Resistance to Pirates 2.0: A Method from Leakage Resilient Cryptography

In the classical model of traitor tracing, one assumes that a traitor contributes its entire secret key to build a pirate decoder. However, new practical scenarios of pirate has been considered, namely Pirate Evolution Attacks at Crypto 2007 and Pirates 2.0 at Eurocrypt 2009, in which pirate decoders could be built from sub-keys of users. The key notion in Pirates 2.0 is the anonymity level of traitors: they can rest assured to remain anonymous when each of them only contributes a very small fraction of its secret information. This scenario encourages dishonest users to participate in collusion and the size of collusion could become very large, possibly beyond the considered threshold in the classical model. There are numerous attempts to deal with Pirates 2.0 each of which only considers a particular form of Pirates 2.0. In this paper, we propose a method for fighting Pirates 2.0 in any form. Our method is based on the researches in key-leakage resilience. It thus gives an interesting and rather surprised connection between the rich domain of key-leakage resilient cryptography and Pirates 2.0. We first formalize the notion of key-leakage resilient revoke system and then identify sufficient conditions so that a key-leakage resilient revoke scheme can resist Pirates 2.0 in any form. We finally propose a construction of a secure key-leakage resilient identity-based revoke system that fulfills the required conditions. The main ingredient in the construction relies on the identity-based encryption with wildcards (\WIBE) and our construction of key-leakage resilient \WIBE could be useful in its own right

Neutron Yield from (γ, n) and (γ, 2n) Reactions following 100 MeV Bremsstrahlung in a Tungsten Target

The photonuclear reactions of (γ, xn) or (γ, xnp) types can be used to produce high-intensity neutron sources for research and applied purposes. In this work a Monte-Carlo calculation has been used to evaluate the production yield of neutrons from the (γ, n) and (γ, 2n) reactions following the bremsstrahlung produced by a 100 MeV electron beam on a tungsten target

Megastigmans and other compounds from Antidesma hainanensis Merr.

Four megastigmans 7-megastigmene-3-ol-9-one 3-O-[α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside]  (1),  alangionoside L (2),  alangioside (3), ampelopsisionoside (4), and other constituents as N–trans-feruloyloctopamide (5), trans-linalool-3,6-oxide-β-D-glucopyranoside (6),  5α,8α-dipioxiergosta-6,22-diene-3β-ol (7), and (Z)-2-hexenyl β-D-glucopyranoside (8) were isolated from the methanol extract of the Antidesma hainanensis leaves. Their chemical structures were successfully determined using NMR and ESI-MS analysis as well as in comparison with the reported data. This is the first report of these compounds from Euphorbiaceae family

The Study of Isomeric Ratios in Photonuclear Reactions Forming High Spin Isomers in the Giant Dipole Resonance Region

We studied the isomeric ratios  in  odd-odd nuclei $^{196}$Au,$^{182}$Ta  and $^{194}$Ir  with    high spin isomeric states  produced  in $^{197}$Au$(\gamma,  n)$ $^{196m,g}$Au, $^{183}$W$(\gamma,  p)$ $^{182m,g}$Ta  and $^{185}$Pt$(\gamma,  p)$$^{194m,g}$Ir  reactions  by  using  the activation  technique  and  $\gamma$-ray  spectroscopic  method  in  the  giant    dipole  resonance  (GDR)  region.  The high-purity natural Au, W and Pt  foils in disc shape were irradiated with bremsstrahlungs  generated from an  electron  accelerator  Microtron.  The  irradiated  foils  were  measured  by  the  high  resolution  $\gamma$-ray spectroscopic system which consists of a Ge(HP) detector and a multichannel analyzer. In order to improve the  accuracy  of  the  experimental  results,  necessary  corrections  were  made  in  the  $\gamma$-ray  activity measurements and data analysis.  The results were  analyzed,  discussed and compared with those of other authors  as well as with theoretical model calculations.  The study shows that the isomeric ratios in  nuclei with high spin isomeric states are much lower than that in low spin isomeric state isomers

