hole attack uses the sequence number that is used to select the freshest route and attract all exchanged data packets to destroy them. Many researchers have dealt with this attack and many solutions have been proposed. These solutions target the network layer only. In this paper, we present our approach to counter black hole attack. This approach is entitled CrossAODV and it is based on verification and validation process. The key point of our approach is the use of the inter layer interaction between networks layer and medium access within the distributed coordination function (DCF to efficiently detect and isolate malicious nodes. During the route discovery, the verification process uses the RTS / CTS frame that contains information about the requested path. The validation process consists of comparing the routing information with the result of verification phase. Our Approach have been implemented, simulated and compared to two related studies using the well know NS2 Simulator. The obtained results show the efficacy our proposal in term of packet delivery with a neglected additional delay.

  10. Morning ambush attacks by black-footed ferrets on emerging prairie dogs

    Science.gov (United States)

    Eads, D.A.; Biggins, D.E.; Jachowski, D.S.; Livieri, T.M.; Millspaugh, J.J.; Forsberg, M.

    2010-01-01

    Black-footed ferrets (Mustela nigripes) often hunt at night, attacking normally diurnal prairie dogs (Cynomys spp.) in underground burrow systems. While monitoring black-footed ferrets in South Dakota during morning daylight hours, we observed an adult female ferret ambush a black-tailed prairie dog (C. ludovicianus) emerging from a burrow. On a neighboring colony, we observed a second adult female ferret engaging in similar ambush behaviors on 12 occasions, although prey was not visible. We retrospectively assessed radio-telemetry data on white-tailed prairie dogs (C. leucurus) and a male and a female ferret to evaluate ferret activity in relation to timing of prairie dog emergence. Activity of radio-collared ferrets was high during the hourly period when prairie dogs first emerged and the following 2 hr, relative to later daylight hours. Such behavior is consistent with behaviors observed in South Dakota. Nighttime movements by ferrets might involve hunting but also reconnaissance of prey preparatory to morning ambush attacks.

  11. AODV Improvement by Modification at Source Node and Securing It from Black Hole Attack.

    Directory of Open Access Journals (Sweden)

    Debarati Roy Choudhury

    2014-08-01

    Full Text Available MANETS suffer from constraints in power, storage and computational resources ,as a result, they are more vulnerable to various communications security related attacks. therefore we attempt to focus on analyzing and improving the security of routing protocol for MANETS viz. the Ad hoc On Demand Distance Vector (AODVrouting protocol. We propose modifications to the AODV we propose an algorithm to counter the Black hole attack on the routing protocols in MANETs. All the routes has unique sequence number and the malicious node has the highest Destination Sequence number and it is the first RREP to arrive. So the comparison is made only to the first entry in the table without checking other entries in the table

  12. Defence against Black Hole and Selective Forwarding Attacks for Medical WSNs in the IoT

    Directory of Open Access Journals (Sweden)

    Avijit Mathur

    2016-01-01

    Full Text Available Wireless sensor networks (WSNs are being used to facilitate monitoring of patients in hospital and home environments. These systems consist of a variety of different components/sensors and many processes like clustering, routing, security, and self-organization. Routing is necessary for medical-based WSNs because it allows remote data delivery and it facilitates network scalability in large hospitals. However, routing entails several problems, mainly due to the open nature of wireless networks, and these need to be addressed. This paper looks at two of the problems that arise due to wireless routing between the nodes and access points of a medical WSN (for IoT use: black hole and selective forwarding (SF attacks. A solution to the former can readily be provided through the use of cryptographic hashes, while the latter makes use of a neighbourhood watch and threshold-based analysis to detect and correct SF attacks. The scheme proposed here is capable of detecting a selective forwarding attack with over 96% accuracy and successfully identifying the malicious node with 83% accuracy.

  13. Defence against Black Hole and Selective Forwarding Attacks for Medical WSNs in the IoT.

    Science.gov (United States)

    Mathur, Avijit; Newe, Thomas; Rao, Muzaffar

    2016-01-19

    Wireless sensor networks (WSNs) are being used to facilitate monitoring of patients in hospital and home environments. These systems consist of a variety of different components/sensors and many processes like clustering, routing, security, and self-organization. Routing is necessary for medical-based WSNs because it allows remote data delivery and it facilitates network scalability in large hospitals. However, routing entails several problems, mainly due to the open nature of wireless networks, and these need to be addressed. This paper looks at two of the problems that arise due to wireless routing between the nodes and access points of a medical WSN (for IoT use): black hole and selective forwarding (SF) attacks. A solution to the former can readily be provided through the use of cryptographic hashes, while the latter makes use of a neighbourhood watch and threshold-based analysis to detect and correct SF attacks. The scheme proposed here is capable of detecting a selective forwarding attack with over 96% accuracy and successfully identifying the malicious node with 83% accuracy.

  14. Alternativas de manejo en el control de la Sigatoka negra (Mycosphaerella fijiensis Morelet./

    Directory of Open Access Journals (Sweden)

    Yurisandra Sierra Reyes

    2015-09-01

    Full Text Available Resumen Con el objetivo de evaluar alternativas en el control de la Sigatoka negra n se desarrolló esta investigación en la Unidad Empresarial de Base “Atención a Productores” en Siboney, municipio Sibanicú, provincia Camagüey. En el período comprendido entre junio del 2008 a octubre del 2009 a través de un experimento con diseño bloques al azar con el fin de establecer el efecto de varias prácticas de manejo en el control de la Sigatoka negra en el plátano Enano Guantanamero. Se estudiaron combinaciones de prácticas de manejo como el uso de fertilizaciones de fórmula completa y orgánica, el marco de plantación utilizado fue de 1 m ×2 m × 3m, la compra de las semillas se realizó en la Biofábrica de Camagüey, que fueron desinfectadas al momento de la plantación durante una hora con una solución de Mancozeb SC (5 g /1 de agua y se adicionó lixiviado de humus de lombriz (ácido fúlvico (5ml/l de agua. Se realizaron labores agrotécnicas de despunte, aplicación de fertilización óptima y de un químico protectante, en combinación hasta llegar a doce tratamientos. Se evaluaron las hojas más jóvenes enfermas, hojas más joven manchada y el índice de severidad. Las combinación de Fertilización + Despunte + Fungicida + lixiviado de humus de lombriz, mostró las mejores respuestas al reducir el Índice de Severidad de las dos enfermedades, con valores medios que oscilaron entre 39,5 y 43,3, así como una alta respuesta a los indicadores morfológicos y productivos del clon AAB Enano Guantanamero. ABSTRACT In order to evaluate alternatives in the control of black Sigatoka n this research was conducted at the Base Business Unit "Attention to Producers" in Siboney, Sibanicú municipality, Camagüey province. In the period from June 2008 to October 2009 by an experiment with randomized block design in order to establish the effect of various management practices on the control of Black Sigatoka in banana Dwarf Guantanamero

  15. Preventive Aspect of Black Hole Attack in Mobile AD HOC Network

    Directory of Open Access Journals (Sweden)

    Kumar Roshan

    2012-06-01

    Full Text Available Mobile ad hoc network is infrastructure less type of network. In this paper we present the prevention mechanism for black hole in mobile ad hoc network. The routing algorithms are analyzed and discrete properties of routing protocols are defined. The discrete properties support in distributed routing efficiently. The protocol is distributed and not dependent upon the centralized controlling node. Important features of Ad hoc on demand vector routing (AODV are inherited and new mechanism is combined with it to get the multipath routing protocol for Mobile ad hoc network (MANET to prevent the black hole attack. When the routing path is discovered and entered into the routing table, the next step is taken by combined protocol to search the new path with certain time interval. The old entered path is refreshed into the routing table. The simulation is taken on 50 moving nodes in the area of 1000 x 1000 square meter and the maximum speed of nodes are 5m/sec. The result is calculated for throughput verses number of black hole nodes with pause time of 0 sec. to 40 sec., 120 sec. and 160 sec. when the threshold value is 1.0.

  16. Performance Comparison of Cluster based and Threshold based Algorithms for Detection and Prevention of Cooperative Black Hole Attack in MANETs

    Directory of Open Access Journals (Sweden)

    P. S. Hiremath

    2014-11-01

    Full Text Available In mobile ad-hoc networks (MANET, the movement of the nodes may quickly change the networks topology resulting in the increase of the overhead message in topology maintenance. The nodes communicate with each other by exchanging the hello packet and constructing the neighbor list at each node. MANET is vulnerable to attacks such as black hole attack, gray hole attack, worm hole attack and sybil attack. A black hole attack makes a serious impact on routing, packet delivery ratio, throughput, and end to end delay of packets. In this paper, the performance comparison of clustering based and threshold based algorithms for detection and prevention of cooperative in MANETs is examined. In this study every node is monitored by its own cluster head (CH, while server (SV monitors the entire network by channel overhearing method. Server computes the trust value based on sent and receive count of packets of the receiver node. It is implemented using AODV routing protocol in the NS2 simulations. The results are obtained by comparing the performance of clustering based and threshold based methods by varying the concentration of black hole nodes and are analyzed in terms of throughput, packet delivery ratio. The results demonstrate that the threshold based method outperforms the clustering based method in terms of throughput, packet delivery ratio and end to end delay.

  17. Comparative Genomics of the Sigatoka Disease Complex on Banana Suggests a Link between Parallel Evolutionary Changes in Pseudocercospora fijiensis and Pseudocercospora eumusae and Increased Virulence on the Banana Host

    Science.gov (United States)

    Chang, Ti-Cheng; Crous, Pedro W.; Stergiopoulos, Ioannis

    2016-01-01

    The Sigatoka disease complex, caused by the closely-related Dothideomycete fungi Pseudocercospora musae (yellow sigatoka), Pseudocercospora eumusae (eumusae leaf spot), and Pseudocercospora fijiensis (black sigatoka), is currently the most devastating disease on banana worldwide. The three species emerged on bananas from a recent common ancestor and show clear differences in virulence, with P. eumusae and P. fijiensis considered the most aggressive. In order to understand the genomic modifications associated with shifts in the species virulence spectra after speciation, and to identify their pathogenic core that can be exploited in disease management programs, we have sequenced and analyzed the genomes of P. eumusae and P. musae and compared them with the available genome sequence of P. fijiensis. Comparative analysis of genome architectures revealed significant differences in genome size, mainly due to different rates of LTR retrotransposon proliferation. Still, gene counts remained relatively equal and in the range of other Dothideomycetes. Phylogenetic reconstruction based on a set of 46 conserved single-copy genes strongly supported an earlier evolutionary radiation of P. fijiensis from P. musae and P. eumusae. However, pairwise analyses of gene content indicated that the more virulent P. eumusae and P. fijiensis share complementary patterns of expansions and contractions in core gene families related to metabolism and enzymatic degradation of plant cell walls, suggesting that the evolution of virulence in these two pathogens has, to some extent, been facilitated by convergent changes in metabolic pathways associated with nutrient acquisition and assimilation. In spite of their common ancestry and shared host-specificity, the three species retain fairly dissimilar repertoires of effector proteins, suggesting that they likely evolved different strategies for manipulating the host immune system. Finally, 234 gene families, including seven putative effectors, were

  18. IMPROVED MCBDS FOR DEFENDING AGAINST GRAY HOLE AND BLACK HOLE ATTACKS IN MANETS

    Directory of Open Access Journals (Sweden)

    Ahmad Haghighi

    2016-06-01

    Full Text Available Mobile Ad-hoc Networks (MANETs are widely used nowadays. Because of their characteristics as open media, dynamic topology, being infrastructure-less and lack of centralized monitoring, MANET is vulnerable to a wide range of attacks like blackhole and grayhole. Blackhole and grayhole attacks refer to the attacks that breach the security by performing packet forwarding and routing misbehavior and cause denial of service in MANETs. In this paper we improved our previous work on MCBDS, we reduced false-positive rate more than before and on average it dropped to zero. The proposed method employs Network Simulator-2 (NS-2 to validate the effectiveness under different scenarios. Simulation results show that improved MCBDS has same performance as CBDS in terms of throughput and end-to-end delay and as much as the presence of malicious nodes increased, improved MCBDS performs better than CBDS.

  19. A Combined Approach for Worm-Hole and Black-Hole Attack Detection in MANET

    Directory of Open Access Journals (Sweden)

    Amber Jain

    2014-09-01

    Full Text Available Mobile ad hoc network is a kind of wireless network, in this network all nodes are connected through the wireless links and perform cooperative communication.Due to limited radio range of these devices any time can leave or join the network. Therefore the routing techniques are responsible for the network organization and communication flow. Due to this the performance of MANET is low as compared with the traditional wired communication networks. In addition of that network is suffers from the probability of attacks. Thus in this paper MANET routing strategy and their attacks are investigated and learned. In addition of that in order to secure the communication recent approaches of security in MANET also investigated. Finally a new algorithm for prevention of malicious attack in MANET is suggested. Additionally the based on the concluded facts, future extension of the proposed work is also suggested.

  20. Diagnostico por PCR del complejo Sigatoka en Colombia.

    Directory of Open Access Journals (Sweden)

    Romero Magally

    1999-06-01

    Full Text Available Las Sigatokas negra y amarilla son enfermedades causadas por Mycosphaerella fijiensis y Mycosphaerella musicola respectivamente. Estas dos especies de hongos estrechamente relacionadas y morfológicamente similares, causan necrosis severa en las hojas de banano y plátano disminuyendo el área de tejido fotosintético y acelerando la maduración del fruto. Las enfermedades producidas por estos hongos afectan la mayoría de las áreas cultivadas de banano y plátano a nivel mundial, generando un gran problema económico y ambiental. Los síntomas que produce cada uno de estos patógenos en el cultivo son similares, por lo que su correcta identificación en campo se hace difícil. Con el fin de hacer una identificación precisa de cada uno de ellos decidimos estandarizar una prueba diagnóstica basada en la reacción en cadena de la polimerasa (PCR utilizando dos oligonucleótidos de 21 bases (MF 137 y MM 137 específicos para cada una de las especies M. fijiensis y M. musicola respectivamente. MF 137 y MM 137 codifican regiones variables identificadas en las secuencias interespaciadoras (ITS del DNA ribosomal.

  1. MANEJO FITOTÉCNICO DA BANANEIRA, CULTIVAR D' ANGOLA (AAB, VISANDO AO CONTROLE DA SIGATOKA-NEGRA

    Directory of Open Access Journals (Sweden)

    MARIA DE JESUS BARBOSA CAVALCANTE

    2014-01-01

    Full Text Available The objective of this work was to evaluate management systems for the control of Black Siga- toka in the cultivation of banana D'Angola cultivar. The experiment was installed and carried out at Embrapa Acre, Rio Branco - AC with the treatments distributed in randomized complete blocks with six replications consisting of different planting densities, corresponding to T1 - (1.111 plants ha-1; T2 - 1.666 plants ha-1; T3 - 2.000 plants ha-1; T4 - 1.333 plants ha-1; T5 - 2.500 plants ha-1 and; T6 - 1.111 plants ha-1 under rubber trees. The evaluations were carried out during two cycles of production. Plants of cv. D'Angola (AAB cultivated in 3.0 x 3.0 m, shaded by the rubber trees, presented higher plant height, higher number of functional leaves at flowering and harvest, higher average bunch weight, greater weight of the bunches, longer cycle production and reduced severity of black sigatoka. Highest yields were obtained when we adopted higher densities. The banana intercropping with rubber trees proved to be a good alternative to permit cultivation of cv. D'Angola (long banana.

  2. Evaluation of banana hybrids for tolerance to black leaf streak (Mycosphaerella fijiensis Morelet) in Puerto Rico

    Science.gov (United States)

    In Puerto Rico, bananas (including plantains) are important agricultural commodities; their combined production totaled 133,500 tons in 2008. Black leaf streak (BLS) and Sigatoka leaf spot diseases, caused by Mycosphaerella fijiensis and M. musicola, respectively, are responsible for significant los...

  3. Investigations into Outbreaks of Black Fly Attacks and Subsequent Avian Haemosporidians in Backyard-Type Poultry and Other Exposed Avian Species.

    Science.gov (United States)

    Jones, Kelli; Johnson, Nora; Yang, Sharon; Stokes, John; Smith, Whitney; Wills, Robert; Goddard, Jerome; Varela-Stokes, Andrea

    2015-03-01

    In late spring of 2009 and 2010, there were reports of severe black fly (Simulium spp., shown in Fig. 1) outbreaks in various counties in Mississippi, especially those in and around the Mississippi River Delta. Complaints were of black flies attacking multiple species of backyard poultry and causing high morbidity and mortality in affected flocks. At several affected locations, black flies were readily observed swarming around and feeding on birds. A large number of these parasites were easily trapped on fly strips (Fig. 2). Multifocal to coalescing cutaneous hemorrhagic lesions, consistent with fly bites, were seen on the birds. Upon necropsy examination, a large number of black flies were also observed in the digestive tract (Fig. 3). Although black flies may cause disease directly, such as cardiopulmonary collapse and anaphylactoid reactions, detection of Leucocytozoon in blood smears (Fig. 4) of affected birds prompted further investigations of this protozoan as a cause of disease. Leucocytozoon spp. are known to be transmitted by black flies and may be associated with morbidity and mortality in birds such as poultry. From June 2009 through July 2012, the investigation included a total collection of 1068 individual blood samples, representing 371 individual premises in 89 counties/parishes across Mississippi (59), Alabama (10), Louisiana (4), and Tennessee (16). Of the 371 premises where blood samples were collected, 96 (26%) were either positive or highly suspected to be positive for Leucocytozoon spp. by blood smear analysis, and 5 (1.2%) were positive for Haemoproteus spp. by blood smear analysis. Attempts to diagnose Leucocytozoon spp. by PCR analysis and sequencing were complicated by coinfections with two closely related haemosporidians (Haemoproteus spp. and Plasmodium spp.). A novel technique involving flow cytometry was also explored. This study discusses the black fly field outbreak, the involvement of haemosporidians, molecular methods for detection

  4. Response of banana genotypes to yellow Sigatoka in coastal tablelands of Sergipe, Brazil

    Directory of Open Access Journals (Sweden)

    Zilná Brito de Rezende Quirino

    Full Text Available Brazil has low availability of productive commercial cultivars with appropriate size and resistance to yellow Sigatoka. The objective of this study was to evaluate the behavior of different banana genotypes against yellow Sigatoka at conditions of Coastal Tablelands of Sergipe. The experiment was conducted at the Experimental Field of Embrapa Tabuleiros Costeiros, municipality of Nossa Senhora das Dores. The experimental design was randomized blocks design with 22 genotypes and three replications, six plants per plot. The genotypes tested were: Enxerto-33, Japira-106, FHIA-23, YB42-17, YB42-47, FHIA-18, PA42-44, PA94-01, PV79-34, Pacovan Ken, Pacovan, Prata-Anã, Maravilha, Garantida, Princesa, Tropical, Maçã, Grande Naine, FHIA-02, Caipira, Bucaneiro and Thap Maeo. The severity of yellow Sigatoka was evaluated at 60, 270 and 420 days after planting (DAP (from July/2009 to July/2010, using a descriptive scale of Stover. Then, the infection rate was calculated at 60, 270 and 420 DAP, and was compared by Scott-Knott test at 5%. It was observed that genotypes have the same behavior at 270 DAP. At 60 DAP, genotypes with lower infection rate were Bucaneiro, Enxerto-33, Japira-106, YB42-17, FHIA-02, FHIA-18, FHIA-23, PA42-44, PA94-01, Caipira, Maçã, Prata-Anã and Thap Maeo. At 420 DAP, the lowest rates were obtained for genotypes YB42-17, FHIA-23, Princesa, YB42-47, Tropical, Grand Naine, Caipira, Maçã, Garantida, Bucaneiro, Pacovan Ken and Thap Maeo.

  5. Forewarning system for controlling Yellow Sigatoka in Northern Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Sara de Almeida Rios

    2013-09-01

    Full Text Available This trial aimed to evaluate the Biological Forewarning System (BFS for controlling Yellow Sigatoka in Northern Minas Gerais, Brazil. It was carried out in the town of Nova Porteirinha. One tested 7 treatments, using 6 gross sum (GS values (1,000; 1,300; 1,600; 1,900; 2,200, and 2,500 and the systematic disease control every 15 days. The treatments were distributed into 7 plots (120 plants/plot with ‘Prata-Anã’ and 10 plants from each plot were weekly evaluated with regard to leaf emission rate and disease incidence on the leaves 2, 3 and 4. The more advanced lesion stages and their intensity were used to calculate the gross sum, which aided in decision-making for chemical control. One collected data on production and firmness, pH, and acidity analysis of fruits. For the GS 2,500 treatment, taking into account 2-year evaluation, there was a reduction from 12 to 3 applications, i.e. 75% less fungicide was applied, without loss in productivity. Therefore, one suggests, taking into account the conditions of Nova Porteirinha, the application of BFS for chemical control of Yellow Sigatoka, using the GS value of 2,500 as an indicator of the correct time to perform pulverization.

  6. Generation of Five New Musa Hybrids With Resistance To Black Sigatoka and High Yield

    Directory of Open Access Journals (Sweden)

    Ricardo Hernandez

    2007-01-01

    Full Text Available The ability to identify genetic variation is indispensable to effective management and use of genetic resources. This work is the first approach concerning to generation and genetic differentiation of new Musa hybrid lines obtained in INIVIT (Cuba, crossing Musa acuminata male diploid (AA x female triploid (ABB, genotypes selected by their resistant character to pests and diseases. From the obtained hybrids, only five were chosen because of their agronomic behavior and were genetically discriminated among them and also respect to the commercial clone FHIA-18 by AFLP polymorphism. Thanks to this prior genetic characterization Musa breeding programs could be consistently dinamised.

  7. A DETECTION STRATEGY FOR BLACK HOLE ATTACK BASED ON AODV%一种针对 AODV 协议黑洞攻击的检测策略

    Institute of Scientific and Technical Information of China (English)

    卜飞飞; 邬春学

    2015-01-01

    无线自组织网络是由若干个移动节点组成的网络,当一个节点需要和另一个节点通信时,它们通过中间节点将数据转发,因此网络中每个节点既是独立的终端设备,也能作为路由器使用. 黑洞攻击是无线自组织网络一种常见的攻击,恶意节点利用协议机制向其他节点广播自己具有到达目的节点的最短路径,导致所有的数据将会流向这些恶意节点. 这些恶意节点通过丢弃数据发动拒绝服务攻击,或者将数据重定向到伪装的目的节点. 基于AODV( Ad Hoc On-Demand Distance Vector Routing)协议,提出一种针对其黑洞攻击的检测策略. 通过NS-2的仿真实验,分析关于无线Ad Hoc网络的三个性能指标,分组投递率,端到端的平均时延和归一化的路由开销,实验结果表明该检测策略能够增强AODV路由协议的安全性.%Mobile ad hoc networks is the networks consisted of a couple of mobile nodes, when one node needs to communicate with anoth-er, they will forward data via intermediate nodes, therefore each node in the networks acts as the independent terminal device as well as to be used as the router.Black hole attack is a common attack in MANET, malicious nodes use protocol mechanism to claim to other nodes that they have the shortest path to the destination and this results in all traffic data being attracted to them.These malicious nodes launch the deni-al service attack through dropping the packets or redirecting the packets to disguised destination node.Based on AODV in this paper we pro-pose a detection strategy targeted at their black hole attacks.Through NS-2 simulation experiment, we analyse three performance metrics in regard to MANET including packet delivery fraction, average end-to-end delay and normalised routing overhead.Experimental result shows that the detection strategy is able to enhance the security of the AODV protocol.

  8. BLACK HOLE ATTACK IN AODV & FRIEND FEATURES UNIQUE EXTRACTION TO DESIGN DETECTION ENGINE FOR INTRUSION DETECTION SYSTEM IN MOBILE ADHOC NETWORK

    Directory of Open Access Journals (Sweden)

    HUSAIN SHAHNAWAZ

    2012-10-01

    Full Text Available Ad-hoc network is a collection of nodes that are capable to form dynamically a temporary network without the support of any centralized fixed infrastructure. Since there is no central controller to determine the reliable & secure communication paths in Mobile Adhoc Network, each node in the ad hoc network has to rely on each other in order to forward packets, thus highly cooperative nodes are required to ensure that the initiated data transmission process does not fail. In a mobile ad hoc network (MANET where security is a crucial issue and they are forced to rely on the neighbor node, trust plays an important role that could improve the number of successful data transmission. Larger the number of trusted nodes, higher successful data communication process rates could be expected. In this paper, Black Hole attack is applied in the network, statistics are collected to design intrusion detection engine for MANET Intrusion Detection System (IDS. Feature extraction and rule inductions are applied to find out the accuracy of detection engine by using support vector machine. In this paper True Positive generated by the detection engine is very high and this is a novel approach in the area of Mobile Adhoc Intrusion detection system.

  9. Physico-chemical characterization of banana varieties resistant to black leaf streak disease for industrial purposes

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    Rossana Catie Bueno de Godoy

    2016-01-01

    Full Text Available ABSTRACT: Cultivated bananas have very low genetic diversity making them vulnerable to diseases such as black-Sigatoka leaf spot. However, the decision to adopt a new banana variety needs to be based on a robust evaluation of agronomical and physical-chemical characteristics. Here, we characterize new banana varieties resistant to black-Sigatoka leaf spot and compare them to the most widely used traditional variety (Grand Naine. Each variety was evaluated for a range of physic-chemical attributes associated with industrial processing and flavor: pH, TTA, TSS/TTA, total sugars, reducing sugars and non-reducing sugars, humidity, total solids and yield. The Thap Maeo variety had the highest potential as a substitute for the Grand Naine variety, having higher levels of total soluble solids, reducing sugars, total sugars and humidity. The Caipira and FHIA 2 varieties also performed well in comparison with the Grand Naine variety. Cluster analysis indicated that the Grand Naine variety was closely associated with varieties from the Gross Michel subgroup (Bucaneiro, Ambrosia and Calipso and the Caipira variety, all of which come from the same AAA genomic group. It was concluded that several of the new resistant varieties could potentially substitute the traditional variety in areas affected by black-Sigatoka leaf spot disease.

  10. Protecting Cryptographic Memory against Tampering Attack

    DEFF Research Database (Denmark)

    Mukherjee, Pratyay

    In this dissertation we investigate the question of protecting cryptographic devices from tampering attacks. Traditional theoretical analysis of cryptographic devices is based on black-box models which do not take into account the attacks on the implementations, known as physical attacks....... In practice such attacks can be executed easily, e.g. by heating the device, as substantiated by numerous works in the past decade. Tampering attacks are a class of such physical attacks where the attacker can change the memory/computation, gains additional (non-black-box) knowledge by interacting...... with the faulty device and then tries to break the security. Prior works show that generically approaching such problem is notoriously difficult. So, in this dissertation we attempt to solve an easier question, known as memory-tampering, where the attacker is allowed tamper only with the memory of the device...

  11. Attack surfaces

    DEFF Research Database (Denmark)

    Gruschka, Nils; Jensen, Meiko

    2010-01-01

    The new paradigm of cloud computing poses severe security risks to its adopters. In order to cope with these risks, appropriate taxonomies and classification criteria for attacks on cloud computing are required. In this work-in-progress paper we present one such taxonomy based on the notion...... of attack surfaces of the cloud computing scenario participants. © 2010 IEEE....

  12. Heart Attack

    Science.gov (United States)

    ... a million people in the U.S. have a heart attack. About half of them die. Many people have permanent heart damage or die because they don't get ... It's important to know the symptoms of a heart attack and call 9-1-1 if someone ...

  13. Sistema de pré-aviso para o controle da sigatoka-amarela da bananeira no Recôncavo Baiano Forecasting for the control of banana 'yellow sigatoka' in the Recôncavo Baiano region, Brazil

    Directory of Open Access Journals (Sweden)

    Danúzia Maria Vieira Ferreira

    2003-12-01

    Full Text Available Entre os problemas que afetam a bananicultura brasileira, a Sigatoka-amarela (Mycosphaerella musicola Leach destaca-se como um dos mais graves, podendo causar perdas superiores a 50% na produção. O controle químico continua sendo uma das principais alternativas disponíveis. Por isto a utilização de um sistema de monitoramento que possa indicar o momento correto da aplicação dos fungicidas é uma alternativa importante para racionalizar seu uso. O objetivo deste trabalho foi definir o valor de soma bruta no sistema de pré-aviso biológico, que permita reduzir o número de aplicações anuais de defensivos capaz de controlar eficientemente a Sigatoka-amarela na região do Recôncavo Baiano. O ensaio foi conduzido na área experimental do Centro Nacional de Pesquisa de Mandioca e Fruticultura Tropical - Embrapa Mandioca e Fruticultura, da Empresa Brasileira de Pesquisa Agropecuária - EMBRAPA, no município de Cruz das Almas, BA. Testaram-se oito tratamentos, seis utilizando a soma bruta ( 1000; 1300; 1600; 1900; 2200 e 2500, o controle sistemático da doença a cada 21 dias e a testemunha controle. Esses tratamentos foram distribuídos em oito quadras de 48 plantas da cultivar Grande Naine, avaliando-se semanalmente dez plantas por tratamento, quanto à taxa de emissão foliar e incidência da doença nas folhas 2, 3 e 4, indicando a intensidade do estádio mais avançado da lesão presente nas mesmas. Os dados semanais foram usados para o cálculo das respectivas somas brutas, recomendando ou não a aplicação do fungicida (propiconazole 3mL mais 1L de óleo mineral . Na colheita coletaram-se os dados de produção e severidade da doença. Apenas os tratamentos controle sistemático, soma bruta 1300 e soma bruta 1600 apresentaram produções estatisticamente diferentes da testemunha sem controle. Considerando a produtividade obtida e o número de aplicações de fungicidas, requeridas durante o ciclo, foi concluído que, para as condi

  14. Relação entre a temperatura e o molhamento foliar no monocíclo da Sigatoka-negra

    Directory of Open Access Journals (Sweden)

    Cleilson do Nascimento Uchôa

    2012-06-01

    Full Text Available A influência da temperatura (21, 24, 27 e 30 °C e da duração do tempo de molhamento foliar (0, 12, 24, 48 e 72 horas na penetração do agente causal da Sigatoka-negra (Mycosphaerella fijiensis foi quantificada em ambiente controlado. A área abaixo da curva do progresso da doença (AACPD e a incidência foram influenciadas pela temperatura e pela duração do tempo de molhamento foliar. Foram constatadas diferenças significativas (P=0,05 nos valores da AACPD para as diferentes temperaturas, bem como verificada a interação significativa (P=0,05 entre temperaturas e o molhamento foliar. Em todas as temperaturas foi possível a observação de sintomas, entretanto, a maior AACPD foi observada em folhas inoculadas que permaneceram na temperatura de 24 e 27°C, a partir de 48 horas de molhamento foliar. Nas temperaturas de 21ºC e 30°C a incidência de Sigatoka-negra foi menor. O período de molhamento foliar mínimo para o progresso da doença foi de 24 horas. Não foram observados sintomas de Sigatoka-negra em folhas inoculados com o molhamento foliar de 0 hora e 12 horas em todas as temperaturas. As folhas assintomáticas, após 5 dias em câmara úmida apresentavam sintomas característicos de Sigatoka-negra, demonstrando que os conídios inoculados nas folhas permaneceram viáveis por um período na ausência de água livre na folha.

  15. Shark attack.

    Science.gov (United States)

    Guidera, K J; Ogden, J A; Highhouse, K; Pugh, L; Beatty, E

    1991-01-01

    Shark attacks are rare but devastating. This case had major injuries that included an open femoral fracture, massive hemorrhage, sciatic nerve laceration, and significant skin and muscle damage. The patient required 15 operative procedures, extensive physical therapy, and orthotic assistance. A review of the literature pertaining to shark bites is included.

  16. Optimal Attack Strategy in Random Scale-Free Networks Based on Incomplete Information

    Institute of Scientific and Technical Information of China (English)

    LI Jun; WU Jun; LI Yong; DENG Hong-Zhong; TAN Yue-Jin

    2011-01-01

    @@ We introduce an attack model based on incomplete information, which means that we can obtain the information from partial nodes.We investigate the optimal attack strategy in random scale-free networks both analytically and numerically.We show that the attack strategy can affect the attack effect remarkably and the OAS can achieve better attack effect than other typical attack strategies.It is found that when the attack intensity is small, the attacker should attack more nodes in the "white area" in which we can obtain attack information; when the attack intensity is greater, the attacker should attack more nodes in the "black area" in which we can not obtain attack information.Moreover, we show that there is an inflection point in the curve of optimal attack proportion.For a given magnitude of attack information, the optimal attack proportion decreases with the attack intensity before the inflection point and then increases after the inflection point.%We introduce an attack model based on incomplete information, which means that we can obtain the information from partial nodes. We investigate the optimal attack strategy in random scale-free networks both analytically and numerically. We show that the attack strategy can affect the attack effect remarkably and the OAS can achieve better attack effect than other typical attack strategies. It is found that when the attack intensity is small, the attacker should attack more nodes in the "white area" in which we can obtain attack information; when the attack intensity is greater, the attacker should attack more nodes in the "black area" in which we can not obtain attack information. Moreover, we show that there is an inflection point in the curve of optimal attack proportion. For a given magnitude of attack information, the optimal attack proportion decreases with the attack intensity before the inflection point and then increases after the inflection point.

  17. British used Congreve Rockets to Attack Napoleon

    Science.gov (United States)

    2004-01-01

    Sir William Congreve developed a rocket with a range of about 9,000 feet. The incendiary rocket used black powder, an iron case, and a 16-foot guide stick. In 1806, British used Congreve rockets to attack Napoleon's headquarters in France. In 1807, Congreve directed a rocket attack against Copenhagen.

  18. An assessment of the benefits of yellow Sigatoka (Mycosphaerella musicola control in the Queensland Northern Banana Pest Quarantine Area

    Directory of Open Access Journals (Sweden)

    David Cook

    2013-09-01

    Full Text Available The banana leaf spotting disease yellow Sigatoka is established and actively controlled in Australia through intensive chemical treatments and diseased leaf removal. In the State of Queensland, the State government imposes standards for de-leafing to minimise the risk of the disease spreading in 6 banana pest quarantine areas. Of these, the Northern Banana Pest Quarantine Area is the most significant in terms of banana production. Previous regulations imposed obligations on owners of banana plants within this area to remove leaves from plants with visible spotting on more than 15 per cent of any leaf during the wet season. Recently, this leaf disease threshold has been lowered to 5 per cent. In this paper we examine the likely impact this more-costly regulation will have on the spread of the disease. We estimate that the average net benefit of reducing the diseased leaf threshold is only likely to be $1.4million per year over the next 30 years, expressed as the annualised present value of tightened regulation. This result varies substantially when the timeframe of the analysis is changed, with shorter time frames indicating poorer net returns from the change in protocols. Overall, the benefit of the regulation change is likely to be minor.

  19. Manejo de Sigatoka negra (Mycosphaerella Fijiensis var. Difformis Morelet en plátano cv. “Curraré” en San Carlos, Zona Norte

    Directory of Open Access Journals (Sweden)

    Carlos Muñoz Ruiz

    2006-05-01

    Full Text Available Se evaluaron los diferentes productos químicos, utilizados en el control de Sigatoka negra en banano, en el cultivo de plátano, en la zona de Santa Clara de San Carlos. Uno de los principales objetivos fue generar un programa de manejo químico de la enfermedad para la zona de San Carlos, posible de ser transferido a otras zonas plataneras del país; el otro objetivo fue establecer las bases para automatizar las actividades culturales de manejo de plantaciones de musáceas, mediante la creación de un Software para computadora y asequible por internet.

  20. The attack navigator

    DEFF Research Database (Denmark)

    Probst, Christian W.; Willemson, Jan; Pieters, Wolter

    2016-01-01

    -technical system, the attack navigator identifies routes to an attacker goal. Specific attacker properties such as skill or resources can be included through attacker profiles. This enables defenders to explore attack scenarios and the effectiveness of defense alternatives under different threat conditions....

  1. EVALUACIÓN DE RESISTENCIA DE GENOTIPOS DE PLÁTANO Y BANANO A LA SIGATOKA NEGRA (MYCOSPHAERELLA FIJIENSIS MORELET. EVALUATION OF RESISTANCE OF PLANTAIN AND BANANA GENOTYPES TO BLACK SIGATOKA (MYSCOSPHAERELLA FIJIENSIS MORELET.

    Directory of Open Access Journals (Sweden)

    Alejandra Cuéllar Quintero

    2011-06-01

    Full Text Available Con el objetivo de evaluar bajo condiciones de invernadero genotipos de plátano y banano frente a poblaciones de Mycosphaerella fijiensis Morelet de diferente virulencia y origen, se estableció una colección de 125 aislamientos monospóricos obtenidos en 10 departamentos de Colombia. Se seleccionaron 50 aislamientos por área geográfica y genotipo hospedante, para la caracterización morfológica y patogénica del hongo en Dominico Hartón. En las pruebas de patogenicidad y resistencia se realizaron inoculaciones de una suspensión acuosa de 5.000 conidias mL-1, la respuesta de las plántulas a la enfermedad se determinó mediante las variables periodo de incubación (PI, tiempo de evolución de los síntomas (TES, área bajo la curva del desarrollo de la enfermedad (ABCDE y tasa de desarrollo de la enfermedad (r. La inoculación de los 50 aislamientos en plántulas de Dominico Hartón, permitió establecer cinco niveles de virulencia (muy alta, alta, media, baja y muy baja. La virulencia de los aislamientos no se relacionó con su origen geográfico ni con el genotipo del cual se obtuvieron; encontrándose en una misma zona y en un mismo genotipo, aislamientos de diferente virulencia. Los genotipos de plátano y banano mostraron un comportamiento diferencial frente a cinco aislamientos de diferente virulencia y origen, resultados que permitieron establecer tres niveles de reacción de los genotipos frente a los aislamientos (resistente, intermedio y susceptible, destacándose los genotipos Topocho, Maqueño, FHIA 20, FHIA 21 de plátano y los genotipos Sedita y FHIA 23 de banano por presentar un mayor nivel de resistencia, expresada como un progreso lento y menos severo de la enfermedad.A study was conducted to evaluate plantain and banana genotypes with Mycosphaerella fijiensis Morelet isolates of different virulence and geographic origin. The pathogenicity test and morphological characterization of the M. fijiensis populations were performed with a group of fifty monosporic isolates representative of the geographic growing areas in Colombia. For the pathogenicity and resistance assays an aqueous spore suspension of 5.000 conidias mL-1 was used to inoculate seedlings of plantain and banana genotypes, disease response of genotypes was rated by measuring the variables incubation period (IP, time of evolution of symptoms (TES, area under disease progress curve (AUDPC and rate of disease development (r.The inoculation of fifty isolates on Dominico Harton cultivar allowed to establish five levels of virulence (very high, high, medium, low and very low, which were not related to their geographic origin nor to genotype of the isolates. Isolates with different virulence level were present in the same zone and in the same genotype. The resistance assay showed that plantain and banana genotypes can present a differential behavior to the M. fijiensis isolates. The disease severity measured in the genotypes allowed to classify the in three disease reactions levels, resistance, intermediate and susceptible genotypes The plantain genotypes Topocho, Maqueno, FHIA 20 and FHIA 21, and the banana genotype Sedita and FHIA 23 were characterized for having a higher level of resistance, that was expressed as a lower disease severity and slower disease progress as compared with the other genotypes.

  2. SURVEY OF PACKET DROPPING ATTACK IN MANET

    Directory of Open Access Journals (Sweden)

    A.Janani

    2014-03-01

    Full Text Available Mobile Ad-hoc NETwork (MANET is an application of wireless network with self-configuring mobile nodes. MANET does not require any fixed infrastructure. Its development never has any threshold range. Nodes in MANET can communicate with each other if and only if all the nodes are in the same range. This wide distribution of nodes makes MANET vulnerable to various attacks, packet dropping attack or black hole attack is one of the possible attack. It is very hard to detect and prevent. To prevent from packet dropping attack, detection of misbehavior links and selfish nodes plays a vital role in MANETs. In this paper, a omprehensive investigation on detection of misbehavior links and malicious nodes is carried out.

  3. The attack navigator

    DEFF Research Database (Denmark)

    Probst, Christian W.; Willemson, Jan; Pieters, Wolter

    2016-01-01

    -technical system, the attack navigator identifies routes to an attacker goal. Specific attacker properties such as skill or resources can be included through attacker profiles. This enables defenders to explore attack scenarios and the effectiveness of defense alternatives under different threat conditions....... that are caused by the strategic behaviour of adversaries. Therefore, technology-supported methods are needed to help us identify and manage these risks. In this paper, we describe the attack navigator: a graph-based approach to security risk assessment inspired by navigation systems. Based on maps of a socio...

  4. Generating IDS Attack Pattern Automatically Based on Attack Tree

    Institute of Scientific and Technical Information of China (English)

    向尕; 曹元大

    2003-01-01

    Generating attack pattern automatically based on attack tree is studied. The extending definition of attack tree is proposed. And the algorithm of generating attack tree is presented. The method of generating attack pattern automatically based on attack tree is shown, which is tested by concrete attack instances. The results show that the algorithm is effective and efficient. In doing so, the efficiency of generating attack pattern is improved and the attack trees can be reused.

  5. Suscetibilidade de oito cultivares de bananeira à sigatoka-amarela na região de Marília (SP Susceptibility to sigatoka of eight banana cultivars in the region of Marília, State of São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Antonio Junqueira Teixeira

    1996-01-01

    Full Text Available A suscetibilidade de oito cultivares de bananeira à sigatoka-amarela (Mycosphaerella musicola foi avaliada em um experimento de campo, na região de Marília (SP. Três cultivares pertenciam ao Grupo AAA ('Nanicão', 'Nanicão Jangada' e 'Grande Naine' e cinco, ao AAB ('Prata', 'Enxerto', 'Maçã', 'Mysore' e 'Prata Zulu'. O experimento foi implantado em fevereiro de 1992 e, durante os três primeiros anos, não foi feito controle de sigatoka. A suscetibilidade dos materiais foi estimada mediante avaliações em três épocas: março de 93, abril e julho de 94. Na primeira avaliação, foi contado o número de manchas na segunda folha e, nas outras, foram atribuídas notas de acordo com a intensidade dos sintomas. Os cultivares foram agrupados em três classes: altamente suscetível (AS, suscetível (S ou parcialmente resistente (PR. Nenhum dos cultivares pôde ser considerado imune, pois todos apresentaram lesões foliares. Os cultivares mais suscetíveis foram os do Grupo AAA, Subgrupo Cavendish ('Nanicão', 'Grande Naine' e 'Nanicão Jangada' e 'Enxerto' (AAB. 'Mysore' (AAB e 'Prata Zulu' (AAB foram classificados como parcialmente resistentes. 'Prata' (AAB e 'Maçã' (AAB mostraram-se medianamente suscetíveis.Susceptibility of eight banana cultivars to sigatoka caused by Mycosphaerella musicola was assessed in a field experiment in the region of Marília, State of São Paulo. Three cultivars were members of AAA Group ('Nanicão', 'Nanicão Jangada' and 'Grande Naine' and five belonged to AAB Group ('Prata', 'Enxerto', 'Maçã', 'Mysore' and 'Prata Zulu'. The experiment was established in February, 1992, and during the first three years, sigatoka disease was not controlled. Susceptibility was assessed in three occasions: March, 1993, April and July, 1994. In the first, it was counted the number of spots on the second leaf, and in the others, the plants were graded according to the amount of leaf scorch due to sigatoka. The cultivars were

  6. Heart attack first aid

    Science.gov (United States)

    First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... A heart attack occurs when the blood flow that carries oxygen to the heart is blocked. The heart muscle ...

  7. An Assessment of Worm Hole attack over Mobile Ad-Hoc Network as serious threats

    Directory of Open Access Journals (Sweden)

    Vikas Kumar Upadhyay

    2013-07-01

    Full Text Available Now these day Mobile Ad hoc networks vulnerable from number of security threats like black hole attack, DOS attack, Byzantine attack and wormhole attack. Wormhole attack is one of most important attack and having great attention in recent year. Wormhole attack, demonstrate a illusion over the network that show two far away node to be an neighbor node and attracted all traffic by presenting an greediness of shortest path over the network. This paper presents a bird eye over different existing wormhole deduction mechanism and their problem.

  8. Composite Dos Attack Model

    Directory of Open Access Journals (Sweden)

    Simona Ramanauskaitė

    2012-04-01

    Full Text Available Preparation for potential threats is one of the most important phases ensuring system security. It allows evaluating possible losses, changes in the attack process, the effectiveness of used countermeasures, optimal system settings, etc. In cyber-attack cases, executing real experiments can be difficult for many reasons. However, mathematical or programming models can be used instead of conducting experiments in a real environment. This work proposes a composite denial of service attack model that combines bandwidth exhaustion, filtering and memory depletion models for a more real representation of similar cyber-attacks. On the basis of the introduced model, different experiments were done. They showed the main dependencies of the influence of attacker and victim’s properties on the success probability of denial of service attack. In the future, this model can be used for the denial of service attack or countermeasure optimization.

  9. Attacks Prevention and Detection Techniques In MANET: A Survey

    Directory of Open Access Journals (Sweden)

    Pranjali D. Nikam,

    2014-11-01

    Full Text Available Wireless sensor network is a set of distributed sensor nodes. Which are randomly deployed in geographical area to capture climatic changes like temperature, humidity and pressure. In Wireless Network MANET is a Mobile Ad-Hoc Networks which is a one self-configurable network. MANET is a collection of Wireless mobile node which is dynamically moves from one location to another location. Both attacks Active as well as Passive attacks is in MANET. It doesn’t have a static structure. Security for wireless network is much difficult as compare to wired networks. In last few years many security and attacks issue are face many researchers in MANET. Attacks like Packet dropping attack, Black-Hole attack, Denial of Service attack, wormhole attacks and Packet modification attacks found in MANET. At the time of data communication all the above mentioned attacks access data easily without permission. To solve the problem of attacks in MANET and secure data communication use Intrusion Detection System. In This paper propose the survey of different kinds of attacks on MANET and Wireless sensor networks. This paper helps to young researcher for implement new hybrid algorithm for secure intrusion detection in MANET.

  10. Performance Evaluation of AODV with Blackhole Attack

    Science.gov (United States)

    Dara, Karuna

    2010-11-01

    A Mobile Ad Hoc Network (MANET) is a temporary network set up by a wireless mobile computers moving arbitrary in the places that have no network infrastructure. These nodes maintain connectivity in a decentralized manner. Since the nodes communicate with each other, they cooperate by forwarding data packets to other nodes in the network. Thus the nodes find a path to the destination node using routing protocols. However, due to security vulnerabilities of the routing protocols, mobile ad-hoc networks are unprotected to attacks of the malicious nodes. One of these attacks is the Black Hole Attack against network integrity absorbing all data packets in the network. Since the data packets do not reach the destination node on account of this attack, data loss will occur. In this paper, we simulated the black hole attack in various mobile ad-hoc network scenarios using AODV routing protocol of MANET and have tried to find a effect if number of nodes are increased with increase in malicious nodes.

  11. PERFORMANCE EVALUATION OF WIRELESS SENSOR NETWORK UNDER HELLO FLOOD ATTACK

    Directory of Open Access Journals (Sweden)

    Mohammad Abdus Salam

    2016-03-01

    Full Text Available Wireless sensor network (WSN is highly used in many fields. The network consists of tiny lightweight sensor nodes and is largely used to scan or detect or monitor environments. Since these sensor nodes are tiny and lightweight, they put some limitations on resources such as usage of power, processing given task, radio frequency range. These limitations allow network vulnerable to many different types of attacks such as hello flood attack, black hole, Sybil attack, sinkhole, and many more. Among these attacks, hello flood is one of the most important attacks. In this paper,we have analyzed the performance of hello flood attack and compared the network performance as number of attackers increases. Network performance is evaluated by modifying the ad-hoc on demand distance vector (AODV routing protocol by using NS2 simulator. It has been tested under different scenarios like no attacker, single attacker, and multiple attackers to know how the network performance changes. The simulation results show that as the number of attackers increases the performance in terms of throughput and delay changes.

  12. Adversary Model: Adaptive Chosen Ciphertext Attack with Timing Attack

    OpenAIRE

    2014-01-01

    We have introduced a novel adversary model in Chosen-Ciphertext Attack with Timing Attack (CCA2-TA) and it was a practical model because the model incorporates the timing attack. This paper is an extended paper for 'A Secure TFTP Protocol with Security Proofs'. Keywords - Timing Attack, Random Oracle Model, Indistinguishabilit, Chosen Plaintext Attack, CPA, Chosen Ciphertext Attack, IND-CCA1, Adaptive Chosen Ciphertext Attack, IND-CCA2, Trivial File Transfer Protocol, TFTP, Security, Trust, P...

  13. Seven Deadliest Microsoft Attacks

    CERN Document Server

    Kraus, Rob; Borkin, Mike; Alpern, Naomi

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting Microsoft products? Then you need Seven Deadliest Microsoft Attacks. This book pinpoints the most dangerous hacks and exploits specific to Microsoft applications, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Windows Operating System-Password AttacksActive Directory-Escalat

  14. Seven Deadliest Network Attacks

    CERN Document Server

    Prowell, Stacy; Borkin, Mike

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting networks? Then you need Seven Deadliest Network Attacks. This book pinpoints the most dangerous hacks and exploits specific to networks, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks detailed in this book include: Denial of Service War Dialing Penetration "Testing" Protocol Tunneling Spanning Tree At

  15. Seven deadliest USB attacks

    CERN Document Server

    Anderson, Brian

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting USB technology? Then you need Seven Deadliest USB Attacks. This book pinpoints the most dangerous hacks and exploits specific to USB, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks detailed in this book include: USB Hacksaw USB Switchblade USB Based Virus/Malicous Code Launch USB Device Overflow RAMdum

  16. Fighting Through a Logistics Cyber Attack

    Science.gov (United States)

    2015-06-19

    cumulative cost of cyber-attacks was more than the combined global black market cost of cocaine, heroin and marijuana. These alarming figures raised...information (in many cases real-time) among many users at a very low cost . The number of networks the DoD uses to execute its mission has increased...the country to its knees. The Luftwaffe was uncontested in the Battle of Britain until radar’s ability to detect inbound aircraft provided the

  17. Mathematical Attacks on RSA Cryptosystem

    Directory of Open Access Journals (Sweden)

    Imad K. Salah

    2006-01-01

    Full Text Available In this paper some of the most common attacks against Rivest, Shamir, and Adleman (RSA cryptosystem are presented. We describe the integer factoring attacks, attacks on the underlying mathematical function, as well as attacks that exploit details in implementations of the algorithm. Algorithms for each type of attacks are developed and analyzed by their complexity, memory requirements and area of usage.

  18. Supply Chain Attack Framework and Attack Patterns

    Science.gov (United States)

    2013-12-01

    Malware is embedded in a replacement server motherboard (e.g., in the flash memory) in order to alter server functionality from that intended. Attack...Slashdot: Dell Ships Infected Motherboards July 21, 2010(c/o Rick Dove) Threat: An adversary with access to hardware procurement, maintenance, or upgrade...control can embed malware in a critical component server motherboard . Vulnerabilities: The control processes and mechanisms for hardware

  19. Nocturnal panic attacks

    Directory of Open Access Journals (Sweden)

    Lopes Fabiana L.

    2002-01-01

    Full Text Available The panic-respiration connection has been presented with increasing evidences in the literature. We report three panic disorder patients with nocturnal panic attacks with prominent respiratory symptoms, the overlapping of the symptoms with the sleep apnea syndrome and a change of the diurnal panic attacks, from spontaneous to situational pattern. The implication of these findings and awareness to the distinct core of the nocturnal panic attacks symptoms may help to differentiate them from sleep disorders and the search for specific treatment.

  20. White or Black Hat? An Economic Analysis of Computer Hacking

    OpenAIRE

    Caitlin Brown

    2015-01-01

    Cyber attacks have increased sharply in recent years. This paper investigates the decision a profit-motivated hacker makes between working as a malicious hacker, called a black hat, and in cybersecurity as a white hat hacker. A key component of the model is the contest between white and black hats for some part of firm output that is vulnerable to attack. White and black hat earnings are increasing, nonlinear functions of the proportion of black hats. Multiple equilibria exist. Increasing the...

  1. Detection techniques of selective forwarding attacks in wireless sensor networks: a survey

    CERN Document Server

    Sharma, Preeti; Saluja, Krishan Kumar

    2012-01-01

    The wireless sensor network has become a hot research area due its wide range of application in military and civilian domain, but as it uses wireless media for communication these are easily prone to security attacks. There are number of attacks on wireless sensor networks like black hole attack, sink hole attack, Sybil attack, selective forwarding attacks etc. in this paper we will concentrate on selective forwarding attacks In selective forwarding attacks, malicious nodes behave like normal nodes and selectively drop packets. The selection of dropping nodes may be random. Identifying such attacks is very difficult and sometimes impossible. In this paper we have listed up some detection techniques, which have been proposed by different researcher in recent years, there we also have tabular representation of qualitative analysis of detection techniques

  2. Heart Attack Payment - State

    Data.gov (United States)

    U.S. Department of Health & Human Services — Payment for heart attack patients measure – state data. This data set includes state-level data for payments associated with a 30-day episode of care for heart...

  3. Heart Attack Payment - Hospital

    Data.gov (United States)

    U.S. Department of Health & Human Services — Payment for heart attack patients measure – provider data. This data set includes provider data for payments associated with a 30-day episode of care for heart...

  4. Heart Attack Payment - National

    Data.gov (United States)

    U.S. Department of Health & Human Services — Payment for heart attack patients measure – national data. This data set includes national-level data for payments associated with a 30-day episode of care for heart...

  5. Transient Ischemic Attack

    Medline Plus

    Full Text Available ... TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an ... a short time. The only difference between a stroke and TIA is that with TIA the blockage ...

  6. Cooperating attackers in neural cryptography.

    Science.gov (United States)

    Shacham, Lanir N; Klein, Einat; Mislovaty, Rachel; Kanter, Ido; Kinzel, Wolfgang

    2004-06-01

    A successful attack strategy in neural cryptography is presented. The neural cryptosystem, based on synchronization of neural networks by mutual learning, has been recently shown to be secure under different attack strategies. The success of the advanced attacker presented here, called the "majority-flipping attacker," does not decay with the parameters of the model. This attacker's outstanding success is due to its using a group of attackers which cooperate throughout the synchronization process, unlike any other attack strategy known. An analytical description of this attack is also presented, and fits the results of simulations.

  7. Impact of Poultry Manure on Growth Behaviour, Black Sigatoka Disease Response and Yield Attributes of Two Plantain (Musa spp. AAB Genotypes

    Directory of Open Access Journals (Sweden)

    Aba, SC.

    2011-01-01

    Full Text Available La baisse de rendement en culture de plantain est un phénomène fréquent après quelques cycles de production; elle est due à de faibles niveaux de matière organique du sol et à une sensibilité accrue à des stress biotiques. L'utilisation de variétés améliorées est une option bon marché et respectueuse de l'environnement pour lutter contre les maladies des plantes, mais le maintien du rendement d'un nouveau cultivar en bananeraie nécessite une bonne gestion de la fertilité des sols qui pourrait être obtenue par une utilisation judicieuse de fumier de volaille. Les effets des trois doses [(0, 10 et 20 t.ha-1] de fumier de volaille décomposé sur la croissance, la réponse à la cercosporiose noire et le rendement de PITA 24' (un hybride de plantain et de son grand-parent maternel 'Mbi-Egome' (une banane plantain locale ont été évalués à Onne (Nigeria dans une station à fortes précipitations de l'IITA. L'expérience a été menée selon un dispositif split plot en blocs aléatoires complets. Les résultats ont montré que les deux clones étudiés avaient des variables de croissance similaires, sauf pour la surface foliaire et la teneur en chlorophylle. Malgré la sensibilité du génotype hybride à la cercosporiose foliaire d'origine atmosphérique, les données sur les composantes du rendement ont montré que 'PITA 24' produisait significativement plus de mains et de doigts par régime, un meilleur rendement du régime et un meilleur rendement végétatif global, toutefois, les deux génotypes ont présenté un schéma similaire pour la répartition de la biomasse. Les plants fumés ont eu un rendement significativement amélioré par rapport aux plants témoins, mais il y a eu un rendement moindre pour la dose de 20 t.ha-1. L'augmentation des doses d'engrais a réduit de plus de 30 jours le temps de récolte; de même, la taille des plants, le drageonnage, la teneur en chlorophylle des feuilles, l'indice des feuilles non contaminées, le cycle de production et la biomasse totale ont augmenté avec la dose de fumier appliquée. Notre étude a montré que l'application de 10 t.ha-1 de fumier de volaille par hectare et par an permettait d'obtenir les meilleures caractéristiques de rendement.

  8. Feasible attack on detector-device-independent quantum key distribution.

    Science.gov (United States)

    Wei, Kejin; Liu, Hongwei; Ma, Haiqiang; Yang, Xiuqing; Zhang, Yong; Sun, Yongmei; Xiao, Jinghua; Ji, Yuefeng

    2017-03-27

    Recently, to bridge the gap between security of Measurement-device-independent quantum key distribution (MDI-QKD) and a high key rate, a novel protocol, the so-called detector-device-independent QKD (DDI-QKD), has been independently proposed by several groups and has attracted great interest. A higher key rate is obtained, since a single photon bell state measurement (BSM) setup is applied to DDI-QKD. Subsequently, Qi has proposed two attacks for this protocol. However, the first attack, in which Bob's BSM setup is assumed to be completely a "black box", is easily prevented by using some additional monitoring devices or by specifically characterizing the BSM. The second attack, which combines the blinding attack and the detector wavelength-dependent efficiency, is not explicitly discussed, and its feasibility is not experimentally confirmed. Here, we show that the second attack is not technically viable because of an intrinsically wavelength-dependent property of a realistic beam splitter, which is an essential component in DDI-QKD. Moreover, we propose a feasible attack that combines a well-known attack-detector blinding attack with intrinsic imperfections of single-photon detectors. The experimental measurement and proof-of-principle test results confirm that our attack can allow Eve to get a copy of quantum keys without being detected and that it is feasible with current technology.

  9. High Order Differential Attack and Trace Attack to Block Ciphers

    Institute of Scientific and Technical Information of China (English)

    HU Yupu; CHEN Kai; Xiao Guozhen

    2001-01-01

    In this paper, we prove a high or-der differential property of power function, then giverespectively high order differential attack and traceattack to block ciphers. These attacks depend onlyon block cipher's algebraic shape on GF(2n) and haveno relation with its designing structure. The condi-tions are given for both effective attacks and strengthagainst attacks.

  10. Manejo de Sigatoka negra (Mycosphaerella Fijiensis var. Difformis Morelet en plátano cv. “Curraré” en San Carlos, Zona Norte

    Directory of Open Access Journals (Sweden)

    Carlos Muñoz Ruiz

    2005-05-01

    Full Text Available Se evaluaron los diferentes productos químicos, utilizados en el control de Sigatoka negra en banano, en el cultivo de plátano, en la zona de Santa Clara de San Carlos. Uno de los principales objetivos fue generar un programa de manejo químico de la enfermedad para la zona de San Carlos, posible de ser transferido a otras zonas plataneras del país; el otro objetivo fue establecer las bases para automatizar las actividades culturales de manejo de plantaciones de musáceas, mediante la creación de un Software para computadora y asequible por internet. Para el primer objetivo, se logró establecer que genéticamente el plátano es más resistente a la enfermedad y, por ser un cultivo donde hasta el momento, no se ha sobrepasado el uso de funguicidas como sucede en el banano, se pueden utilizar sin problema los productos protectantes mas comunes, como el Vondozeb y el Ridodur, tanto en aceite como en agua, así como el aceite puro a 7 litros/ha, presentando un efecto aceptable en el control de la infección de Mycospharella. Los productos sistémicos utilizados mostraron su eficiencia aunque, por su costo, no se sugiere su uso en plátano, solo para casos de emergencia. La mezcla de protectantes con sistémicos y aceite (cocteles, se consideran muy efectivos pero innecesarios para ser utilizados en plátano en forma comercial. Para esta evaluación se hicieron 35 aplicaciones o semanas de evaluación, en dos periodos climatológicos (verano e invierno de enero a septiembre del 2001, combinadas con las prácticas culturales tradicionales de deshoja, deshija, fertilización, y el monitoreo, utilizando la escala de signos visuales de 6 puntos de Stover y el método francés. Se evaluaron las variables: Hojas por planta (H/P, Hoja mas joven enferma (HMJE y Porcentaje ponderado de infecci��n (PPI, para cada tipo de grupo químico evaluado. La variable H/P, en la mayoría de los grupos se inició con un mínimo de 3 hojas hasta un máximo de 14

  11. Comportamiento de la severidad de ataque de Sigatoka negra (myscosphaerella fijiensis morelet en áreas productoras de plátano...

    Directory of Open Access Journals (Sweden)

    Vidal Sáez Sáez

    1999-01-01

    Full Text Available Condiciones de precipitación, temperatura y humedad del aire, determinan la severidad y daño que hace la Sigatoka Negra (Myscosphaerella fijiensis Morelet en plátanos (Musa AAB. En 1991, se identificó por primera vez esta enfermedad en Venezuela, y penetró por la región Sur del Lago de Maracaibo, la cual a su vez es una de las principales áreas productoras del renglón. Durante 1997 las precipitaciones disminuyeron en comparación con la serie histórica. El objetivo del trabajo fue determinar el comportamiento de la severidad de la enfermedad en el año 1997 bajo condiciones irregulares de la distribución de las lluvias. Para cumplir el mismo, se registró la precipitación en una estación meteorológica que se emplazó en una área productora de plátanos. Se evalúo la enfermedad a través promedio ponderado de infección (PPI de la Metodología de Stover (1989. Se estimaron los acumulados de precipitación, número de días con precipitación, número de eventos sin precipitación, y número de días sin precipitación para cuatro intervalos de tiempo previos a las fechas de evaluación de la enfermedad, se realizaron los análisis comparativos entre los registros de la estación y los índices de enfermedad. Los resultados evidencian que los repuntes de severidad, parecen ser favorecidos de la continuidad de los eventos de precipitación.

  12. XQuery Injection Attack and Countermeasures

    Institute of Scientific and Technical Information of China (English)

    谭玉森

    2014-01-01

    As a database that allows data to be stored in XML format, XML database suffers from some similar attacks as traditional relational database does. These attacks include injection attack by XQuey function in application software. These include BaseX, eXist and MarkLogic. In order to defeat these attacks, countermeasures are proposed.

  13. Seven Deadliest Wireless Technologies Attacks

    CERN Document Server

    Haines, Brad

    2010-01-01

    How can an information security professional keep up with all of the hacks, attacks, and exploits? One way to find out what the worst of the worst are is to read the seven books in our Seven Deadliest Attacks Series. Not only do we let you in on the anatomy of these attacks but we also tell you how to get rid of them and how to defend against them in the future. Countermeasures are detailed so that you can fight against similar attacks as they evolve. Attacks featured in this book include:Bluetooth AttacksCredit Card, Access Card, and Passport AttacksBad Encryption

  14. The political attack ad

    Directory of Open Access Journals (Sweden)

    Palma Peña-Jiménez, Ph.D.

    2011-01-01

    Full Text Available During election campaigns the political spot has a clear objective: to win votes. This message is communicated to the electorate through television and Internet, and usually presents a negative approach, which includes a direct critical message against the opponent, rather than an exposition of proposals. This article is focused on the analysis of the campaign attack video ad purposely created to encourage the disapproval of the political opponent among voters. These ads focus on discrediting the opponent, many times, through the transmission of ad hominem messages, instead of disseminating the potential of the political party and the virtues and manifesto of its candidate. The article reviews the development of the attack ad since its first appearance, which in Spain dates back to 1996, when the famous Doberman ad was broadcast, and examines the most memorable campaign attack ads.

  15. Shark attack in Natal.

    Science.gov (United States)

    White, J A

    1975-02-01

    The injuries in 5 cases of shark attack in Natal during 1973-74 are reviewed. Experience in shark attacks in South Africa during this period is discussed (1965-73), and the value of protecting heavily utilized beaches in Natal with nets is assessed. The surgical applications of elasmobranch research at the Oceanographic Research Institute (Durban) and at the Headquarters of the Natal Anti-Shark Measures Board (Umhlanga Rocks) are described. Modern trends in the training of surf life-guards, the provision of basic equipment for primary resuscitation of casualties on the beaches, and the policy of general and local care of these patients in Natal are discussed.

  16. Performance Comparison of Routing Attacks in Manet and WSN

    Directory of Open Access Journals (Sweden)

    Shyamala Ramachandran

    2012-08-01

    Full Text Available Routing is a basic step for data exchange. In wirel ess ad-hoc networks each node acts as a router and executes a routing protocol. Wireless ad-hoc networ ks are highly resource constrained in terms of network topology, memory and computation power. The reliable data transfer is a difficult task in wireless ad-hoc networks because of resource constr aints. A mobile ad-hoc network (MANET is a kind of wireless ad-hoc network, and is a self-configuri ng network of mobile routers connected by wireless links. A wireless sensor network (WSN is a highly constrained wireless ad-hoc network. In these network, multicast is the efficient routing service for data broadcasting. Denial of service (DOS att ack, sinkhole, wormhole, sybil, black hole and rushing a ttacks are some routing attacks. So, it is necessar y to study the impact of routing attacks on existing mul ticast routing protocols to suggest a suitable secu re multicast routing protocol. The objective of this p aper is to study the effects of black hole and rush ing attack on MANET and WSN. The NS-2 based simulation is used in analyzing the black hole and rushing attacks. From performance metrics such as packet de livery ratio (PDR, packet drop ratio (PDrR, network throughput (NTh and energy consumption it is observed that the routing attacks have severe impact on MANET than WSN.

  17. Bluetooth security attacks comparative analysis, attacks, and countermeasures

    CERN Document Server

    Haataja, Keijo; Pasanen, Sanna; Toivanen, Pekka

    2013-01-01

    This overview of Bluetooth security examines network vulnerabilities and offers a comparative analysis of recent security attacks. It also examines related countermeasures and proposes a novel attack that works against all existing Bluetooth versions.

  18. E-Canada and the Emerging Cyber Attack Exigency

    Directory of Open Access Journals (Sweden)

    Craig MacEachern

    2011-10-01

    Full Text Available

    black; font-family: "Arial","sans-serif"; mso-bidi-font-family: Calibri;">This paper examines the growing concern surrounding cyber-attacks, and warns about the possible impacts of a cyber-attack upon Canadian e-government, economy, and infrastructure. This paper covers historical examples of cyber-attacks on a global scale, then focuses on Canadian e-government vulnerabilities, and suggests some ways in which Canadian government must adapt its domestic security and internet policies to confront the future inevitability of cyber-attacks.  

  19. When women attack.

    Science.gov (United States)

    McLaughlin, Bryan; Davis, Catasha; Coppini, David; Kim, Young Mie; Knisely, Sandra; McLeod, Douglas

    2015-01-01

    The common assumption that female candidates on the campaign trail should not go on the attack, because such tactics contradict gender stereotypes, has not received consistent support. We argue that in some circumstances gender stereotypes will favor female politicians going negative. To test this proposition, this study examines how gender cues affect voter reactions to negative ads in the context of a political sex scandal, a context that should prime gender stereotypes that favor females. Using an online experiment involving a national sample of U.S. adults (N = 599), we manipulate the gender and partisan affiliation of a politician who attacks a male opponent caught in a sex scandal involving sexually suggestive texting to a female intern. Results show that in the context of a sex scandal, a female candidate going on the attack is evaluated more positively than a male. Moreover, while female participants viewed the female sponsor more favorably, sponsor gender had no effect on male participants. Partisanship also influenced candidate evaluations: the Democratic female candidate was evaluated more favorably than her Republican female counterpart.

  20. Black America: Looking Inward or Outward?

    Science.gov (United States)

    Jordan, Vernon E.

    1996-01-01

    Presents some observations on what the recent attacks on affirmative action, the O. J. Simpson trial, and the Million Man March say about racism in America. In particular, the author assesses the Million Man March in terms of black leadership and its influence in helping black men to become more involved in constructive community service. (GR)

  1. Replacement Attack: A New Zero Text Watermarking Attack

    Science.gov (United States)

    Bashardoost, Morteza; Mohd Rahim, Mohd Shafry; Saba, Tanzila; Rehman, Amjad

    2017-03-01

    The main objective of zero watermarking methods that are suggested for the authentication of textual properties is to increase the fragility of produced watermarks against tampering attacks. On the other hand, zero watermarking attacks intend to alter the contents of document without changing the watermark. In this paper, the Replacement attack is proposed, which focuses on maintaining the location of the words in the document. The proposed text watermarking attack is specifically effective on watermarking approaches that exploit words' transition in the document. The evaluation outcomes prove that tested word-based method are unable to detect the existence of replacement attack in the document. Moreover, the comparison results show that the size of Replacement attack is estimated less accurate than other common types of zero text watermarking attacks.

  2. Structural Learning of Attack Vectors for Generating Mutated XSS Attacks

    Directory of Open Access Journals (Sweden)

    Yi-Hsun Wang

    2010-09-01

    Full Text Available Web applications suffer from cross-site scripting (XSS attacks that resulting from incomplete or incorrect input sanitization. Learning the structure of attack vectors could enrich the variety of manifestations in generated XSS attacks. In this study, we focus on generating more threatening XSS attacks for the state-of-the-art detection approaches that can find potential XSS vulnerabilities in Web applications, and propose a mechanism for structural learning of attack vectors with the aim of generating mutated XSS attacks in a fully automatic way. Mutated XSS attack generation depends on the analysis of attack vectors and the structural learning mechanism. For the kernel of the learning mechanism, we use a Hidden Markov model (HMM as the structure of the attack vector model to capture the implicit manner of the attack vector, and this manner is benefited from the syntax meanings that are labeled by the proposed tokenizing mechanism. Bayes theorem is used to determine the number of hidden states in the model for generalizing the structure model. The paper has the contributions as following: (1 automatically learn the structure of attack vectors from practical data analysis to modeling a structure model of attack vectors, (2 mimic the manners and the elements of attack vectors to extend the ability of testing tool for identifying XSS vulnerabilities, (3 be helpful to verify the flaws of blacklist sanitization procedures of Web applications. We evaluated the proposed mechanism by Burp Intruder with a dataset collected from public XSS archives. The results show that mutated XSS attack generation can identify potential vulnerabilities.

  3. Seven Deadliest Unified Communications Attacks

    CERN Document Server

    York, Dan

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting Unified Communications technology? Then you need Seven Deadliest Unified Communication Attacks. This book pinpoints the most dangerous hacks and exploits specific to Unified Communications, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks featured in this book include: UC Ecosystem Attacks Insecure Endpo

  4. 云南河口地区香蕉褐缘灰斑病的发生规律研究%Occurrence Regularity of Banana Sigatoka Leaf Spot Disease in Hekou of Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    张建春; 邓成菊; 陈伟强; 李芹; 刘学敏; 杨绍琼; 王晓燕; 胡原鸿; 黄绍忠

    2013-01-01

    The study is about banana sigatoka leaf spot disease in Hekou of Yunnan province. The findings show that the occurrence and the rule of development of the disease are influenced by temperature and rainfall. The disease begins at spring, when the temperature rises and reaches peak between October and December. The degree of harm of the disease differs greatly between different geographic environments, disease index: eastern district (11.81) > central and southern district (10.40) >western district (7.94) but the basic rule is that the disease in low altitude districts begins earlier than high altitude districts and is more harmful than that of the low districts and the disease index decreased with the rises of altitude, which has certain guiding significance for agricultural production.%对云南河口地区香蕉褐缘灰斑病(Banana Sigatoka Leaf Spot Disease)进行研究,结果表明:病害的发生、发展规律主要受温度和降雨量的影响;春季气温回升时开始发病,10~11月危害达到高峰值;不同地理环境危害程度有明显差异,病情指数东部地区(11.81)>中南部地区(10.40)>西部地区(7.94),但危害的基本规律是低海拔地区比高海拔地区先发病,且发病程度比高海拔地区严重,病情指数随着海拔的升高而降低。

  5. Structural Learning of Attack Vectors for Generating Mutated XSS Attacks

    CERN Document Server

    Wang, Yi-Hsun; Lee, Hahn-Ming; 10.4204/EPTCS.35.2

    2010-01-01

    Web applications suffer from cross-site scripting (XSS) attacks that resulting from incomplete or incorrect input sanitization. Learning the structure of attack vectors could enrich the variety of manifestations in generated XSS attacks. In this study, we focus on generating more threatening XSS attacks for the state-of-the-art detection approaches that can find potential XSS vulnerabilities in Web applications, and propose a mechanism for structural learning of attack vectors with the aim of generating mutated XSS attacks in a fully automatic way. Mutated XSS attack generation depends on the analysis of attack vectors and the structural learning mechanism. For the kernel of the learning mechanism, we use a Hidden Markov model (HMM) as the structure of the attack vector model to capture the implicit manner of the attack vector, and this manner is benefited from the syntax meanings that are labeled by the proposed tokenizing mechanism. Bayes theorem is used to determine the number of hidden states in the model...

  6. An Attack Investigation, Characterization and Simulation of Various Attacks in MANET

    Directory of Open Access Journals (Sweden)

    Pratik Gite

    2015-01-01

    Full Text Available Mobile Ad-hoc Network is one of the most popular network technology in the field of research and development community. Due to their dynamic and ad-hoc nature, the network suffers from the various performance and security issues. The main objective of this paper is to evaluate the performance of Ad-hoc On Demand Distance Vector (AODV routing protocol under normal condition and attacks conditions on the basis of different performance metrics. This paper is also concerned about the different kinds of attacks formation viz. Black Hole, Worm Hole, Gray Hole and Denial of Service attacks on MANET environment. In addition of that different kinds of approaches available for detection and prevention of such attacks are also investigated. Finally using different experimentation and simulations through NS-2, the effort is made to identify the effective network characteristics. After concluding the effects and simulation the need of a new Intrusion Detection System (IDS model is presented for future implementation.

  7. Attacks on computer systems

    Directory of Open Access Journals (Sweden)

    Dejan V. Vuletić

    2012-01-01

    Full Text Available Computer systems are a critical component of the human society in the 21st century. Economic sector, defense, security, energy, telecommunications, industrial production, finance and other vital infrastructure depend on computer systems that operate at local, national or global scales. A particular problem is that, due to the rapid development of ICT and the unstoppable growth of its application in all spheres of the human society, their vulnerability and exposure to very serious potential dangers increase. This paper analyzes some typical attacks on computer systems.

  8. Black to Black

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander

    2012-01-01

    ’s a lifestyle I enjoy.” For Monáe, the tuxedo is both working clothes and a superhero uniform. Together with futuristic references to Fritz Lang’s dystopian Metropolis, her trademark starched shirt and tuxedo also recall Weimar and pre-war Berlin. While outwardly dissimilar, Sioux’s and Monáe’s shared black...... suggested that appreciation of the highly personal motives of both Siouxsie Sioux and Janelle Monáe in wearing black may be achieved via analogies with the minimalist sublime of American artists Frank Stella’s and Ad Reinhardt’s black canvasses....

  9. Recent "phishing" attacks

    CERN Multimedia

    IT Department

    2009-01-01

    Over the last few weeks there has been a marked increase in the number of attacks on CERN made by cybercriminals. Typical attacks arrive in the form of e-mail messages purporting to come from the CERN Help Desk, Mail Service, or some similarly official-sounding entity and suggest that there is a problem with your account, such as it being over-quota. They then ask you to click on a link or to reply and give your password. Please don’t! Be cautious of any unexpected messages containing web links even if they appear to come from known contacts. If you happen to click on such a link and if your permission is requested to run or install software, always decline it. NEVER provide your password or other details if these are requested. These messages try to trick you into clicking on Web links which will help them to install malicious software on your computer, and anti-virus software cannot be relied on to detect all cases. In case of questions on this topic, you may contact mailto:helpdesk@cern.ch. CERN Comput...

  10. Tracing Technique for Blaster Attack

    CERN Document Server

    S., Siti Rahayu; S., Shahrin; A., Faizal M; M, Mohd Zaki; R, Irda

    2009-01-01

    Blaster worm of 2003 is still persistent, the infection appears to have successfully transitioned to new hosts as the original systems are cleaned or shut off, suggesting that the Blaster worm, and other similar worms, will remain significant Internet threats for many years after their initial release. This paper is to propose technique on tracing the Blaster attack from various logs in different OSI layers based on fingerprint of Blaster attack on victim logs, attacker logs and IDS alert log. The researchers intended to do a preliminary investigation upon this particular attack so that it can be used for further research in alert correlation and computer forensic investigation.

  11. Seven Deadliest Web Application Attacks

    CERN Document Server

    Shema, Mike

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting web applications? Then you need Seven Deadliest Web Application Attacks. This book pinpoints the most dangerous hacks and exploits specific to web applications, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. .. .. Attacks detailed in this book include: ..: ..; Cross-Site Scripting (XSS) ..; Cross-Site Request Fo

  12. The Timing of Terrorist Attacks

    DEFF Research Database (Denmark)

    Jensen, Thomas

    2016-01-01

    I use a simple optimal stopping model to derive policy relevant insights on the timing of one-shot attacks by small autonomous terrorist units or “lone wolf” individuals. A main insight is that an increase in proactive counterterrorism measures can lead to a short term increase in the number...... of attempted terrorist attacks because it makes it more risky for existing terrorist units to pursue further development of capabilities. This is consistent with the events in London in 2005 where a terrorist attack on 7 July was followed by a similar but unsuccessful attack two weeks later....

  13. Seven Deadliest Social Network Attacks

    CERN Document Server

    Timm, Carl

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting social networks? Then you need Seven Deadliest Social Network Attacks. This book pinpoints the most dangerous hacks and exploits specific to social networks like Facebook, Twitter, and MySpace, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks detailed in this book include: Social Networking Infrastruct

  14. WILD PIG ATTACKS ON HUMANS

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, J.

    2013-04-12

    Attacks on humans by wild pigs (Sus scrofa) have been documented since ancient times. However, studies characterizing these incidents are lacking. In an effort to better understand this phenomenon, information was collected from 412 wild pig attacks on humans. Similar to studies of large predator attacks on humans, data came from a variety of sources. The various attacks compiled occurred in seven zoogeographic realms. Most attacks occurred within the species native range, and specifically in rural areas. The occurrence was highest during the winter months and daylight hours. Most happened under non-hunting circumstances and appeared to be unprovoked. Wounded animals were the chief cause of these attacks in hunting situations. The animals involved were typically solitary, male and large in size. The fate of the wild pigs involved in these attacks varied depending upon the circumstances, however, most escaped uninjured. Most human victims were adult males traveling on foot and alone. The most frequent outcome for these victims was physical contact/mauling. The severity of resulting injuries ranged from minor to fatal. Most of the mauled victims had injuries to only one part of their bodies, with legs/feet being the most frequent body part injured. Injuries were primarily in the form of lacerations and punctures. Fatalities were typically due to blood loss. In some cases, serious infections or toxemia resulted from the injuries. Other species (i.e., pets and livestock) were also accompanying some of the humans during these attacks. The fates of these animals varied from escaping uninjured to being killed. Frequency data on both non-hunting and hunting incidents of wild pig attacks on humans at the Savannah River Site, South Carolina, showed quantitatively that such incidents are rare.

  15. Superposition Attacks on Cryptographic Protocols

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Funder, Jakob Løvstad; Nielsen, Jesper Buus

    2011-01-01

    Attacks on classical cryptographic protocols are usually modeled by allowing an adversary to ask queries from an oracle. Security is then defined by requiring that as long as the queries satisfy some constraint, there is some problem the adversary cannot solve, such as compute a certain piece...... of information. In this paper, we introduce a fundamentally new model of quantum attacks on classical cryptographic protocols, where the adversary is allowed to ask several classical queries in quantum superposition. This is a strictly stronger attack than the standard one, and we consider the security...

  16. Multiculturalism & The Charlie Hebdo Attack

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2016-01-01

    The attack on Charlie Hebdo has by many been linked to multiculturalism. But it is unclear exactly how the connection between multiculturalism and the attack should be understood and whether there indeed is such a connection. The article discusses this by distinguishing between different senses o...... of multiculturalism and different ways in which one might think that there is a link between multiculturalism and the attack. On this basis the resulting claims are discussed as to whether they are in fact plausible, which many of them turn out not to be....

  17. The Cyber-Physical Attacker

    DEFF Research Database (Denmark)

    Vigo, Roberto

    2012-01-01

    The world of Cyber-Physical Systems ranges from industrial to national interest applications. Even though these systems are pervading our everyday life, we are still far from fully understanding their security properties. Devising a suitable attacker model is a crucial element when studying...... the security properties of CPSs, as a system cannot be secured without defining the threats it is subject to. In this work an attacker scenario is presented which addresses the peculiarities of a cyber-physical adversary, and we discuss how this scenario relates to other attacker models popular in the security...

  18. Multiculturalism & The Charlie Hebdo Attack

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2016-01-01

    The attack on Charlie Hebdo has by many been linked to multiculturalism. But it is unclear exactly how the connection between multiculturalism and the attack should be understood and whether there indeed is such a connection. The article discusses this by distinguishing between different senses...... of multiculturalism and different ways in which one might think that there is a link between multiculturalism and the attack. On this basis the resulting claims are discussed as to whether they are in fact plausible, which many of them turn out not to be....

  19. Black Droplets

    CERN Document Server

    Santos, Jorge E

    2014-01-01

    Black droplets and black funnels are gravitational duals to states of a large N, strongly coupled CFT on a fixed black hole background. We numerically construct black droplets corresponding to a CFT on a Schwarzchild background with finite asymptotic temperature. We find two branches of such droplet solutions which meet at a turning point. Our results suggest that the equilibrium black droplet solution does not exist, which would imply that the Hartle-Hawking state in this system is dual to the black funnel constructed in \\cite{Santos:2012he}. We also compute the holographic stress energy tensor and match its asymptotic behaviour to perturbation theory.

  20. Dpraodv: A Dyanamic Learning System Against Blackhole Attack in Aodv Based Manet

    OpenAIRE

    Raj, Payal N.; Swadas, Prashant B.

    2009-01-01

    Security is an essential requirement in mobile ad hoc networks to provide protected communication between mobile nodes. Due to unique characteristics of MANETS, it creates a number of consequential challenges to its security design. To overcome the challenges, there is a need to build a multifence security solution that achieves both broad protection and desirable network performance. MANETs are vulnerable to various attacks, blackhole, is one of the possible attacks. Black hole is a type of ...

  1. DPRAODV: A Dynamic Learning System Against Blackhole Attack In AODV Based MANET

    OpenAIRE

    Swadas, Prashant B.; Raj, Payal N.

    2009-01-01

    Security is an essential requirement in mobile ad hoc networks to provide protected communication between mobile nodes. Due to unique characteristics of MANETS, it creates a number of consequential challenges to its security design. To overcome the challenges, there is a need to build a multifence security solution that achieves both broad protection and desirable network performance. MANETs are vulnerable to various attacks, blackhole, is one of the possible attacks. Black hole is a type of ...

  2. Genetic attack on neural cryptography.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Naeh, Rivka; Kanter, Ido

    2006-03-01

    Different scaling properties for the complexity of bidirectional synchronization and unidirectional learning are essential for the security of neural cryptography. Incrementing the synaptic depth of the networks increases the synchronization time only polynomially, but the success of the geometric attack is reduced exponentially and it clearly fails in the limit of infinite synaptic depth. This method is improved by adding a genetic algorithm, which selects the fittest neural networks. The probability of a successful genetic attack is calculated for different model parameters using numerical simulations. The results show that scaling laws observed in the case of other attacks hold for the improved algorithm, too. The number of networks needed for an effective attack grows exponentially with increasing synaptic depth. In addition, finite-size effects caused by Hebbian and anti-Hebbian learning are analyzed. These learning rules converge to the random walk rule if the synaptic depth is small compared to the square root of the system size.

  3. Social Engineering:A Partial Technical attack

    Directory of Open Access Journals (Sweden)

    P. S. Maan

    2012-03-01

    Full Text Available This paper suggests the crystal clear concept behind the social engineering attack. Basically social engineering is a non technical attack. But social engineering attack is an attack on human psychology to get the information, but using what? Basically it is an attack on human psychology by using some technical skills or technology. Social engineering attack has many types like fake mail, telephonic cheat etc. which are impossible without any technical skills, so in this paper we suggest that , it is a partial technical attack and can be divided in human based and typical computer based social engineering attack.

  4. Black psyllium

    Science.gov (United States)

    Black psyllium is a weed that grows aggressively throughout the world. The plant was spread with the ... to make medicine. Be careful not to confuse black psyllium with other forms of psyllium including blond ...

  5. Effect of Blackhole Attack on Single Hop and Multihop Leach Protocol

    Directory of Open Access Journals (Sweden)

    Siddiq Iqbal,

    2014-05-01

    Full Text Available Wireless micro sensor networks provide reliable monitoring of remote areas for data-gathering. Due to the limited battery capacity of sensor nodes, energy consumption plays an important role in the operation of WSN. This can be improved by using a protocol called Low energy adaptive clustering hierarchy (LEACH.Malicious attacks are generated in the network due to power supply, processing abilities and capacity for high power radio transmission. In this paper one such attack namely BlackHole attack and its effect on single hop LEACH and multihop LEACH has been compared, simulated and analyzed.

  6. Network Coding Based Security for Routing Attacks in WRN: Frechet Interference and Rayleigh Outage Evaluation

    Directory of Open Access Journals (Sweden)

    R. Villalpando-Hernández

    2011-08-01

    Full Text Available We present a network coding security method capable of detecting several routing attacks in wireless reconfigurablenetworks. Routing security attacks include selective forwarding, black holes, and wormholes. The proposed methodperforms linear network coding over intermediate nodes composing a given route, not only to distribute content, butalso to provide data confidentiality by cooperation as a mechanism of detection. The method presents a robust,accurate and fast response under security attacks for varying network conditions, such as interference and outagedue to channel fading. It also provides a gain in network throughput by increasing the number of successfully receivedpackets without a significant increase of the bandwidth usage.

  7. PERFORMANCE ANALYSIS OF ADHOC ON DEMAND DISTANCE VECTOR PROTOCOL WITH BLACKHOLE ATTACK IN WSN

    Directory of Open Access Journals (Sweden)

    Adnan Ahmed

    2014-01-01

    Full Text Available The security is major challenging issue in wireless sensor network applications because they are operated in public and unrestrained areas which also makes difficult to protect against tampering or captured by an adversary force that can launch insider attacks to make a node compromised. One type of such attack is black hole attack. Existing AODV routing protocol does not have mechanism to defend against such attacks. In this study, we comprehensively investigates the performance of AODV protocol by simulating it on the various network parameters with various number of blackhole nodes. The metrics for evaluation has been considered as packet delivery ratio, end to end delay, normalized routing overhead and total number of packets drop. The simulation results show that blackhole attack severely degrades the performance of WSN.

  8. Black Holes

    Science.gov (United States)

    Luminet, Jean-Pierre

    1992-09-01

    Foreword to the French edition; Foreword to the English edition; Acknowledgements; Part I. Gravitation and Light: 1. First fruits; 2. Relativity; 3. Curved space-time; Part II. Exquisite Corpses: 4. Chronicle of the twilight years; 5. Ashes and diamonds; 6. Supernovae; 7. Pulsars; 8. Gravitation triumphant; Part III. Light Assassinated: 9. The far horizon; 10. Illuminations; 11. A descent into the maelstrom; 12. Map games; 13. The black hole machine; 14. The quantum black hole; Part IV. Light Regained: 15. Primordial black holes; 16. The zoo of X-ray stars; 17. Giant black holes; 18. Gravitational light; 19. The black hole Universe; Appendices; Bibliography; Name index; Subject index.

  9. Analytical Characterization of Internet Security Attacks

    Science.gov (United States)

    Sellke, Sarah H.

    2010-01-01

    Internet security attacks have drawn significant attention due to their enormously adverse impact. These attacks includes Malware (Viruses, Worms, Trojan Horse), Denial of Service, Packet Sniffer, and Password Attacks. There is an increasing need to provide adequate defense mechanisms against these attacks. My thesis proposal deals with analytical…

  10. La medición y vigilancias de la enfermedad de la mancha foliar producida por la sigatoka negra (Mycospharella fijiensis var diformis Morelet en la producción de musáceas: un enfoque para lograr la sostenibilidad del desarrollo

    Directory of Open Access Journals (Sweden)

    Edgardo Vargas Jarquín

    2013-05-01

    Full Text Available En el presente trabajo se discute la necesidad de utilizar tecnología, como el procesamiento digital de imágenes para mejorar los procesos de medición y vigilancia de la enfermedad de la mancha de la hoja causada por SIGATOKA NEGRA (Mycospharella fijiensis var diformis Morelet, pero partiendo de un análisis epistemológico que fundamenta al desarrollo sostenible, que es el marco dentro del cual se encuentra sentido a la aplicación de esta tecnología. Así se define que es la gobernabilidad benéfica del ambiente lo que dirige la gestión de los diferentes actores y esta se da en virtud de comprender, mantener, proteger y administrar la complejidad ambiental.  Se señala como uno de los principales inconvenientes de la producción de musáceas la enfermedad de la sigatoka negra, pues produce costos de producción de aproximadamente 1.300 dólares al año costo en uso y aplicación de pesticidas.  Se discute sobre el enfoque de los trabajos de investigación para el desarrollo sostenible en el cultivo de las musáceas.  Se presentan dos experiencias para medir y vigilar la sigatoka negra. En un caso se desarrolla un sistema convencional denominado SiMu, que permite utilizar medios computacionales asistidos para, sobre todo, medir y vigilar la incidencia de la sigatoka. En el otro caso se utiliza tecnología de procesamiento digital de imágenes para realizar ese mismo trabajo pero con un mayor nivel de automatización.  Queda planteada la interrogante de si esta tecnología se puede usar para pequeños y medianos productores, tanto de banano como de plátano, puesto que en ese tipo de unidades no se podría tener una forma económicamente viable para obtener imágenes digitales aéreas.

  11. Automated Generation of Attack Trees

    DEFF Research Database (Denmark)

    Vigo, Roberto; Nielson, Flemming; Nielson, Hanne Riis

    2014-01-01

    Attack trees are widely used to represent threat scenarios in a succinct and intuitive manner, suitable for conveying security information to non-experts. The manual construction of such objects relies on the creativity and experience of specialists, and therefore it is error-prone and impractica......Attack trees are widely used to represent threat scenarios in a succinct and intuitive manner, suitable for conveying security information to non-experts. The manual construction of such objects relies on the creativity and experience of specialists, and therefore it is error...

  12. Black Holes and the Large Hadron Collider

    Science.gov (United States)

    Roy, Arunava

    2011-01-01

    The European Center for Nuclear Research or CERN's Large Hadron Collider (LHC) has caught our attention partly due to the film "Angels and Demons." In the movie, an antimatter bomb attack on the Vatican is foiled by the protagonist. Perhaps just as controversial is the formation of mini black holes (BHs). Recently, the American Physical Society…

  13. Impact of Sybil and Wormhole Attacks in Location Based Geographic Multicast Routing Protocol for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Shyamala Ramachandran

    2011-01-01

    Full Text Available Problem statement: Wireless sensor networks have been used in many applications, such as home automation, military surveillances and entity tracking systems. The sensor nodes have low computational capabilities and are highly resource constrained. Routing protocols of wireless sensor networks are prone to various routing attacks, such as black hole, rushing, wormhole, Sybil and denial of service attacks. Approach: The objective of this study was to examine the effects of wormhole in conjunction with Sybil attack on a location based-Geographic Multicast Routing (GMR protocol. Results: The NS-2 based simulation was used in analyzing the wormhole in conjunction with Sybil attack on GMR. Conclusion: It is found that, the Sybil attack degrades the network performance by 24% and the wormhole attack by 20%.

  14. Black Culture

    Directory of Open Access Journals (Sweden)

    Angela Khristin Brown

    2013-07-01

    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life.

  15. FLOODING ATTACK AWARE SECURE AODV

    Directory of Open Access Journals (Sweden)

    S. Madhavi

    2013-01-01

    Full Text Available Providing security in a Mobile Ad hoc Network (MANET is a challenging task due to its inherent nature. Flooding is a type of Denial of Service (DoS attack in MANET. Intentional flooding may lead to disturbances in the networking operation. This kind of attack consumes battery power, storage space and bandwidth. Flooding the excessive number of packets may degrade the performance of the network. This study considers hello flooding attack. As the hello packets are continuously flooded by the malicious node, the neighbor node is not able to process other packets. The functioning of the legitimate node is diverted and destroys the networking operation. Absence of hello packet during the periodical hello interval may lead to wrong assumption that the neighbor node has moved away. So one of the intermediate neighbor nodes sends Route Error (RERR message and the source node reinitiates the route discovery process. In a random fashion the hello interval values are changed and convey this information to other nodes in the network in a secured manner. This study identifies and prevents the flooding attack. This methodology considers the performance parameters such as packet delivery ratio, delay and throughput. This algorithm is implemented in Secure AODV and tested in ad hoc environment. The result of the proposed algorithm decreases the control overhead by 2%.

  16. Mitigating Higher Ed Cyber Attacks

    Science.gov (United States)

    Rogers, Gary; Ashford, Tina

    2015-01-01

    In this presentation we will discuss the many and varied cyber attacks that have recently occurred in the higher ed community. We will discuss the perpetrators, the victims, the impact and how these institutions have evolved to meet this threat. Mitigation techniques and defense strategies will be covered as will a discussion of effective security…

  17. Television journalism during terror attacks

    DEFF Research Database (Denmark)

    Mogensen, Kirsten

    2008-01-01

    This article views television news coverage of ongoing terrorist attacks and their immediate aftermath as a special genre within journalism, and describes norms connected with the genre. The description is based on qualitative analyses of the coverage on major American networks the first 24 hours...

  18. Television Journalism During Terror Attacks

    DEFF Research Database (Denmark)

    Mogensen, Kirsten

    This article views television news coverage of ongoing terrorist attacks and their immediate aftermath as a special genre within journalism, and describes norms connected with the genre. The description is based on qualitative analyses of the coverage on the major American networks in the fi rst ...

  19. Performance of attack strategies on modular networks

    CERN Document Server

    da Cunha, Bruno Requião

    2016-01-01

    Vulnerabilities of complex networks have became a trend topic in complex systems recently due to its real world applications. Most real networks tend to be very fragile to high betweenness adaptive attacks. However, recent contributions have shown the importance of interconnected nodes in the integrity of networks and module-based attacks have appeared promising when compared to traditional malicious non-adaptive attacks. In the present work we deeply explore the trade-off associated with attack procedures, introducing a generalized robustness measure and presenting an attack performance index that takes into account both robustness of the network against the attack and the run-time needed to obtained the list of targeted nodes for the attack. Besides, we introduce the concept of deactivation point aimed to mark the point at which the network stops to function properly. We then show empirically that non-adaptive module-based attacks perform better than high degree and betweenness adaptive attacks in networks ...

  20. Terrorist attacks escalate in frequency and fatalities preceding highly lethal attacks.

    Science.gov (United States)

    Martens, Andy; Sainudiin, Raazesh; Sibley, Chris G; Schimel, Jeff; Webber, David

    2014-01-01

    Highly lethal terrorist attacks, which we define as those killing 21 or more people, account for 50% of the total number of people killed in all terrorist attacks combined, yet comprise only 3.5% of terrorist attacks. Given the disproportionate influence of these incidents, uncovering systematic patterns in attacks that precede and anticipate these highly lethal attacks may be of value for understanding attacks that exact a heavy toll on life. Here we examined whether the activity of terrorist groups escalates--both in the number of people killed per attack and in the frequency of attacks--leading up to highly lethal attacks. Analyses of terrorist attacks drawn from a state-of-the-art international terrorism database (The Global Terrorism Database) showed evidence for both types of escalation leading up to highly lethal attacks, though complexities to the patterns emerged as well. These patterns of escalation do not emerge among terrorist groups that never commit a highly lethal attack.

  1. Attack Vulnerability of Network Controllability.

    Science.gov (United States)

    Lu, Zhe-Ming; Li, Xin-Feng

    2016-01-01

    Controllability of complex networks has attracted much attention, and understanding the robustness of network controllability against potential attacks and failures is of practical significance. In this paper, we systematically investigate the attack vulnerability of network controllability for the canonical model networks as well as the real-world networks subject to attacks on nodes and edges. The attack strategies are selected based on degree and betweenness centralities calculated for either the initial network or the current network during the removal, among which random failure is as a comparison. It is found that the node-based strategies are often more harmful to the network controllability than the edge-based ones, and so are the recalculated strategies than their counterparts. The Barabási-Albert scale-free model, which has a highly biased structure, proves to be the most vulnerable of the tested model networks. In contrast, the Erdős-Rényi random model, which lacks structural bias, exhibits much better robustness to both node-based and edge-based attacks. We also survey the control robustness of 25 real-world networks, and the numerical results show that most real networks are control robust to random node failures, which has not been observed in the model networks. And the recalculated betweenness-based strategy is the most efficient way to harm the controllability of real-world networks. Besides, we find that the edge degree is not a good quantity to measure the importance of an edge in terms of network controllability.

  2. DPRAODV: A Dynamic Learning System Against Blackhole Attack In AODV Based MANET

    Directory of Open Access Journals (Sweden)

    Prashant B. Swadas

    2009-08-01

    Full Text Available Security is an essential requirement in mobile ad hoc networks to provide protected communication between mobile nodes. Due to unique characteristics of MANETS, it creates a number of consequential challenges to its security design. To overcome the challenges, there is a need to build a multifence security solution that achieves both broad protection and desirable network performance. MANETs are vulnerable to various attacks, blackhole, is one of the possible attacks. Black hole is a type of routing attack where a malicious node advertise itself as having the shortest path to all nodes in the environment by sending fake route reply. By doing this, the malicious node can deprive the traffic from the source node. It can be used as a denial-of-service attack where it can drop the packets later. In this paper, we proposed a DPRAODV (Detection, Prevention and Reactive AODV to prevent security threats of blackhole by notifying other nodes in the network of the incident. The simulation results in ns2 (ver-2.33 demonstrate that our protocol not only prevents blackhole attack but consequently improves the overall performance of (normal AODV in presence of black hole attack.

  3. Attack Methodology Analysis: Emerging Trends in Computer-Based Attack Methodologies and Their Applicability to Control System Networks

    Energy Technology Data Exchange (ETDEWEB)

    Bri Rolston

    2005-06-01

    Threat characterization is a key component in evaluating the threat faced by control systems. Without a thorough understanding of the threat faced by critical infrastructure networks, adequate resources cannot be allocated or directed effectively to the defense of these systems. Traditional methods of threat analysis focus on identifying the capabilities and motivations of a specific attacker, assessing the value the adversary would place on targeted systems, and deploying defenses according to the threat posed by the potential adversary. Too many effective exploits and tools exist and are easily accessible to anyone with access to an Internet connection, minimal technical skills, and a significantly reduced motivational threshold to be able to narrow the field of potential adversaries effectively. Understanding how hackers evaluate new IT security research and incorporate significant new ideas into their own tools provides a means of anticipating how IT systems are most likely to be attacked in the future. This research, Attack Methodology Analysis (AMA), could supply pertinent information on how to detect and stop new types of attacks. Since the exploit methodologies and attack vectors developed in the general Information Technology (IT) arena can be converted for use against control system environments, assessing areas in which cutting edge exploit development and remediation techniques are occurring can provide significance intelligence for control system network exploitation, defense, and a means of assessing threat without identifying specific capabilities of individual opponents. Attack Methodology Analysis begins with the study of what exploit technology and attack methodologies are being developed in the Information Technology (IT) security research community within the black and white hat community. Once a solid understanding of the cutting edge security research is established, emerging trends in attack methodology can be identified and the gap between

  4. Perfection of Recent Attacks using IP

    Directory of Open Access Journals (Sweden)

    A. RENGARAJAN

    2012-02-01

    Full Text Available The Internet threat monitoring (ITM systems have been deployed to detect widespread attacks on the Internet in recent years. However, the effectiveness of ITM systems critically depends on the confidentiality of the location of their monitors. If adversaries learn the monitor locations of an ITM system, they can bypass the monitors and focus on the uncovered IP address space without being detected. In this paper, we study a new class of attacks, the invisible LOCalization (iLOC attack. The iLOC attack can accurately and invisibly localize monitors of ITM systems. In the iLOC attack, the attacker launches low-rate port-scan traffic, encoded with a selected pseudo noise code (PN-code, to targeted networks. While the secret PN-code is invisible to others, the attacker can accurately determine the existence of monitors in the targeted networks based on whether the PN-code is embedded in the report data queried from the data center of the ITM system. We formally analyze the impact of various parameters on attack effectiveness. We implement the iLOC attack and conduct the performance evaluation on a real-world ITM system to demonstrate the possibility of such attacks. We also conduct extensive simulations on the iLOC attack using real-world traces. Our data show that the iLOC attack can accurately identify monitors while being invisible to ITM systems. Finally, we present a set of guidelines to counteract the iLOC attack.

  5. Zika Attacks Nerves, Muscles, Other Tissues

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_164010.html Zika Attacks Nerves, Muscles, Other Tissues Monkey study may ... 2017 (HealthDay News) -- Scientists have learned where the Zika virus attacks the body in monkeys. In their ...

  6. Stochastic Model of TCP SYN Attacks

    Directory of Open Access Journals (Sweden)

    Simona Ramanauskaitė

    2011-08-01

    Full Text Available A great proportion of essential services are moving into internet space making the threat of DoS attacks even more actual. To estimate the real risk of some kind of denial of service (DoS attack in real world is difficult, but mathematical and software models make this task easier. In this paper we overview the ways of implementing DoS attack models and offer a stochastic model of SYN flooding attack. It allows evaluating the potential threat of SYN flooding attacks, taking into account both the legitimate system flow as well as the possible attack power. At the same time we can assess the effect of such parameters as buffer capacity, open connection storage in the buffer or filte­ring efficiency on the success of different SYN flooding attacks. This model can be used for other type of memory depletion denial of service attacks.Article in Lithuanian

  7. Attacks and countermeasures on AES and ECC

    DEFF Research Database (Denmark)

    Tange, Henrik; Andersen, Birger

    2013-01-01

    is foreseeable while the rounds are performed. ECC (Elliptic Curve Cryptography) is used as a public key crypto system with the key purpose of creating a private shared between two participants in a communication network. Attacks on ECC include the Pohlig-Hellman attack and the Pollard's rho attack. Furthermore......AES (Advanced Encryption Standard) is widely used in LTE and Wi-Fi communication systems. AES has recently been exposed to new attacks which have questioned the overall security of AES. The newest attack is a so called biclique attack, which is using the fact that the content of the state array...... side-channels attacks can be applied to ECC. This paper reflects an ongoing research in the field of countermeasures against the attacks mentioned above....

  8. Vulnerability assessment of IPv6 websites to SQL injection and other application level attacks.

    Science.gov (United States)

    Cho, Ying-Chiang; Pan, Jen-Yi

    2013-01-01

    Given the proliferation of internet connected devices, IPv6 has been proposed to replace IPv4. Aside from providing a larger address space which can be assigned to internet enabled devices, it has been suggested that the IPv6 protocol offers increased security due to the fact that with the large number of addresses available, standard IP scanning attacks will no longer become feasible. However, given the interest in attacking organizations rather than individual devices, most initial points of entry onto an organization's network and their attendant devices are visible and reachable through web crawling techniques, and, therefore, attacks on the visible application layer may offer ways to compromise the overall network. In this evaluation, we provide a straightforward implementation of a web crawler in conjunction with a benign black box penetration testing system and analyze the ease at which SQL injection attacks can be carried out.

  9. Biomechanics of knife stab attacks.

    Science.gov (United States)

    Chadwick, E K; Nicol, A C; Lane, J V; Gray, T G

    1999-10-25

    Equipment, materials and methods for the measurement of the biomechanical parameters governing knife stab attacks have been developed and data have been presented that are relevant to the improvement of standards for the testing of stab-resistant materials. A six-camera Vicon motion analysis system was used to measure velocity, and derive energy and momentum during the approach phase of the attack and a specially developed force-measuring knife was used to measure three-dimensional forces and torque during the impact phase. The body segments associated with the knife were modelled as a series of rigid segments: trunk, upper arm, forearm and hand. The velocities of these segments, together with knowledge of the mass distribution from biomechanical tables, allowed the calculation of the individual segment energy and momentum values. The instrumented knife measured four components of load: axial force (along the length of the blade), cutting force (parallel to the breadth of the blade), lateral force (across the blade) and torque (twisting action) using foil strain gauges. Twenty volunteers were asked to stab a target with near maximal effort. Three styles of stab were used: a short thrust forward, a horizontal style sweep around the body and an overhand stab. These styles were chosen based on reported incidents, providing more realistic data than had previously existed. The 95th percentile values for axial force and energy were 1885 N and 69 J, respectively. The ability of current test methods to reproduce the mechanical parameters measured in human stab attacks has been assessed. It was found that current test methods could reproduce the range of energy and force values measured in the human stab attacks, although the simulation was not accurate in some respects. Non-axial force and torque values were also found to be significant in the human tests, but these are not reproduced in the standard mechanical tests.

  10. Sybil attack in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Abirami.K

    2013-04-01

    Full Text Available Wireless network is very susceptible to different types of attack. The main attack is Sybil attack, which allows forming other attacks on the network. Security is very important to the wireless network. In wireless sensor network, to verify node identities by cryptographic authentication but this is not easy because sensor node which contains limited resources. Therefore the current research is going on how to handling the situation of different traffic levels and transmission power for security.

  11. New Multi-step Worm Attack Model

    OpenAIRE

    Robiah, Y.; Rahayu, S. Siti; Shahrin , S.; M. FAIZAL A.; Zaki, M. Mohd; Marliza, R.

    2010-01-01

    The traditional worms such as Blaster, Code Red, Slammer and Sasser, are still infecting vulnerable machines on the internet. They will remain as significant threats due to their fast spreading nature on the internet. Various traditional worms attack pattern has been analyzed from various logs at different OSI layers such as victim logs, attacker logs and IDS alert log. These worms attack pattern can be abstracted to form worms' attack model which describes the process of worms' infection. Fo...

  12. 47 CFR 76.1612 - Personal attack.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Personal attack. 76.1612 Section 76.1612... CABLE TELEVISION SERVICE Notices § 76.1612 Personal attack. (a) When, during origination cablecasting of issues of public importance, an attack is made upon the honesty, character, integrity, or like...

  13. Cyberprints: Identifying Cyber Attackers by Feature Analysis

    Science.gov (United States)

    Blakely, Benjamin A.

    2012-01-01

    The problem of attributing cyber attacks is one of increasing importance. Without a solid method of demonstrating the origin of a cyber attack, any attempts to deter would-be cyber attackers are wasted. Existing methods of attribution make unfounded assumptions about the environment in which they will operate: omniscience (the ability to gather,…

  14. Attack Tree Generation by Policy Invalidation

    DEFF Research Database (Denmark)

    Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, Rene Rydhof;

    2015-01-01

    through brainstorming of experts. In this work we formalize attack tree generation including human factors; based on recent advances in system models we develop a technique to identify possible attacks analytically, including technical and human factors. Our systematic attack generation is based...

  15. On Mitigating Distributed Denial of Service Attacks

    Science.gov (United States)

    Gao, Zhiqiang

    2006-01-01

    Denial of service (DoS) attacks and distributed denial of service (DDoS) attacks are probably the most ferocious threats in the Internet, resulting in tremendous economic and social implications/impacts on our daily lives that are increasingly depending on the well-being of the Internet. How to mitigate these attacks effectively and efficiently…

  16. Impact Comparison and Simulation Research of Three Attacks Under DSR Protocol%DSR协议下3种攻击的影响比较与仿真研究

    Institute of Scientific and Technical Information of China (English)

    蔡继文; 易平; 周雍恺; 田野; 柳宁

    2009-01-01

    针对移动Ad Hoc网络的动态拓扑容易遭受各种网络攻击的特点,研究和比较现有的多种攻击模型,在动态源路由(DSR)协议下提出将黑洞节点按主动攻击和被动攻击进行分类的方法.在NS2网络仿真平台上实现包括RREQ洪泛攻击、被动型黑洞攻击和主动型黑洞攻击在内的3种攻击模式.通过仿真实验评估和比较这3种攻击对网络性能的影响,得出结论,就破坏性而言,RREQ洪泛攻击强于黑洞攻击,而主动型黑洞攻击强于被动型黑洞攻击.%This paper compares several attack 'models aiming at mobile Ad Hoc network's prosperity of routing vulnerable, and presents a classification that divides black hole attacks into two specific types, such as passive black hole attacks and active black hole attacks under Dynamic Source Routing(DSR) protocol. It implements three attack patterns, including the RREQ flooding attacks, the passive black hole attacks and the active black hole attacks, on DSR protocol using the Network Simulator 2(NS2). It demonstrates different performances of the network under these attacks and compares their fatality, so as to draw the conclusion that RREQ flooding attack is more harmful than the two kinds of black holes, and additionally, among black hole attacks, an active one is more dangerous.

  17. Methods of Identifying and Preventing SQL Attacks

    Directory of Open Access Journals (Sweden)

    Bojken Shehu

    2012-11-01

    Full Text Available The paper begins by identifying the organizations which are vulnerable to the SQL attack referred to as an SQL injection attack. The term SQL injection attack is defined and a diagram is used to illustrate the way that attack occurs. In another section, the paper identifies the methods used to detect an attack to SQL, whereby the techniques are discussed extensively using relevant diagrams for illustration. The other sections cover the preventive methods, where the methods are also discussed with an illustration using diagrams.

  18. Lightweight Distance Bounding Protocol against Relay Attacks

    Science.gov (United States)

    Kim, Jin Seok; Cho, Kookrae; Yum, Dae Hyun; Hong, Sung Je; Lee, Pil Joong

    Traditional authentication protocols are based on cryptographic techniques to achieve identity verification. Distance bounding protocols are an enhanced type of authentication protocol built upon both signal traversal time measurement and cryptographic techniques to accomplish distance verification as well as identity verification. A distance bounding protocol is usually designed to defend against the relay attack and the distance fraud attack. As there are applications to which the distance fraud attack is not a serious threat, we propose a streamlined distance bounding protocol that focuses on the relay attack. The proposed protocol is more efficient than previous protocols and has a low false acceptance rate under the relay attack.

  19. Black tea

    Science.gov (United States)

    ... combination.Talk with your health provider.Birth control pills (Contraceptive drugs)Black tea contains caffeine. The body breaks down caffeine to get rid of it. Birth control pills can decrease how quickly the body breaks down ...

  20. Continuous Weight Attack on Complex Network

    Institute of Scientific and Technical Information of China (English)

    YIN Yan-Ping; ZHANG Duan-Ming; TAN Jin; PAN Gui-Jun; HE Min-Hua

    2008-01-01

    We introduce a continuous weight attack strategy and numerically investigate the effect of continuous use a weight coefficient ω to define the attack intensity. The weight coefficient ω increases continuously from 1 to infinity, where 1 represents no attack and infinity represents complete destructive attack. Our results show that the continuous weight attack on two selected nodes with small ω (ω≈ 3) could achieve the same damage of complete elimination of a single selected node on both BA and ER networks. It is found that the continuous weight attack on a single selected edge with small ω (ω≈ 2) can reach the same effect of complete elimination of a single edge on BA network, but on ER network the damage of the continuous weight attack on a single edge is close to but always smaller than that of complete elimination of edge even if ω is very large.

  1. Whispering through DDoS attack

    Directory of Open Access Journals (Sweden)

    Miralem Mehic

    2016-03-01

    Full Text Available Denial of service (DoS attack is an attempt of the attacker to disable victim's machine by depleting network or computing resources. If this attack is performed with more than one machine, it is called distributed denial of service (DDoS attack. Covert channels are those channels which are used for information transmission even though they are neither designed nor intended to transfer information at all. In this article, we investigated the possibility of using of DDoS attack for purposes of hiding data or concealing the existing covert channel. In addition, in this paper we analyzed the possibility of detection of such covert communication with the well-known statistical method. Also, we proposed the coordination mechanisms of the attack which may be used. A lot of research has been done in order to describe and prevent DDoS attacks, yet research on steganography on this field is still scarce.

  2. Network Protection Against DDoS Attacks

    Directory of Open Access Journals (Sweden)

    Petr Dzurenda

    2015-03-01

    Full Text Available The paper deals with possibilities of the network protection against Distributed Denial of Service attacks (DDoS. The basic types of DDoS attacks and their impact on the protected network are presented here. Furthermore, we present basic detection and defense techniques thanks to which it is possible to increase resistance of the protected network or device against DDoS attacks. Moreover, we tested the ability of current commercial Intrusion Prevention Systems (IPS, especially Radware DefensePro 6.10.00 product against the most common types of DDoS attacks. We create five scenarios that are varied in type and strength of the DDoS attacks. The attacks intensity was much greater than the normal intensity of the current DDoS attacks.

  3. NETWORK SECURITY ATTACKS. ARP POISONING CASE STUDY

    Directory of Open Access Journals (Sweden)

    Luminiţa DEFTA

    2010-12-01

    Full Text Available Arp poisoning is one of the most common attacks in a switched network. A switch is a network device that limits the ability of attackers that use a packet sniffer to gain access to information from internal network traffic. However, using ARP poisoning the traffic between two computers can be intercepted even in a network that uses switches. This method is known as man in the middle attack. With this type of attack the affected stations from a network will have invalid entries in the ARP table. Thus, it will contain only the correspondence between the IP addresses of the stations from the same network and a single MAC address (the station that initiated the attack. In this paper we present step by step the initiation of such an attack in a network with three computers. We will intercept the traffic between two stations using the third one (the attacker.

  4. Attack Tree Generation by Policy Invalidation

    DEFF Research Database (Denmark)

    Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, Rene Rydhof

    2015-01-01

    Attacks on systems and organisations increasingly exploit human actors, for example through social engineering, complicating their formal treatment and automatic identification. Formalisation of human behaviour is difficult at best, and attacks on socio-technical systems are still mostly identifi...... on invalidating policies in the system model by identifying possible sequences of actions that lead to an attack. The generated attacks are precise enough to illustrate the threat, and they are general enough to hide the details of individual steps....... through brainstorming of experts. In this work we formalize attack tree generation including human factors; based on recent advances in system models we develop a technique to identify possible attacks analytically, including technical and human factors. Our systematic attack generation is based...

  5. SQL Injection Attacks and Defense

    CERN Document Server

    Clarke, Justin

    2012-01-01

    SQL Injection Attacks and Defense, First Edition: Winner of the Best Book Bejtlich Read Award "SQL injection is probably the number one problem for any server-side application, and this book unequaled in its coverage." -Richard Bejtlich, Tao Security blog SQL injection represents one of the most dangerous and well-known, yet misunderstood, security vulnerabilities on the Internet, largely because there is no central repository of information available for penetration testers, IT security consultants and practitioners, and web/software developers to turn to for help. SQL Injection Att

  6. Migraine attacks the Basal Ganglia

    Directory of Open Access Journals (Sweden)

    Bigal Marcelo

    2011-09-01

    Full Text Available Abstract Background With time, episodes of migraine headache afflict patients with increased frequency, longer duration and more intense pain. While episodic migraine may be defined as 1-14 attacks per month, there are no clear-cut phases defined, and those patients with low frequency may progress to high frequency episodic migraine and the latter may progress into chronic daily headache (> 15 attacks per month. The pathophysiology of this progression is completely unknown. Attempting to unravel this phenomenon, we used high field (human brain imaging to compare functional responses, functional connectivity and brain morphology in patients whose migraine episodes did not progress (LF to a matched (gender, age, age of onset and type of medication group of patients whose migraine episodes progressed (HF. Results In comparison to LF patients, responses to pain in HF patients were significantly lower in the caudate, putamen and pallidum. Paradoxically, associated with these lower responses in HF patients, gray matter volume of the right and left caudate nuclei were significantly larger than in the LF patients. Functional connectivity analysis revealed additional differences between the two groups in regard to response to pain. Conclusions Supported by current understanding of basal ganglia role in pain processing, the findings suggest a significant role of the basal ganglia in the pathophysiology of the episodic migraine.

  7. Where can an Insider attack?

    DEFF Research Database (Denmark)

    Probst, Christian W.; Hansen, René Rydhof; Nielson, Flemming

    2006-01-01

    By definition, an insider has better access, is more trusted, and has better information about internal procedures, high-value targets, and potential weak spots in the security, than an outsider. Consequently, an insider attack has the potential to cause significant, even catastrophic, damage to ...... of the modelled systems. Our analysis of processes identifies which actions may be performed by whom, at which locations, accessing which data. This allows to compute a superset of audit results---before an incident occurs.......By definition, an insider has better access, is more trusted, and has better information about internal procedures, high-value targets, and potential weak spots in the security, than an outsider. Consequently, an insider attack has the potential to cause significant, even catastrophic, damage...... to the targeted organisation. While the problem is well recognised in the security community as well as in law-enforcement and intelligence communities, the main resort still is to audit log files \\$\\backslash\\$emph{after the fact}. There has been little research into developing models, automated tools...

  8. ACTIVITY ATTACK ON REDUCED VARIANTS OF RIJNDAEL

    Institute of Scientific and Technical Information of China (English)

    Wei Baodian; Liu Dongsu; Wang Xinmei

    2004-01-01

    The famous Square attacks against the Rijndael algorithm have taken advantage of the change of the balance of some bytes. Further study shows that the change of activity always happens before the change of balance, which builds the foundation for a new activity attack presented in this paper. In the activity attack, the round in which the activity changes is executed in an equivalent form to avoid the obstructive restriction of the subkeys of that round.The existence of the birthday paradox guarantees much fewer plaintexts necessary for activity attacks comparing with that for corresponding Square attacks. But no benefit may result from the new attacks performed independently because the activity attacks guess four instead of one key byte once. Only when both the balance property and the activity property are exploited at the same time can much better performance be obtained. The better performance in the simulation shows that the consuming time and chosen plaintexts necessary are both reduced to one tenth of those of the corresponding Square attacks. So the activity attacks could be viewed as an efficient supplement to the Square attacks.

  9. Black holes

    CERN Document Server

    Chrúsciel, P T

    2002-01-01

    This paper is concerned with several not-quantum aspects of black holes, with emphasis on theoretical and mathematical issues related to numerical modeling of black hole space-times. Part of the material has a review character, but some new results or proposals are also presented. We review the experimental evidence for existence of black holes. We propose a definition of black hole region for any theory governed by a symmetric hyperbolic system of equations. Our definition reproduces the usual one for gravity, and leads to the one associated with the Unruh metric in the case of Euler equations. We review the global conditions which have been used in the Scri-based definition of a black hole and point out the deficiencies of the Scri approach. Various results on the structure of horizons and apparent horizons are presented, and a new proof of semi-convexity of horizons based on a variational principle is given. Recent results on the classification of stationary singularity-free vacuum solutions are reviewed. ...

  10. Detection of Denial-of-service Attacks

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Denial-of-service (DOS) is a type of computer attack, which can essentially disable computers and networks.Resource consumption type of DOS attack could not be detected by the traditional misuse detection technique. This paper presents a new method of support vector mchine (SVM) to detect these attacks. We find that a DOS attack to a host is related to the activities within an impact data set of the host. The SVM method is used to classify the subsets of an impact data set to estimate its anomalism. The experiment result shows that this method can detect resource consumption type of DOS attacks, such as SYNflood, Smurf and UDP-storm. A receiver operating characteristic curve is plotted to determine performance for any possible operating point of the DOS attacks detection.

  11. Fault Attack on the Balanced Shrinking Generator

    Institute of Scientific and Technical Information of China (English)

    GAO Juntao; LI Xuelian; HU Yupu

    2006-01-01

    Fault analysis, belonging to indirect attack, is a cryptanalysis technique for the physical implementation of cryptosystem. In this paper, we propose a fault attack on the Balanced Shrinking Generator. The results show that the attacker can obtain the secret key by analyzing faulty output sequences which is produced by changing control clock of one of Linear Feedback Shift Registers (LFSR). Therefore, the balanced shrinking generator has a trouble in hardware implementation.

  12. Impact of Alleged Russian Cyber Attacks

    Science.gov (United States)

    2009-05-01

    March 14, 2009). 96 Ivan Buranov, Vladimir Vodo, and Seda Yegikyan, Pro-Kremlin Activist Admits Attack on Estonian Websites, Denies Criminal...Vladimir Vodo, and Seda Yegikyan, Pro-Kremlin Activist Admits Attack on Estonian Websites, Denies Criminal Wrongdoing, Translated by Open Source...Buranov, Ivan; Vodo, Vladimir; and Yegikyan, Seda Pro-Kremlin Activist Admits Attack on Estonian Websites, Denies Criminal Wrongdoing, Translated

  13. Localized attack on clustering networks

    CERN Document Server

    Dong, Gaogao; Du, Ruijin; Shao, Shuai; Stanley, H Eugene; Shlomo, Havlin

    2016-01-01

    Clustering network is one of which complex network attracting plenty of scholars to discuss and study the structures and cascading process. We primarily analyzed the effect of clustering coefficient to other various of the single clustering network under localized attack. These network models including double clustering network and star-like NON with clustering and random regular (RR) NON of ER networks with clustering are made up of at least two networks among which exist interdependent relation among whose degree of dependence is measured by coupling strength. We show both analytically and numerically, how the coupling strength and clustering coefficient effect the percolation threshold, size of giant component, critical coupling point where the behavior of phase transition changes from second order to first order with the increase of coupling strength between the networks. Last, we study the two types of clustering network: one type is same with double clustering network in which each subnetwork satisfies ...

  14. Attacks on Local Searching Tools

    CERN Document Server

    Nielson, Seth James; Wallach, Dan S

    2011-01-01

    The Google Desktop Search is an indexing tool, currently in beta testing, designed to allow users fast, intuitive, searching for local files. The principle interface is provided through a local web server which supports an interface similar to Google.com's normal web page. Indexing of local files occurs when the system is idle, and understands a number of common file types. A optional feature is that Google Desktop can integrate a short summary of a local search results with Google.com web searches. This summary includes 30-40 character snippets of local files. We have uncovered a vulnerability that would release private local data to an unauthorized remote entity. Using two different attacks, we expose the small snippets of private local data to a remote third party.

  15. Evaluation of Hypervisor Stability towards Insider Attacks

    Institute of Scientific and Technical Information of China (English)

    Roman Kulikov; Svetlana Kolesnikova

    2016-01-01

    Virtualization technology plays a key role in cloud computing. Thus, the security issues of virtualization tools (hypervisors, emulators, etc.) should be under precise consideration. However, threats of insider attacks are underestimated. The virtualization tools and hypervisors have been poorly protected from this type of attacks. Furthermore, hypervisor is one of the most critical elements in cloud computing infrastructure. Firstly, hypervisor vulnerabilities analysis is provided. Secondly, a formal model of insider attack on hypervisor is developed. Consequently, on the basis of the formal attack model, we propose a new methodology of hypervisor stability evaluation. In this paper, certain security countermeasures are considered that should be integrated in hypervisor software architecture.

  16. Colluding attacks on a group signature scheme

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Xie and Yu (2005) proposed a group signature scheme and claimed that it is the most efficient group signature scheme so far and secure. In this paper, we show that two dishonest group members can collude to launch two attacks on the scheme. In the first attack they can derive the group secret key and then generate untraceable group signatures. In the second attack, they can impersonate other group members once they see their signatures. Therefore we conclude that the signature scheme is not secure.We show that some parameters should be carefully selected in the scheme to resist our attacks.

  17. Off-Path Attacking the Web

    CERN Document Server

    Gilad, Yossi

    2012-01-01

    We show how an off-path (spoofing-only) attacker can perform cross-site scripting (XSS), cross-site request forgery (CSRF) and site spoofing/defacement attacks, without requiring vulnerabilities in either web-browser or server and circumventing known defenses. Attacker can also launch devastating denial of service (DoS) attacks, even when the connection between the client and the server is secured with SSL/TLS. The attacks are practical and require a puppet (malicious script in browser sandbox) running on a the victim client machine, and attacker capable of IP-spoofing on the Internet. Our attacks use a technique allowing an off-path attacker to learn the sequence numbers of both client and server in a TCP connection. The technique exploits the fact that many computers, in particular those running Windows, use a global IP-ID counter, which provides a side channel allowing efficient exposure of the connection sequence numbers. We present results of experiments evaluating the learning technique and the attacks ...

  18. Spatially localized attacks on interdependent networks: the existence of a finite critical attack size

    CERN Document Server

    Berezin, Yehiel; Danziger, Michael M; Li, Daqing; Havlin, Shlomo

    2013-01-01

    Many real world complex systems such as infrastructure, communication and transportation networks are embedded in space, where entities of one system may depend on entities of other systems. These systems are subject to geographically localized failures due to malicious attacks or natural disasters. Here we study the resilience of a system composed of two interdependent spatially embedded networks to localized geographical attacks. We find that if an attack is larger than a finite (zero fraction of the system) critical size, it will spread through the entire system and lead to its complete collapse. If the attack is below the critical size, it will remain localized. In contrast, under random attack a finite fraction of the system needs to be removed to initiate system collapse. We present both numerical simulations and a theoretical approach to analyze and predict the effect of local attacks and the critical attack size. Our results demonstrate the high risk of local attacks on interdependent spatially embedd...

  19. A Novel Protective Framework for Defeating HTTP-Based Denial of Service and Distributed Denial of Service Attacks

    Directory of Open Access Journals (Sweden)

    Mohammed A. Saleh

    2015-01-01

    Full Text Available The growth of web technology has brought convenience to our life, since it has become the most important communication channel. However, now this merit is threatened by complicated network-based attacks, such as denial of service (DoS and distributed denial of service (DDoS attacks. Despite many researchers’ efforts, no optimal solution that addresses all sorts of HTTP DoS/DDoS attacks is on offer. Therefore, this research aims to fix this gap by designing an alternative solution called a flexible, collaborative, multilayer, DDoS prevention framework (FCMDPF. The innovative design of the FCMDPF framework handles all aspects of HTTP-based DoS/DDoS attacks through the following three subsequent framework’s schemes (layers. Firstly, an outer blocking (OB scheme blocks attacking IP source if it is listed on the black list table. Secondly, the service traceback oriented architecture (STBOA scheme is to validate whether the incoming request is launched by a human or by an automated tool. Then, it traces back the true attacking IP source. Thirdly, the flexible advanced entropy based (FAEB scheme is to eliminate high rate DDoS (HR-DDoS and flash crowd (FC attacks. Compared to the previous researches, our framework’s design provides an efficient protection for web applications against all sorts of DoS/DDoS attacks.

  20. Terrorist attacks escalate in frequency and fatalities preceding highly lethal attacks.

    Directory of Open Access Journals (Sweden)

    Andy Martens

    Full Text Available Highly lethal terrorist attacks, which we define as those killing 21 or more people, account for 50% of the total number of people killed in all terrorist attacks combined, yet comprise only 3.5% of terrorist attacks. Given the disproportionate influence of these incidents, uncovering systematic patterns in attacks that precede and anticipate these highly lethal attacks may be of value for understanding attacks that exact a heavy toll on life. Here we examined whether the activity of terrorist groups escalates--both in the number of people killed per attack and in the frequency of attacks--leading up to highly lethal attacks. Analyses of terrorist attacks drawn from a state-of-the-art international terrorism database (The Global Terrorism Database showed evidence for both types of escalation leading up to highly lethal attacks, though complexities to the patterns emerged as well. These patterns of escalation do not emerge among terrorist groups that never commit a highly lethal attack.

  1. Evaluation of Crosstalk Attacks in Access Networks

    DEFF Research Database (Denmark)

    Wagner, Christoph; Eiselt, Michael; Grobe, Klaus

    2016-01-01

    WDM-PON systems regained interest as low-cost solution for metro and access networks. We present a comparative analysis of resilience of wavelength-selective and wavelength-routed architectures against crosstalk attackers. We compare the vulnerability of these architectures against attacks...

  2. Fast Collision Attack on MD5

    NARCIS (Netherlands)

    Stevens, M.M.J.

    2006-01-01

    In this paper, we present an improved attack algorithm to find two-block collisions of the hash function MD5. The attack uses the same differential path of MD5 and the set of sufficient conditions that was presented by Wang et al. We present a new technique which allows us to deterministically fulfi

  3. Minimization and Reliability Analyses of Attack Graphs

    Science.gov (United States)

    2002-02-01

    they model only attacks. Since we have a generic state machine model , we can simultaneously model not just attacks, but also seemingly benign system...Finite State Machine Model The Network We model the network as a set of facts, each represented as a relational predicate. The state of the network

  4. Quantifying Shannon's work function for cryptanalytic attacks

    NARCIS (Netherlands)

    van Son, R.J.J.H.

    2010-01-01

    Attacks on cryptographic systems are limited by the available computational resources. A theoretical understanding of these resource limitations is needed to evaluate the security of cryptographic primitives and procedures. This study uses an Attacker versus Environment game formalism based on compu

  5. Attack tree generation by policy invalidation

    NARCIS (Netherlands)

    Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, René Rydhof; Kammüller, Florian; Naeem Akram, R.; Jajodia, S.

    2015-01-01

    Attacks on systems and organisations increasingly exploit human actors, for example through social engineering, complicating their formal treatment and automatic identification. Formalisation of human behaviour is difficult at best, and attacks on socio-technical systems are still mostly identified th

  6. New Multi-step Worm Attack Model

    CERN Document Server

    Robiah, Y; Shahrin, S; Faizal, M A; Zaki, M Mohd; Marliza, R

    2010-01-01

    The traditional worms such as Blaster, Code Red, Slammer and Sasser, are still infecting vulnerable machines on the internet. They will remain as significant threats due to their fast spreading nature on the internet. Various traditional worms attack pattern has been analyzed from various logs at different OSI layers such as victim logs, attacker logs and IDS alert log. These worms attack pattern can be abstracted to form worms' attack model which describes the process of worms' infection. For the purpose of this paper, only Blaster variants were used during the experiment. This paper proposes a multi-step worm attack model which can be extended into research areas in alert correlation and computer forensic investigation.

  7. Use of Attack Graphs in Security Systems

    Directory of Open Access Journals (Sweden)

    Vivek Shandilya

    2014-01-01

    Full Text Available Attack graphs have been used to model the vulnerabilities of the systems and their potential exploits. The successful exploits leading to the partial/total failure of the systems are subject of keen security interest. Considerable effort has been expended in exhaustive modeling, analyses, detection, and mitigation of attacks. One prominent methodology involves constructing attack graphs of the pertinent system for analysis and response strategies. This not only gives the simplified representation of the system, but also allows prioritizing the security properties whose violations are of greater concern, for both detection and repair. We present a survey and critical study of state-of-the-art technologies in attack graph generation and use in security system. Based on our research, we identify the potential, challenges, and direction of the current research in using attack graphs.

  8. Automatic Classification of Attacks on IP Telephony

    Directory of Open Access Journals (Sweden)

    Jakub Safarik

    2013-01-01

    Full Text Available This article proposes an algorithm for automatic analysis of attack data in IP telephony network with a neural network. Data for the analysis is gathered from variable monitoring application running in the network. These monitoring systems are a typical part of nowadays network. Information from them is usually used after attack. It is possible to use an automatic classification of IP telephony attacks for nearly real-time classification and counter attack or mitigation of potential attacks. The classification use proposed neural network, and the article covers design of a neural network and its practical implementation. It contains also methods for neural network learning and data gathering functions from honeypot application.

  9. Rotational Rebound Attacks on Reduced Skein

    DEFF Research Database (Denmark)

    Khovratovich, Dmitry; Nikolić, Ivica; Rechberger, Christian

    2014-01-01

    ciphers, including the new standard SHA-3 (Keccak). The rebound attack is a start-from-the-middle approach for finding differential paths and conforming pairs in byte-oriented designs like Substitution-Permutation networks and AES. We apply our new compositional attack to the reduced version of the hash......In this paper we combine two powerful methods of symmetric cryptanalysis: rotational cryptanalysis and the rebound attack. Rotational cryptanalysis was designed for the analysis of bit-oriented designs like ARX (Addition-Rotation-XOR) schemes. It has been applied to several hash functions and block...... function Skein, a finalist of the SHA-3 competition. Our attack penetrates more than two thirds of the Skein core—the cipher Threefish, and made the designers to change the submission in order to prevent it. The rebound part of our attack has been significantly enhanced to deliver results on the largest...

  10. CompChall: Addressing Password Guessing Attacks

    CERN Document Server

    Goyal, Vipul; Singh, Mayank; Abraham, Ajith; Sanyal, Sugata

    2011-01-01

    Even though passwords are the most convenient means of authentication, they bring along themselves the threat of dictionary attacks. Dictionary attacks may be of two kinds: online and offline. While offline dictionary attacks are possible only if the adversary is able to collect data for a successful protocol execution by eavesdropping on the communication channel and can be successfully countered using public key cryptography, online dictionary attacks can be performed by anyone and there is no satisfactory solution to counter them. This paper presents a new authentication protocol which is called CompChall (computational challenge). The proposed protocol uses only one way hash functions as the building blocks and attempts to eliminate online dictionary attacks by implementing a challenge-response system. This challenge-response system is designed in a fashion that it does not pose any difficulty to a genuine user but is time consuming and computationally intensive for an adversary trying to launch a large n...

  11. Combating Memory Corruption Attacks On Scada Devices

    Science.gov (United States)

    Bellettini, Carlo; Rrushi, Julian

    Memory corruption attacks on SCADA devices can cause significant disruptions to control systems and the industrial processes they operate. However, despite the presence of numerous memory corruption vulnerabilities, few, if any, techniques have been proposed for addressing the vulnerabilities or for combating memory corruption attacks. This paper describes a technique for defending against memory corruption attacks by enforcing logical boundaries between potentially hostile data and safe data in protected processes. The technique encrypts all input data using random keys; the encrypted data is stored in main memory and is decrypted according to the principle of least privilege just before it is processed by the CPU. The defensive technique affects the precision with which attackers can corrupt control data and pure data, protecting against code injection and arc injection attacks, and alleviating problems posed by the incomparability of mitigation techniques. An experimental evaluation involving the popular Modbus protocol demonstrates the feasibility and efficiency of the defensive technique.

  12. Evaluating Deterioration of Concrete by Sulfate Attack

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Effects of factors such as water to cement ratio, fly ash and silica fume on the resistance of concrete to sulfate attack were investigated by dry-wet cycles and immersion method. The index of the resistance to sulfate attack was used to evaluate the deterioration degree of concrete damaged by sulfate. The relationship between the resistance of concrete to sulfate attack and its permeability/porosity were analyzed as well as its responding mechanism. Results show that the depth of sulfate crystal attack from surface to inner of concrete can be reduced by decreasing w/c and addition of combining fly ash with silica fume. The variation of relative elastic modulus ratio and relative flexural strength ratio of various specimens before and after being subjected to sulfate attack was compared.

  13. Detection Block Model for SQL Injection Attacks

    Directory of Open Access Journals (Sweden)

    Diksha G. Kumar

    2014-10-01

    Full Text Available With the rapid development of Internet, more and more organizations connect their databases to the Internet for resource sharing. However, due to developers' lack of knowledge of all possible attacks, web applications become vulnerable to multiple attacks. Thus the network databases could face multiple threats. Web applications generally consist of a three tier architecture where database is in the third pole, which is the most valuable asset in any organization. SQL injection is an attack technique in which specially crafted input string is entered in user input field. It is submitted to server and result is returned to the user. In SQL injection vulnerability, the database server is forced to execute malicious operations which may cause the data loss or corruption, denial of access, and unauthentic access to sensitive data by crafting specific inputs. An attacker can directly compromise the database, and that is why this is a most threatening web attack. SQL injection attack occupies first position in top ten vulnerabilities as specified by Open Web Application Security Project. It is probably the most common Website vulnerability today. Current scenarios which provide solutions to SQL injection attack either have limited scope i.e. can’t be implemented across all platforms, or do not cover all types of SQL injection attacks. In this work we implement Message Authentication Code (MAC based solution against SQL injection attacks. The model works both on client and server side. Client side implements a filter function and server side is based on information theory. MAC of static and dynamic queries is compared to detect SQL injection attack.

  14. Analysis of Black Hole Effect and Prevention through IDS in MANET

    Directory of Open Access Journals (Sweden)

    Nisha

    2013-10-01

    Full Text Available A mobile ad hoc network (MANET is an autonomous network. It is a collection of mobile nodes that communicate with each other over wireless links. From last few years, the interest in the area of Mobile Adhoc Network (MANET is growing due to its practical applications and requirement of communication in mobile devices. In the comparison to wired or infrastructure-based wireless network, MANET is vulnerable to security attacks due to its fundamental characteristics, e.g., the open medium, dynamic network topology, lack of clear lines of defense, autonomous terminal, lack of centralized monitoring and management. There are various types of attacks in MANET which drops the network performance. Black hole attack is one of them. Ad hoc On-demand Distance Vector routing (AODV is a popular routing algorithm MANET. In this paper we investigated the effects of Black Hole attacks on the network performance. In our work we simulated black hole attacks in Network Simulator 2 (ns-2 and measured the throughput, PDF and routing load in the network withand without a black hole. We also proposed a solution against black hole attacks using intrusion detection system (IDS.

  15. VBSM: VCC-Based Black Box Service Model with Enhanced Data Integrity

    Directory of Open Access Journals (Sweden)

    Won Min Kang

    2014-10-01

    Full Text Available Recently, intelligent transport systems have been applied to vehicle cloud environments. Such technology is especially useful for the systematic management of road traffic. Moreover, automobiles are increasingly equipped with a black box for accident prevention and preservation of evidence. Vehicle black boxes have become mandatory because black box images and voice data have served as forensic evidence in courts. However, the data from black boxes can be forged or modified by man-in-the-middle (MITM attacks and message hijacking. In this paper, we propose a vehicle cloud computing-based black box service model that can provide integrity for black box data through digital signatures in vehicle cloud computing (VCC environments. Our proposed model protects against MITM attacks and message hijacking using only a hash value and digital signature. Moreover, a mirroring technique (RAID 1 provides backup and recovery to protect the data from a traffic accident.

  16. black cat

    Institute of Scientific and Technical Information of China (English)

    杜铁梅

    2016-01-01

    The black cat is a masterpiece of short fiction of Poe. He successfully solved the problem of creating of the horror effect by using scene description, symbol, repetition and first-person narrative methods. And created a complete and unified mysterious terror, achieved the effect of shocking. This paper aims to discuss the mystery in-depth and to enrich the research system in Poe’s novels.

  17. Terrorist Attacks Escalate in Frequency and Fatalities Preceding Highly Lethal Attacks

    Science.gov (United States)

    Martens, Andy; Sainudiin, Raazesh; Sibley, Chris G.; Schimel, Jeff; Webber, David

    2014-01-01

    Highly lethal terrorist attacks, which we define as those killing 21 or more people, account for 50% of the total number of people killed in all terrorist attacks combined, yet comprise only 3.5% of terrorist attacks. Given the disproportionate influence of these incidents, uncovering systematic patterns in attacks that precede and anticipate these highly lethal attacks may be of value for understanding attacks that exact a heavy toll on life. Here we examined whether the activity of terrorist groups escalates–both in the number of people killed per attack and in the frequency of attacks–leading up to highly lethal attacks. Analyses of terrorist attacks drawn from a state-of-the-art international terrorism database (The Global Terrorism Database) showed evidence for both types of escalation leading up to highly lethal attacks, though complexities to the patterns emerged as well. These patterns of escalation do not emerge among terrorist groups that never commit a highly lethal attack. PMID:24755753

  18. Modified AODV Protocol against Blackhole Attacks in MANET

    Directory of Open Access Journals (Sweden)

    K.Rama,

    2010-12-01

    Full Text Available Mobile Adhoc Network (MANET consists of a collection of wireless mobile hosts without the required intervention of any existing infrastructure or centralized access point such as base station. The dynamic topology of MANET allows nodes to join and leave the network at any point of time. Wireless MANET is particularly vulnerabledue to its fundamental characteristics such as open medium, dynamic topology, distributed cooperation and constrained capability. So security in MANET is a complex issue. There are many routing protocols that establish the routes between the nodes in the network. The control towards the management of the nodes in the MANET is distributed. This features does not give assurance towards the security aspects of the network. There are many routing attacks caused due to lack of security. In this paper, therefore, we attempt to focus on analyzing and improving the security of one of the popularrouting protocol for MANET viz. the Adhoc On Demand Distance Vector (AODV routing protocol. Our focus specifically, is on ensuring the security against the Blackhole Attack. The proposed solution is that capable of detecting and removing black hole nodes in the MANET at the initial stage itself without any delay.

  19. An Intrusion Detection System Against UDP Flood Attack and Ping of Death Attack (DDOS in MANET

    Directory of Open Access Journals (Sweden)

    Ankur Ashok Acharya

    2016-04-01

    Full Text Available DDoS is one of the serious attacks in the ad hoc network. Among lot many DDoS attacks, UDP flood attack and Ping of death attack are considered to be important as these two attacks may cause severe damage to the network. To provide better security to the network, efficient intrusion detection (IDS system is required to monitor the network continuously, keeping track of malicious activities and policy violations and produce report to the network administrator. UDP flood attack and ping of death attack are given importance in this paper as they are not well addressed in the existing research works. Packet capture and packet decoder is used to identify the packets and retrieve the packet details. A threshold is set for each node that is connected to the network. If the packet flow into the node exceeds the threshold that is set then the administrator is notified about the same.

  20. Forensics Investigation of Web Application Security Attacks

    Directory of Open Access Journals (Sweden)

    Amor Lazzez

    2015-02-01

    Full Text Available Nowadays, web applications are popular targets for security attackers. Using specific security mechanisms, we can prevent or detect a security attack on a web application, but we cannot find out the criminal who has carried out the security attack. Being unable to trace back an attack, encourages hackers to launch new attacks on the same system. Web application forensics aims to trace back and attribute a web application security attack to its originator. This may significantly reduce the security attacks targeting a web application every day, and hence improve its security. The aim of this paper is to carry out a detailed overview about the web application forensics. First, we define the web applications forensics, and we present a taxonomic structure of the digital forensics. Then, we present the methodology of a web application forensics investigation. After that, we illustrate the forensics supportive tools for a web application forensics investigation. After that, we present a detailed presentation of a set of the main considered web application forensics tools. Finally, we provide a comparison of the main considered web application forensics tools.

  1. Utilizing Probabilistic Linear Equations in Cube Attacks

    Institute of Scientific and Technical Information of China (English)

    Yuan Yao; Bin Zhang; Wen-Ling Wu

    2016-01-01

    Cube attacks, proposed by Dinur and Shamir at EUROCRYPT 2009, have shown huge power against stream ciphers. In the original cube attacks, a linear system of secret key bits is exploited for key recovery attacks. However, we find a number of equations claimed linear in previous literature actually nonlinear and not fit into the theoretical framework of cube attacks. Moreover, cube attacks are hard to apply if linear equations are rare. Therefore, it is of significance to make use of probabilistic linear equations, namely nonlinear superpolys that can be approximated by linear expressions effectively. In this paper, we suggest a way to test out and utilize these probabilistic linear equations, thus extending cube attacks to a wider scope. Concretely, we employ the standard parameter estimation approach and the sequential probability ratio test (SPRT) for linearity test in the preprocessing phase, and use maximum likelihood decoding (MLD) for solving the probabilistic linear equations in the online phase. As an application, we exhibit our new attack against 672 rounds of Trivium and reduce the number of key bits to search by 7.

  2. Rotational Rebound Attacks on Reduced Skein

    DEFF Research Database (Denmark)

    Khovratovich, Dmitry; Nikolic, Ivica; Rechberger, Christian

    2010-01-01

    In this paper we combine a recent rotational cryptanalysis with the rebound attack, which results in the best cryptanalysis of Skein, a candidate for the SHA-3 competition. The rebound attack approach was so far only applied to AES-like constructions. For the first time, we show that this approac...... inside-out computations and neutral bits in the inbound phase of the rebound attack, and give well-defined rotational distinguishers as certificates of weaknesses for the compression functions and block ciphers.......In this paper we combine a recent rotational cryptanalysis with the rebound attack, which results in the best cryptanalysis of Skein, a candidate for the SHA-3 competition. The rebound attack approach was so far only applied to AES-like constructions. For the first time, we show that this approach...... and the Threefish cipher. The new techniques include an analytical search for optimal input values in the rotational cryptanalysis, which allows to extend the outbound phase of the attack with a precomputation phase, an approach never used in any rebound-style attack before. Further we show how to combine multiple...

  3. Multiple Partial Attacks on Complex Networks

    Institute of Scientific and Technical Information of China (English)

    YIN Yan-Ping; ZHANG Duan-Ming; TAN Jin; PAN Gui-Jun; HE Min-Hua

    2008-01-01

    We numerically investigate the effect of four kinds of partial attacks of multiple targets on the Barabási-Albert (BA) scale-free network and the Erd(o)s-Rényi (ER) random network.Comparing with the effect of single target complete knockout we find that partial attacks of multiple targets may produce an effect higher than the complete knockout of a single target on both BA scale-free network and ER random network.We also find that the BA ecale-free network seems to be more susceptible to multi-target partial attacks than the ER random network.

  4. Measuring a System’s Attack Surface

    Science.gov (United States)

    2004-01-01

    fold: • In terms of a state machine model of the system, we present formal definitions of attack, attack surface, and attack class. Our definitions are...versions. The rest of this paper is organized as follows. In Section 2, we introduce our state machine model and point out the key differences from...approach in Section 6 and compare it to related work in Section 7. We conclude in Section 8. 2 State Machine Model We use a state machine to model the

  5. Optimizing Decision Tree Attack on CAS Scheme

    Directory of Open Access Journals (Sweden)

    PERKOVIC, T.

    2016-05-01

    Full Text Available In this paper we show a successful side-channel timing attack on a well-known high-complexity cognitive authentication (CAS scheme. We exploit the weakness of CAS scheme that comes from the asymmetry of the virtual interface and graphical layout which results in nonuniform human behavior during the login procedure, leading to detectable variations in user's response times. We optimized a well-known probabilistic decision tree attack on CAS scheme by introducing this timing information into the attack. We show that the developed classifier could be used to significantly reduce the number of login sessions required to break the CAS scheme.

  6. FAST CORRELATION ATTACKS ON BLUETOOTH COMBINER

    Institute of Scientific and Technical Information of China (English)

    Ma Weiju; Feng Dengguo

    2006-01-01

    A simple fast correlation attack is used to analysis the security of Bluetooth combiner in this paper.This attack solves the tradeoff between the length of the keystream and the computing complexity needed to recover the secret key. We give the computing complexities of the attack algorithm according to different lengths of the known keystream. The result is less time-consuming than before. It is also shown that the security of the modified Bluetooth combiner by Hermelin and Nyberg is not significantly enhanced.

  7. What Are the Symptoms of a Heart Attack?

    Science.gov (United States)

    ... from the NHLBI on Twitter. What Are the Symptoms of a Heart Attack? Not all heart attacks ... symptoms are called silent heart attacks. Most Common Symptoms The most common warning symptoms of a heart ...

  8. Detecting Pulsing Denial-of-Service Attacks with Nondeterministic Attack Intervals

    Directory of Open Access Journals (Sweden)

    Xiapu Luo

    2009-01-01

    Full Text Available This paper addresses the important problem of detecting pulsing denial of service (PDoS attacks which send a sequence of attack pulses to reduce TCP throughput. Unlike previous works which focused on a restricted form of attacks, we consider a very broad class of attacks. In particular, our attack model admits any attack interval between two adjacent pulses, whether deterministic or not. It also includes the traditional flooding-based attacks as a limiting case (i.e., zero attack interval. Our main contribution is Vanguard, a new anomaly-based detection scheme for this class of PDoS attacks. The Vanguard detection is based on three traffic anomalies induced by the attacks, and it detects them using a CUSUM algorithm. We have prototyped Vanguard and evaluated it on a testbed. The experiment results show that Vanguard is more effective than the previous methods that are based on other traffic anomalies (after a transformation using wavelet transform, Fourier transform, and autocorrelation and detection algorithms (e.g., dynamic time warping.

  9. Black gold

    CERN Document Server

    Fletcher, MW

    2016-01-01

    Following the Yom Kippur war of October 1973, OPEC raises the price of oil by 70% along with a 5% reduction in oil production. Len Saunders a highly skilled and knowledgeable British engineer for Jaguar motors, is approached by the UK energy commission in the January of 1974 to create a new propulsion system; using a secret document from a German WW2 scientist, that they have come into possession of. Len Saunders sets to work on creating the holy grail of energy. Seven years later 1981, Haidar Farooq the Kuwait oil minister working at OPEC and head of a secret organisation named Black Gold bec

  10. Taxonomy of SSL/TLS Attacks

    Directory of Open Access Journals (Sweden)

    Keerthi Vasan K.

    2016-02-01

    Full Text Available Secure Socket Layer (SSL and Transport Layer Security (TLS protocols use cryptographic algorithms to secure data and ensure security goals such as Data Confidentiality and Integrity in networking. They are used along with other protocols such as HTTP, SMTP, etc. in applications such as web browsing, electronic mail, and VoIP. The existing versions of the protocols as well as the cryptographic algorithms they use have vulnerabilities and is not resistant towards Man-In-The- Middle (MITM attacks. Exploiting these vulnerabilities, several attacks have been launched on SSL/TLS such as session hijacking, version degradation, heart bleed, Berserk etc. This paper is a comprehensive analysis of the vulnerabilities in the protocol, attacks launched by exploiting the vulnerabilities and techniques to mitigate the flaws in protocols. A novel taxonomy of the attacks against SSL/TLS has been proposed in this paper.

  11. Women's Heart Disease: Heart Attack Symptoms

    Science.gov (United States)

    ... this page please turn JavaScript on. Feature: Women's Heart Disease Heart Attack Symptoms Past Issues / Winter 2014 Table ... NHLBI has uncovered some of the causes of heart diseases and conditions, as well as ways to prevent ...

  12. Diabetes - preventing heart attack and stroke

    Science.gov (United States)

    Diabetes complications - heart; Coronary artery disease - diabetes; CAD - diabetes; Cerebrovascular disease - diabetes ... People with diabetes have a higher chance of having heart attacks and strokes. Smoking and having high blood pressure and high ...

  13. A NEW METHOD FOR RESYNCHRONIZATION ATTACK

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper presents a new method for resynchronization attack, which is the combination of the differential cryptanalysis and algebraic attack. By using the new method one gets a system of linear equations or low-degree equations about initial keys, and the solution of the system of equations results in the recovery of the initial keys. This method has a lower computational complexity and better performance of attack in contrast to the known methods. Accordingly, the design of the resynchronization stream generators should be reconsidered to make them strong enough to avoid our attacks. When implemented to the Toyocrypt, our method gains the computational complexity of O(217), and that of O(267) for LILI-128.

  14. AN APPROACH OF DEFENDING AGAINST DDOS ATTACK

    Institute of Scientific and Technical Information of China (English)

    Wu Zhijun; Duan Haixin; Li Xing

    2006-01-01

    An approach of defending against Distributed Denial of Service (DDoS) attack based on flow model and flow detection is presented. The proposed approach can protect targets from DDoS attacking, and allow targets to provide good service to legitimate traffic under DDoS attacking, with fast reaction. This approach adopts the technique of dynamic comb filter, yields a low level of false positives of less than 1.5%,drops similar percentage of good traffic, about 1%, and passes neglectable percentage of attack bandwidth to the victim, less than 1.5%. The prototype of commercial product, D-fighter, is developed by implementing this proposed approach on Intel network processor platform IXP 1200.

  15. Correlations in complex networks under attack

    CERN Document Server

    Srivastava, Animesh; Ganguly, Niloy; Peruani, Fernando; 10.1103/PhysRevE.86.036106

    2013-01-01

    For any initial correlated network after any kind of attack where either nodes or edges are removed, we obtain general expressions for the degree-degree probability matrix and degree distribution. We show that the proposed analytical approach predicts the correct topological changes after the attack by comparing the evolution of the assortativity coefficient for different attack strategies and intensities in theory and simulations. We find that it is possible to turn an initial assortative network into a disassortative one, and vice versa, by fine-tuning removal of either nodes or edges. For an initial uncorrelated network, on the other hand, we discover that only a targeted edge-removal attack can induce such correlations.

  16. SECURING MANET FROM BLACKHOLE AND WORMHOLE ATTACKS

    Directory of Open Access Journals (Sweden)

    C.M.Vidhyapathi

    2013-06-01

    Full Text Available Mobile Ad-Hoc networks are self-configuring and self-organizing multi-hop wireless networks. They do not have any fixed infrastructure or centralized management. Due to this, the ad hoc networks are vulnerable to attacks. The routing protocol for MANET considered in this paper is AODV(Ad hoc On-demand Distance Vector Routing Protocol. Blackhole and Wormhole nodes are malicious nodeswhich degrade the performance of the network. They actively participate in the network and conform to forward packets to the destination. The Watchdog Mechanism is used to correct the network from both blackhole and wormhole attacks. The networks originally, with the attacks and after being prevented from attacks are compared on the basis of packets received, throughput, end-to-end delay and packet delivery ratio. ns2 software is used for the simulation.

  17. How Is a Heart Attack Treated?

    Science.gov (United States)

    ... medicines also keep existing clots from getting larger. Beta blockers . Beta blockers decrease your heart’s workload. These medicines also are ... discomfort and to help prevent another heart attack. Beta blockers also are used to treat arrhythmias (irregular heartbeats). ...

  18. Preventing Coordinated Attacks Via Distributed Alert Exchange

    CERN Document Server

    Garcia-Alfaro, Joaquin; Muehl, Gero; Borrell, Joan

    2008-01-01

    Attacks on information systems followed by intrusions may cause large revenue losses. The prevention of both is not always possible by just considering information from isolated sources of the network. A global view of the whole system is necessary to recognize and react to the different actions of such an attack. The design and deployment of a decentralized system targeted at detecting as well as reacting to information system attacks might benefit from the loose coupling realized by publish/subscribe middleware. In this paper, we present the advantages and convenience in using this communication paradigm for a general decentralized attack prevention framework. Furthermore, we present the design and implementation of our approach based on existing publish/subscribe middleware and evaluate our approach for GNU/Linux systems.

  19. The role of sleep in migraine attacks

    Directory of Open Access Journals (Sweden)

    Elaine Inamorato

    1993-11-01

    Full Text Available Migraine attacks may be precipitated by sleep deprivation or excessive sleep and sleep is also associated with relief of migraine attacks. In view of this variable relationship we studied the records of 159 consecutive outpatients of our Headache Unit. In 121 records there was reference to sleep involvement, in 55% by a single form and in 45% by more than one form. When only one form was related, relief was most common (70%. 30% of that group of patients had the migraine attack precipitated by sleep, 24% by deprivation and 6% by sleep excess. When the effects of sleep were multiple, these effects were as expected logically in 65%: «in accordance» group (e.g attack precipitated by sleep deprivation and relieved by sleep onset. In a second group, («conflicting» where the involvement was not logical, there were three different combinations of sleep involvement, possibly due to more than one pathophysiological mechanism.

  20. Longest-path attacks on complex networks

    CERN Document Server

    Pu, Cunlai

    2014-01-01

    We investigate the longest-path attacks on complex networks. Specifically, we remove approximately the longest simple path from a network iteratively until there are no paths left in the network. We propose two algorithms, the random augmenting approach (RPA) and the Hamilton-path based approach (HPA), for finding the approximately longest simple path in a network. Results demonstrate that steps of longest-path attacks increase with network density linearly for random networks, while exponentially increasing for scale-free networks. The more homogeneous the degree distribution is, the more fragile the network, which is totally different from the previous results of node or edge attacks. HPA is generally more efficient than RPA in the longest-path attacks of complex networks. These findings further help us understand the vulnerability of complex systems, better protect complex systems, and design more tolerant complex systems.

  1. Study Shows How Zika Attacks Infant Brain

    Science.gov (United States)

    ... gov/news/fullstory_162514.html Study Shows How Zika Attacks Infant Brain Virus can copy itself thousands ... New research paints a chilling portrait of how Zika ravages the infant brain. Scientists from the U.S. ...

  2. Thatcher condemns attacks on abortion mp.

    Science.gov (United States)

    1987-12-19

    The Prime Minister, Mrs Margaret Thatcher, has stepped in to condemn a series of violent attacks on Liberal MP David Alton who is trying to reduce the [Illegible word] limit on abortions from 28 to 18 weeks.

  3. Twisted Polynomials and Forgery Attacks on GCM

    DEFF Research Database (Denmark)

    Abdelraheem, Mohamed Ahmed A. M. A.; Beelen, Peter; Bogdanov, Andrey;

    2015-01-01

    nonce misuse resistance, such as POET. The algebraic structure of polynomial hashing has given rise to security concerns: At CRYPTO 2008, Handschuh and Preneel describe key recovery attacks, and at FSE 2013, Procter and Cid provide a comprehensive framework for forgery attacks. Both approaches rely...... heavily on the ability to construct forgery polynomials having disjoint sets of roots, with many roots (“weak keys”) each. Constructing such polynomials beyond naïve approaches is crucial for these attacks, but still an open problem. In this paper, we comprehensively address this issue. We propose to use...... in an improved key recovery algorithm. As cryptanalytic applications of our twisted polynomials, we develop the first universal forgery attacks on GCM in the weak-key model that do not require nonce reuse. Moreover, we present universal weak-key forgeries for the nonce-misuse resistant AE scheme POET, which...

  4. Prevention of Routing Attacks In Manet

    Directory of Open Access Journals (Sweden)

    N.Rajesh

    2013-01-01

    Full Text Available Mobile Ad hoc Networks (MANET are easily prone to attacks due to its network infrastructure. In previous routing attacks the malicious node is isolated using naive fuzzy response decisions. In this paper a new technology of broadcasting the awareness information about attacker node to all the existing nodes in the network is discussed. The awareness approach is based on an extended Dempster-Shafer mathematical theory(D-S Theory. Dempster-Shafer mathematical theory is used to collect the evidence notion of importance factors. The adaptiveness of the mechanism allows to systematically cope with the identified MANET routing attacks. The intrusion response action in MANET was addressed by isolating uncooperative nodes based on the node reputation derived from their behaviors. Here the effectiveness of the approach with the consideration of the packet delivery ratio and routing cost were demonstrated using java swing concepts

  5. Randomized, controlled trial of telcagepant over four migraine attacks

    DEFF Research Database (Denmark)

    Ho, Andrew P; Dahlöf, Carl Gh; Silberstein, Stephen D

    2010-01-01

    This study evaluated the calcitonin gene-related peptide (CGRP) receptor antagonist telcagepant (tablet formulation) for treatment of a migraine attack and across four attacks. Adults with migraine were randomized, double-blind, to telcagepant 140 mg, telcagepant 280 mg, or control treatment...... sequences to treat four moderate-to-severe migraine attacks. Control patients received placebo for three attacks and telcagepant 140 mg for one attack. Efficacy for the first attack (Attack 1) and consistency of efficacy over multiple attacks were assessed. For an individual patient, consistent efficacy...

  6. Heart Attack Prediction System Based Neural Arbitration

    OpenAIRE

    Helwan, Abdulkader

    2015-01-01

    Heart attack is an asymptomatic and epidemic medical condition that may suddenly occur and causes “death”. Therefore, it is a life-threatening condition and it should be detected before it occurs. Heart attack is so far predicted using the conventional ways of doctor’s examination and by performing some medical tests such as stress test, ECG, and heart CTScan etc. The coronary vessels constriction, the cholesterol levels in the arteries, and other attributes can be good indicators for making ...

  7. Cyber Security Audit and Attack Detection Toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Dale

    2012-05-31

    This goal of this project was to develop cyber security audit and attack detection tools for industrial control systems (ICS). Digital Bond developed and released a tool named Bandolier that audits ICS components commonly used in the energy sector against an optimal security configuration. The Portaledge Project developed a capability for the PI Historian, the most widely used Historian in the energy sector, to aggregate security events and detect cyber attacks.

  8. Management of acute attacks of hereditary angioedema: role of ecallantide

    Directory of Open Access Journals (Sweden)

    Duffey H

    2015-04-01

    Full Text Available Hannah Duffey,1 Rafael Firszt1,2 1Department of Pediatrics, 2Division of Allergy, Immunology and Rheumatology, University of Utah, Salt Lake City, UT, USA Abstract: Hereditary angioedema (HAE is characterized as an episodic swelling disorder with autosomal dominant inheritance. Clinical features include nonpitting edema of external or mucosal body surfaces, and patients often present with swelling of the extremities, abdominal pain, and swelling of the mouth and throat, which can lead to asphyxiation. Patients with HAE classically have no associated urticaria, which is often referred to as nonhistaminergic angioedema. Treatment for HAE involves long-term prophylaxis, short-term prophylaxis, and management of acute attacks. Up until the past few years, acute HAE episodes were predominately treated with supportive measures. Three classes of medications have recently been approved by the US Food and Drug Administration (FDA for the management of acute HAE attacks. Ecallantide, a recombinant protein that acts as a reversible inhibitor of kallikrein, is currently indicated for acute attacks of HAE in those aged 12 years. In two randomized, double-blind, placebo-controlled, multicenter trials, EDEMA3 and EDEMA4, patients treated with 30 mg of ecallantide demonstrated statistically significant improvement in symptoms compared to those on placebo. In addition to its use as treatment for HAE, ecallantide has been used off label in the management of nonhistaminergic angioedema, not due to HAE. Ecallantide has shown promise in the treatment of these other forms; however, data are limited to mainly case reports at this time. Ecallantide is generally a safe and well-tolerated medication; however, based on reports of anaphylaxis, ecallantide does contain a black box warning. Due to the risk of anaphylaxis, ecallantide cannot be self-administered and must be given by a health care professional. Overall, ecallantide is a safe and effective medication for the

  9. Collision Attack on the Full Extended MD4 and Pseudo-Preimage Attack on RIPEMD

    Institute of Scientific and Technical Information of China (English)

    Gao-Li Wang

    2013-01-01

    The cryptographic hash functions Extended MD4 and RIPEMD are double-branch hash functions,which consist of two parallel branches.Extended MD4 was proposed by Rivest in 1990,and RIPEMD was devised in the framework of the RIPE project (RACE Integrity Primitives Evaluation,1988~1992).On the basis of differential analysis and meet-in-the-middle attack principle,this paper proposes a collision attack on the full Extended MD4 and a pseudo-preimage attack on the full RIPEMD respectively.The collision attack on Extended MD4 holds with a complexity of 237,and a collision instance is presented.The pseudo-preimage attack on RIPEMD holds with a complexity of 2125,4,which optimizes the complexity order for brute-force attack.The results in this study will also be beneficial to the analysis of other double-branch hash functions such as RIPEMD-160.

  10. Black Urine

    Directory of Open Access Journals (Sweden)

    Rahim Vakili

    2016-06-01

    Full Text Available A 2-year-old boy was born at term of healthy, non-consanguineous Iranian parents. His mother attended in the clinic with the history of sometimes discoloration of diapers after passing urine. She noticed that first at the age of one month with intensified in recent months. His Physical examination and growth parameters were normal. His mother denied taking any medication (sorbitol, nitrofurantoin, metronidazole, methocarbamol, sena and methyldopa (5. Qualitative urine examination showed dark black discoloration. By this history, alkaptonuria was the most clinical suspicious. A 24-hour-urine sample was collected and sent for quantitative measurements. The urine sample was highly positive for homogentisic acid and negative for porphyrin metabolites.

  11. Pathologic features of fatal shark attacks.

    Science.gov (United States)

    Byard, R W; Gilbert, J D; Brown, K

    2000-09-01

    To examine the pattern of injuries in cases of fatal shark attack in South Australian waters, the authors examined the files of their institution for all cases of shark attack in which full autopsies had been performed over the past 25 years, from 1974 to 1998. Of the seven deaths attributed to shark attack during this period, full autopsies were performed in only two cases. In the remaining five cases, bodies either had not been found or were incomplete. Case 1 was a 27-year-old male surfer who had been attacked by a shark. At autopsy, the main areas of injury involved the right thigh, which displayed characteristic teeth marks, extensive soft tissue damage, and incision of the femoral artery. There were also incised wounds of the right wrist. Bony injury was minimal, and no shark teeth were recovered. Case 2 was a 26-year-old male diver who had been attacked by a shark. At autopsy, the main areas of injury involved the left thigh and lower leg, which displayed characteristic teeth marks, extensive soft tissue damage, and incised wounds of the femoral artery and vein. There was also soft tissue trauma to the left wrist, with transection of the radial artery and vein. Bony injury was minimal, and no shark teeth were recovered. In both cases, death resulted from exsanguination following a similar pattern of soft tissue and vascular damage to a leg and arm. This type of injury is in keeping with predator attack from underneath or behind, with the most severe injuries involving one leg. Less severe injuries to the arms may have occurred during the ensuing struggle. Reconstruction of the damaged limb in case 2 by sewing together skin, soft tissue, and muscle bundles not only revealed that no soft tissue was missing but also gave a clearer picture of the pattern of teeth marks, direction of the attack, and species of predator.

  12. Dissonant Black Droplets and Black Funnels

    CERN Document Server

    Fischetti, Sebastian; Way, Benson

    2016-01-01

    A holographic field theory on a fixed black hole background has a gravitational dual represented by a black funnel or a black droplet. These states are "detuned" when the temperature of the field theory near the horizon does not match the temperature of the background black hole. In particular, the gravitational dual to the Boulware state must be a detuned solution. We construct detuned droplets and funnels dual to a Schwarzschild background and show that the Boulware phase is represented by a droplet. We also construct hairy black droplets associated to a low-temperature scalar condensation instability and show that they are thermodynamically preferred to their hairless counterparts.

  13. Modelling social-technical attacks with timed automata

    NARCIS (Netherlands)

    David, Nicolas; David, Alexandre; Hansen, René Rydhof; Larsen, Kim G.; Legay, Axel; Olesen, Mads Chr.; Probst, Christian W.

    2015-01-01

    Attacks on a system often exploit vulnerabilities that arise from human behaviour or other human activity. Attacks of this type, so-called socio-technical attacks, cover everything from social engineering to insider attacks, and they can have a devastating impact on an unprepared organisation. In th

  14. A Game Theoretic Approach to Cyber Attack Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Peng Liu

    2005-11-28

    The area investigated by this project is cyber attack prediction. With a focus on correlation-based prediction, current attack prediction methodologies overlook the strategic nature of cyber attack-defense scenarios. As a result, current cyber attack prediction methodologies are very limited in predicting strategic behaviors of attackers in enforcing nontrivial cyber attacks such as DDoS attacks, and may result in low accuracy in correlation-based predictions. This project develops a game theoretic framework for cyber attack prediction, where an automatic game-theory-based attack prediction method is proposed. Being able to quantitatively predict the likelihood of (sequences of) attack actions, our attack prediction methodology can predict fine-grained strategic behaviors of attackers and may greatly improve the accuracy of correlation-based prediction. To our best knowledge, this project develops the first comprehensive framework for incentive-based modeling and inference of attack intent, objectives, and strategies; and this project develops the first method that can predict fine-grained strategic behaviors of attackers. The significance of this research and the benefit to the public can be demonstrated to certain extent by (a) the severe threat of cyber attacks to the critical infrastructures of the nation, including many infrastructures overseen by the Department of Energy, (b) the importance of cyber security to critical infrastructure protection, and (c) the importance of cyber attack prediction to achieving cyber security.

  15. Panic Attack during Elective Gastrointestinal Endoscopy

    Directory of Open Access Journals (Sweden)

    Charalampos Mitsonis

    2011-01-01

    Full Text Available Background. Esophagogastroduodenoscopy (EGD and colonoscopy (CS can evoke anxiety, embarrassment, and discomfort. These concerns can culminate in panic attacks, which may traumatize patients and significantly decrease their compliance to the procedure. The objective of this study was to evaluate the relationship between preendoscopic anxiety and the possibility of a panic attack during an elective gastrointestinal endoscopy (EGE. Methods. The study population comprised of 79 Greek outpatients. The examination was carried out without the use of conscious sedation. Patients' anxiety levels were assessed before the procedure using the Greek version of the Spielberger State-Trait Anxiety Inventory (STAI-Y. Results. Seventy-nine patients were enrolled: 45 EGD and 34 CS. Females had higher state and trait anxiety levels than males (48.14 ± 7.94 versus 44.17 ± 7.43, <0.05; and 43.68 ± 6.95 versus 39.86 ± 7.46, <0.05. Patients who experienced panic attack had significantly higher levels of both trait and state anxiety, compared to those who were panic-free. There was no significant relationship between panic attacks and sex or type of procedure. Conclusions. Patients who experience panic attacks during endoscopic procedures appear to have significantly higher anxiety levels before the procedure. Administering the STAI questionnaire prior to the endoscopy seems to be a useful screening method for vulnerable patients.

  16. Trace Attack against Biometric Mobile Applications

    Directory of Open Access Journals (Sweden)

    Sanaa Ghouzali

    2016-01-01

    Full Text Available With the exponential increase in the dependence on mobile devices in everyday life, there is a growing concern related to privacy and security issues in the Gulf countries; therefore, it is imperative that security threats should be analyzed in detail. Mobile devices store enormous amounts of personal and financial information, unfortunately without any security. In order to secure mobile devices against different threats, biometrics has been applied and shown to be effective. However, biometric mobile applications are also vulnerable to several types of attacks that can decrease their security. Biometric information itself is considered sensitive data; for example, fingerprints can leave traces in touched objects and facial images can be captured everywhere or accessed by the attacker if the facial image is stored in the mobile device (lost or stolen. Hence, an attacker can easily forge the identity of a legitimate user and access data on a device. In this paper, the effects of a trace attack on the sensitivity of biometric mobile applications are investigated in terms of security and user privacy. Experimental results carried out on facial and fingerprint mobile authentication applications using different databases have shown that these mobile applications are vulnerable to the proposed attack, which poses a serious threat to the overall system security and user privacy.

  17. Cross-site scripting attacks procedure and Prevention Strategies

    Directory of Open Access Journals (Sweden)

    Wang Xijun

    2016-01-01

    Full Text Available Cross-site scripting attacks and defense has been the site of attack and defense is an important issue, this paper, the definition of cross-site scripting attacks, according to the current understanding of the chaos on the cross-site scripting, analyzes the causes and harm cross-site scripting attacks formation of attacks XXS complete process XSS attacks made a comprehensive analysis, and then for the web program includes Mobility there are cross-site scripting filter laxity given from ordinary users browse the web and web application developers two the defense cross-site scripting attacks effective strategy.

  18. Pareto Efficient Solutions of Attack-Defence Trees

    DEFF Research Database (Denmark)

    Aslanyan, Zaruhi; Nielson, Flemming

    2015-01-01

    Attack-defence trees are a promising approach for representing threat scenarios and possible countermeasures in a concise and intuitive manner. An attack-defence tree describes the interaction between an attacker and a defender, and is evaluated by assigning parameters to the nodes, such as proba......Attack-defence trees are a promising approach for representing threat scenarios and possible countermeasures in a concise and intuitive manner. An attack-defence tree describes the interaction between an attacker and a defender, and is evaluated by assigning parameters to the nodes...... on a new and general formalism for attack-defence trees....

  19. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io;

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....

  20. Attack Prevention for Collaborative Spectrum Sensing in Cognitive Radio Networks

    CERN Document Server

    Duan, Lingjie; Huang, Jianwei; Shin, Kang G

    2011-01-01

    Collaborative spectrum sensing can significantly improve the detection performance of secondary unlicensed users (SUs). However, the performance of collaborative sensing is vulnerable to sensing data falsification attacks, where malicious SUs (attackers) submit manipulated sensing reports to mislead the fusion center's decision on spectrum occupancy. Moreover, attackers may not follow the fusion center's decision regarding their spectrum access. This paper considers a challenging attack scenario where multiple rational attackers overhear all honest SUs' sensing reports and cooperatively maximize attackers' aggregate spectrum utilization. We show that, without attack-prevention mechanisms, honest SUs are unable to transmit over the licensed spectrum, and they may further be penalized by the primary user for collisions due to attackers' aggressive transmissions. To prevent such attacks, we propose two novel attack-prevention mechanisms with direct and indirect punishments. The key idea is to identify collisions...

  1. Attack-tolerant networked control system: an approach for detection the controller stealthy hijacking attack

    Science.gov (United States)

    Atta Yaseen, Amer; Bayart, Mireille

    2017-01-01

    In this work, a new approach will be introduced as a development for the attack-tolerant scheme in the Networked Control System (NCS). The objective is to be able to detect an attack such as the Stuxnet case where the controller is reprogrammed and hijacked. Besides the ability to detect the stealthy controller hijacking attack, the advantage of this approach is that there is no need for a priori mathematical model of the controller. In order to implement the proposed scheme, a specific detector for the controller hijacking attack is designed. The performance of this scheme is evaluated be connected the detector to NCS with basic security elements such as Data Encryption Standard (DES), Message Digest (MD5), and timestamp. The detector is tested along with networked PI controller under stealthy hijacking attack. The test results of the proposed method show that the hijacked controller can be significantly detected and recovered.

  2. Distributed Denial of Service Attacks: A Review

    Directory of Open Access Journals (Sweden)

    Sonali Swetapadma Sahu

    2014-01-01

    Full Text Available A wireless sensor network (WSN is a wireless network consisting of spatially distributed autonomous devices using sensors to monitor physical or environmental conditions.WSN is a fluorishing network that has numerous applications and could be used in diverse scenarios. DDoS (Distributed Denial of Service is an attack where a number of compromised systems attack a single target, thereby causing denial of service for users of the targeted system. The flood of incoming messages to the target system essentially forces it to shut down, thereby denying service to the system to legitimate users.Not much research work has been done in DDoS in WSN.We are conducting a review on DDoS attack to show its impact on networks and to present various defensive, detection and preventive measures adopted by researchers till now.

  3. Key Recovery Attacks on Recent Authenticated Ciphers

    DEFF Research Database (Denmark)

    Bogdanov, Andrey; Dobraunig, Christoph; Eichlseder, Maria

    2014-01-01

    and wireless networks. All these schemes use well-established and secure components such as the AES, Grain-like NFSRs, ChaCha and SipHash as their building blocks. However, we discover key recovery attacks for all three designs, featuring square-root complexities. Using a key collision technique, we can...... recover the secret key of AVALANCHE in 2n/2, where n 2∈ {28; 192; 256} is the key length. This technique also applies to the authentication part of Calico whose 128-bit key can be recovered in 264 time. For RBS, we can recover its full 132-bit key in 265 time with a guess-and-determine attack. All attacks...

  4. Quantifying Mixed Uncertainties in Cyber Attacker Payoffs

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Samrat; Halappanavar, Mahantesh; Tipireddy, Ramakrishna; Oster, Matthew R.; Saha, Sudip

    2015-04-15

    Representation and propagation of uncertainty in cyber attacker payoffs is a key aspect of security games. Past research has primarily focused on representing the defender’s beliefs about attacker payoffs as point utility estimates. More recently, within the physical security domain, attacker payoff uncertainties have been represented as Uniform and Gaussian probability distributions, and intervals. Within cyber-settings, continuous probability distributions may still be appropriate for addressing statistical (aleatory) uncertainties where the defender may assume that the attacker’s payoffs differ over time. However, systematic (epistemic) uncertainties may exist, where the defender may not have sufficient knowledge or there is insufficient information about the attacker’s payoff generation mechanism. Such epistemic uncertainties are more suitably represented as probability boxes with intervals. In this study, we explore the mathematical treatment of such mixed payoff uncertainties.

  5. A Traceability Attack against e-Passports

    Science.gov (United States)

    Chothia, Tom; Smirnov, Vitaliy

    Since 2004, many nations have started issuing "e-passports" containing an RFID tag that, when powered, broadcasts information. It is claimed that these passports are more secure and that our data will be protected from any possible unauthorised attempts to read it. In this paper we show that there is a flaw in one of the passport's protocols that makes it possible to trace the movements of a particular passport, without having to break the passport's cryptographic key. All an attacker has to do is to record one session between the passport and a legitimate reader, then by replaying a particular message, the attacker can distinguish that passport from any other. We have implemented our attack and tested it successfully against passports issued by a range of nations.

  6. Resistance of the double random phase encryption against various attacks.

    Science.gov (United States)

    Frauel, Yann; Castro, Albertina; Naughton, Thomas J; Javidi, Bahram

    2007-08-06

    Several attacks are proposed against the double random phase encryption scheme. These attacks are demonstrated on computer-generated ciphered images. The scheme is shown to be resistant against brute force attacks but susceptible to chosen and known plaintext attacks. In particular, we describe a technique to recover the exact keys with only two known plain images. We compare this technique to other attacks proposed in the literature.

  7. Intelligent Intrusion Detection of Grey Hole and Rushing Attacks in Self-Driving Vehicular Networks

    Directory of Open Access Journals (Sweden)

    Khattab M. Ali Alheeti

    2016-07-01

    Full Text Available Vehicular ad hoc networks (VANETs play a vital role in the success of self-driving and semi self-driving vehicles, where they improve safety and comfort. Such vehicles depend heavily on external communication with the surrounding environment via data control and Cooperative Awareness Messages (CAMs exchanges. VANETs are potentially exposed to a number of attacks, such as grey hole, black hole, wormhole and rushing attacks. This work presents an intelligent Intrusion Detection System (IDS that relies on anomaly detection to protect the external communication system from grey hole and rushing attacks. These attacks aim to disrupt the transmission between vehicles and roadside units. The IDS uses features obtained from a trace file generated in a network simulator and consists of a feed-forward neural network and a support vector machine. Additionally, the paper studies the use of a novel systematic response, employed to protect the vehicle when it encounters malicious behaviour. Our simulations of the proposed detection system show that the proposed schemes possess outstanding detection rates with a reduction in false alarms. This safe mode response system has been evaluated using four performance metrics, namely, received packets, packet delivery ratio, dropped packets and the average end to end delay, under both normal and abnormal conditions.

  8. Dpraodv: A Dyanamic Learning System Against Blackhole Attack in Aodv Based Manet

    CERN Document Server

    Raj, Payal N

    2009-01-01

    Security is an essential requirement in mobile ad hoc networks to provide protected communication between mobile nodes. Due to unique characteristics of MANETS, it creates a number of consequential challenges to its security design. To overcome the challenges, there is a need to build a multifence security solution that achieves both broad protection and desirable network performance. MANETs are vulnerable to various attacks, blackhole, is one of the possible attacks. Black hole is a type of routing attack where a malicious node advertise itself as having the shortest path to all nodes in the environment by sending fake route reply. By doing this, the malicious node can deprive the traffic from the source node. It can be used as a denial-of-service attack where it can drop the packets later. In this paper, we proposed a DPRAODV (Detection, Prevention and Reactive AODV) to prevent security threats of blackhole by notifying other nodes in the network of the incident. The simulation results in ns2 (ver- 2.33) de...

  9. Playing Attack and Defense with Trusted Storage

    DEFF Research Database (Denmark)

    Gonzalez, Javier; Bonnet, Philippe; Bouganim, Luc

    2014-01-01

    It is often convenient to assume in a data management platform that one or several computing devices are trusted, specially when the goal is to provide privacy guarantees over personal data. But what does it take for a computing device to be trusted? More specifically, how can a personal device...... provide trusted storage? This is the question we tackle in this demonstration. We describe how secure devices, equipped with a trusted execution environment, differ from general purpose devices. We illustrate with our demonstration scenario, that it is much more difficult to attack a storage service...... running on a secure device, than to attack the same service running on a general purpose device....

  10. Defending Against Wormhole Attack in OLSR

    Institute of Scientific and Technical Information of China (English)

    HONG Liang; HONG Fan; FU Cai

    2006-01-01

    OLSR (optimal link state routing) is one of the four basic routing protocols used in mobile ad hoc Networks by the MANET working group of IETF(Internet engineering task force). OLSR, a proactive routing protocol, is based on a multipoint relaying flooding technique to reduce the number of topology broadcast. OLSR uses periodic HELLO packets to neighbor detection. As introduced in Reference [1], the wormhole attack can form a serious threat in wireless Networks, especially against many ad hoc Network routing protocols and location-based wireless security systems. Here, a trust model to handle this attack in OLSR is provided and simulated in NS2.

  11. Textual Manipulation for SQL Injection Attacks

    Directory of Open Access Journals (Sweden)

    Hussein AlNabulsi

    2013-11-01

    Full Text Available SQL injection attacks try to use string or text manipulations to access illegally websites and their databases. This is since using some symbols or characters in SQL statements may trick the authentication system to incorrectly allow such SQL statements to be processed or executed. In this paper, we highlighted several examples of such text manipulations that can be successfully used in SQL injection attacks. We evaluated the usage of those strings on several websites and web pages using SNORT open source. We also conducted an extensive comparison study of some relevant papers.

  12. The Black Black Woman and the Black Middle Class.

    Science.gov (United States)

    Jeffers, Trellie

    1981-01-01

    Reprint of a 1973 article that describes the discrimination that particularly dark-skinned Black women suffer, especially at the hands of a color-conscious Black middle class. Calls for dark women to look to the African appearance and working-class roots as sources of pride and strength. (GC)

  13. Attack Classification Schema for Smart City WSNs.

    Science.gov (United States)

    Garcia-Font, Victor; Garrigues, Carles; Rifà-Pous, Helena

    2017-04-05

    Urban areas around the world are populating their streets with wireless sensor networks (WSNs) in order to feed incipient smart city IT systems with metropolitan data. In the future smart cities, WSN technology will have a massive presence in the streets, and the operation of municipal services will be based to a great extent on data gathered with this technology. However, from an information security point of view, WSNs can have failures and can be the target of many different types of attacks. Therefore, this raises concerns about the reliability of this technology in a smart city context. Traditionally, security measures in WSNs have been proposed to protect specific protocols in an environment with total control of a single network. This approach is not valid for smart cities, as multiple external providers deploy a plethora of WSNs with different security requirements. Hence, a new security perspective needs to be adopted to protect WSNs in smart cities. Considering security issues related to the deployment of WSNs as a main data source in smart cities, in this article, we propose an intrusion detection framework and an attack classification schema to assist smart city administrators to delimit the most plausible attacks and to point out the components and providers affected by incidents. We demonstrate the use of the classification schema providing a proof of concept based on a simulated selective forwarding attack affecting a parking and a sound WSN.

  14. Strengthening Crypto-1 Cipher Against Algebraic Attacks

    Directory of Open Access Journals (Sweden)

    Farah Afianti

    2015-08-01

    Full Text Available In the last few years, several studies addressed the problem of data security in Mifare Classic. One of its weaknesses is the low random number quality. This causes SAT solver attacks to have lower complexity. In order to strengthen Crypto-1 against SAT solver attacks, a modification of the feedback function with better cryptographic properties is proposed. It applies a primitive polynomial companion matrix. SAT solvers cannot directly attack the feedback shift register that uses the modified Boolean feedback function, the register has to be split into smaller groups. Experimental testing showed that the amount of memory and CPU time needed were highest when attacking the modified Crypto-1 using the modified feedback function and the original filter function. In addition, another modified Crypto-1, using the modified feedback function and a modified filter function, had the lowest percentage of revealed variables. It can be concluded that the security strength and performance of the modified Crypto-1 using the modified feedback function and the modified filter function are better than those of the original Crypto-1.

  15. Plant defences against herbivore and insect attack

    Science.gov (United States)

    Plants deploy a number of defences against attack by insects and other herbivores. Direct defence is conferred by plant products and structures that deter or kill the herbivores. Chemical toxins and deterrents vary widely among plant species, and some typical toxins include alkaloids, terpenoids, st...

  16. Why Does Asthma Attack Severely at Night?

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The rhythmic changes of human physiological activities by day and at night may cause regular change of the patient's condition within one day. The following is the explanation with the theory of Chinese medicine for the reason why asthma attacks severely at night.

  17. Rhode Island School Terrorist Attack Preparedness

    Science.gov (United States)

    Dube, Michael W. M.

    2012-01-01

    This study examined the state of safety and terrorist attack preparedness in Rhode Island Schools as determined by Rhode Island school leader perceptions. The study is descriptive in nature as it gathers data to describe a particular event or situation. Using a researcher generated survey based on terrorist preparedness guidelines and suggestions…

  18. The diagnosis of transient ischemic attacks

    NARCIS (Netherlands)

    P.J. Koudstaal (Peter Jan)

    1989-01-01

    textabstractThe diagnosis of transient ischemic attack (TIA) is fraught with difficulty, since the diagnosis rests entirely upon the history of the patient's symptoms and the neurologist's skill in questioning the patient. The aim of this thesis is to investigate various measures to improve the reli

  19. Persistent cognitive impairment after transient ischemic attack

    NARCIS (Netherlands)

    Rooij, F.G. van; Schaapsmeerders, P.; Maaijwee, N.A.; Duijnhoven, D.A. van; Leeuw, F.E. de; Kessels, R.P.; Dijk, E.J. van

    2014-01-01

    BACKGROUND AND PURPOSE: By definition, the symptoms of a transient ischemic attack (TIA) subside completely within 24 hours. Imaging studies show signs of persistent ischemic tissue damage in a substantial amount of patients with TIA. Cerebral infarction can cause permanent cognitive impairment. Whe

  20. Persistent Cognitive Impairment After Transient Ischemic Attack

    NARCIS (Netherlands)

    Rooij, F.G. van; Schaapsmeerders, P.; Maaijwee, N.A.M.M.; Duijnhoven, D.A. van; de Leeuw, F.E.; Kessels, R.P.C.; Dijk, E.J. van

    2014-01-01

    Background and Purpose—By definition, the symptoms of a transient ischemic attack (TIA) subside completely within 24 hours. Imaging studies show signs of persistent ischemic tissue damage in a substantial amount of patients with TIA. Cerebral infarction can cause permanent cognitive impairment. Whet

  1. Chemical Attack of Malaysian Pozzolans Concrete

    Directory of Open Access Journals (Sweden)

    Mohd Hilton Ahmad

    2011-09-01

    Full Text Available Malaysia produces more than 10 million tonne of by-product from industrial sector per year. As the environmental impact concerns, more than half of the by-product can be recycled to be used as construction materials. One of them is pozzolan, a cement replacing material that can be used to enhance the properties of the concrete. This paper studies the chemical attack to local prozzolans concrete. The parameters studied include weight loss, length change, and residual strength of local pozzolans concrete after been exposed to severe environment. The specimen were tested under normal room temperature, exposed to magnesium sulfate, MgSO4. 2H2O where both sulfate attack and acid attack take place. Two series of pozzolans< which is Pulverized fly ash (PFA and Palm oil fuel ash (POFA were identified. Another series of admixture, Quarry Dust (QD from quarry waste that contain high amount of silica content also been carried out. Each series will study the effect of cement replacement percentage of 5%, 10% and 15%. The parameters were compared to conventional ordinary Portland cement (OPC concrete as control mix. Accelerated testing was conducted at 3, 7, 28, 56 and 90 days. The result shows that the local pozzolans concrete were found to be in good resistance against sulfate attack compared to conventional concrete. Compared to all series conducted, series of PFA replacement gave the best resistance followed by POFA and QD replacement series.

  2. Intrusion-Tolerant Replication under Attack

    Science.gov (United States)

    Kirsch, Jonathan

    2010-01-01

    Much of our critical infrastructure is controlled by large software systems whose participants are distributed across the Internet. As our dependence on these critical systems continues to grow, it becomes increasingly important that they meet strict availability and performance requirements, even in the face of malicious attacks, including those…

  3. Shark Attack! Sinking Your Teeth into Anatomy.

    Science.gov (United States)

    House, Herbert

    2002-01-01

    Presents a real life shark attack story and studies arm reattachment surgery to teach human anatomy. Discusses how knowledge of anatomy can be put to use in the real world and how the arm functions. Includes teaching notes and suggestions for classroom management. (YDS)

  4. Association between Terror Attacks and Suicide Attempts

    Science.gov (United States)

    Weizman, Tal; Yagil, Yaron; Schreiber, Shaul

    2009-01-01

    Based on Durkheim's "Control theory," we explored the association between frequency of terror attacks in Israel and the frequency of suicide attempts admitted to the Emergency Room of a major general hospital in Tel-Aviv (1999-2004). Analysis of the six-year study period as a whole revealed no significant correlation between the…

  5. An Adaptive Approach for Defending against DDoS Attacks

    Directory of Open Access Journals (Sweden)

    Muhai Li

    2010-01-01

    Full Text Available In various network attacks, the Distributed Denial-of-Service (DDoS attack is a severe threat. In order to deal with this kind of attack in time, it is necessary to establish a special type of defense system to change strategy dynamically against attacks. In this paper, we introduce an adaptive approach, which is used for defending against DDoS attacks, based on normal traffic analysis. The approach can check DDoS attacks and adaptively adjust its configurations according to the network condition and attack severity. In order to insure the common users to visit the victim server that is being attacked, we provide a nonlinear traffic control formula for the system. Our simulation test indicates that the nonlinear control approach can prevent the malicious attack packets effectively while making legitimate traffic flows arrive at the victim.

  6. A graph based system for multi-stage attacks recognition

    Institute of Scientific and Technical Information of China (English)

    Safaa O. Al-Mamory; Zhai Jianhong; Zhang Hongli

    2008-01-01

    Building attack scenario is one of the most important aspects in network security. This paper proposed a system which collects intrusion alerts, clusters them as sub-attacks using alerts abstraction, aggregates the similar sub-attacks, and then correlates and generates correlation graphs. The scenarios were represented by alert classes instead of alerts themselves so as to reduce the required rules and have the ability of detecting new variations of attacks. The proposed system is capable of passing some of the missed attacks. To evaluate system effectiveness, it was tested with different datasets which contain multi-step attacks. Compressed and easily understandable correlation graphs which reflect attack scenarios were generated. The proposed system can correlate related alerts, uncover the attack strategies, and detect new variations of attacks.

  7. Quantitative Verification and Synthesis of Attack-Defence Scenarios

    DEFF Research Database (Denmark)

    Aslanyan, Zaruhi; Nielson, Flemming; Parker, David

    2016-01-01

    Attack-defence trees are a powerful technique for formally evaluating attack-defence scenarios. They represent in an intuitive, graphical way the interaction between an attacker and a defender who compete in order to achieve conflicting objectives. We propose a novel framework for the formal...... analysis of quantitative properties of complex attack-defence scenarios, using an extension of attack-defence trees which models temporal ordering of actions and allows explicit dependencies in the strategies adopted by attackers and defenders. We adopt a game-theoretic approach, translating attack......-defence trees to two-player stochastic games, and then employ probabilistic model checking techniques to formally analyse these models. This provides a means to both verify formally specified security properties of the attack-defence scenarios and, dually, to synthesise strategies for attackers or defenders...

  8. Assessing Terrorist Motivations for Attacking Critical Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Ackerman, G; Abhayaratne, P; Bale, J; Bhattacharjee, A; Blair, C; Hansell, L; Jayne, A; Kosal, M; Lucas, S; Moran, K; Seroki, L; Vadlamudi, S

    2006-12-04

    Certain types of infrastructure--critical infrastructure (CI)--play vital roles in underpinning our economy, security and way of life. These complex and often interconnected systems have become so ubiquitous and essential to day-to-day life that they are easily taken for granted. Often it is only when the important services provided by such infrastructure are interrupted--when we lose easy access to electricity, health care, telecommunications, transportation or water, for example--that we are conscious of our great dependence on these networks and of the vulnerabilities that stem from such dependence. Unfortunately, it must be assumed that many terrorists are all too aware that CI facilities pose high-value targets that, if successfully attacked, have the potential to dramatically disrupt the normal rhythm of society, cause public fear and intimidation, and generate significant publicity. Indeed, revelations emerging at the time of this writing about Al Qaida's efforts to prepare for possible attacks on major financial facilities in New York, New Jersey, and the District of Columbia remind us just how real and immediate such threats to CI may be. Simply being aware that our nation's critical infrastructure presents terrorists with a plethora of targets, however, does little to mitigate the dangers of CI attacks. In order to prevent and preempt such terrorist acts, better understanding of the threats and vulnerabilities relating to critical infrastructure is required. The Center for Nonproliferation Studies (CNS) presents this document as both a contribution to the understanding of such threats and an initial effort at ''operationalizing'' its findings for use by analysts who work on issues of critical infrastructure protection. Specifically, this study focuses on a subsidiary aspect of CI threat assessment that has thus far remained largely unaddressed by contemporary terrorism research: the motivations and related factors that

  9. Recovery of human remains after shark attack.

    Science.gov (United States)

    Byard, Roger W; James, Ross A; Heath, Karen J

    2006-09-01

    Two cases of fatal shark attack are reported where the only tissues recovered were fragments of lung. Case 1: An 18-year-old male who was in the sea behind a boat was observed by friends to be taken by a great white shark (Carcharodon carcharias). The shark dragged him under the water and then, with a second shark, dismembered the body. Witnesses noted a large amount of blood and unrecognizable body parts coming to the surface. The only tissues recovered despite an intensive beach and sea search were 2 fragments of lung. Case 2: A 19-year-old male was attacked by a great white shark while diving. A witness saw the shark swim away with the victim's body in its mouth. Again, despite intensive beach and sea searches, the only tissue recovered was a single piece of lung, along with pieces of wetsuit and diving equipment. These cases indicate that the only tissue to escape being consumed or lost in fatal shark attacks, where there is a significant attack with dismemberment and disruption of the integrity of the body, may be lung. The buoyancy of aerated pulmonary tissue ensures that it rises quickly to the surface, where it may be recovered by searchers soon after the attack. Aeration of the lung would be in keeping with death from trauma rather than from drowning and may be a useful marker in unwitnessed deaths to separate ante- from postmortem injury, using only relatively small amounts of tissues. Early organ recovery enhances the identification of human tissues as the extent of morphologic alterations by putrefactive processes and sea scavengers will have been minimized. DNA testing is also possible on such recovered fragments, enabling confirmation of the identity of the victim.

  10. A Survey of Mobile Ad Hoc Network Attacks

    Directory of Open Access Journals (Sweden)

    PRADIP M. JAWANDHIYA,

    2010-09-01

    Full Text Available Security is an essential requirement in mobile ad hoc network (MANETs. Compared to wired networks, MANETs are more vulnerable to security attacks due to the lack of a trusted centralized authority and limited resources. Attacks on ad hoc networks can be classified as passive and active attacks, depending on whether the normal operation of the network is disrupted or not. In this paper, we are describing the all prominent attacks described in literature in a consistent manner to provide a concise comparison on attack types. To the best of our knowledge, this is the first paper that studies all the existing attacks on MANETs.

  11. Analysis of the SYN Flood DoS Attack

    Directory of Open Access Journals (Sweden)

    Mitko Bogdanoski

    2013-06-01

    Full Text Available The paper analyzes systems vulnerability targeted by TCP (Transmission Control Protocol segments when SYN flag is ON, which gives space for a DoS (Denial of Service attack called SYN flooding attack or more often referred as a SYN flood attack. The effects of this type of attack are analyzed and presented in OPNET simulation environment. Furthermore, the paper presents two anomaly detection algorithms as an effective mechanism against this type of attack. Finally, practical approaches against SYN flood attack for Linux and Windows environment which are followed by are shown.

  12. Black hole hair removal

    Science.gov (United States)

    Banerjee, Nabamita; Mandal, Ipsita; Sen, Ashoke

    2009-07-01

    Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair — degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

  13. Black Hole Hair Removal

    CERN Document Server

    Banerjee, Nabamita; Sen, Ashoke

    2009-01-01

    Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair, -- degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

  14. Noncommutative black holes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-DomInguez, J C [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); RamIrez, C [Facultad de Ciencias FIsico Matematicas, Universidad Autonoma de Puebla, PO Box 1364, 72000 Puebla (Mexico); Sabido, M [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico)

    2007-11-15

    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole.

  15. Black Hole Thermodynamics

    Science.gov (United States)

    Israel, Werner

    This chapter reviews the conceptual developments on black hole thermodynamics and the attempts to determine the origin of black hole entropy in terms of their horizon area. The brick wall model and an operational approach are discussed. An attempt to understand at the microlevel how the quantum black hole acquires its thermal properties is included. The chapter concludes with some remarks on the extension of these techniques to describing the dynamical process of black hole evaporation.

  16. Life inside black holes

    CERN Document Server

    Dokuchaev, V I

    2012-01-01

    We consider test planet and photon orbits of the third kind inside a black hole, which are stable, periodic and neither come out of the black hole nor terminate at the singularity. Interiors of supermassive black holes may be inhabited by advanced civilizations living on planets with the third-kind orbits. In principle, one can get information from the interiors of black holes by observing their white hole counterparts.

  17. Charged Lifshitz Black Holes

    OpenAIRE

    Dehghani, M. H.; Pourhasan, R.; Mann, R. B.

    2011-01-01

    We investigate modifications of the Lifshitz black hole solutions due to the presence of Maxwell charge in higher dimensions for arbitrary $z$ and any topology. We find that the behaviour of large black holes is insensitive to the topology of the solutions, whereas for small black holes significant differences emerge. We generalize a relation previously obtained for neutral Lifshitz black branes, and study more generally the thermodynamic relationship between energy, entropy, and chemical pot...

  18. Modelling Social-Technical Attacks with Timed Automata

    DEFF Research Database (Denmark)

    David, Nicolas; David, Alexandre; Hansen, Rene Rydhof

    2015-01-01

    in our model and perform analysis and simulation of both model and attack, revealing details about the specific interaction between attacker and victim. Using timed automata also allows for intuitive modelling of systems, in which quantities like time and cost can be easily added and analysed.......Attacks on a system often exploit vulnerabilities that arise from human behaviour or other human activity. Attacks of this type, so-called socio-technical attacks, cover everything from social engineering to insider attacks, and they can have a devastating impact on an unprepared organisation....... In this paper we develop an approach towards modelling socio-technical systems in general and socio-technical attacks in particular, using timed automata and illustrate its application by a complex case study. Thanks to automated model checking and automata theory, we can automatically generate possible attacks...

  19. Flooding attack and defence in Ad hoc networks

    Institute of Scientific and Technical Information of China (English)

    Yi Ping; Hou Yafei; Zhong Yiping; Zhang Shiyong; Dai Zhoulin

    2006-01-01

    Mobile ad hoc networks are particularly vulnerable to denial of service (DOS) attacks launched through compromised nodes or intruders. In this paper, we present a new DOS attack and its defense in ad hoc networks. The new DOS attack, called Ad hoc Flooding Attack(AHFA), is that intruder broadcasts mass Route Request packets to exhaust the communication bandwidth and node resource so that the valid communication can not be kept. After analyzed Ad hoc Flooding Attack, we develop Flooding Attack Prevention (FAP), a generic defense against the Ad hoc Flooding Attack. When the intruder broadcasts exceeding packets of Route Request, the immediate neighbors of the intruder record the rate of Route Request. Once the threshold is exceeded, nodes deny any future request packets from the intruder. The results of our implementation show FAP can prevent the Ad hoc Flooding attack efficiently.

  20. Comparative Analysis of Routing Attacks in Ad Hoc Network

    Directory of Open Access Journals (Sweden)

    Bipul Syam Purkayastha

    2012-03-01

    Full Text Available In the mobile ad hoc networks the major role is played by the routing protocols in order to route the data from one mobile node to another mobile node. But in such mobile networks, routing protocols are vulnerable to various kinds of security attacks such as blackhole node attacks. The routing protocols of MANET are unprotected and hence resulted into the network with the malicious mobile nodes in the network. These malicious nodes in the network are basically acts as attacks in the network. In this paper, we modify the existing DSR protocol with the functionality of attacks detection without affecting overall performance of the network. Also, we are considering the various attacks on mobile ad hoc network called blackhole attack, flooding attack and show the comparative analysis of these attacks using network simulator ns-2.

  1. An Attack Modeling Based on Colored Petri Net

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shijie; QIN Zhiguang; ZHANG Feng; LIU Jinde

    2004-01-01

    A color petri net (CPN) based attack modeling approach is addressed.Compared with graph-based modeling,CPN based attack model is fiexible enough to model Intemet intrusions,because of their static and dynamic features.The processes and rules of building CPN based attack model from attack tree are also presented.In order to evaluate the risk of intrusion,some cost elements are added to CPN based attack modeling.This extended model is useful in intrusion detection and risk evaluation.Experiences show that it is easy to exploit CPN based attack modeling approach to provide the controlling functions,such as intrusion response and intrusion defense.A case study given in this paper shows that CPN based attack model has many unique characters which attack tree model hasn't.

  2. Robustness of Complex Networks against Attacks Guided by Damage

    CERN Document Server

    Wang, Hui; Xu, Xiaomin; Xiao, Yanghua; Wang, Wei

    2011-01-01

    Extensive researches have been dedicated to investigating the performance of real networks and synthetic networks against random failures or intentional attack guided by degree (degree attack). Degree is one of straightforward measures to characterize the vitality of a vertex in maintaining the integrity of the network but not the only one. Damage, the decrease of the largest component size that was caused by the removal of a vertex, intuitively is a more destructive guide for intentional attack on networks since the network functionality is usually measured by the largest component size. However, it is surprising to find that little is known about behaviors of real networks or synthetic networks against intentional attack guided by damage (damage attack), in which adversaries always choose the vertex with the largest damage to attack. In this article, we dedicate our efforts to understanding damage attack and behaviors of real networks as well as synthetic networks against this attack. To this end, existing ...

  3. Denial of Service Attack Techniques: Analysis, Implementation and Comparison

    Directory of Open Access Journals (Sweden)

    Khaled Elleithy

    2005-02-01

    Full Text Available A denial of service attack (DOS is any type of attack on a networking structure to disable a server from servicing its clients. Attacks range from sending millions of requests to a server in an attempt to slow it down, flooding a server with large packets of invalid data, to sending requests with an invalid or spoofed IP address. In this paper we show the implementation and analysis of three main types of attack: Ping of Death, TCP SYN Flood, and Distributed DOS. The Ping of Death attack will be simulated against a Microsoft Windows 95 computer. The TCP SYN Flood attack will be simulated against a Microsoft Windows 2000 IIS FTP Server. Distributed DOS will be demonstrated by simulating a distribution zombie program that will carry the Ping of Death attack. This paper will demonstrate the potential damage from DOS attacks and analyze the ramifications of the damage.

  4. New attacks on Wi-Fi Protected Setup

    Directory of Open Access Journals (Sweden)

    Hamed Mohtadi

    2015-09-01

    Full Text Available Wi-Fi Protected Setup (WPS is a network security standard that is used to secure networks in home and office, introduced in 2006 by the Wi-Fi Alliance. It provides easier configuration setup and is used in almost all recent Wi-Fi devices. In this paper we propose two attacks on this standard. The first attack is an offline brute force attack that uses imbalance on registration protocol. This attack needs user action, but it is more efficient than previous attacks. The second attack uses weaknesses in the implementation of WPS and provides an improved evil twin attack. This attack shows that even by completely disabling the WPS on the routers, all vulnerabilities are not covered.

  5. Understanding how components of organisations contribute to attacks

    NARCIS (Netherlands)

    Gu, Min; Aslanyan, Zaruhi; Probst, Christian W.

    2016-01-01

    Attacks on organisations today explore many different layers, including buildings infrastructure, IT infrastructure, and human factor – the physical, virtual, and social layer. Identifying possible attacks, understanding their impact, and attributing their origin and contributing factors is difficul

  6. Aspirin to Prevent a First Heart Attack or Stroke

    Science.gov (United States)

    ... Aspirin to Prevent a First Heart Attack or Stroke Also known as aspirin primary prevention. Aspirin is ... taking aspirin to prevent another heart attack or stroke? The information discussed in Who may benefit? only ...

  7. Monopole black hole skyrmions

    OpenAIRE

    Moss, I. G.; Shiiki, N.; Winstanley, E.

    2000-01-01

    Charged black hole solutions with pion hair are discussed. These can be\\ud used to study monopole black hole catalysis of proton decay.\\ud There also exist\\ud multi-black hole skyrmion solutions with BPS monopole behaviour.

  8. Marketing for Black Alums.

    Science.gov (United States)

    Harris, Tracy A.

    1994-01-01

    Considers need for colleges and universities to develop effective marketing plan for recruitment of black students. Highlights advantages of designing marketing plan for recruitment of black alumni to assist in recruitment and retention of black students. Identifies key indicators that often hinder institutions in their recruitment of black…

  9. Quantum Communication Attacks on Classical Cryptographic Protocols

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre

    In the literature on cryptographic protocols, it has been studied several times what happens if a classical protocol is attacked by a quantum adversary. Usually, this is taken to mean that the adversary runs a quantum algorithm, but communicates classically with the honest players. In several cases......, one can show that the protocol remains secure even under such an attack. However, there are also cases where the honest players are quantum as well, even if the protocol uses classical communication. For instance, this is the case when classical multiparty computation is used as a “subroutine......” in quantum multiparty computation. Furthermore, in the future, players in a protocol may employ quantum computing simply to improve efficiency of their local computation, even if the communication is supposed to be classical. In such cases, it no longer seems clear that a quantum adversary must be limited...

  10. Mitigation of Malicious Attacks on Networks

    CERN Document Server

    Schneider, Christian M; Andrade, Jose S; Havlin, Shlomo; Herrmann, Hans J; 10.1073/pnas.1009440108

    2011-01-01

    Terrorist attacks on transportation networks have traumatized modern societies. With a single blast, it has become possible to paralyze airline traffic, electric power supply, ground transportation or Internet communication. How and at which cost can one restructure the network such that it will become more robust against a malicious attack? We introduce a unique measure for robustness and use it to devise a method to mitigate economically and efficiently this risk. We demonstrate its efficiency on the European electricity system and on the Internet as well as on complex networks models. We show that with small changes in the network structure (low cost) the robustness of diverse networks can be improved dramatically while their functionality remains unchanged. Our results are useful not only for improving significantly with low cost the robustness of existing infrastructures but also for designing economically robust network systems.

  11. Making MANET secured against malicious attack

    Science.gov (United States)

    Kush, Ashwani; Taneja, Sunil; Kush, Shagun

    2011-12-01

    A Mobile Adhoc Network (MANET) is characterized by mobile nodes, multihop wireless connectivity, infrastructureless environment and dynamic topology. A recent trend in Ad Hoc network routing is the reactive ondemand philosophy where routes are established only when required. Stable Routing is of major concern in Ad hoc routing. Security and Power efficiency are the major concerns in this field. This paper is an effort to use security to achieve more reliable routing. The ad hoc environment is accessible to both legitimate network users and malicious attackers. The proposed scheme is intended to incorporate security aspect on existing protocols. The study will help in making protocol more robust against attacks to achieve stable routing in routing protocols.

  12. Two fatal tiger attacks in zoos.

    Science.gov (United States)

    Tantius, Britta; Wittschieber, Daniel; Schmidt, Sven; Rothschild, Markus A; Banaschak, Sibylle

    2016-01-01

    Two captive tiger attacks are presented that took place in Cologne and Münster zoos. Both attacks occurred when the handlers, intent on cleaning the enclosures, entered whilst the tigers accidently retained access to the location, and thus defended their territory against the perceived intruders. Both victims suffered fatal neck injuries from the bites. At Münster, colleagues managed to lure the tiger away from its victim to enable treatment, whilst the Cologne zoo tiger had to be shot in order to allow access to be gained. Whilst it was judged that human error led to the deaths of the experienced zookeepers, the investigation in Münster was closed as no third party was found to be at fault, whereas the Cologne zoo director was initially charged with being negligent. These charges were subsequently dismissed as safety regulations were found to be up to date.

  13. GNSS-based positioning: Attacks and Countermeasures

    CERN Document Server

    Papadimitratos, P

    2010-01-01

    Increasing numbers of mobile computing devices, user-portable, or embedded in vehicles, cargo containers, or the physical space, need to be aware of their location in order to provide a wide range of commercial services. Most often, mobile devices obtain their own location with the help of Global Navigation Satellite Systems (GNSS), integrating, for example, a Global Positioning System (GPS) receiver. Nonetheless, an adversary can compromise location-aware applications by attacking the GNSS-based positioning: It can forge navigation messages and mislead the receiver into calculating a fake location. In this paper, we analyze this vulnerability and propose and evaluate the effectiveness of countermeasures. First, we consider replay attacks, which can be effective even in the presence of future cryptographic GNSS protection mechanisms. Then, we propose and analyze methods that allow GNSS receivers to detect the reception of signals generated by an adversary, and then reject fake locations calculated because of ...

  14. Quantifying Shannon's Work Function for Cryptanalytic Attacks

    CERN Document Server

    van Son, R J J H

    2010-01-01

    Attacks on cryptographic systems are limited by the available computational resources. A theoretical understanding of these resource limitations is needed to evaluate the security of cryptographic primitives and procedures. This study uses an Attacker versus Environment game formalism based on computability logic to quantify Shannon's work function and evaluate resource use in cryptanalysis. A simple cost function is defined which allows to quantify a wide range of theoretical and real computational resources. With this approach the use of custom hardware, e.g., FPGA boards, in cryptanalysis can be analyzed. Applied to real cryptanalytic problems, it raises, for instance, the expectation that the computer time needed to break some simple 90 bit strong cryptographic primitives might theoretically be less than two years.

  15. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  16. Sharkonomics How to attack market leaders

    CERN Document Server

    Engeseth, Stefan

    2012-01-01

    Sharks are nature's most revered and feared killing machines. But if you study the behaviour of sharks, you will learn they are also highly strategic and efficient in the way they survive and thrive in nature's competitive environment. Inspired by the shark's evolved (over 420 million years) instincts and strategic moves, this book provides businesses with 10 ways on how to attack the market leaders, and take market share, in your sector.

  17. Afghanistan: Green-on-Blue Attacks

    Science.gov (United States)

    2013-05-02

    Afghanistan, December 2012, p 35 15 Yousafzai, Sami and Moreau , Ron, http://www.thedailybeast.com/newsweek/2012/08/26/ afghanistan-green-on-blue-killings...spike-insider-attacks- stress-ramadan-fasting, 24 August 2012 37 Yousafzai, Sami and Moreau , Ron, http://www.thedailybeast.com/newsweek/2012/08/26...afghanistan-green-on-blue-killings- explained.html, Afghanistan: ‘Green on Blue’ Killings Explained, 27 August 2012 38 Yousafzai, Sami and Moreau , Ron

  18. Coal Slag Attack-A Review

    Institute of Scientific and Technical Information of China (English)

    GUO Zongqi

    2004-01-01

    Although slagging coal gasifiers have served the commercial systems of electricity and chemical fertilizer productions for more than ten years, refractory service life still is a critical factor for gasifier availability. Some investigations were attracted, focusing on coal slag attack on high chromia refractories. A general introduction is made in order to have further understanding about slag corrosion in coal gasification environment. Microstructural deterioration and wear process of high chromia refractory in slagging gasifiers are discussed.

  19. Defending Against LDoS Attacks Using Fair AQM

    Directory of Open Access Journals (Sweden)

    Bianqin Wang

    2011-12-01

    Full Text Available According to the instant high rate and high intensity of LDoS attacks, this paper explores using fair queue management mechanism to mitigate their effect. We perform simulation experiments to evaluate the performance of fair AQM FRED and CHOKe under LDoS attacks. The simulation results show that they are able to reduce the impact of the attacks in various degrees. FRED outperforms CHOKe in throttling the attacks, but it is slightly inferior to CHOKe in time performance.

  20. Research and Implementation of Three HTTPS Attacks

    Directory of Open Access Journals (Sweden)

    Kefei Cheng

    2011-05-01

    Full Text Available With the rapid development of network applications, the issues of Network transmission security become very important. Therefore, SSL protocol is more and more widely used in a variety of network services. But the SSL protocol itself is not perfect, in practice, there are also problems. For the deficiencies of endpoint authentication in the SSL handshake process, the paper analyzes two kinds of defects existing in the SSL hand-shake process. Firstly, handshake process, in the first stage of the SSL connection, using plaintexts, existing the possibility of  being monitored and tampered. Secondly, SSL deployment of the actual application. Because of considering the factors about the performance of the network connection, that usually uses the way of switch connection based on HTTP protocol. In response to these deficiencies, this thesis adopts the two ways of forged certificates and converting the data stream from HTTPS to HTTP to attack them. In addition, a new attack mode against the data stream of HTTPS is designed and implemented. Experiments show that the above three methods cause significant security risks to HTTPS communications. Therefore, taking a static ARP table, enhanced certificate mechanism and mutual authentication of three different measures are proposed to enhance network security in the paper. It is shown that three ways can relative effectively defense against attacks on HTTPS in the experiments.

  1. A Formal Classification of Internet Banking Attacks and Vulnerabilities

    Directory of Open Access Journals (Sweden)

    Laerte Peotta

    2011-02-01

    Full Text Available A formal classification of attacks and vulnerabilities that affect current internet banking systems is presented along with two attacks which demonstrate the insecurity of such systems. Based ona thoroughanalysis of current security models, we propose a guidelines for designing secure internet banking systems which are not affected by the presented attacks and vulnerabilities.

  2. Link-layer jamming attacks on S-MAC

    NARCIS (Netherlands)

    Law, Yee Wei; Hartel, Pieter; Hartog, den Jerry; Havinga, Paul

    2005-01-01

    We argue that among denial-of-service (DoS) attacks, link-layer jamming is a more attractive option to attackers than radio jamming is. By exploiting the semantics of the link-layer protocol (aka MAC protocol), an attacker can achieve better efficiency than blindly jamming the radio signals alone. W

  3. Assessing Terrorist Motivations for Attacking Critical Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Ackerman, G; Abhayaratne, P; Bale, J; Bhattacharjee, A; Blair, C; Hansell, L; Jayne, A; Kosal, M; Lucas, S; Moran, K; Seroki, L; Vadlamudi, S

    2006-12-04

    Certain types of infrastructure--critical infrastructure (CI)--play vital roles in underpinning our economy, security and way of life. These complex and often interconnected systems have become so ubiquitous and essential to day-to-day life that they are easily taken for granted. Often it is only when the important services provided by such infrastructure are interrupted--when we lose easy access to electricity, health care, telecommunications, transportation or water, for example--that we are conscious of our great dependence on these networks and of the vulnerabilities that stem from such dependence. Unfortunately, it must be assumed that many terrorists are all too aware that CI facilities pose high-value targets that, if successfully attacked, have the potential to dramatically disrupt the normal rhythm of society, cause public fear and intimidation, and generate significant publicity. Indeed, revelations emerging at the time of this writing about Al Qaida's efforts to prepare for possible attacks on major financial facilities in New York, New Jersey, and the District of Columbia remind us just how real and immediate such threats to CI may be. Simply being aware that our nation's critical infrastructure presents terrorists with a plethora of targets, however, does little to mitigate the dangers of CI attacks. In order to prevent and preempt such terrorist acts, better understanding of the threats and vulnerabilities relating to critical infrastructure is required. The Center for Nonproliferation Studies (CNS) presents this document as both a contribution to the understanding of such threats and an initial effort at ''operationalizing'' its findings for use by analysts who work on issues of critical infrastructure protection. Specifically, this study focuses on a subsidiary aspect of CI threat assessment that has thus far remained largely unaddressed by contemporary terrorism research: the motivations and related factors that

  4. On Accelerated Black Holes

    CERN Document Server

    Letelier, P S; Letelier, Patricio S.; Oliveira, Samuel R.

    1998-01-01

    The C-metric is revisited and global interpretation of some associated spacetimes are studied in some detail. Specially those with two event horizons, one for the black hole and another for the acceleration. We found that the spacetime fo an accelerated Schwarzschild black hole is plagued by either conical singularities or lack of smoothness and compactness of the black hole horizon. By using standard black hole thermodynamics we show that accelerated black holes have higher Hawking temperature than Unruh temperature. We also show that the usual upper bound on the product of the mass and acceleration parameters (<1/sqrt(27)) is just a coordinate artifact. The main results are extended to accelerated Kerr black holes. We found that they are not changed by the black hole rotation.

  5. Unified communications forensics anatomy of common UC attacks

    CERN Document Server

    Grant, Nicholas Mr

    2013-01-01

    Unified Communications Forensics: Anatomy of Common UC Attacks is the first book to explain the issues and vulnerabilities and demonstrate the attacks, forensic artifacts, and countermeasures required to establish a secure (UC) environment. This book is written by leading UC experts Nicholas Grant and Joseph W. Shaw II and provides material never before found on the market, including: analysis of forensic artifacts in common UC attacks an in-depth look at established UC technologies and attack exploits hands-on understanding of UC attack vectors and associated countermeasures

  6. Link-layer jamming attacks on S-MAC

    OpenAIRE

    Law, Yee Wei; Hartel, Pieter; Hartog, den, D.N.; Havinga, Paul

    2005-01-01

    We argue that among denial-of-service (DoS) attacks, link-layer jamming is a more attractive option to attackers than radio jamming is. By exploiting the semantics of the link-layer protocol (aka MAC protocol), an attacker can achieve better efficiency than blindly jamming the radio signals alone. In this paper, we investigate some jamming attacks on S-MAC, the level of effectiveness and efficiency the attacks can potentially achieve, and a countermeasure that can be implemented against one o...

  7. Penetration and impact resistance of PDC cutters inclined at different attack angles

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to develop a rotary-percussive bit with diamond-enhanced cutters assisted by high pressure water jets,it is necessary to study the damage mechanism and the penetration properties of PDC cutters subject to different impactload level and rock types. Therefore the impact experiments of the single PDC cutters with different attack angles in fourrocks: black basalt, Missouri red granite, Halston limestone, and a very soft (Roubidoux) sandstone were carried out,and the effects of rake angles of PDC cutters on both the penetration and impact resistance of PDC cutters have been discussed in detail. Test results show that a PDC insert can withstand a very strong impact in compression but is easily damaged by impact shearing, the PDC cutters are more easily damaged by shearing if the attack angles are relatively small, the45 PDC cutters have the least penetration resistance among the cutters tested. Thus it is suggested that the attack anglesof PDC cutters should be larger than 30 for bits which must withstand impact from a hammer

  8. Efficient certificate-based signcryption secure against public key replacement attacks and insider attacks.

    Science.gov (United States)

    Lu, Yang; Li, Jiguo

    2014-01-01

    Signcryption is a useful cryptographic primitive that achieves confidentiality and authentication in an efficient manner. As an extension of signcryption in certificate-based cryptography, certificate-based signcryption preserves the merits of certificate-based cryptography and signcryption simultaneously. In this paper, we present an improved security model of certificate-based signcryption that covers both public key replacement attack and insider security. We show that an existing certificate-based signcryption scheme is insecure in our model. We also propose a new certificate-based signcryption scheme that achieves security against both public key replacement attacks and insider attacks. We prove in the random oracle model that the proposed scheme is chosen-ciphertext secure and existentially unforgeable. Performance analysis shows that the proposed scheme outperforms all the previous certificate-based signcryption schemes in the literature.

  9. Efficient Certificate-Based Signcryption Secure against Public Key Replacement Attacks and Insider Attacks

    Directory of Open Access Journals (Sweden)

    Yang Lu

    2014-01-01

    Full Text Available Signcryption is a useful cryptographic primitive that achieves confidentiality and authentication in an efficient manner. As an extension of signcryption in certificate-based cryptography, certificate-based signcryption preserves the merits of certificate-based cryptography and signcryption simultaneously. In this paper, we present an improved security model of certificate-based signcryption that covers both public key replacement attack and insider security. We show that an existing certificate-based signcryption scheme is insecure in our model. We also propose a new certificate-based signcryption scheme that achieves security against both public key replacement attacks and insider attacks. We prove in the random oracle model that the proposed scheme is chosen-ciphertext secure and existentially unforgeable. Performance analysis shows that the proposed scheme outperforms all the previous certificate-based signcryption schemes in the literature.

  10. Machine Learning Methods for Attack Detection in the Smart Grid.

    Science.gov (United States)

    Ozay, Mete; Esnaola, Inaki; Yarman Vural, Fatos Tunay; Kulkarni, Sanjeev R; Poor, H Vincent

    2016-08-01

    Attack detection problems in the smart grid are posed as statistical learning problems for different attack scenarios in which the measurements are observed in batch or online settings. In this approach, machine learning algorithms are used to classify measurements as being either secure or attacked. An attack detection framework is provided to exploit any available prior knowledge about the system and surmount constraints arising from the sparse structure of the problem in the proposed approach. Well-known batch and online learning algorithms (supervised and semisupervised) are employed with decision- and feature-level fusion to model the attack detection problem. The relationships between statistical and geometric properties of attack vectors employed in the attack scenarios and learning algorithms are analyzed to detect unobservable attacks using statistical learning methods. The proposed algorithms are examined on various IEEE test systems. Experimental analyses show that machine learning algorithms can detect attacks with performances higher than attack detection algorithms that employ state vector estimation methods in the proposed attack detection framework.

  11. Mitigating App-DDoS Attacks on Web Servers

    Directory of Open Access Journals (Sweden)

    Manisha M. Patil

    2011-07-01

    Full Text Available In this paper, a lightweight mechanism is proposed to mitigate session flooding and request flooding app-DDoS attacks on web servers. App-DDoS attack is Application layer Distributed Denial of Service attack. This attack prevents legitimate users from accessing services. Numbers of mechanisms are available and can be installed on routers and firewalls to mitigate network layer DDoS attacks like SYNflood attack, ping of death attack. But Network layer solution is not applicable because App-DDoS attacks are indistinguishable based on packets and protocols. A lightweight mechanism is proposed which uses trust to differentiate legitimate users and attackers. Trust to client is evaluated based on his visiting history and requests are scheduled in decreasing order of trust. In this mechanism trust information is stored at client side in the form of cookies. This mitigation mechanism can be implemented as a java package which can run separately and forward valid requests to server. This mechanism also mitigates request flooding attacks by using Client Puzzle Protocol. When server is under request flooding attack source throttling is done by imposing cost on client. Cost is collected in terms of CPU cycles.

  12. Activity Modelling and Comparative Evaluation of WSN MAC Security Attacks

    DEFF Research Database (Denmark)

    Pawar, Pranav M.; Nielsen, Rasmus Hjorth; Prasad, Neeli R.

    2012-01-01

    and initiate security attacks that disturb the normal functioning of the network in a severe manner. Such attacks affect the performance of the network by increasing the energy consumption, by reducing throughput and by inducing long delays. Of all existing WSN attacks, MAC layer attacks are considered....... The second aim of the paper is to simulate these attacks on hybrid MAC mechanisms, which shows the performance degradation of aWSN under the considered attacks. The modelling and implementation of the security attacks give an actual view of the network which can be useful in further investigating secure......Applications of wireless sensor networks (WSNs) are growing tremendously in the domains of habitat, tele-health, industry monitoring, vehicular networks, home automation and agriculture. This trend is a strong motivation for malicious users to increase their focus on WSNs and to develop...

  13. Replication Attack Mitigations for Static and Mobile WSN

    CERN Document Server

    Manjula, V; 10.5121/ijnsa.2011.3210

    2011-01-01

    Security is important for many sensor network applications. Wireless Sensor Networks (WSN) are often deployed in hostile environments as static or mobile, where an adversary can physically capture some of the nodes. once a node is captured, adversary collects all the credentials like keys and identity etc. the attacker can re-program it and replicate the node in order to eavesdrop the transmitted messages or compromise the functionality of the network. Identity theft leads to two types attack: clone and sybil. In particularly a harmful attack against sensor networks where one or more node(s) illegitimately claims an identity as replicas is known as the node replication attack. The replication attack can be exceedingly injurious to many important functions of the sensor network such as routing, resource allocation, misbehavior detection, etc. This paper analyzes the threat posed by the replication attack and several novel techniques to detect and defend against the replication attack, and analyzes their effect...

  14. Quantitative Verification and Synthesis of Attack-Defence Scenarios

    DEFF Research Database (Denmark)

    Aslanyan, Zaruhi; Nielson, Flemming; Parker, David

    2016-01-01

    which guarantee or optimise some quantitative property, such as the probability of a successful attack, the expected cost incurred, or some multi-objective trade-off between the two. We implement our approach, building upon the PRISM-games model checker, and apply it to a case study of an RFID goods...... analysis of quantitative properties of complex attack-defence scenarios, using an extension of attack-defence trees which models temporal ordering of actions and allows explicit dependencies in the strategies adopted by attackers and defenders. We adopt a game-theoretic approach, translating attack......-defence trees to two-player stochastic games, and then employ probabilistic model checking techniques to formally analyse these models. This provides a means to both verify formally specified security properties of the attack-defence scenarios and, dually, to synthesise strategies for attackers or defenders...

  15. LAN attack detection using Discrete Event Systems.

    Science.gov (United States)

    Hubballi, Neminath; Biswas, Santosh; Roopa, S; Ratti, Ritesh; Nandi, Sukumar

    2011-01-01

    Address Resolution Protocol (ARP) is used for determining the link layer or Medium Access Control (MAC) address of a network host, given its Internet Layer (IP) or Network Layer address. ARP is a stateless protocol and any IP-MAC pairing sent by a host is accepted without verification. This weakness in the ARP may be exploited by malicious hosts in a Local Area Network (LAN) by spoofing IP-MAC pairs. Several schemes have been proposed in the literature to circumvent these attacks; however, these techniques either make IP-MAC pairing static, modify the existing ARP, patch operating systems of all the hosts etc. In this paper we propose a Discrete Event System (DES) approach for Intrusion Detection System (IDS) for LAN specific attacks which do not require any extra constraint like static IP-MAC, changing the ARP etc. A DES model is built for the LAN under both a normal and compromised (i.e., spoofed request/response) situation based on the sequences of ARP related packets. Sequences of ARP events in normal and spoofed scenarios are similar thereby rendering the same DES models for both the cases. To create different ARP events under normal and spoofed conditions the proposed technique uses active ARP probing. However, this probing adds extra ARP traffic in the LAN. Following that a DES detector is built to determine from observed ARP related events, whether the LAN is operating under a normal or compromised situation. The scheme also minimizes extra ARP traffic by probing the source IP-MAC pair of only those ARP packets which are yet to be determined as genuine/spoofed by the detector. Also, spoofed IP-MAC pairs determined by the detector are stored in tables to detect other LAN attacks triggered by spoofing namely, man-in-the-middle (MiTM), denial of service etc. The scheme is successfully validated in a test bed.

  16. Quantum attacks on public-key cryptosystems

    CERN Document Server

    Yan, Song Y

    2013-01-01

    The cryptosystems based on the Integer Factorization Problem (IFP), the Discrete Logarithm Problem (DLP) and the Elliptic Curve Discrete Logarithm Problem (ECDLP) are essentially the only three types of practical public-key cryptosystems in use. The security of these cryptosystems relies heavily on these three infeasible problems, as no polynomial-time algorithms exist for them so far. However, polynomial-time quantum algorithms for IFP, DLP and ECDLP do exist, provided that a practical quantum computer exists.Quantum Attacks on Public-Key Cryptosystems presemts almost all?known quantum comput

  17. SQL Injection Attacks: Techniques and Protection Mechanisms

    Directory of Open Access Journals (Sweden)

    Santosh Soni

    2011-01-01

    Full Text Available When an internet user interacts in web environment by surfing the Net, sending electronic mail messages and participating in online forums lot of data is generated which may have user’s private information. If this information is captured by third party tools and techniques; it may cause a breach in end user privacy. In the Web environment, end user privacy is one of the most controversial legal issues. In this paper issues related to information leakage through SQL injection attacks are presented and protection mechanisms are also discussed.

  18. Cooperative Guidance for Multimissile Salvo Attack

    Institute of Scientific and Technical Information of China (English)

    Zhao Shiyu; Zhou Rui

    2008-01-01

    Cooperative guidance problems of multiple missiles are considered in this article. A cooperative guidance scheme, where coordi-nation algorithms and local guidance laws are combined together, is proposed. This scheme actually builds up a hierarchical cooperative guidance architecture, which may provide a general solution to the multimissile cooperative guidance problems. In the case of salvo attacks which require missiles to hit the target simultaneously, both centralized and distributed coordination algorithms are derived based on the impact-time-control guidance (ITCG) law. Numerical simulations are performed to demonstrate the effectiveness of the proposed approaches.

  19. Cardiogenic embolism producing crescendo transient ischemic attacks.

    Science.gov (United States)

    Geraghty, Patrick J; Oak, Jack; Choi, Eric T

    2005-09-01

    Lateralizing, repetitive transient ischemic attacks are characteristic of symptomatic carotid bifurcation atherosclerotic plaques. We report a case in which a cardiogenic embolus, after lodging at the left carotid bifurcation, produced crescendo episodes of expressive aphasia and mild right upper extremity weakness. Complete neurological recovery was achieved following emergent carotid embolectomy and endarterectomy. This case demonstrates that the laminar nature of internal carotid blood flow may result in the localization of embolic events to a single region of the cerebral vasculature, regardless of the source lesion in the carotid artery. The role of endoluminal techniques in the diagnosis and management of such lesions is discussed.

  20. A Method to Defend File-Attacking

    Institute of Scientific and Technical Information of China (English)

    HE Hongjun; LUO Li; CAO Sihua; FENG Tao; PAN Li; ZOU Zhiji

    2006-01-01

    The paper points out that the deep reason why modern computer system fails to defense malware lies in that user has no right to control the access of information, and proposes an explicit authorization mechanism. Its basic idea is that user explicitly authorizes program the file set it can access, and monitor all file access operations; once program requests to access file out of the authorized file set, refuse it, and this means that the program is malicious or has design errors. Computers based on this novel mechanism can protect information from attacking reliably, and have good software and hardware compatibility. A testing system is presented to validate our theory.

  1. Bobcat attack on a cottontail rabbit

    Science.gov (United States)

    Biggins, D.E.; Biggins, D.M.

    2006-01-01

    We observed an attack by a bobcat (Lynx rufus) on a cottontail rabbit (Sylvilagus) that involved stealthy approach by the cat for >1 h, followed by a 12.3-s chase covering 116.0 m for the cat and 128.4 m for the rabbit. During the chase, the route of the cat from starting point to kill site was more direct than the semi-circular route of the rabbit. Stride lengths for the cat and total distance covered by the chase were longer than those previously reported for bobcats.

  2. Suicide bomb attack causing penetrating craniocerebral injury

    Institute of Scientific and Technical Information of China (English)

    Manzar Hussain; Muhammad Ehsan Bari

    2013-01-01

    Penetrating cerebral injuries caused by foreign bodies are rare in civilian neurosurgical trauma,although there are various reports of blast or gunshot injuries in warfare due to multiple foreign bodies like pellets and nails.In our case,a 30-year-old man presented to neurosurgery clinic with signs and symptoms of right-sided weakness after suicide bomb attack.The skull X-ray showed a single intracranial nail.Small craniotomy was done and the nail was removed with caution to avoid injury to surrounding normal brain tissue.At 6 months' follow-up his right-sided power improved to against gravity.

  3. Discovery of Peptide-based Inhibitors against Dendrotoxin B from Black Mamba through Phage Display Screening

    DEFF Research Database (Denmark)

    O. Cob, Saioa; Munk, Andreas; Laustsen, Andreas Hougaard

    The black mamba (Dendroaspis polylepis) is Africa’s most feared snake due to its potent, rapidacting venom and its speed of attack. The most abundant toxins in D. polylepis venom are the Kunitz-type proteinase inhibitors, dendrotoxins, which are unique for mamba. Dendrotoxinsare poorly neutralized...

  4. Extremal Hairy Black Holes

    CERN Document Server

    Gonzalez, P A; Saavedra, Joel; Vasquez, Yerko

    2014-01-01

    We consider a gravitating system consisting of a scalar field minimally coupled to gravity with a self-interacting potential and an U(1) electromagnetic field. Solving the coupled Einstein-Maxwell-scalar system we find exact hairy charged black hole solutions with the scalar field regular everywhere. We go to the zero temperature limit and we study the effect of the scalar field on the near horizon geometry of an extremal black hole. We find that except a critical value of the charge of the black hole there is also a critical value of the charge of the scalar field beyond of which the extremal black hole is destabilized. We study the thermodynamics of these solutions and we find that if the space is flat then at low temperature the Reissner-Nordstr\\"om black hole is thermodynamically preferred, while if the space is AdS the hairy charged black hole is thermodynamically preferred at low temperature.

  5. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  6. Public knowledge of heart attack symptoms in Beijing residents

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qing-tan; HU Da-yi; YANG Jin-gang; ZHANG Shou-yan; ZHANG Xin-quan; LIU Shu-shan

    2007-01-01

    Background Definitive treatment for heart attack is early reperfusion with either angioplasty or thrombolytic therapy,and the benefit is strictly time-dependent. Patient outcomes are improved with either therapy when initiated as soon as possible. Recognition of heart attack symptoms is logically tied to taking action to receive prompt emergency care.Inadequate knowledge of heart attack symptoms may prolong delay. The purpose of this study was to document knowledge about heart attack symptoms in Beijing residents and to identify the characteristics associated with increased knowledge of heart attack.Methods A structured survey was conducted in 18 communities in Beijing from March 1 through June 10 in 2006.Addresses and participants were selected randomly following a stratification. The survey was designed to collect knowledge of heart attack symptoms from sampled adults in each community.Results A total of 4627 respondents completed the questionnaires correctly, and 50.29% of them were female. Totally 64.15% of the respondents reported chest pain or discomfort (common symptoms) as a symptom of heart attack; 75.38% reported at least one of the following eight symptoms as a symptom of heart attack: back pain, shortness of breath, arm pain or numbness, nausea or vomiting, neck, jaw or shoulder pain, epigastric pain, sweating, weakness (less common symptoms); 20.36% correctly reported four or more heart attack symptoms, only 7.4% knew all the correct heart attack symptoms, and 28.94% knew about reperfusion therapy for heart attack; 31.7% reported to call 120 or 999 while having a heart attack themselves; however 89.6% reported to call 120 or 999 when someone else is suffering from a heart attack. Very old persons and those with health insurance coverage, high education level, high household income, longer living in Beijing and previous experience with heart disease had greater knowledge of heart attack symptoms.Conclusions Public knowledge of common heart attack

  7. Black Branes as Piezoelectrics

    CERN Document Server

    Armas, Jay; Obers, Niels A

    2012-01-01

    We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six.

  8. Black branes as piezoelectrics.

    Science.gov (United States)

    Armas, Jay; Gath, Jakob; Obers, Niels A

    2012-12-14

    We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six.

  9. Perturbations around black holes

    CERN Document Server

    Wang, B

    2005-01-01

    Perturbations around black holes have been an intriguing topic in the last few decades. They are particularly important today, since they relate to the gravitational wave observations which may provide the unique fingerprint of black holes' existence. Besides the astrophysical interest, theoretically perturbations around black holes can be used as testing grounds to examine the proposed AdS/CFT and dS/CFT correspondence.

  10. Enhancing network robustness for malicious attacks

    CERN Document Server

    Zeng, An

    2012-01-01

    In a recent work [Proc. Natl. Acad. Sci. USA 108, 3838 (2011)], the authors proposed a simple measure for network robustness under malicious attacks on nodes. With a greedy algorithm, they found the optimal structure with respect to this quantity is an onion structure in which high-degree nodes form a core surrounded by rings of nodes with decreasing degree. However, in real networks the failure can also occur in links such as dysfunctional power cables and blocked airlines. Accordingly, complementary to the node-robustness measurement ($R_{n}$), we propose a link-robustness index ($R_{l}$). We show that solely enhancing $R_{n}$ cannot guarantee the improvement of $R_{l}$. Moreover, the structure of $R_{l}$-optimized network is found to be entirely different from that of onion network. In order to design robust networks resistant to more realistic attack condition, we propose a hybrid greedy algorithm which takes both the $R_{n}$ and $R_{l}$ into account. We validate the robustness of our generated networks a...

  11. Recent computer attacks via Instant Messaging

    CERN Multimedia

    IT Department

    2008-01-01

    Be cautious of any unexpected messages containing web links even if they appear to come from known contacts. If you happen to click on such a link and if your permission is requested to run or install software, always decline it. Several computers at CERN have recently been broken into by attackers who have tricked users of Instant Messaging applications (e.g. MSN, Yahoo Messenger, etc.) into clicking on web links which appeared to come from known contacts. The links appeared to be photos from ‘friends’ and requested software to be installed. In practice, attacker software was installed and the messages did not come from real contacts. In the past such fake messages were mainly sent by email but now a wider range of applications are being targeted, including Instant Messaging. Cybercriminals are making growing use of fake messages to try to trick you into clicking on Web links which will help them to install malicious software on your computer. Anti-virus software cann...

  12. Gemcitabine-induced gouty arthritis attacks.

    Science.gov (United States)

    Bottiglieri, Sal; Tierson, Neil; Patel, Raina; Mo, Jae-Hyun; Mehdi, Syed

    2013-09-01

    In this case report, we review the experience of a patient who presented with early stage pancreatic cancer (Stage IIb) who underwent a Whipple procedure and adjuvant chemoradiation. The patient's past medical history included early stage colon cancer in remission, post-traumatic-stress-disorder, hypertension, hyperlipidemia, osteoarthritis, gout, and pre-diabetes. Chemotherapy initially consisted of weekly gemcitabine. The patient developed acute gouty attacks after his second dose of gemcitabine, which brought him to the emergency room for emergent treatment on several occasions. Gemcitabine was held and treatment began with fluorouracil and concurrent radiation. After completion of his chemoradiation with fluorouracil, he was again treated with weekly gemcitabine alone. As soon as the patient started gemcitabine chemotherapy the patient developed gouty arthritis again, requiring discontinuation of chemotherapy. The patient received no additional treatment until his recent recurrence 8 months later where gemcitabine chemotherapy was again introduced with prophylactic medications consisting of allopurinol 100 mg by mouth daily and colchicine 0.6 mg by mouth daily throughout gemcitabine chemotherapy, and no signs of gouty arthritis occurred. To our knowledge, this is the first case report describing gout attacks associated with gemcitabine therapy. There is limited data available describing the mechanism that gouty arthritis may be precipitated from gemcitabine chemotherapy. Further monitoring and management may be required in patients receiving gemcitabine chemotherapy with underlying gout.

  13. Swarm Flooding Attack against Directed Diffusion in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Ibrahim S. I. Abuhaiba

    2012-11-01

    Full Text Available The objective of this paper is to study the vulnerabilities of sensor networks, design, and implement new approaches for routing attack. As one of the cornerstones of network infrastructure, routing systems are facing more threats than ever; they are vulnerable by nature and challenging to protect. We present a new attack, Swarm Flooding Attack, against Directed Diffusion based WSNs, which targets the consumption of sensors computational resources, such as bandwidth, disk space, or processor time. Two variants of swarm attack have been introduced: Bee and Ant. Both approaches are inspired from the natural swarming difference between bees and ants. In all cases, the strategy used to mount an attack is the same. An attack consists of a set of malicious user queries represented by interests that are inserted into the network. However, the two forms of attack vary in the synchronization aspects among attackers. These types of attacks are hard to defend against as illustrated. For each of the proposed attack models, we present analysis, simulation, and experimental measurements. We show that the system achieves maximal damage on system performance represented by many metrics.

  14. Simulation of Attacks for Security in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Alvaro Diaz

    2016-11-01

    Full Text Available The increasing complexity and low-power constraints of current Wireless Sensor Networks (WSN require efficient methodologies for network simulation and embedded software performance analysis of nodes. In addition, security is also a very important feature that has to be addressed in most WSNs, since they may work with sensitive data and operate in hostile unattended environments. In this paper, a methodology for security analysis of Wireless Sensor Networks is presented. The methodology allows designing attack-aware embedded software/firmware or attack countermeasures to provide security in WSNs. The proposed methodology includes attacker modeling and attack simulation with performance analysis (node’s software execution time and power consumption estimation. After an analysis of different WSN attack types, an attacker model is proposed. This model defines three different types of attackers that can emulate most WSN attacks. In addition, this paper presents a virtual platform that is able to model the node hardware, embedded software and basic wireless channel features. This virtual simulation analyzes the embedded software behavior and node power consumption while it takes into account the network deployment and topology. Additionally, this simulator integrates the previously mentioned attacker model. Thus, the impact of attacks on power consumption and software behavior/execution-time can be analyzed. This provides developers with essential information about the effects that one or multiple attacks could have on the network, helping them to develop more secure WSN systems. This WSN attack simulator is an essential element of the attack-aware embedded software development methodology that is also introduced in this work.

  15. Simulation of Attacks for Security in Wireless Sensor Network.

    Science.gov (United States)

    Diaz, Alvaro; Sanchez, Pablo

    2016-11-18

    The increasing complexity and low-power constraints of current Wireless Sensor Networks (WSN) require efficient methodologies for network simulation and embedded software performance analysis of nodes. In addition, security is also a very important feature that has to be addressed in most WSNs, since they may work with sensitive data and operate in hostile unattended environments. In this paper, a methodology for security analysis of Wireless Sensor Networks is presented. The methodology allows designing attack-aware embedded software/firmware or attack countermeasures to provide security in WSNs. The proposed methodology includes attacker modeling and attack simulation with performance analysis (node's software execution time and power consumption estimation). After an analysis of different WSN attack types, an attacker model is proposed. This model defines three different types of attackers that can emulate most WSN attacks. In addition, this paper presents a virtual platform that is able to model the node hardware, embedded software and basic wireless channel features. This virtual simulation analyzes the embedded software behavior and node power consumption while it takes into account the network deployment and topology. Additionally, this simulator integrates the previously mentioned attacker model. Thus, the impact of attacks on power consumption and software behavior/execution-time can be analyzed. This provides developers with essential information about the effects that one or multiple attacks could have on the network, helping them to develop more secure WSN systems. This WSN attack simulator is an essential element of the attack-aware embedded software development methodology that is also introduced in this work.

  16. Minimizing Expected Maximum Risk from Cyber-Attacks with Probabilistic Attack Success

    Energy Technology Data Exchange (ETDEWEB)

    Bhuiyan, Tanveer H.; Nandi, Apurba; Medal, Hugh; Halappanavar, Mahantesh

    2016-07-16

    The goal of our work is to enhance network security by generating partial cut-sets, which are a subset of edges that remove paths from initially vulnerable nodes (initial security conditions) to goal nodes (critical assets), on an attack graph given costs for cutting an edge and a limited overall budget.

  17. Dishonest Behaviors in Online Rating Systems: Cyber Competition, Attack Models, and Attack Generator

    Institute of Scientific and Technical Information of China (English)

    Ya-Fei Yang; Qin-Yuan Feng; Yen(Lindsay)Sun; Ya-Fei Dai

    2009-01-01

    Recently,online rating systems are gaining popularity.Dealing with unfair ratings in such systems has been recognized as an important but challenging problem.Many unfair rating detection approaches have been developed and evaluated against simple attack models.However,the lack of unfair rating data from real human users and realistic attack behavior models has become an obstacle toward developing reliable rating systems.To solve this problem,we design and launch a rating challenge to coHect anfair rating data from real human users.In order to broaden the scope of the data collection,we also develop a comprehensive signal-based unfair rating detection system.Based on the analysis of real attack data,we discover important features in unfair ratings,build attack models,and develop an unfair rating generator.The models and generator developed in this paper can be directly used to test current rating aggregation systems,as well as to assist the design of future rating systems.

  18. Asymptotic Black Holes

    CERN Document Server

    Ho, Pei-Ming

    2016-01-01

    Following earlier works on the KMY model of black-hole formation and evaporation, we construct the metric for a matter sphere in gravitational collapse, with the back-reaction of pre-Hawking radiation taken into consideration. The mass distribution and collapsing velocity of the matter sphere are allowed to have an arbitrary radial dependence. We find that a generic gravitational collapse asymptote to a universal configuration which resembles a black hole but without horizon. This approach clarifies several misunderstandings about black-hole formation and evaporation, and provides a new model for black-hole-like objects in the universe.

  19. Asymptotic black holes

    Science.gov (United States)

    Ho, Pei-Ming

    2017-04-01

    Following earlier works on the KMY model of black-hole formation and evaporation, we construct the metric for a matter sphere in gravitational collapse, with the back-reaction of pre-Hawking radiation taken into consideration. The mass distribution and collapsing velocity of the matter sphere are allowed to have an arbitrary radial dependence. We find that a generic gravitational collapse asymptote to a universal configuration which resembles a black hole but without horizon. This approach clarifies several misunderstandings about black-hole formation and evaporation, and provides a new model for black-hole-like objects in the universe.

  20. Black Hole Thermodynamics

    CERN Document Server

    Carlip, S

    2014-01-01

    The discovery in the early 1970s that black holes radiate as black bodies has radically affected our understanding of general relativity, and offered us some early hints about the nature of quantum gravity. In this chapter I will review the discovery of black hole thermodynamics and summarize the many independent ways of obtaining the thermodynamic and (perhaps) statistical mechanical properties of black holes. I will then describe some of the remaining puzzles, including the nature of the quantum microstates, the problem of universality, and the information loss paradox.

  1. AN INTEGRATED APPROACH AGAINST APP-DDoS FOR MITIGATING IP SPOOFED ATTACKS AND MAC ATTACKS

    Directory of Open Access Journals (Sweden)

    S.PRABHA

    2013-06-01

    Full Text Available The nature of data traffic flow from wired network is extremely different from wireless network. Therefore as the DDoS application service attacks from the wired ones are produced from IP frame and wireless ones from Media Access Control (MAC frame. The variant in the frames motivates the requirement of enhanced resistive mechanism for application DDoS attacks for interfaced internet application servers enabled with both wired and wireless infrastructure. With the wired and wireless interface access in internet application services made us to present an Application Service Network Request Identification (ASNRI scheme in this work. ASNRI scheme first identifies the type of data stream frame and input it to the IHBCM method. In Bayes packet classifier, separated data frames are verified for its malicious characteristic in its data frame attributes to filter out the malicious data packet frames. Simulations are carried out to evaluate the performance of ASNRI to conventional application DDoS attack resistance schemes by measuring its true positive and true negative of data frame classification and its malicious attack resistance rate at different traffic volumes.In the process of applying Bayes has been planned to provide insight into the behavior of this technique itself. In this paper has been illustrated the sensitivity of the algorithm to its initial assumptions and demonstrated the use of two techniques, one to break the Gaussian assumptions and the other to improve the quality of discriminators as input, It leads to significant improvements in the accuracy of the Bayes technique. Integrated Hidden Markov Model (HMM and Bayes Packet Classifier based Gaussian distribution factor to detect and respond to the App-DDoS attacks if they occur during a flash crowd event for both dynamic and stationary objects.

  2. Detection and Defense Against Packet Drop Attack in MANET

    Directory of Open Access Journals (Sweden)

    Tariq Ahamad

    2016-02-01

    Full Text Available MANET is a temporary network for a specified work and with the enormous growth MANETs it is becoming important and simultaneously challenging to protect this network from attacks and other threats. Packet drop attack or gray hole attack is the easiest way to make a denial of service in these dynamic networks. In this attack the malicious node reflects itself as the shortest path and receives all the packets and drops the selected packets in order to give the user the service that that is not correct. It is a specific kind of attack and protects the network and user from detecting this malicious activity. In this article I have proposed an efficient for step technique that confirms that this attack can be detected and defended with least efforts and resource consumption.

  3. Extended Password Recovery Attacks against APOP, SIP, and Digest Authentication

    Science.gov (United States)

    Sasaki, Yu; Wang, Lei; Ohta, Kazuo; Kunihiro, Noboru

    In this paper, we propose password recovery attacks against challenge-response authentication protocols. Our attacks use a message difference for a MD5 collision attack proposed in IEICE 2008. First, we show how to efficiently find a message pair that collides with the above message difference. Second, we show that a password used in authenticated post office protocol (APOP) can be recovered practically. We also show that the password recovery attack can be applied to a session initiation protocol (SIP) and digest authentication. Our attack can recover up to the first 31 password characters in a short time and up to the first 60 characters faster than the naive search method. We have implemented our attack and confirmed that 31 characters can be successfully recovered.

  4. Relating Admissibility Standards for Digital Evidence to Attack Scenario Reconstruction

    Directory of Open Access Journals (Sweden)

    Changwei Liu

    2014-09-01

    Full Text Available Attackers tend to use complex techniques such as combining multi-step, multi-stage attack with anti-forensic tools to make it difficult to find incriminating evidence and reconstruct attack scenarios that can stand up to the expected level of evidence admissibility in a court of law. As a solution, we propose to integrate the legal aspects of evidence correlation into a Prolog based reasoner to address the admissibility requirements by creating most probable attack scenarios that satisfy admissibility standards for substantiating evidence. Using a prototype implementation, we show how evidence extracted by using forensic tools can be integrated with legal reasoning to reconstruct network attack scenarios. Our experiment shows this implemented reasoner can provide pre-estimate of admissibility on a digital crime towards an attacked network.

  5. Variability of clinical features in attacks of migraine with aura

    DEFF Research Database (Denmark)

    Hansen, Jakob M; Goadsby, Peter J; Charles, Andrew C

    2016-01-01

    BACKGROUND: There is significant variability in the clinical presentation of migraine, both among patients, and between attacks in an individual patient. We examined clinical features of migraine with aura in a large group of patients enrolled in a clinical trial, and compared retrospective...... migraine attack characteristics reported upon enrollment in the trial with those recorded prospectively in the trial. METHODS: Patients with migraine (n = 267) with typical visual aura in more than 30% of their attacks were enrolled from 16 centers for a clinical trial. Upon enrollment, patients provided...... a detailed retrospective description of the clinical features of their attacks of migraine. During the trial, clinical symptoms in migraine attacks starting with aura were recorded prospectively in 861 attacks. RESULTS: Retrospectively reported visual aura symptoms were variable and often overlapping...

  6. Detection and Isolation of Packet Dropping Attacker in MANETs

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed Abdalla

    2013-05-01

    Full Text Available Several approaches have been proposed for Intrusion Detection Systems (IDS in Mobile Ad hoc Networks (MANETs. Due to lack of MANETs infrastructure and well defined perimeter MANETs are susceptible to a variety of attacker types. To develop a strong security mechanism it is necessary to understand how malicious nodes can attack the MANETs. A new IDS mechanism is presented based on End-to-End connection for securing Optimized Link State Routing (OLSR routing protocol. This new mechanism is named as Detection and Isolation Packet Dropped Attackers in MANETs (DIPDAM. DIPDAM mechanism based on three ID messages Path Validation Message (PVM , Attacker Finder Message (AFM and Attacker Isolation Message (AIM. DIPDAM mechanism based on End-to-End (E2E communication between the source and the destination is proposed. The simulation results showed that the proposed mechanism is able to detect any number of attackers while keeping a reasonably low overhead in terms of network traffic.

  7. Preventing Recommendation Attack in Trust-Based Recommender Systems

    Institute of Scientific and Technical Information of China (English)

    Fu-Guo Zhang

    2011-01-01

    Despite its success,similarity-based collaborative filtering suffers from some limitations,such as scalability,sparsity and recommendation attack.Prior work has shown incorporating trust mechanism into traditional collaborative filtering recommender systems can improve these limitations.We argue that trust-based recommender systems are facing novel recommendation attack which is different from the profile injection attacks in traditional recommender system.To the best of our knowledge,there has not any prior study on recommendation attack in a trust-based recommender system.We analyze the attack problem,and find that "victim" nodes play a significant role in the attack.Furthermore,we propose a data provenance method to trace malicious users and identify the "victim" nodes as distrust users of recommender system.Feasibility study of the defend method is done with the dataset crawled from Epinions website.

  8. Attacks on Web Based Software and Modelling Defence Mechanisms

    Directory of Open Access Journals (Sweden)

    D.R. Ingle

    2012-08-01

    Full Text Available The software life cycle was in use to develop the good software. Now a day’s the software development life cycle should incorporate the security features. Input Validation Attacks are one of the most wide spread forms of vulnerability on the Web application. Our main intention is to focuses on detection and prevention of Input Validation attacks like SQL Injection, Cross Site Scripting and Buffer Overflow by incorporating security in software development life cycle. We have introduced a novel approach of preclusion and uncovering of Input Validation Attacks. SQL Injection , Cross Site Scripting, A buffer overflow attacks, experimentations are made to do these attacks on various sides and the defense mechanism model is proposed to avoid these attacks on the code.

  9. Attacker Control and Impact for Confidentiality and Integrity

    CERN Document Server

    Askarov, Aslan

    2011-01-01

    Language-based information flow methods offer a principled way to enforce strong security properties, but enforcing noninterference is too inflexible for realistic applications. Security-typed languages have therefore introduced declassification mechanisms for relaxing confidentiality policies, and endorsement mechanisms for relaxing integrity policies. However, a continuing challenge has been to define what security is guaranteed when such mechanisms are used. This paper presents a new semantic framework for expressing security policies for declassification and endorsement in a language-based setting. The key insight is that security can be characterized in terms of the influence that declassification and endorsement allow to the attacker. The new framework introduces two notions of security to describe the influence of the attacker. Attacker control defines what the attacker is able to learn from observable effects of this code; attacker impact captures the attacker's influence on trusted locations. This ap...

  10. Why cryptography should not rely on physical attack complexity

    CERN Document Server

    Krämer, Juliane

    2015-01-01

    This book presents two practical physical attacks. It shows how attackers can reveal the secret key of symmetric as well as asymmetric cryptographic algorithms based on these attacks, and presents countermeasures on the software and the hardware level that can help to prevent them in the future. Though their theory has been known for several years now, since neither attack has yet been successfully implemented in practice, they have generally not been considered a serious threat. In short, their physical attack complexity has been overestimated and the implied security threat has been underestimated. First, the book introduces the photonic side channel, which offers not only temporal resolution, but also the highest possible spatial resolution. Due to the high cost of its initial implementation, it has not been taken seriously. The work shows both simple and differential photonic side channel analyses. Then, it presents a fault attack against pairing-based cryptography. Due to the need for at least two indepe...

  11. REVIEW CLUSTERING MECHANISMS OF DISTRIBUTED DENIAL OF SERVICE ATTACKS

    Directory of Open Access Journals (Sweden)

    Wesam Bhaya

    2014-01-01

    Full Text Available Distributed Denial of Service attacks (DDoS overwhelm network resources with useless or harmful packets and prevent normal users from accessing these network resources. These attacks jeopardize the confidentiality, privacy and integrity of information on the internet. Since it is very difficult to set any predefined rules to correctly identify genuine network traffic, an anomaly-based Intrusion Detection System (IDS for network security is commonly used to detect and prevent new DDoS attacks. Data mining methods can be used in intrusion detection systems, such as clustering k-means, artificial neural network. Since the clustering methods can be used to aggregate similar objects, they can detect DDoS attacks to reduce false-positive rates. In this study, a review of DDoS attacks using clustering data mining techniques is presented. A review illustrates the most recent, state-of-the art science for clustering techniques to detect DDoS attacks.

  12. Breakdown of an Inhomogeneous Scale- Free Network Under Intentional Attack

    Institute of Scientific and Technical Information of China (English)

    LIN Guo-Ji; CHENG Xiang; OU-YANG Qi

    2003-01-01

    Using a recently introduced network model with node and connection diversity, we study the breakdown of different scale-free networks under intentional attacks. Our simulation results show that inhomogeneous networks are more sensitive to intentional attack than the homogeneous ones and that the centralization of the networks is an important variable, reflecting the characteristics of the network under intentional attack. Using a recently introduced method we can theoretically develop the critical point of the inhomogeneous networks.

  13. Cooperative Defense Against DDoS Attack using GOSSIP Protocol

    OpenAIRE

    Sohail, Imran; Hayat,Sikandar

    2009-01-01

    The ability to detect and prevent a network from DDoS attack and to ensure the high quality infrastructure is a back bone of today’s network security issues. In this thesis, we have successfully validated an algorithm using OmNet++ Ver. 4.0 simulation to show how a DDoS attack can be detected and how the nodes can be protected from such an attack using GOSSIP protocol.

  14. Participant attack on quantum secret sharing based on entanglement swapping

    Institute of Scientific and Technical Information of China (English)

    Song Ting-Ting; Zhang Jie; Gao Fei; Wen Qiao-Yan; Zhu Fu-Chen

    2009-01-01

    The security of quantum secret sharing based on entanglement swapping is revisited and a participant attack is presented.In this attack two dishonest agents together can illegally recover the secret quantum state without the help of any other controller,and it will not be detected by any othcr users.Furthermore,by modifying the distribution process of particles and adding a detection step after each distribution process,we propose an improved protocol which can resist this kind of attack.

  15. Non-harmful insertion of data mimicking computer network attacks

    Energy Technology Data Exchange (ETDEWEB)

    Neil, Joshua Charles; Kent, Alexander; Hash, Jr, Curtis Lee

    2016-06-21

    Non-harmful data mimicking computer network attacks may be inserted in a computer network. Anomalous real network connections may be generated between a plurality of computing systems in the network. Data mimicking an attack may also be generated. The generated data may be transmitted between the plurality of computing systems using the real network connections and measured to determine whether an attack is detected.

  16. The Sniper Attack: Anonymously Deanonymizing and Disabling the Tor Network

    Science.gov (United States)

    2014-02-01

    ping-o-death. html. [40] S. Savage, N. Cardwell, D. Wetherall, and T. Anderson, “TCP Con- gestion Control with a Misbehaving Receiver,” ACM SIGCOMM CCR...forcing them to choose guard nodes in control of the adversary. Finally, we discuss defenses against the Sniper Attack that provably render the attack...in control of the adversary. Our attack thus imposes real, significant threats to Tor’s users,1 and we believe it constitutes the most devastating

  17. New trends in Internet attacks: Clickjacking in detail

    OpenAIRE

    Thoresen, Torgeir Dahlqvist

    2009-01-01

    While the complexity of web applications and their functionality continually increase, so do the number of opportunities for an attacker to launch successful attacks against a web application's users. In this thesis we investigate and describe clickjacking in great detail. To our knowledge, this work represent the first systematic scientific approach to assess clickjacking that also consider the attack's social consequences for users' security through an experiment and survey. We address the...

  18. Securing Oracle Database from Search Engines Attack

    Directory of Open Access Journals (Sweden)

    N. M. A. Ayad

    2012-09-01

    Full Text Available Database security has recently become A victim of misused search engines. This can be accomplished simply by searching for a URL containing the name of the vulnerable web page or application. Oracle ships several sample web applications along with its databases. The security holes in these applications allow a web user to exploit SQL Injection to submit arbitrary SQL statements to the database. These applications are enabled by default, listening on port 7777, and known to be vulnerable to SQL Injection. This paper focuses on exploiting search engines to attack oracle database using SQL injection technique from web applications, when a website is vulnerable by SQL injection and this side is connected by oracle database vulnerable by SQL injection.

  19. Inorganic nanoparticles engineered to attack bacteria.

    Science.gov (United States)

    Miller, Kristen P; Wang, Lei; Benicewicz, Brian C; Decho, Alan W

    2015-11-01

    Antibiotics were once the golden bullet to constrain infectious bacteria. However, the rapid and continuing emergence of antibiotic resistance (AR) among infectious microbial pathogens has questioned the future utility of antibiotics. This dilemma has recently fueled the marriage of the disparate fields of nanochemistry and antibiotics. Nanoparticles and other types of nanomaterials have been extensively developed for drug delivery to eukaryotic cells. However, bacteria have very different cellular architectures than eukaryotic cells. This review addresses the chemistry of nanoparticle-based antibiotic carriers, and how their technical capabilities are now being re-engineered to attack, kill, but also non-lethally manipulate the physiologies of bacteria. This review also discusses the surface functionalization of inorganic nanoparticles with small ligand molecules, polymers, and charged moieties to achieve drug loading and controllable release.

  20. Attacks on lexical natural language steganography systems

    Science.gov (United States)

    Taskiran, Cuneyt M.; Topkara, Umut; Topkara, Mercan; Delp, Edward J.

    2006-02-01

    Text data forms the largest bulk of digital data that people encounter and exchange daily. For this reason the potential usage of text data as a covert channel for secret communication is an imminent concern. Even though information hiding into natural language text has started to attract great interest, there has been no study on attacks against these applications. In this paper we examine the robustness of lexical steganography systems.In this paper we used a universal steganalysis method based on language models and support vector machines to differentiate sentences modified by a lexical steganography algorithm from unmodified sentences. The experimental accuracy of our method on classification of steganographically modified sentences was 84.9%. On classification of isolated sentences we obtained a high recall rate whereas the precision was low.

  1. [Acute ischemic proctitis following an epileptic attack

    DEFF Research Database (Denmark)

    Klintmann, C.K.; Hillingso, J.G.; Glenthøj, Andreas

    2008-01-01

    Acute ischemic proctitis is a rare diagnosis mainly because the rectum is supplied by an extensive arterial network. Consequently, in more than 90% of patients with ischemic colitis the rectum is spared. Previously reported cases are related to severe vascular insufficiency of the rectal circulat......Acute ischemic proctitis is a rare diagnosis mainly because the rectum is supplied by an extensive arterial network. Consequently, in more than 90% of patients with ischemic colitis the rectum is spared. Previously reported cases are related to severe vascular insufficiency of the rectal...... circulation caused by systemic atherosclerosis, usually following aortic or aortoiliac operations. We report one case of acute ischemic proctitis following an epileptic attack Udgivelsesdato: 2008/9/29...

  2. Detecting Cyber Attacks On Nuclear Power Plants

    Science.gov (United States)

    Rrushi, Julian; Campbell, Roy

    This paper proposes an unconventional anomaly detection approach that provides digital instrumentation and control (I&C) systems in a nuclear power plant (NPP) with the capability to probabilistically discern between legitimate protocol frames and attack frames. The stochastic activity network (SAN) formalism is used to model the fusion of protocol activity in each digital I&C system and the operation of physical components of an NPP. SAN models are employed to analyze links between protocol frames as streams of bytes, their semantics in terms of NPP operations, control data as stored in the memory of I&C systems, the operations of I&C systems on NPP components, and NPP processes. Reward rates and impulse rewards are defined in the SAN models based on the activity-marking reward structure to estimate NPP operation profiles. These profiles are then used to probabilistically estimate the legitimacy of the semantics and payloads of protocol frames received by I&C systems.

  3. Resveratrol products resulting by free radical attack

    Science.gov (United States)

    Bader, Yvonne; Quint, R. M.; Getoff, Nikola

    2008-06-01

    Trans-resveratrol ( trans-3,4',5-trihydroxystilbene; RES), which is contained in red wine and many plants, is one of the most relevant and extensively investigated stilbenes with a broad spectrum of biological activities. Among other duties, RES has been reported to have anti-carcinogenetic activities, which could be attributed to its antioxidant properties. The degradation of RES was studied under various conditions. The products (aldehydes, carboxylic acids, etc.) generated from RES by the attack of free radicals were registered as a function of the radical concentration (absorbed radiation dose). Based on the obtained data it appears that the OH radicals are initiating the rather complicated process, which involves of the numerous consecutive reactions. A possible starting reaction mechanism is presented.

  4. Resveratrol products resulting by free radical attack

    Energy Technology Data Exchange (ETDEWEB)

    Bader, Yvonne; Quint, R.M. [Section Radiation Biology, Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, UZAII, Althanstrasse 14, A-1090 Vienna (Austria); Getoff, Nikola [Section Radiation Biology, Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, UZAII, Althanstrasse 14, A-1090 Vienna (Austria)], E-mail: nikola.getoff@univie.ac.at

    2008-06-15

    Trans-resveratrol (trans-3,4',5-trihydroxystilbene; RES), which is contained in red wine and many plants, is one of the most relevant and extensively investigated stilbenes with a broad spectrum of biological activities. Among other duties, RES has been reported to have anti-carcinogenetic activities, which could be attributed to its antioxidant properties. The degradation of RES was studied under various conditions. The products (aldehydes, carboxylic acids, etc.) generated from RES by the attack of free radicals were registered as a function of the radical concentration (absorbed radiation dose). Based on the obtained data it appears that the OH radicals are initiating the rather complicated process, which involves of the numerous consecutive reactions. A possible starting reaction mechanism is presented.

  5. [Cerebral infarction and transient ischemic attack].

    Science.gov (United States)

    Sahara, Noriyuki; Kuwashiro, Takahiro; Okada, Yasushi

    2016-04-01

    Japanese Guidelines for the Management of Stroke 2015 was published. Here, we describe several points revised from the 2009 edition about "Cerebral infarction and transient ischemic attack (TIA)". The revision points are as follows; 1. Extension of possible time window of intravenous recombinant tissue-plasminogen activator treatment (from within 3 hours to within 4.5 hours); 2. Antiplatelet therapy in acute stage (dual antiplatelet therapy (DAPT) for non-cardioembolic ischemic stroke or TIA); 3. Endovascular recanalization therapy in acute stage; 4. Antiplatelet therapy in chronic stage (Cilostazol is recommended similar to aspirin or clopidogrel); 5. Non-vitamin K antagonist oral anticoagulants (NOACs) for non-valvular atrial fibrillation (NVAF) stroke or TIA patients; 6. Management of TIA. We explain the revised points of the guideline in the text.

  6. Arbitrators, Blacks and Discipline

    Science.gov (United States)

    Jennings, Kenneth

    1975-01-01

    A discussion of the handling of disciplinary problems of black employees concludes that management should be concerned because of the effect that grievance resolution may have on the company's overall employee discipline program and the additional appeal alternatives available to the black employee. (Author/EA)

  7. Perturbing supersymmetric black hole

    CERN Document Server

    Onozawa, H; Mishima, T; Ishihara, H; Onozawa, Hisashi; Okamura, Takashi; Mishima, Takashi; Ishihara, Hideki

    1996-01-01

    An investigation of the perturbations of the Reissner-Nordstr\\"{o}m black hole in the N=2 supergravity is presented. In the extreme case, the black hole responds to the perturbation of each field in the same manner. This is possibly because we can match the modes of the graviton, gravitino, and photon using supersymmetry transformations.

  8. Black Hole Dynamic Potentials

    Indian Academy of Sciences (India)

    Koustubh Ajit Kabe

    2012-09-01

    In the following paper, certain black hole dynamic potentials have been developed definitively on the lines of classical thermodynamics. These potentials have been refined in view of the small differences in the equations of the laws of black hole dynamics as given by Bekenstein and those of thermodynamics. Nine fundamental black hole dynamical relations have been developed akin to the four fundamental thermodynamic relations of Maxwell. The specific heats , and , have been defined. For a black hole, these quantities are negative. The d equation has been obtained as an application of these fundamental relations. Time reversible processes observing constancy of surface gravity are considered and an equation connecting the internal energy of the black hole , the additional available energy defined as the first free energy function , and the surface gravity , has been obtained. Finally as a further application of the fundamental relations, it has been proved for a homogeneous gravitational field in black hole space times or a de Sitter black hole that $C_{\\Omega,\\Phi}-C_{J,Q}=\\kappa \\left[\\left(\\dfrac{\\partial J}{\\partial \\kappa}\\right)_{\\Omega,\\Phi}\\left(\\dfrac{\\partial \\Omega}{\\partial \\kappa}\\right)_{J,Q}+\\left(\\dfrac{\\partial Q}{\\partial \\kappa}\\right)_{\\Omega,\\Phi}\\left(\\dfrac{\\partial\\Phi}{\\partial \\kappa}\\right)_{J,Q}\\right]$. This is dubbed as the homogeneous fluid approximation in context of the black holes.

  9. Black holes matter

    DEFF Research Database (Denmark)

    Kragh, Helge Stjernholm

    2016-01-01

    Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015).......Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015)....

  10. Scattering by Black Holes

    CERN Document Server

    Andersson, N

    2000-01-01

    This is a chapter on Black-hole Scattering that was commissioned for an Encyclopaedia on Scattering edited by Pike and Sabatier, to be published by Academic Press. The chapter surveys wave propagation in black-hole spacetimes, diffraction effects in wave scattering, resonances, quasinormal modes and related topics.

  11. Blacks and Trade Unionism

    Science.gov (United States)

    Ashenfelter, Orley

    1975-01-01

    This testimony, before a public hearing of the New York City Commission on Human Rights in May 1974, focuses on two issues: (1) the effect of the presence of trade unionism on the position of black workers in the labor market relative to white workers; and (2) the effect of federal government efforts to increase the position of black workers…

  12. Fifty shades of black

    Science.gov (United States)

    Cartwright, Jon

    2015-11-01

    Creating dark materials that prevent reflections has become hot competition recently, with Guinness World Records having to keep revising the darkest substance yet created. But depending on who's asking, the best black may not be the blackest black, as Jon Cartwright discovers.

  13. Noncombatants and liability to be attacked in wars

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2013-01-01

    The paper assumes that some people, at least, are liable to attack in war. In a number of ways, this is an ambiguous statement, so before proceeding, I need to clarify the specific senses in which I shall generally be using the terms "liable" and "attack." When I write that "S is liable to military...... attack," I mean that S has forfeited his or her right not to be attacked by armed forces. Here, "liable" is used in a normative-cum-legal sense, not descriptively as it is when one says "some colors are liable to darken in perpetual shade," and "attack" is used passively, as an equivalent of be attacked....... Colloquially, then, "S is liable to attack" means roughly that S is a legitimate target. Given this, it should be clear that when I talk about the criteria of "liability to attack," I am talking in effect about the features separating people who may and may not be attacked. Unless I indicate otherwise, I also...

  14. PASSWORD BASED SCHEME AND GROUP TESTING FOR DEFENDING DDOS ATTACKS

    Directory of Open Access Journals (Sweden)

    Ravinuthala Sruthi

    2013-06-01

    Full Text Available DOS ATTACKS ARE ONE OF THE TOP SECURITY PROBLEMS AFFECTING NETWORKS AND DISRUPTING SERVICES TO LEGITIMATE USERS. THE VITAL STEP IN DEALING WITH THIS PROBLEM IS THE NETWORK'S ABILITY TO DETECT SUCH ATTACKS. APPLICATION DDOS ATTACK, WHICH AIMS AT DISRUPTING APPLICATION SERVICE RATHER THAN DEPLETING THE NETWORK RESOURCE. UP TO NOW ALL THE RESEARCHES MADE ON THIS DDOS ATTACKS ONLY CONCENTRATES EITHER ON NETWORK RESOURCES OR ON APPLICATION SERVERS BUT NOT ON BOTH. IN THIS PAPER WE PROPOSED A SOLUTION FOR BOTH THESE PROBLEMS BY AUTHENTICATION METHODS AND GROUP TESTING.

  15. Flooding Distributed Denial of Service Attacks-A Review

    Directory of Open Access Journals (Sweden)

    Khadijah W.M. Ghazali

    2011-01-01

    Full Text Available Problem statement: Flaws either in users’ implementation of a network or in the standard specification of protocols has resulted in gaps that allow various kinds of network attack to be launched. Of the kinds of network attacks, denial-of-service flood attacks have caused the most severe impact. Approach: This study reviews recent researches on flood attacks and their mitigation, classifying such attacks as either high-rate flood or low-rate flood. Finally, the attacks are compared against criteria related to their characteristics, methods and impacts. Results: Denial-of-service flood attacks vary in their rates, traffic, targets, goals and impacts. However, they have general similarities that are the methods used are flooding and the main purpose is to achieve denial of service to the target. Conclusion/Recommendations: Mitigation of the denial-of-service flood attacks must correspond to the attack rates, traffic, targets, goals and impacts in order to achieve effective solution.

  16. Cyber-physical attacks a growing invisible threat

    CERN Document Server

    Loukas, George

    2015-01-01

    Cyber-Physical Attacks: A Growing Invisible Threat presents the growing list of harmful uses of computers and their ability to disable cameras, turn off a building's lights, make a car veer off the road,  or a drone land in enemy hands. In essence, it details the ways cyber-physical attacks are replacing physical attacks in crime, warfare, and terrorism. The book explores how attacks using computers affect the physical world in ways that were previously only possible through physical means. Perpetrators can now cause damage without the same risk, and without the political, social, or moral

  17. Cybersecurity protecting critical infrastructures from cyber attack and cyber warfare

    CERN Document Server

    Johnson, Thomas A

    2015-01-01

    The World Economic Forum regards the threat of cyber attack as one of the top five global risks confronting nations of the world today. Cyber attacks are increasingly targeting the core functions of the economies in nations throughout the world. The threat to attack critical infrastructures, disrupt critical services, and induce a wide range of damage is becoming more difficult to defend against. Cybersecurity: Protecting Critical Infrastructures from Cyber Attack and Cyber Warfare examines the current cyber threat landscape and discusses the strategies being used by governments and corporatio

  18. Network attacks and defenses a hands-on approach

    CERN Document Server

    Trabelsi, Zouheir; Al Braiki, Arwa; Mathew, Sujith Samuel

    2012-01-01

    The attacks on computers and business networks are growing daily, and the need for security professionals who understand how malfeasants perform attacks and compromise networks is a growing requirement to counter the threat. Network security education generally lacks appropriate textbooks with detailed, hands-on exercises that include both offensive and defensive techniques. Using step-by-step processes to build and generate attacks using offensive techniques, Network Attacks and Defenses: A Hands-on Approach enables students to implement appropriate network security solutions within a laborat

  19. Application distribution model and related security attacks in VANET

    Science.gov (United States)

    Nikaein, Navid; Kanti Datta, Soumya; Marecar, Irshad; Bonnet, Christian

    2013-03-01

    In this paper, we present a model for application distribution and related security attacks in dense vehicular ad hoc networks (VANET) and sparse VANET which forms a delay tolerant network (DTN). We study the vulnerabilities of VANET to evaluate the attack scenarios and introduce a new attacker`s model as an extension to the work done in [6]. Then a VANET model has been proposed that supports the application distribution through proxy app stores on top of mobile platforms installed in vehicles. The steps of application distribution have been studied in detail. We have identified key attacks (e.g. malware, spamming and phishing, software attack and threat to location privacy) for dense VANET and two attack scenarios for sparse VANET. It has been shown that attacks can be launched by distributing malicious applications and injecting malicious codes to On Board Unit (OBU) by exploiting OBU software security holes. Consequences of such security attacks have been described. Finally, countermeasures including the concepts of sandbox have also been presented in depth.

  20. Intrusions into Privacy in Video Chat Environments: Attacks and Countermeasures

    CERN Document Server

    Xing, Xinyu; Han, Richard; Liu, Xue; Mishra, Shivakant

    2010-01-01

    Video chat systems such as Chatroulette have become increasingly popular as a way to meet and converse one-on-one via video and audio with other users online in an open and interactive manner. At the same time, security and privacy concerns inherent in such communication have been little explored. This paper presents one of the first investigations of the privacy threats found in such video chat systems, identifying three such threats, namely de-anonymization attacks, phishing attacks, and man-in-the-middle attacks. The paper further describes countermeasures against each of these attacks.

  1. Attacks on biometric systems: a case study in fingerprints

    Science.gov (United States)

    Uludag, Umut; Jain, Anil K.

    2004-06-01

    In spite of numerous advantages of biometrics-based personal authentication systems over traditional security systems based on token or knowledge, they are vulnerable to attacks that can decrease their security considerably. In this paper, we analyze these attacks in the realm of a fingerprint biometric system. We propose an attack system that uses a hill climbing procedure to synthesize the target minutia templates and evaluate its feasibility with extensive experimental results conducted on a large fingerprint database. Several measures that can be utilized to decrease the probability of such attacks and their ramifications are also presented.

  2. The timing of terrorist attacks: An optimal stopping approach

    Directory of Open Access Journals (Sweden)

    Thomas Jensen

    2016-02-01

    Full Text Available I use a simple optimal stopping model to derive policy relevant insights on the timing of one-shot attacks by small autonomous terrorist units or “lone wolf” individuals. A main insight is that an increase in proactive counterterrorism measures can lead to a short term increase in the number of attempted terrorist attacks because it makes it more risky for existing terrorist units to pursue further development of capabilities. This is consistent with the events in London in 2005 where a terrorist attack on 7 July was followed by a similar but unsuccessful attack two weeks later.

  3. Optimal counterterrorism and the recruitment effect of large terrorist attacks

    DEFF Research Database (Denmark)

    Jensen, Thomas

    2011-01-01

    We analyze a simple dynamic model of the interaction between terrorists and authorities. Our primary aim is to study optimal counterterrorism and its consequences when large terrorist attacks lead to a temporary increase in terrorist recruitment. First, we show that an increase in counterterrorism...... makes it more likely that terrorist cells plan small rather than large attacks and therefore may increase the probability of a successful attack. Analyzing optimal counterterrorism we see that the recruitment effect makes authorities increase the level of counterterrorism after large attacks. Therefore...

  4. Fake BTS Attacks of GSM System on Software Radio Platform

    Directory of Open Access Journals (Sweden)

    Yubo Song

    2012-02-01

    Full Text Available The 2G GSM communication system only provides one-way authentication mechanism which just authenticate the identities of mobile users. As we know, this is not resistant to fake BTS attack. But for the huge cost for building a fake BTS before, this kind of attack were not really implemented before. This paper presents an implement of fake BTS based on software radio technologies. Furthermore, this paper discusses two types of fake BTS attacks on our software radio platform. The first attack is IMSI/IMEI catch attack, which can get the mobile phone’s IMSI and IMEI. With this information, attacker can got the track of the man with this phone. The second attack is selective jamming attack. After get the IMSI and IMEI of the mobile phone, the attackers can decide whether the mobile phone is blocked or not. We will analyze the GSM protocol which is relevant to the interception system and later present the performance of such a system by real tests and demonstrate its feasibility.

  5. Impact Analysis of Recent DDoS Attacks

    Directory of Open Access Journals (Sweden)

    Ketki Arora

    2011-02-01

    Full Text Available In the present era Internet has changed the way of traditional essential services such as banking, transportation, power, health, and defence being operated. These operations are being replacedby cheaper, more efficient Internet-based applications. It is all because of rapid growth and success of Internet in every sector. Unfortunately with the growth of Internet, count of attacks on Internet has also increased incredibly fast. Denial-of-service attack is one of them, which poses immense threat on the availability. Since, the World is highly dependent on the Internet, availability of the Internet is very critical for the socio-economic growth of the society. Denial-of-service attacks occur almost every day,and the frequency and the volume of these attacks are increasing day by day. One of the biggest challenges before researchers is to find the details of such attacks because due to damaging reputationissues, most of the commercial sites do not even disclose that they were blitzed by such attacks. Details of attacks can guide very well in the formulation of comprehensive defensive solution for such attacks. In this paper, an overview on DDoS problem, major factors causing DDoS attacks are demonstrated, brief detail of most recent DDoS incidents on online organizations is outlined and finally, the need for a comprehensive distributed solution is highlighted.

  6. An Improved Model of Attack Probability Prediction System

    Institute of Scientific and Technical Information of China (English)

    WANG Hui; LIU Shufen; ZHANG Xinjia

    2006-01-01

    This paper presents a novel probability generation algorithm to predict attacks from an insider who exploits known system vulnerabilities through executing authorized operations. It is different from most intrusion detection systems (IDSs) because these IDSs are inefficient to resolve threat from authorized insiders. To deter cracker activities, this paper introduces an improved structure of augmented attack tree and a notion of "minimal attack tree", and proposes a new generation algorithm of minimal attack tree. We can provide a quantitative approach to help system administrators make sound decision.

  7. The Need for Situational Awareness in a CBRNE Attack

    Directory of Open Access Journals (Sweden)

    Jordan Nelms

    2011-02-01

    Full Text Available Six years before the terrorist attacks on the World Trade Center and the Pentagon, and eight years before the United States went to war with Saddam Hussein for his alleged concealment of chemical and biological weapons caches, Japan's Tokyo subway was struck by one of the most vicious terror attacks in modern history.  The 1995 Sarin terrorist attack represents an important case study for post-9/11 emergency managers because it highlights the key issues first responders and public health officials face when confronted with a CBRNE ('C'hemical, 'B'iological, 'R'adiological, 'N'uclear, 'E'xplosive mass-casualty attack.

  8. Prevention Of WormholeAttacks In Geographic Routing Protocol

    Directory of Open Access Journals (Sweden)

    E.Poornima,

    2011-01-01

    Full Text Available As mobile ad hoc network applications are deployed, security emerges as a central requirement..Position aided routing protocols can offer a significant performance increase over traditional ad hoc routing protocols. Boundary State Routing (BSR is a geographic routing protocol which routes the data using the location of the nodes. Geographic routing protocols are known to be particularly susceptible to attacks.. In this paper we present the possible attacks on BSR protocol. One of the most popular and serious attacks in ad hoc networks is wormhole attack in which two or more colluding attackers record packets at one location, and tunnel them to another location for a replay at that remote location. A wormhole attack is very powerful, and preventing the attack has proven to be very difficult. In this paper, we devise efficient methods to detect and avoid wormhole attacks in the BSR protocol. The first method namely Reverse Routing Scheme (RRS attempts to detect the intrusion action .The second technique namely Authentication of Nodes Scheme (ANS uses cryptographic concepts to detect and prevent wormhole attacks. It not only detects the fake route but also adopts preventive measures against action wormhole nodes from reappearing during routing. The proposed system is designed in Boundary state routing (BSRprotocol and analysis and simulations are performed in network simulator (NS-2.

  9. Software test attacks to break mobile and embedded devices

    CERN Document Server

    Hagar, Jon Duncan

    2013-01-01

    Address Errors before Users Find Them Using a mix-and-match approach, Software Test Attacks to Break Mobile and Embedded Devices presents an attack basis for testing mobile and embedded systems. Designed for testers working in the ever-expanding world of ""smart"" devices driven by software, the book focuses on attack-based testing that can be used by individuals and teams. The numerous test attacks show you when a software product does not work (i.e., has bugs) and provide you with information about the software product under test. The book guides you step by step starting with the basics. It

  10. A Distributed and Cooperative Algorithm for the Detection and Elimination of Multiple Black Hole Nodes in Ad Hoc Networks

    Science.gov (United States)

    Yu, Chang Wu; Wu, Tung-Kuang; Cheng, Rei-Heng; Yu, Kun-Ming; Chang, Shun Chao

    A mobile node in ad hoc networks may move arbitrarily and act as a router and a host simultaneously. Such a characteristic makes nodes in MANET vulnerable to potential attacks. The black hole problem, in which some malicious nodes pretend to be intermediate nodes of a route to some given destinations and drop packets that pass through it, is one of the major types of attack. In this paper, we propose a distributed and cooperative mechanism to tackle the black hole problem. The mechanism is distributed so that it suits the ad hoc nature of network, and nodes in the protocol cooperate so that they can analyze, detect, and eliminate possible multiple black-hole nodes in a more reliable fashion. Simulation results show that our method achieves a high black hole detection rate and good packet delivery rate, while the overhead is comparatively lower as the network traffic increases.

  11. A Black Hole Attack Model for Reactive Ad-Hoc Protocols

    Science.gov (United States)

    2012-03-01

    similar to AODV ; however, the major differences between the protocols are the manner of packet routing and how the routes are stored. Unlike 12...and route reply exchange when establishing a new route . While DSR and AODV certainly do this, protocols such as Admission Control enabled On-demand...The particular 16 routing metric used in a protocol can be design and implementation specific. DSR and AODV both use the shortest hop-count

  12. Cosmological Black Holes

    CERN Document Server

    Stornaiolo, C

    2002-01-01

    In this letter we propose the existence of low density black holes and discuss its compatibility with the cosmological observations. The origin of these black holes can be traced back to the collapse of long wavelength cosmological perturbations during the matter dominated era, when the densities are low enough to neglect any internal and thermal pressure. By introducing a threshold density $\\hat{\\rho}$ above which pressure and non-gravitational interactions become effective, we find the highest wavelength for the perturbations that can reach an equilibrium state instead of collapsing to a black hole. The low density black holes introduced here, if they exist, can be observed through weak and strong gravitational lensing effects. Finally we observe that we obtained here a cosmological model which is capable to explain in a qualitative way the void formation together with the value $\\Omega=1$. But we remark that it needs to be improved by considering non spherical symmetric black holes.

  13. Primordial Black Hole Baryogenesis

    CERN Document Server

    Baumann, D; Turok, N G; Baumann, Daniel; Steinhardt, Paul J.; Turok, Neil

    2007-01-01

    We reconsider the possibility that the observed baryon asymmetry was generated by the evaporation of primordial black holes that dominated the early universe. We present a simple derivation showing that the baryon asymmetry is insensitive to the initial black hole density and the cosmological model but is sensitive to the temperature-dependence of the CP and baryon-violating (or lepton-violating) interactions. We also consider the possibility that black holes stop evaporating and form Planck-mass remnants that act as dark matter. We show that primordial black holes cannot simultaneously account for both the observed baryon asymmetry and the (remnant) dark matter density unless the magnitude of CP violation is much greater than expected from most particle physics models. Finally, we apply these results to ekpyrotic/cyclic models, in which primordial black holes may form when branes collide. We find that obtaining the observed baryon asymmetry is compatible with the other known constraints on parameters.

  14. Lifshitz Topological Black Holes

    CERN Document Server

    Mann, R B

    2009-01-01

    I find a class of black hole solutions to a (3+1) dimensional theory gravity coupled to abelian gauge fields with negative cosmological constant that has been proposed as the dual theory to a Lifshitz theory describing critical phenomena in (2+1) dimensions. These black holes are all asymptotic to a Lifshitz fixed point geometry and depend on a single parameter that determines both their area (or size) and their charge. Most of the solutions are obtained numerically, but an exact solution is also obtained for a particular value of this parameter. The thermodynamic behaviour of large black holes is almost the same regardless of genus, but differs considerably for small black holes. Screening behaviour is exhibited in the dual theory for any genus, but the critical length at which it sets in is genus-dependent for small black holes.

  15. Seeing red over black and white: popular and media representations of inter-racial relationships as precursors to racial violence

    OpenAIRE

    Perry, B; Sutton, M.

    2006-01-01

    The recent murder in the UK of Anthony Walker attests to the lingering antipathy, indeed hostility, toward intimate inter-racial relationships, especially those involving black men and white women. Seventeen year-old Walker was brutally beaten then fatally assaulted with an axe to his head - the 'provocation' for the attack was this young black man’s relationship with his white girl friend. This paper assesses the historical and contemporary images and mythologies that continue to stigmatize ...

  16. SURVEY ON SURVIVAL APPROACHES IN WIRELESS NETWORK AGAINST JAMMING ATTACK

    Directory of Open Access Journals (Sweden)

    FARAZ AHSAN

    2011-08-01

    Full Text Available Wireless networks are more depicted to intentional or unintentional threats than their wired based equivalent networks. Major reason being the wireless medium which can be approached by others, who can listen and interfere in an on-going valid communication. In the absence of a collision detection mechanism and relying mainly on cooperation of each other for packet routing, the standard defined for wireless network is unable to identify any malicious activity, by default. Among attacks the ones which create isolation of the nodes on the network are considered more severe. If they last long enough, can result in denial-of-service and hence network collapses completely. The simplest form of such attacks is jamming attack which can block any current legitimate communication. It is easy to launch as no especial hardware is required and the area in range for a particular time can be jammed for any legal communication. Jamming is a specialized Denial of Service attack in which purpose is not to overflow buffers, instead to choke the physical communication channel, hence avoiding jammer is much harder than other forms of denial of service attacks. Unlike other attacks, especially routing attacks, no network parameter and topology etc need to be known in advance before launching jamming attack. However, if the network parameters are known and the attack is intelligently placed, a jammer can last longer resulting in more survival time on the network and damage. This paper surveys on different types of jamming attack and the mitigation techniques generally used. Besides this, we investigate about the approaches proposed that are considered efficient to survive in a jammed region, actively. Finally, we conclude by highlighting the potential areas which can be targeted to optimize in minimizing the effects of a jamming attack, as future directions.

  17. Efficient Certificate-Based Signcryption Secure against Public Key Replacement Attacks and Insider Attacks

    OpenAIRE

    Yang Lu; Jiguo Li

    2014-01-01

    Signcryption is a useful cryptographic primitive that achieves confidentiality and authentication in an efficient manner. As an extension of signcryption in certificate-based cryptography, certificate-based signcryption preserves the merits of certificate-based cryptography and signcryption simultaneously. In this paper, we present an improved security model of certificate-based signcryption that covers both public key replacement attack and insider security. We show that an existing certific...

  18. Words Mean Things: The Case for Information System Attack and Control System Attack

    Science.gov (United States)

    2008-10-31

    databases , reservation system, documents, web pages…”ix On the other hand, infrastructure control systems interact with the physical world, and...Week and Space Technology, 4 September 2002, 3, EBSCOhost (accessed 8 September 2008). xxvii Barnes, Julian E., “Hacking Could Become Weapon in...September 2002, EBSCOhost (accessed 8 September 2008). Gibson, Tim, “What You Should Know About Attacking Computer Networks

  19. Black Hole Critical Phenomena Without Black Holes

    CERN Document Server

    Liebling, S L

    2000-01-01

    Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. Power-law mass scaling, aspects of universality, and self-similarity have now been found for a large variety of models. However, questions remain. Here I briefly review critical phenomena, discuss some recent results, and describe a model which demonstrates similar phenomena without gravity.

  20. Avaliação de genótipos de banana à sigatoca-amarela na amazônia ocidental Evaluation of the bananas genotypes to yellow sigatoka in ocidental amazon

    Directory of Open Access Journals (Sweden)

    Amauri Siviero

    2002-12-01

    Full Text Available A resistência de genótipos de banana em relação à Mycosphaerella musicola foi avaliada em condições naturais de infecção. Foram avaliadas 24 plantas de cada genótipo. As cultivares 'Pacovan' e 'Prata-anã' atuaram como fonte de inóculo do patógeno. A avaliação da doença foi realizada com uso de uma escala de notas variando de 1 (plantas sem sintomas até 8 (folhas velhas e novas com sintomas, obtendo-se o índice de doença pela média ponderada das notas. As cultivares 'Mysore' e 'Nam' e o híbrido 'PA 12-03' foram classificados como suscetíveis ao patógeno. Os demais genótipos 'Yangambi km5', 'Thap Maeo', 'Pelipita', 'Pioneira', 'JV 03-15' e 'PV 03-44' foram classificados como resistentes ao patógeno.The reactions of hybrids and cultivars of banana were evaluated in response to Mycosphaerella musicola in field conditions. A total of twenty-four plants of each genotype were evaluated using 'Pacovan' and 'Prata-anã' cultivars as the source pathogen. The disease response was ranged from 1 to 8, where 1 represented a weak attack with few or no symptoms and 8 when lesions were observed both in young and old leaves. Disease index (DI was calculated for each genotype by multiplying the number of plant with the same scoring by the score and dividing the total by 24 (total mumber of one genotypes. The highest DIs were verified for susceptible genotypes, 'Nam', 'Mysore' and hybrid 'PA 12-03'. 'Yangambi km5', 'Thap Maeo', 'Pelipita', 'Pioneira', 'JV 03-15' and 'PV 03-44' were classified as resistant in our test.

  1. On the Charter Question: Black Marxism and Black Nationalism

    Science.gov (United States)

    Stern, Mark; Hussain, Khuram

    2015-01-01

    This article brings two black intellectual traditions to bear on the question of charter schools: black Marxism and black nationalism. The authors examine the theoretical and rhetorical devices used to talk about charters schools by focusing on how notions of "black liberation" are deployed by the charter movement, and to what end. The…

  2. Pattern association--a key to recognition of shark attacks.

    Science.gov (United States)

    Cirillo, G; James, H

    2004-12-01

    Investigation of a number of shark attacks in South Australian waters has lead to recognition of pattern similarities on equipment recovered from the scene of such attacks. Six cases are presented in which a common pattern of striations has been noted.

  3. The Rebound Attack and Subspace Distinguishers: Application to Whirlpool

    DEFF Research Database (Denmark)

    Lamberger, Mario; Mendel, Florian; Schläffer, Martin;

    2015-01-01

    We introduce the rebound attack as a variant of differential cryptanalysis on hash functions and apply it to the hash function Whirlpool, standardized by ISO/IEC. We give attacks on reduced variants of the 10-round Whirlpool hash function and compression function. Our results are collisions for 5...

  4. Fault attacks, injection techniques and tools for simulation

    NARCIS (Netherlands)

    Piscitelli, R.; Bhasin, S.; Regazzoni, F.

    2015-01-01

    Faults attacks are a serious threat to secure devices, because they are powerful and they can be performed with extremely cheap equipment. Resistance against fault attacks is often evaluated directly on the manufactured devices, as commercial tools supporting fault evaluation do not usually provide

  5. Transforming Graphical System Models to Graphical Attack Models

    DEFF Research Database (Denmark)

    Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, Rene Rydhof;

    2016-01-01

    Manually identifying possible attacks on an organisation is a complex undertaking; many different factors must be considered, and the resulting attack scenarios can be complex and hard to maintain as the organisation changes. System models provide a systematic representation of organisations that...

  6. Understanding bifurcation of slow versus fast cyber-attackers

    NARCIS (Netherlands)

    Wieren, van Maarten; Doerr, Christian; Jacobs, Vivian; Pieters, Wolter; Livraga, Giovanni; Torra, Vicenç; Aldini, Alessandro; Martinelli, Fabio; Suri, Neeraj

    2016-01-01

    Anecdotally, the distinction between fast “Smash-and-Grab” cyber-attacks on the one hand and slow attacks or “Advanced Persistent Threats” on the other hand is well known. In this article, we provide an explanation for this phenomenon as the outcome of an optimization from the perspective of the att

  7. Transforming graphical system models to graphical attack models

    NARCIS (Netherlands)

    Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, René Rydhof; Kammüller, Florian; Mauw, S.; Kordy, B.

    2015-01-01

    Manually identifying possible attacks on an organisation is a complex undertaking; many different factors must be considered, and the resulting attack scenarios can be complex and hard to maintain as the organisation changes. System models provide a systematic representation of organisations that he

  8. Ethical Considerations of Computer Network Attack in Information Warfare

    Science.gov (United States)

    2001-01-16

    attack/destruction, and special information operations (SIO). CNA and the other methods of offensive IO represent the incorporation of information...psychological operations, electronic warfare, physical attack and/or destruction, and special information operations, and could include computer network...to computer networks to record information sent over them. 41 special information operations. Information operations that by their sensitive nature

  9. Survey of Attacks on Mobile AdhocWireless Networks

    Directory of Open Access Journals (Sweden)

    Vikas Solomon Abel

    2011-02-01

    Full Text Available Security has always been a key issue with wireless networks since there are no physical boundaries. Experience has shown numerous vulnerabilities to a variety of attacks even when security measures are in place. In the combined Internet-MANET environment also security is an important issue keeping in view the Internet connectivity and attack on the MANET protocols.

  10. Treatment of HAE Attacks in the Icatibant Outcome Survey

    DEFF Research Database (Denmark)

    Hernández Fernandez de Rojas, Dolores; Ibañez, Ethel; Longhurst, Hilary;

    2015-01-01

    BACKGROUND: Icatibant, a selective bradykinin B2 receptor antagonist for the treatment of acute hereditary angio-oedema (HAE) attacks in adults, can be administered by health care professionals (HCPs) or self-administered. This analysis compared characteristics and outcomes of acute HAE attacks t...

  11. Defensive Cyber Battle Damage Assessment Through Attack Methodology Modeling

    Science.gov (United States)

    2011-03-25

    3 focuses on steganography use. Table 30. DCBDA Experiment ASL. Scenario 1 Scenario 2 Scenario 3 Covering Tracks Covering Tracks Covering Tracks...Covert Channel Log Obfuscation Hide Attack Data ICMP Covert Channel Disable Auditing Steganography Persistent Access Obfuscation Hide Attack Data...Marker Forensic Tool Suspicious files/sizes Steganography Suspicious files/sizes Stegdetect Suspicious files/sizes Steganography Suspicious files

  12. Hereditary Angioedema Attacks: Local Swelling at Multiple Sites.

    Science.gov (United States)

    Hofman, Zonne L M; Relan, Anurag; Hack, C Erik

    2016-02-01

    Hereditary angioedema (HAE) patients experience recurrent local swelling in various parts of the body including painful swelling of the intestine and life-threatening laryngeal oedema. Most HAE literature is about attacks located in one anatomical site, though it is mentioned that HAE attacks may also involve multiple anatomical sites simultaneously. A detailed description of such multi-location attacks is currently lacking. This study investigated the occurrence, severity and clinical course of HAE attacks with multiple anatomical locations. HAE patients included in a clinical database of recombinant human C1-inhibitor (rhC1INH) studies were evaluated. Visual analog scale scores filled out by the patients for various symptoms at various locations and investigator symptoms scores during the attack were analysed. Data of 219 eligible attacks in 119 patients was analysed. Thirty-three patients (28%) had symptoms at multiple locations in anatomically unrelated regions at the same time during their first attack. Up to five simultaneously affected locations were reported. The observation that severe HAE attacks often affect multiple sites in the body suggests that HAE symptoms result from a systemic rather than from a local process as is currently believed.

  13. Hereditary Angioedema Attacks : Local Swelling at Multiple Sites

    NARCIS (Netherlands)

    Hofman, Zonne L M; Relan, Anurag; Hack, C. Erik

    2016-01-01

    Hereditary angioedema (HAE) patients experience recurrent local swelling in various parts of the body including painful swelling of the intestine and life-threatening laryngeal oedema. Most HAE literature is about attacks located in one anatomical site, though it is mentioned that HAE attacks may al

  14. Effectiveness of the Call in Beach Volleyball Attacking Play

    Directory of Open Access Journals (Sweden)

    Künzell Stefan

    2014-12-01

    Full Text Available In beach volleyball the setter has the opportunity to give her or his hitter a “call”. The call intends that the setter suggests to her or his partner where to place the attack in the opponent’s court. The effectiveness of a call is still unknown. We investigated the women’s and men’s Swiss National Beach Volleyball Championships in 2011 and analyzed 2185 attacks. We found large differences between female and male players. While men called in only 38.4% of attacks, women used calls in 85.5% of attacks. If the male players followed a given call, 63% of the attacks were successful. The success rate of attacks without any call was 55.8% and 47.6% when the call was ignored. These differences were not significant (χ2(2 = 4.55, p = 0.103. In women’s beach volleyball, the rate of successful attacks was 61.5% when a call was followed, 35% for attacks without a call, and 42.6% when a call was ignored. The differences were highly significant (χ2(2 = 23.42, p < 0.0005. Taking into account the findings of the present study, we suggested that the call was effective in women’s beach volleyball, while its effect in men’s game was unclear. Considering the quality of calls we indicate that there is a significant potential to increase the effectiveness of a call.

  15. Refractory Degradation by Slag Attack in Coal Gasification

    Science.gov (United States)

    2009-02-01

    REFRACTORY DEGRADATION BY SLAG ATTACK IN COAL GASIFICATION Jinichiro Nakano 1,2 , Sridhar Seetharaman 1,2 , James Bennett 3 , Kyei-Sing...00-2009 4. TITLE AND SUBTITLE Refractory Degradation by Slag Attack in Coal Gasification 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

  16. An active attack on a multiparty key exchange protocol

    Directory of Open Access Journals (Sweden)

    Reto Schnyder

    2016-01-01

    Full Text Available The multiparty key exchange introduced in Steiner et al. and presented in more general form by the authors is known to be secure against passive attacks. In this paper, an active attack is presented assuming malicious control of the communications of the last two users for the duration of only the key exchange.

  17. Correct-by-Construction Attack-Tolerant Systems

    Science.gov (United States)

    2015-05-01

    for rendering systems Byzantine fault tolerant and to ideas for monitoring distributed system behavior and responding to unusual events . We believe...attack-tolerance, fault tolerant systems, correct-by-construction protocols, formal methods, event logic, functional distributed processes, cyber...nation’s ability to use advanced computer science and substantial computing power to enhance the ability of our systems to detect attacks and

  18. Israeli Adolescents' Coping Strategies in Relation to Terrorist Attacks

    Science.gov (United States)

    Tatar, Moshe; Amram, Sima

    2007-01-01

    Exposure to terrorism seriously threatens the well-being of children and adolescents. Israeli citizens have witnessed massive ongoing terrorist attacks during the last few years. The present research, conducted among 330 Israeli adolescents, examined coping strategies in relation to terrorist attacks. We found that adolescents utilize more…

  19. Understanding How Components of Organisations Contribute to Attacks

    DEFF Research Database (Denmark)

    Gu, Min; Aslanyan, Zaruhi; Probst, Christian W.

    2016-01-01

    components quickly results in a large quantity of interrelations, which are hard to grasp. In this work we present several approaches for visualising attributes of attacks such as likelihood of success, impact, and required time or skill level. The resulting visualisations provide a link between attacks...

  20. [Banana tree pests attacking Heliconia latispatha Benth. (Heliconiaceae)].

    Science.gov (United States)

    Watanabe, Maria A

    2007-01-01

    In mid-May 2005, the caterpillars Antichloris eriphia (Fabr.) (Lepidoptera: Arctiidae) and Calligo illioneus (Cramer) (Lepidoptera: Nymphalidae) which are banana tree pests, were found attacking six-month old stalks of Heliconia latispatha Benth., planted near a banana tree plantation in Jaguariuna, SP, Brazil. The attack by C. illioneus is observed by the first time in Brazil.

  1. Air Superiority and Airfield Attack - Lessons from History.

    Science.gov (United States)

    1984-05-15

    operation carried out as a surprise attack on German airfields on a 1200 kilometer-wide front from Smolensk to the Sea of Azov . This operation was to combine...damaged. EAF gun camera films show the attack at Ras Nasrani and explosions on the taxiways. They also show two Mirage fighters becoming airborne

  2. Performance evaluation of DSR Protocol under DoS attack

    Directory of Open Access Journals (Sweden)

    Ms. Trupti Patel

    2012-03-01

    Full Text Available A mobile ad-hoc network (MANET consists of mobile hosts equipped with wireless communication devices. A Mobile Ad hoc Network is a self-organizing, infrastructure less, multi-hop network. The transmission of a mobile host is received by all hosts within its transmission range due to the broadcast nature of wireless communication and unidirectional antenna. If two wireless hosts are out of their transmission ranges in the ad hoc networks, other mobile hosts located between them can forward their message, which effectively builds connected networks among the mobile hosts in the deployed area. One main challenge in design of these networks is their vulnerable nature to security attack. These attacks can be deployed by insider or outsider attacker. Sometime, the node from network can be attacker. This is happen because of mobility of nodes and changing network topology. There are different kind of attacks available in literature and can be implemented on MANET. One of these attacks is Grey Hole attack that has dangerous effect on Mobile Ad-Hoc Network. In this paper, we study the effect of Grey Hole attack on Dynamic Source Routing (DSR protocol in Mobile Ad-Hoc Network.

  3. A NOVEL ROUTING ATTACK IN MOBILE AD HOC NETWORKS

    Directory of Open Access Journals (Sweden)

    DR. N. SATYANARAYANA

    2010-12-01

    Full Text Available Mobile ad hoc networks will often be deployed in environments where the nodes of the networks are unattended and have little or no physical protection against tampering. The nodes of mobile ad hoc networks are thus susceptible to compromise. The networks are particularly vulnerable to denial of service (DOS attacks launched through compromised nodes or intruders. In this paper, we present a new DOS attack and its defense in ad hoc networks. The new DOS attack, called Ad Hoc Flooding Attack (AHFA, can result in denial of service when used against on-demand routing protocols for mobile ad hoc networks, such as AODV, DSR. The intruder broadcasts mass Route Request packets to exhaust the communication bandwidth and node resource so that the valid communication cannot be kept. After analyzed Ad Hoc Flooding Attack, we develop Flooding Attack Prevention (FAP, a generic defense against the Ad Hoc Flooding Attack in mobile ad hoc networks. When the intruder broadcasts exceeding packets of Route Request, the immediate neighbors of the intruder record the rate of Route Request. Once the threshold is exceeded, nodes deny any future request packets from the intruder. The results of our implementation show FAP can prevent the Ad Hoc Flooding attack efficiently.

  4. New Attacks on Animal Researchers Provoke Anger and Worry

    Science.gov (United States)

    Guterman, Lila

    2008-01-01

    This article reports on firebomb attacks at the homes of two animal researchers which have provoked anger and unease. The firebomb attacks, which set the home of a neuroscientist at the University of California at Santa Cruz aflame and destroyed a car parked in the driveway of another university researcher's home, have left researchers and…

  5. Black holes new horizons

    CERN Document Server

    Hayward, Sean Alan

    2013-01-01

    Black holes, once just fascinating theoretical predictions of how gravity warps space-time according to Einstein's theory, are now generally accepted as astrophysical realities, formed by post-supernova collapse, or as supermassive black holes mysteriously found at the cores of most galaxies, powering active galactic nuclei, the most powerful objects in the universe. Theoretical understanding has progressed in recent decades with a wider realization that local concepts should characterize black holes, rather than the global concepts found in textbooks. In particular, notions such as trapping h

  6. Scalarized hairy black holes

    Energy Technology Data Exchange (ETDEWEB)

    Kleihaus, Burkhard, E-mail: b.kleihaus@uni-oldenburg.de [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Kunz, Jutta [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Yazadjiev, Stoytcho [Department of Theoretical Physics, Faculty of Physics, Sofia University, Sofia 1164 (Bulgaria)

    2015-05-11

    In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  7. Scalarized hairy black holes

    Directory of Open Access Journals (Sweden)

    Burkhard Kleihaus

    2015-05-01

    Full Text Available In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  8. Black Hole Entropy

    OpenAIRE

    P. Mitra

    1994-01-01

    In the talk different definitions of the black hole entropy are discussed and compared. It is shown that the Bekenstein-Hawking entropy $S^{BH}$ (defined by the response of the free energy of a system containing a black hole on the change of the temperature) differs from the statistical- mechanical entropy $S^{SM}=-\\mbox{Tr}(\\hat{\\rho}\\ln \\hat{\\rho})$ (defined by counting internal degrees of freedom of a black hole). A simple explanation of the universality of the Bekenstein-Hawking entropy (...

  9. Black hole entropy

    CERN Document Server

    Frolov, V

    1994-01-01

    In the talk different definitions of the black hole entropy are discussed and compared. It is shown that the Bekenstein-Hawking entropy S^{BH} (defined by the response of the free energy of a system containing a black hole on the change of the temperature) differs from the statistical- mechanical entropy S^{SM}=-\\mbox{Tr}(\\hat{\\rho}\\ln \\hat{\\rho}) (defined by counting internal degrees of freedom of a black hole). A simple explanation of the universality of the Bekenstein-Hawking entropy (i.e. its independence of the number and properties of the fields which might contribute to S^{SM}) is given.

  10. Primordial Black Holes

    CERN Document Server

    MacGibbon, Jane H; Linnemann, J T; Marinelli, S S; Stump, D; Tollefson, K

    2015-01-01

    Primordial Black Holes (PBHs) are of interest in many cosmological contexts. PBHs lighter than about 1012 kg are predicted to be directly detectable by their Hawking radiation. This radiation should produce both a diffuse extragalactic gamma-ray background from the cosmologically-averaged distribution of PBHs and gamma-ray burst signals from individual light black holes. The Fermi, Milagro, Veritas, HESS and HAWC observatories, in combination with new burst recognition methodologies, offer the greatest sensitivity for the detection of such black holes or placing limits on their existence.

  11. Attack Vulnerability of Network with Duplication-Divergence Mechanism

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We study the attack vulnerability of network with duplication-divergence mechanism. Numerical results have shown that the duplication-divergence network with larger retention probability a is more robust against target attack relatively. Furthermore, duplication-divergence network is broken down more quickly than its counterpart BA network under target attack. Such result is consistent with the fact of WWW and Internet networks under target attack. So duplication-divergence model is a more realistic one for us to investigate the characteristics of the world wide web in future. We also observe that the exponent 7 of degree distribution and average degree are important parameters of networks, reflecting the performance of networks under target attack. Our results are helpful to the research on the security of network.

  12. The research of DPA attacks against AES implementations

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This article examines vulnerabilities to power analysis attacks between software and hardware implementations of cryptographic algorithms. Representative platforms including an Atmel 89S8252 8-bit processor and a 0.25 μm 1.8 v standard cell circuit are proposed to implement the advance encryption standard (AES). A simulation-based experimental environment is built to acquire power data, and single-bit differential power analysis (DPA), and multi-bit DPA and correlation power analysis (CPA) attacks are conducted on two implementations respectively. The experimental results show that the hardware implementation has less data-dependent power leakages to resist power attacks. Furthermore, an improved DPA approach is proposed. It adopts hamming distance of intermediate results as power model and arranges plaintext inputs to differentiate power traces to the maximal probability. Compared with the original power attacks, our improved DPA performs a successful attack on AES hardware implementations with acceptable power measurements and fewer computations.

  13. Anti-discrimination Analysis Using Privacy Attack Strategies

    KAUST Repository

    Ruggieri, Salvatore

    2014-09-15

    Social discrimination discovery from data is an important task to identify illegal and unethical discriminatory patterns towards protected-by-law groups, e.g., ethnic minorities. We deploy privacy attack strategies as tools for discrimination discovery under hard assumptions which have rarely tackled in the literature: indirect discrimination discovery, privacy-aware discrimination discovery, and discrimination data recovery. The intuition comes from the intriguing parallel between the role of the anti-discrimination authority in the three scenarios above and the role of an attacker in private data publishing. We design strategies and algorithms inspired/based on Frèchet bounds attacks, attribute inference attacks, and minimality attacks to the purpose of unveiling hidden discriminatory practices. Experimental results show that they can be effective tools in the hands of anti-discrimination authorities.

  14. A Survey of Man in the Middle Attacks

    DEFF Research Database (Denmark)

    Conti, Mauro; Dragoni, Nicola; Lesyk, Viktor

    2016-01-01

    extensively review the literature on MITM to analyse and categorize the scope of MITM attacks, considering both a reference model, such as the open systems interconnection (OSI) model, as well as two specific widely used network technologies, i.e., GSM and UMTS. In particular, we classify MITM attacks based......The Man-In-The-Middle (MITM) attack is one of the most well known attacks in computer security, representing one of the biggest concerns for security professionals. MITM targets the actual data that flows between endpoints, and the confidentiality and integrity of the data itself. In this paper, we...... on several parameters, like location of an attacker in the network, nature of a communication channel, and impersonation techniques. Based on an impersonation techniques classification, we then provide execution steps for each MITM class. We survey existing countermeasures and discuss the comparison among...

  15. Detecting peripheral-based attacks on the host memory

    CERN Document Server

    Stewin, Patrick

    2015-01-01

    This work addresses stealthy peripheral-based attacks on host computers and presents a new approach to detecting them. Peripherals can be regarded as separate systems that have a dedicated processor and dedicated runtime memory to handle their tasks. The book addresses the problem that peripherals generally communicate with the host via the host’s main memory, storing cryptographic keys, passwords, opened files and other sensitive data in the process – an aspect attackers are quick to exploit.  Here, stealthy malicious software based on isolated micro-controllers is implemented to conduct an attack analysis, the results of which provide the basis for developing a novel runtime detector. The detector reveals stealthy peripheral-based attacks on the host’s main memory by exploiting certain hardware properties, while a permanent and resource-efficient measurement strategy ensures that the detector is also capable of detecting transient attacks, which can otherwise succeed when the applied strategy only me...

  16. A Robust Image Hashing Algorithm Resistant Against Geometrical Attacks

    Directory of Open Access Journals (Sweden)

    Y.L. Liu

    2013-12-01

    Full Text Available This paper proposes a robust image hashing method which is robust against common image processing attacks and geometric distortion attacks. In order to resist against geometric attacks, the log-polar mapping (LPM and contourlet transform are employed to obtain the low frequency sub-band image. Then the sub-band image is divided into some non-overlapping blocks, and low and middle frequency coefficients are selected from each block after discrete cosine transform. The singular value decomposition (SVD is applied in each block to obtain the first digit of the maximum singular value. Finally, the features are scrambled and quantized as the safe hash bits. Experimental results show that the algorithm is not only resistant against common image processing attacks and geometric distortion attacks, but also discriminative to content changes.

  17. New-Fangled Method Against Data Flooding Attacks in MANET

    Directory of Open Access Journals (Sweden)

    Kavuri Roshan

    2012-07-01

    Full Text Available Mobile users like to use their own consumer electronic devices anywhere and at anytime to accessmultimedia data. Hence, we expect that wireless ad hoc networks will be widely used in the near futuresince these networks form the topology with low cost on the fly. However, consumer electronic devicesgenerally operate on limited battery power and therefore are vulnerable to security threats like dataflooding attacks. The data flooding attack causes Denial of Service (DoS attacks by flooding many datapackets. However, there are a few existing defence systems against data flooding attacks. Moreover, theexisting schemes may not guarantee the Quality of Service (QoS of burst traffic since multimedia data areusually burst. Therefore, we propose a novel defence mechanism against data flooding attacks with the aimof enhancing the throughput.

  18. SDN-Based Double Hopping Communication against Sniffer Attack

    Directory of Open Access Journals (Sweden)

    Zheng Zhao

    2016-01-01

    Full Text Available Sniffer attack has been a severe threat to network communication security. Traditional network usually uses static network configuration, which provides convenience to sniffer attack. In this paper, an SDN-based double hopping communication (DHC approach is proposed to solve this problem. In DHC, ends in communication packets as well as the routing paths are changed dynamically. Therefore, the traffic will be distributed to multiple flows and transmitted along different paths. Moreover, the data from multiple users will be mixed, bringing difficulty for attackers in obtaining and recovering the communication data, so that sniffer attack will be prevented effectively. It is concluded that DHC is able to increase the overhead of sniffer attack, as well as the difficulty of communication data recovery.

  19. Robustness of Complex Networks under Attack and Repair

    Institute of Scientific and Technical Information of China (English)

    HU Bin; LI Fang; ZHOU Hou-Shun

    2009-01-01

    To study the robustness of complex networks under attack and repair,we introduce a repair model of complex networks.Based on the model,we introduce two new quantities,i.e.attack fraction f_a and the maximum degree of the nodes that have never been attacked K_a,to study analytically the critical attack fraction and the relati ve size of the giant component of complex networks under attack and repair,using the method of generating function.We show analytically and numerically that the repair strategy significantly enhances the robustness of the scale-free network and the effect of robustness improvement is better for the scale-free networks with a smaller degree exponent.We discuss the application of our theory in relation to the understanding of robustness of complex networks with reparability.

  20. Comprehensive Study of Selective Forwarding Attack in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Wazir Zada Khan

    2011-02-01

    Full Text Available Sensor networks are becoming closer towards wide-spread deployment so security issues become a vital concern. Selective forwarding attack is one of the harmful attacks against sensor networks and can affect the whole sensor network communication. The variety of defense approaches against selective forwarding attack is overwhelming. In this paper we have described all the existing defensive schemes according to our best knowledge against this attack along with their drawbacks, thus providing researchers a better understanding of the attack and current solution space. This paper also classifies proposed schemes according to their nature and defense. Nature of scheme classifies into Distributed and Centralized. Defense of scheme classifies into detection and prevention.

  1. Weak laws against acid attacks on women: an Indian perspective.

    Science.gov (United States)

    Ahmad, Nehaluddin

    2012-01-01

    Acid attacks, especially on women, have seen an alarming growth in India over the last decade. While these attacks can be attributed to various factors such as the social weakness of women in a male-dominated society, the situation is exacerbated by the general neglect of the lawmakers. As acid is inexpensive and easily available, it serves as an ideal weapon for the perpetrators. Further, as this offence is bailable in certain situations, the punishment does not act as a sufficient deterrent in most cases. This paper describes the horrendous effects that acid attacks have on the victims physically, psychologically and socially. It also examines the contemporary laws governing acid attacks on victims and offenders. Ideas for a better legal approach will also be examined with special reference to acid attacks as a crime, and the validity of specific legal provisions for female victims.

  2. THE REPRISAL ATTACKS BY AL-SHABAAB AGAINST KENYA

    Directory of Open Access Journals (Sweden)

    E.O.S.ODHIAMBO

    2013-10-01

    Full Text Available The incursion of Kenya Defence Forces (KDF into Somalia was met by a series of threats from the Al-Shabaab that it would increase the attacks against Kenya if the troops were not withdrawn. The capture of Kismayu by KDF has weakened the nerve of Al-Shabaab but has not eliminated the imminent danger of a substantive terror attack. Since the incursion by KDF, Kenya has succumbed to a sequence of grenade and Improvised Explosive Devices attacks, roadside bombs, landmines and raids by fighters using small arms and light weapons and Rocket Propelled Grenades against Kenyans mostly in North Eastern, Coastal and Nairobi counties, marking the resurgence of terrorism in the country. We argue that Kenya is more vulnerable to Al-Shabaab terrorists attack than before the KDF incursion by citing the frequencies of reprisal attacks from October 2011 to January 2013. Hence, our troops should be withdrawn and deployed within our boundary.

  3. Attacks on Bluetooth Security Architecture and Its Countermeasures

    Science.gov (United States)

    Iqbal, Mian Muhammad Waseem; Kausar, Firdous; Wahla, Muhammad Arif

    WPANs compliment the traditional IEEE 802.11 wireless networks by facilitating the clients with flexibility in network topologies, higher mobility and relaxed configuration/hardware requirements. Bluetooth, a WPAN technology, is an open standard for short-range radio frequency (RF) communication. However, it is also susceptible to typical security threats found in wireless LANs. This paper discuses some of the attack scenarios against the bluetooth network such as hostile intrusion, active Man-in-the-Middle (MITM) attack using unit key and various forms of denial of service (DoS) attacks. These threats and attacks compromise the confidentiality and availability of bluetooth data and services. This paper proposes an improved security architecture for bluetooth device which provides protection against the above mentioned attacks.

  4. Robustness of controllability for networks based on edge-attack.

    Science.gov (United States)

    Nie, Sen; Wang, Xuwen; Zhang, Haifeng; Li, Qilang; Wang, Binghong

    2014-01-01

    We study the controllability of networks in the process of cascading failures under two different attacking strategies, random and intentional attack, respectively. For the highest-load edge attack, it is found that the controllability of Erdős-Rényi network, that with moderate average degree, is less robust, whereas the Scale-free network with moderate power-law exponent shows strong robustness of controllability under the same attack strategy. The vulnerability of controllability under random and intentional attacks behave differently with the increasing of removal fraction, especially, we find that the robustness of control has important role in cascades for large removal fraction. The simulation results show that for Scale-free networks with various power-law exponents, the network has larger scale of cascades do not mean that there will be more increments of driver nodes. Meanwhile, the number of driver nodes in cascading failures is also related to the edges amount in strongly connected components.

  5. Impact of Multipath Routing on WSN Security Attacks

    Directory of Open Access Journals (Sweden)

    Koffka Khan

    2014-05-01

    Full Text Available Multipath routing does not minimize the consequences of security attacks. Due to this many WSNs are still in danger of most security attacks even when multipath routing is used. In critical situations, for example, in military and health applications this may lead to undesired, harmful and disastrous effects. These applications need to get their data communicated efficiently and in a secure manner. In this paper, we show the results of a series of security attacks on a multipath extension to the ad hoc on-demand distance vector AODV protocol, AOMDV. It is proved that many security parameters are negatively affected by security attacks on AOMDV, which is contradictory to research claims. This means that alternative refinements have to be made to present multipath routing protocols in order to make them more effective against network security attacks.

  6. Improved Impossible Differential Attacks on Large-Block Rijndael

    DEFF Research Database (Denmark)

    Wang, Qingju; Gu, Dawu; Rijmen, Vincent;

    2012-01-01

    . The improvement can lead to 10-round attack on Rijndael-256 as well. With 2198.1 chosen plaintexts, an attack is demonstrated on 9-round Rijndael-224 with 2 195.2 encryptions and 2140.4 bytes memory. Increasing the data complexity to 2216 plaintexts, the time complexity can be reduced to 2130 encryptions...... and the memory requirements to 2 93.6 bytes. For 9-round Rijndael-256, we provide an attack requiring 2229.3 chosen plaintexts, 2194 encryptions, and 2 139.6 bytes memory. Alternatively, with 2245.3 plaintexts, an attack with a reduced time of 2127.1 encryptions and a memory complexity of 290.9 bytes can...... be mounted. With 2244.2 chosen plaintexts, we can attack 10-round Rijndael-256 with 2253.9 encryptions and 2186.8 bytes of memory....

  7. Study on Sinkhole Attacks in Wireless Ad hoc Networks

    Directory of Open Access Journals (Sweden)

    GAGANDEEP

    2012-06-01

    Full Text Available Wireless ad hoc network is a collection of wireless mobile nodes that dynamically self-organize in arbitrary and temporary network topologies. As compared to conventional network, wireless ad hocnetwork are more vulnerable to the security attacks. The nature and structure of wireless ad hoc network makes it very attractive to attackers, because there is no fixed infrastructure and administrativeapproach in it. “Sinkhole attack” is one of the severe attacks in this type of network; this makes trustable nodes to malicious nodes that result in loss of secure information. This paper focuses on sinkhole attacks on routing protocols such as DSR, AODV. To overcome the problems occur due to sinkhole we discuss about Security-aware routing (SAR which helps to reduce the impact of such attack.

  8. Step to improve neural cryptography against flipping attacks.

    Science.gov (United States)

    Zhou, Jiantao; Xu, Qinzhen; Pei, Wenjiang; He, Zhenya; Szu, Harold

    2004-12-01

    Synchronization of neural networks by mutual learning has been demonstrated to be possible for constructing key exchange protocol over public channel. However, the neural cryptography schemes presented so far are not the securest under regular flipping attack (RFA) and are completely insecure under majority flipping attack (MFA). We propose a scheme by splitting the mutual information and the training process to improve the security of neural cryptosystem against flipping attacks. Both analytical and simulation results show that the success probability of RFA on the proposed scheme can be decreased to the level of brute force attack (BFA) and the success probability of MFA still decays exponentially with the weights' level L. The synchronization time of the parties also remains polynomial with L. Moreover, we analyze the security under an advanced flipping attack.

  9. Expected losses, insurability, and benefits from reducing vulnerability to attacks.

    Energy Technology Data Exchange (ETDEWEB)

    Nozick, Linda Karen (Cornell University, Ithaca, NY); Carlson, Rolf Erik; Turnquist, Mark Alan (Cornell University, Ithaca, NY)

    2004-03-01

    A model of malicious attacks against an infrastructure system is developed that uses a network representation of the system structure together with a Hidden Markov Model of an attack at a node of that system and a Markov Decision Process model of attacker strategy across the system as a whole. We use information systems as an illustration, but the analytic structure developed can also apply to attacks against physical facilities or other systems that provide services to customers. This structure provides an explicit mechanism to evaluate expected losses from malicious attacks, and to evaluate changes in those losses that would result from system hardening. Thus, we provide a basis for evaluating the benefits of system hardening. The model also allows investigation of the potential for the purchase of an insurance contract to cover the potential losses when safeguards are breached and the system fails.

  10. Feminism and Black Women's Studies.

    Science.gov (United States)

    Hooks, Bell

    1989-01-01

    Women's studies programs have largely ignored Black women. Until Black women's studies courses are developed, feminist scholarship on Black women will not advance, and the contributions of Black women to women's rights movements and African American literature and scholarship may be neglected. (DM)

  11. The Price of "Black Dominance."

    Science.gov (United States)

    Hoberman, John

    2000-01-01

    Discusses the harmful effects of stereotyping black males as athletes, noting that over-identification with athletes and the world of physical performance limits black children's development by discouraging academic achievement. Examines the negative influence of mass media focus on black athletes, rappers, and stylized ghetto blackness. Discusses…

  12. Metrics for Assessment of Smart Grid Data Integrity Attacks

    Energy Technology Data Exchange (ETDEWEB)

    Annarita Giani; Miles McQueen; Russell Bent; Kameshwar Poolla; Mark Hinrichs

    2012-07-01

    There is an emerging consensus that the nation’s electricity grid is vulnerable to cyber attacks. This vulnerability arises from the increasing reliance on using remote measurements, transmitting them over legacy data networks to system operators who make critical decisions based on available data. Data integrity attacks are a class of cyber attacks that involve a compromise of information that is processed by the grid operator. This information can include meter readings of injected power at remote generators, power flows on transmission lines, and relay states. These data integrity attacks have consequences only when the system operator responds to compromised data by redispatching generation under normal or contingency protocols. These consequences include (a) financial losses from sub-optimal economic dispatch to service loads, (b) robustness/resiliency losses from placing the grid at operating points that are at greater risk from contingencies, and (c) systemic losses resulting from cascading failures induced by poor operational choices. This paper is focused on understanding the connections between grid operational procedures and cyber attacks. We first offer two examples to illustrate how data integrity attacks can cause economic and physical damage by misleading operators into taking inappropriate decisions. We then focus on unobservable data integrity attacks involving power meter data. These are coordinated attacks where the compromised data are consistent with the physics of power flow, and are therefore passed by any bad data detection algorithm. We develop metrics to assess the economic impact of these attacks under re-dispatch decisions using optimal power flow methods. These metrics can be use to prioritize the adoption of appropriate countermeasures including PMU placement, encryption, hardware upgrades, and advance attack detection algorithms.

  13. Current therapy for chronic cerebrovascular attack

    Directory of Open Access Journals (Sweden)

    A. A. Shmonin

    2015-01-01

    Full Text Available Chronic cerebrovascular attack (CCVA is a brain lesion caused by vascular factors. CCVA appears as cognitive impairments (CIs, affective (emotional disorders and focal syndromes. Treatment for CCVA requires a comprehensive approach. Effective combination therapy for CCVA involves secondary prevention of stroke and CIs; treatment of CIs; treatment of depression and other affective disorders; and neuroprotective therapy. Basic therapy for CCVA includes modification of risk factors, antihypertensive, hypolipidemic, and antithrombotic therapies. Central acetylcholinesterase inhibitors (galantamine, rivastigmine, donepezil and a reversible NMDA receptor blocker (memantine are symptomatically used at a stage of vascular and mixed dementia. There are no unique guidelines for the therapy of mild and moderate vascular nondementia-related CIs. Drug use, based on the neurochemical mechanisms underlying the development of vascular CIs, is substantiated. When choosing psychotropic agents, it is necessary to take into account the causes and clinical manifestations of neuromediator deficiency. Antidepressants are used as essential drugs. Neuroleptics and tranquilizers are additionally administered in complex-pattern syndromes, such as depression with marked anxiety. Prescription of neuroprotectors may be effective in treating both stroke and CCVA. These medicaments are most effective when a damaging factor acts, i.e. neuroprotectors should be given in a risk situation and to reduce damage. Citicoline is one of the most test drugs in a group of neuroprotectors. 

  14. Temporal characterization of experimental recorder attack transients.

    Science.gov (United States)

    Ernoult, A; Fabre, B

    2017-01-01

    Through the comparison of notes produced on two recorders by one novice and two experienced players in musical contexts, this study identifies the temporal aspects of the attack transients which are controlled by the player and those which are imposed by the dynamic response of the instrument. The rise times of mouth pressure used by the novice player are longer than the ones produced by the experienced players, which are the shortest ones preserving the control of the jet velocity rise times. For shortest rise times, the jet development is limited by the inertia of the channel. The onset time of the acoustic oscillation is divided in two parts: the time needed to initiate the oscillation and the duration of the growth. The times of growth are similar for the novice and the experienced players, which is linked to the similarity of the gain characterizing the linear behavior of the instrument. The times needed to initiate the oscillation show the most pronounced difference between the two types of players; it is much longer for a novice player. This difference is interpreted in terms of the initial input of energy in the system which is larger for the experienced players.

  15. Multilayer Approach to Defend Phishing Attacks

    CERN Document Server

    Dhinakaran, Cynthia; Lee, Jae Kwang

    2011-01-01

    Spam messes up users inbox, consumes resources and spread attacks like DDoS, MiM, phishing etc. Phishing is a byproduct of email and causes financial loss to users and loss of reputation to financial institutions. In this paper we examine the characteristics of phishing and technology used by Phishers. In order to counter anti-phishing technology, phishers change their mode of operation; therefore a continuous evaluation of phishing only helps us combat phisher effectiveness. In our study, we collected seven hundred thousand spam from a corporate server for a period of 13 months from February 2008 to February 2009. From the collected data, we identified different kinds of phishing scams and mode of operation. Our observation shows that phishers are dynamic and depend more on social engineering techniques rather than software vulnerabilities. We believe that this study will develop more efficient anti-phishing methodologies. Based on our analysis, we developed an anti-phishing methodology and implemented in ou...

  16. Alcohol Cuts Heart Attack Risk in Men

    Institute of Scientific and Technical Information of China (English)

    Gene; Emery; 方笑丰

    2003-01-01

    选注者言:本文的主题句开门见山地告诉读者:frequent tippling(少喝常饮,常饮少量烈酒)of beer,wine or even spirits lowers a man’s risk of heart attack(心脏病发作)。但是,让我们感到不解的是文中的另一句话:alcohol affects womendifferently than men and that it would be"premature and unwise"to extrapolate(推断)the results beyond men。现代科技尚不能揭开这个谜:男性每日少量饮酒能降低心脏病的风险,而女性经常喝酒,却会增加得乳腺癌的机会。此句中的premature and unwise可以学用,而extrapolate一词则用得太文绉绉了。

  17. Node Survival in Networks under Correlated Attacks.

    Directory of Open Access Journals (Sweden)

    Yan Hao

    Full Text Available We study the interplay between correlations, dynamics, and networks for repeated attacks on a socio-economic network. As a model system we consider an insurance scheme against disasters that randomly hit nodes, where a node in need receives support from its network neighbors. The model is motivated by gift giving among the Maasai called Osotua. Survival of nodes under different disaster scenarios (uncorrelated, spatially, temporally and spatio-temporally correlated and for different network architectures are studied with agent-based numerical simulations. We find that the survival rate of a node depends dramatically on the type of correlation of the disasters: Spatially and spatio-temporally correlated disasters increase the survival rate; purely temporally correlated disasters decrease it. The type of correlation also leads to strong inequality among the surviving nodes. We introduce the concept of disaster masking to explain some of the results of our simulations. We also analyze the subsets of the networks that were activated to provide support after fifty years of random disasters. They show qualitative differences for the different disaster scenarios measured by path length, degree, clustering coefficient, and number of cycles.

  18. Efficient Techniques to Detect the Various Attacks in Ad-Hoc Network

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Sahu

    2012-09-01

    Full Text Available This paper is mainly focused on Denial of Service (DoS attack, where a server or a node cannot give service to the other nodes as it is under an attack. There are various attacks in the Ad hoc network but our paper is mainly focused on two types of DoS attacks viz SYN-Flooding and Worm-Hole attacks. How we can detect any one of attacks is addressed in this paper. We have discussed the CPU and memory utilization during the attack. We have given two separate algorithms for each attack and also suggest how to get rid of this type of attacks .

  19. Serial analysis of gene expression predicts structural differences in hippocampus of long attack latency and short attack latency mice

    NARCIS (Netherlands)

    Feldker, DEM; Datson, NA; Veenema, AH; Meulmeester, E; de Kloet, ER; Vreugdenhil, E

    2003-01-01

    The genetically selected long attack latency (LAL) and short attack latency (SAL) mice differ in a wide variety of behavioural traits and display differences in the serotonergic system and the hypothalamus-pituitary-adrenocortical (HPA)-axis. Serial analysis of gene expression (SAGE) was used to gen

  20. Black Teenage Pregnancy

    Directory of Open Access Journals (Sweden)

    Loretta I. Winters

    2012-01-01

    Full Text Available This article examines the relative importance of race and socioeconomic status (SES in determining whether Black and White teenagers report having ever been pregnant. Data gathered from 1999 to 2006 by the National Center for Health Statistics of the Center for Disease Control and Prevention included 1,580 Black and White females aged 15 to 19 years. Results supported the effects of race and SES, with SES having the stronger effect. However, the effects of race and SES differ when controlling for the state of the economy. No difference between Blacks and Whites was found during better economic times. During 2003-2004, the period of greatest economic stress, race was determined to be the only predictor of teenage pregnancy. In particular, during 2005-2006, the reduction in pregnancy rates for Black minors (15-17 fell below those for White minors within their respective SES categories. Policy implications are discussed in light of these findings.

  1. Janus black holes

    Science.gov (United States)

    Bak, Dongsu; Gutperle, Michael; Janik, Romuald A.

    2011-10-01

    In this paper Janus black holes in A dS 3 are considered. These are static solutions of an Einstein-scalar system with broken translation symmetry along the horizon. These solutions are dual to interface conformal field theories at finite temperature. An approximate solution is first constructed using perturbation theory around a planar BTZ blackhole. Numerical and exact solutions valid for all sets of parameters are then found and compared. Using the exact solution the thermodynamics of the system is analyzed. The entropy associated with the Janus black hole is calculated and it is found that the entropy of the black Janus is the sum of the undeformed black hole entropy and the entanglement entropy associated with the defect.

  2. Black Rail Pilot Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aural surveys using tape recorded calls proved to be an efficient and effective way to survey large expanses of shallow marsh for black rails (Laterallus...

  3. Black Friday = Broget Branding?

    DEFF Research Database (Denmark)

    Hansen, Heidi

    2015-01-01

    Black Friday er et godt eksempel på, hvordan ikke kun produktbrands og corporate brands rejser på tværs af landegrænser, men også traditioner som Halloween, Valentines Day og i dette tilfælde den ultimative tilbuds-fredag, som i USA går under navnet Black Friday. Men hvad er Black Friday i Danmark......? Essensen ved Black Friday er lave priser, og det er der ved første øjekast ikke mange brandingmuligheder forbundet ved, hvis man forstår branding som en måde at skabe ekstra værdi omkring sit produkt eller sin virksomhed. Som brand bliver man dog alligevel nødt til at forholde sig til konceptet, da det er...

  4. A LocationGuard Approach: An Efficacious Scheme to Alleviate DoS Attacks

    DEFF Research Database (Denmark)

    Banoth, Rajkumar

    2011-01-01

    from a denial-of- service (DoS) attack or a host compromise attack. Hence, most of these distributed file systems are vulnerable to targeted file attacks, wherein a n adversary attempts to attack a small (chosen) set of files by attacking the nodes that host them. This paper presents Location Guard—a...

  5. Modelling quantum black hole

    CERN Document Server

    Govindarajan, T R

    2016-01-01

    Novel bound states are obtained for manifolds with singular potentials. These singular potentials require proper boundary conditions across boundaries. The number of bound states match nicely with what we would expect for black holes. Also they serve to model membrane mechanism for the black hole horizons in simpler contexts. The singular potentials can also mimic expanding boundaries elegantly, there by obtaining appropriately tuned radiation rates.

  6. Helical superconducting black holes.

    Science.gov (United States)

    Donos, Aristomenis; Gauntlett, Jerome P

    2012-05-25

    We construct novel static, asymptotically five-dimensional anti-de Sitter black hole solutions with Bianchi type-VII(0) symmetry that are holographically dual to superconducting phases in four spacetime dimensions with a helical p-wave order. We calculate the precise temperature dependence of the pitch of the helical order. At zero temperature the black holes have a vanishing entropy and approach domain wall solutions that reveal homogenous, nonisotropic dual ground states with an emergent scaling symmetry.

  7. Black Is Cool!

    Institute of Scientific and Technical Information of China (English)

    Dorine; Houston

    1997-01-01

    Do you remember the colors the college freshmen dyed their hair when you were here? Turquoise, orange, bright yellow.... Things have changed. Black has (?)ome the color of choice among the young people. Young men and women alike dye their hair coal black. The women let their hair grow very long. and it hangs straight and stringy down their backs. The young men leave it long on

  8. Braneworld black holes

    CERN Document Server

    Gregory, Ruth

    2008-01-01

    In these lectures, I give an introduction to and overview of braneworlds and black holes in the context of warped compactifications. I first describe the general paradigm of braneworlds, and introduce the Randall-Sundrum model. I discuss braneworld gravity, both using perturbation theory, and also non perturbative results. I then discuss black holes on the brane, the obstructions to finding exact solutions, and ways of tackling these difficulties. I describe some known solutions, and conclude with some open questions and controversies.

  9. Black Hole Induced Ejections

    OpenAIRE

    Pelletier, G.

    2004-01-01

    Black Holes generate a particular kind of environments dominated by an accretion flow which concentrates a magnetic field. The interplay of gravity and magnetism creates this paradoxical situation where relativistic ejection is allowed and consequently high energy phenomena take place. Therefore Black Holes, which are very likely at the origin of powerfull astrophysical phenomena such as AGNs, micro- quasars and GRBs where relativistic ejections are observed, are at the heart of high energy a...

  10. Defending against Key Abuse Attacks in KP-ABE Enabled Broadcast Systems

    Science.gov (United States)

    Yu, Shucheng; Ren, Kui; Lou, Wenjing; Li, Jin

    Key-Policy Attribute-Based Encryption (KP-ABE) is a promising cryptographic primitive which enables fine-grained access control over sensitive data. However, key abuse attacks in KP-ABE may impede its wide application especially in copyright-sensitive systems. To defend against this kind of attacks, this paper proposes a novel KP-ABE scheme which is able to disclose any illegal key distributor’s ID when key abuse is detected. In our scheme, each bit of user ID is defined as an attribute and the user secret key is associated with his unique ID. The tracing algorithm fulfills its task by tricking the pirate device into decrypting the ciphertext associated with the corresponding bits of his ID. Our proposed scheme has the salient property of black box tracing, i.e., it traces back to the illegal key distributor’s ID only by observing the pirate device’s outputs on certain inputs. In addition, it does not require the pirate device’s secret keys to be well-formed as compared to some previous work. Our proposed scheme is provably secure under the Decisional Bilinear Diffie-Hellman (DBDH) assumption and the Decisional Linear (DL) assumption.

  11. Cosmic censorship inside black holes

    CERN Document Server

    Thorlacius, L

    2006-01-01

    A simple argument is given that a traversable Cauchy horizon inside a black hole is incompatible with unitary black hole evolution. The argument assumes the validity of black hole complementarity and applies to a generic black hole carrying angular momentum and/or charge. In the second part of the paper we review recent work on the semiclassical geometry of two-dimensional charged black holes.

  12. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    Steven L Liebling

    2000-10-01

    Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. Power-law mass scaling, aspects of universality, and self-similarity have now been found for a large variety of models. However, questions remain. Here I briefly review critical phenomena, discuss some recent results, and describe a model which demonstrates similar phenomena without gravity.

  13. Charged Galileon black holes

    Science.gov (United States)

    Babichev, Eugeny; Charmousis, Christos; Hassaine, Mokhtar

    2015-05-01

    We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematically compatible with the field equations. This opens up the possibility for novel searches of hairy black holes in a far more general setting of Horndeski theory.

  14. Ultramassive Black Hole Coalescence

    CERN Document Server

    Khan, Fazeel; Berczik, Peter

    2015-01-01

    Although supermassive black holes (SMBHs) correlate well with their host galaxies, there is an emerging view that outliers exist. Henize 2-10, NGC 4889, and NGC1277 are examples of SMBHs at least an order of magnitude more massive than their host galaxy suggests. The dynamical effects of such ultramassive central black holes is unclear. Here, we perform direct N-body simulations of mergers of galactic nuclei where one black hole is ultramassive to study the evolution of the remnant and the black hole dynamics in this extreme regime. We find that the merger remnant is axisymmetric near the center, while near the large SMBH influence radius, the galaxy is triaxial. The SMBH separation shrinks rapidly due to dynamical friction, and quickly forms a binary black hole; if we scale our model to the most massive estimate for the NGC1277 black hole, for example, the timescale for the SMBH separation to shrink from nearly a kiloparsec to less than a parsec is roughly 10 Myr. By the time the SMBHs form a hard binary, gr...

  15. Resist DoS attacks in UMTS-WLAN

    Science.gov (United States)

    Qu, Huyu; Cheng, Qiang

    2005-06-01

    Wireless network is more vulnerable to denial of service (DoS) attacks than wired one. In this paper we propose two methods to resist DoS attacks in UMTS-WLAN network, one is active and the other is passive. These two are complementary to each other. In active DoS defense method, a mobile terminal generates an authorized anonymous ID (AAI) using its true ID such as IP address, MAC address, PIN code, or asymmetric key, and substitutes its true ID with the authorized anonymous ID. The mobile terminal may be authenticated by the UMTS-WLAN, however its true ID is anonymous to intending attackers. This method can be used to isolate de-authenticating/disassociating DoS attackers, spoofing power-save DoS attacker, etc. In passive DoS defense method, we propose a trace back scheme. We use covert channels in the header of mobile IP packets to trace back the malicious nodes by embedding some address information of intermediate nodes, and recovering the embedded information by the victim. After the victim successfully traces the attacking paths from malicious nodes, it can segregate the malicious nodes and protect itself. This method can be used to resist DoS attacks of mass-produced junk message congestions.

  16. A Survey of DDOS Attacks in TCP/IP Stack

    Directory of Open Access Journals (Sweden)

    P.C. Senthil Mahesh

    2014-08-01

    Full Text Available The aim of study is to discuss DDOS attack in TCP/IP layer. A Denial-of-Service (DoS or Distributed Denial-of-Service (DDoS attack is an attempt to make a device or network source not available to its designed customers. The purposes and objectives of a DoS attack may differ, it usually includes initiatives to momentarily or consistently disrupt or hold solutions of a variety linked with the Online. As explanation, DDoS (Distributed Denial of Service attack are sent by two or more individuals, or bots. DoS (Denial of Service attack are sent by one person or system. DoS attack typically focus on sites or solutions organized on high-profile web or web servers such as financial institutions, bank card payment gateways and even main name servers. This technique has now seen comprehensive use in certain activities, used by server owners, or dissatisfied opponents on activities. Progressively, DoS attack have also been used as a way of level of resistance.

  17. Attack resilience of the evolving scientific collaboration network.

    Directory of Open Access Journals (Sweden)

    Xiao Fan Liu

    Full Text Available Stationary complex networks have been extensively studied in the last ten years. However, many natural systems are known to be continuously evolving at the local ("microscopic" level. Understanding the response to targeted attacks of an evolving network may shed light on both how to design robust systems and finding effective attack strategies. In this paper we study empirically the response to targeted attacks of the scientific collaboration networks. First we show that scientific collaboration network is a complex system which evolves intensively at the local level--fewer than 20% of scientific collaborations last more than one year. Then, we investigate the impact of the sudden death of eminent scientists on the evolution of the collaboration networks of their former collaborators. We observe in particular that the sudden death, which is equivalent to the removal of the center of the egocentric network of the eminent scientist, does not affect the topological evolution of the residual network. Nonetheless, removal of the eminent hub node is exactly the strategy one would adopt for an effective targeted attack on a stationary network. Hence, we use this evolving collaboration network as an experimental model for attack on an evolving complex network. We find that such attacks are ineffectual, and infer that the scientific collaboration network is the trace of knowledge propagation on a larger underlying social network. The redundancy of the underlying structure in fact acts as a protection mechanism against such network attacks.

  18. Data-plane Defenses against Routing Attacks on Tor

    Directory of Open Access Journals (Sweden)

    Tan Henry

    2016-10-01

    Full Text Available Tor is susceptible to traffic correlation attacks in which an adversary who observes flows entering and leaving the anonymity network can apply statistical techniques to correlate flows and de-anonymize their endpoints. While an adversary may not be naturally positioned to conduct such attacks, a recent study shows that the Internet’s control-plane can be manipulated to increase an adversary’s view of the network, and consequently, improve its ability to perform traffic correlation. This paper explores, in-depth, the effects of control-plane attacks on the security of the Tor network. Using accurate models of the live Tor network, we quantify Tor’s susceptibility to these attacks by measuring the fraction of the Tor network that is vulnerable and the advantage to the adversary of performing the attacks. We further propose defense mechanisms that protect Tor users from manipulations at the control-plane. Perhaps surprisingly, we show that by leveraging existing trust anchors in Tor, defenses deployed only in the data-plane are sufficient to detect most control-plane attacks. Our defenses do not assume the active participation of Internet Service Providers, and require only very small changes to Tor. We show that our defenses result in a more than tenfold decrease in the effectiveness of certain control-plane attacks.

  19. Risk factors for hypertensive attack during pheochromocytoma resection

    Science.gov (United States)

    Kwon, Se Yun; Lee, Kyung Seop; Lee, Jun Nyung; Ha, Yun-Sok; Choi, Seock Hwan; Kim, Hyun Tae; Kim, Tae-Hwan; Yoo, Eun Sang

    2016-01-01

    Purpose We aimed to retrospectively evaluate the risk factors for hypertensive attack during adrenalectomy in patients with pheochromocytoma. Despite the development of newer surgical and anesthetic techniques for the management of pheochromocytoma, intraoperative hypertensive attack continues to present a challenge. Materials and Methods Data from 53 patients diagnosed with pheochromocytoma at Kyungpook National Uriversity Medical Center between January 2000 and June 2012 were retrospectively analyzed. The subjects were divided into 2 groups depending on the presence or absence of hypertensive attack at the time of surgery. Patient demographic characteristics and preoperative evaluations were assessed for their prognostic relevance with respect to hypertensive attack. A univariate analysis was conducted, and a multivariate logistic regression analysis was also performed. Results In the univariate analysis, systolic blood pressure at presentation, preoperative hormonal status (including epinephrine, norepinephrine, vanillylmandelic acid, and metanephrine levels in a 24-hour urine sample), tumor size, and postoperative systolic blood pressure were significantly associated with the development of hypertensive attack. In the multivariate analysis, preoperative epinephrine level and tumor size were independent factors that predicted hypertensive attack. The highest odds ratio for tumor size (2.169) was obtained at a cutoff value of 4.25 cm and the highest odds ratio for preoperative epinephrine (1.020) was obtained at a cutoff value of 166.3 µg/d. Conclusions In this study, a large tumor size and an elevated preoperative urinary epinephrine level were risk factors for intraoperative hypertensive attack in patients with pheochromocytoma. PMID:27194549

  20. Discovery of Selective Nanobodies against α-elapitoxin Dpp2c from Black Mamba through Phage Display Screening

    DEFF Research Database (Denmark)

    Milbo, Christina; Laustsen, Andreas Hougaard; Lohse, Brian

    Feared for its highly neurotoxic venom and rapid attack technique, the Black mamba (Dendroaspis polylepis) is Africa’s largest venomous snake. The clinical manifestations of a bitefrom D. polylepis include flaccid paralysis leading to respiratory failure and death due to postsynaptic blockade...