Rapid onset of collectivity in the vicinity of 78Ni

gamma-rays following the B and B-n decay of the very neutron rich 84Ga produced by photo-fission of 238U have been studied at the newly built ISOL facility of IPN Orsay: ALTO. Two activities were observed and assigned to two B-decaying states: 84gGa, I = (0\^-) and 84mGa, I = (3\^-, 4\^-). Excitation energies of the 2+1 and 4+1 excited states of 84Ge were measured at E(2+1) = 624.3 keV and E(4+1) = 1670.1 keV. Comparison with HFB+GCM calculations allows to establish the collective character of this nucleus indicating a substantial N=50 core polarization. The excitation energy of the 1/2+1 state in 83Ga known to carry a large part of the neutron 3s1/2 strength was measured at 247.8keV. Altogether these data allow to confirm the new single particle state ordering which appears immediately after the double Z=28 and N=50 shell closure and to designate 78Ni as a fragile and easily polarized doubly-magic core.Comment: 4 pages, ReVTe

Study of the Isomeric Ratio of 135m,g 54Xe in Photofission 23793Np in Giant Dipole Resonance Region

In this work we present the results of measurement of the isomeric ratio of fission fragment e in photofission of 237Np induced by bremsstrahlung in the Giant Dipole Resonance Region by the method using the inert gaseous flow. The experiments have been performed at the electron accelerator Microtron MT-25 of the Flerov laboratory of Nuclear Reaction, Joint Institute for Nuclear Research, Dubna, Russia. The results were discussed and compared with that of other authors

Simulation for Optimizing the Design of Cryogenic Stopping Cell for the IGISOL Facility at ELI-NP

The production of the exotic neutron-rich ion beams from photofission of the actinide targets in an IGISOL facility will be studied via an experimental program that will take place at the Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility. Geant4 simulation toolkit was used for optimizing the target configuration in order to maximize the rate of released photofission fragments from targets placed in a cell filled with He gas

Discrepancies in prevalence trends for HIV, hepatitis B virus, and hepatitis C virus in Haiphong, Vietnam from 2007 to 2012

We previously reported a significant reduction in the prevalence of human immunodeficiency virus type 1 (HIV) from 2007 to 2012 in people who inject drugs (PWID; 35.9% to 18.5%, p < 0.001) and female sex workers (FSW; 23.1% to 9.8%, p < 0.05), but not in blood donors (BD) or pregnant women, in Haiphong, Vietnam. Our aim in the present study was to assess trends in the prevalence of infection with hepatitis B and C viruses (HBV and HCV, respectively). We also investigated the coinfection rates of HBV and HCV with HIV in the same groups. Between 2007 and 2012, HBV prevalence was significantly decreased in BD (18.1% vs. 9.0%, p = 0.007) and slightly decreased in FSW (11.0% vs. 3.9%, p = 0.21), but not in PWID (10.7% vs. 11.1%, p = 0.84). HCV prevalence was significantly decreased in PWID (62.1% in 2007 vs. 42.7% in 2008, p < 0.0001), but it had rebounded to 58.4% in 2012 (2008 vs. 2012, p < 0.0001). HCV prevalence also increased in FSW: 28.6% in 2007 and 2009 vs. 35.3% in 2012; however, this difference was not significant (2007 vs. 2012, p = 0.41). Rates of coinfection with HBV and HCV among HIV-infected PWID and FSW did not change significantly during the study period. Our findings suggest that the current harm reduction programs designed to prevent HIV transmission in PWID and FSW may be insufficient to prevent the transmission of hepatitis viruses, particularly HCV, in Haiphong, Vietnam. New approaches, such as the introduction of catch-up HBV vaccination to vulnerable adult populations and the introduction of HCV treatment as prevention, should be considered to reduce morbidity and mortality due to HIV and hepatitis virus coinfection in Vietnam. © 2017 Ishizaki et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited