1,965 research outputs found
IST Austria Thesis
Many security definitions come in two flavors: a stronger âadaptiveâ flavor, where the adversary can arbitrarily make various choices during the course of the attack, and a weaker âselectiveâ flavor where the adversary must commit to some or all of their choices a-priori. For example, in the context of identity-based encryption, selective security requires the adversary to decide on the identity of the attacked party at the very beginning of the game whereas adaptive security allows the attacker to first see the master public key and some secret keys before making this choice. Often, it appears to be much easier to achieve selective security than it is to achieve adaptive security. A series of several recent works shows how to cleverly achieve adaptive security in several such scenarios including generalized selective decryption [Pan07][FJP15], constrained PRFs [FKPR14], and Yaoâs garbled circuits [JW16]. Although the above works expressed vague intuition that they share a common technique, the connection was never made precise. In this work we present a new framework (published at Crypto â17 [JKK+17a]) that connects all of these works and allows us to present them in a unified and simplified fashion. Having the framework in place, we show how to achieve adaptive security for proxy re-encryption schemes (published at PKC â19 [FKKP19]) and provide the first adaptive security proofs for continuous group key agreement protocols (published at S&P â21 [KPW+21]). Questioning optimality of our framework, we then show that currently used proof techniques cannot lead to significantly better security guarantees for "graph-building" games (published at TCC â21 [KKPW21a]). These games cover generalized selective decryption, as well as the security of prominent constructions for constrained PRFs, continuous group key agreement, and proxy re-encryption. Finally, we revisit the adaptive security of Yaoâs garbled circuits and extend the analysis of Jafargholi and Wichs in two directions: While they prove adaptive security only for a modified construction with increased online complexity, we provide the first positive results for the original construction by Yao (published at TCC â21 [KKP21a]). On the negative side, we prove that the results of Jafargholi and Wichs are essentially optimal by showing that no black-box reduction can provide a significantly better security bound (published at Crypto â21 [KKPW21c])
Giant chirality-induced spin-selectivity of polarons
The chirality-induced spin selectivity (CISS) effect gives rise to strongly
spin-dependent transport through many organic molecules and structures. Its
discovery raises fascinating fundamental questions as well as the prospect of
possible applications. The basic phenomenology, a strongly asymmetric
magnetoresistance despite the absence of magnetism, is now understood to result
from the combination of spin-orbit coupling and chiral geometry. However,
experimental signatures of electronic helicity were observed at room
temperature, i.e., at an energy scale that exceeds the typical spin-orbit
coupling in organic systems by several orders of magnitude. This work shows
that a new energy scale for CISS emerges for currents carried by polarons,
i.e., in the presence of strong electron-phonon coupling. In particular, we
found that polaron fluctuations play a crucial role in the two manifestations
of CISS in transport measurements -- the spin-dependent transmission
probability through the system and asymmetric magnetoresistance
Obstetric violence: a Latin American legal response to mistreatment during childbirth
Over the last several years, a new legal construct has emerged in Latin America that encompasses elements of quality of obstetric care and mistreatment of women during childbirth - both issues of global maternal health import. Termed "obstetric violence," this legal construct refers to disrespectful and abusive treatment that women may experience from health care providers during pregnancy, childbirth, and the postpartum period, as well as other elements of poor quality care, such as failure to adhere to evidence-based best practices. This new legal term emerged out of concerted efforts by women's groups and networks, feminists, professional organizations, international and regional bodies, and public health agents and researchers to improve the quality of care that women receive across the region.Fil: Williams, Caitlin R.. University of North Carolina; Estados UnidosFil: Jerez, Celeste. Universidad de Buenos Aires. Facultad de FilosofĂa y Letras. Instituto Interdisciplinario de Estudios de GĂ©nero; ArgentinaFil: Klein, Karen. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: Correa, Malena. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: Belizan, Jose. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Instituto de Efectividad ClĂnica y Sanitaria; ArgentinaFil: Cormick, Gabriela. Instituto de Efectividad ClĂnica y Sanitaria; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. University of Cape Town; SudĂĄfric
Resilience and community response to climate-related events: Case studies from four countries
It is important for governments, aid organizations, and researchers to understand how developing communities respond to climate change and how their efforts can be improved within a framework of resilience thinking. This review explores the definition of resilience and, more specifically, community resilience and its components, then presents four case studies of community response to extreme weather events to illustrate community resilience in action. The review is intended to provide context for and inform more detailed exploration of community resilience in integrated programming (specifically, programming designed to improve health, environment, and population outcomes). It is also intended to capture references to population dynamics and family planning in the literature on community resilience, but is not intended as a definitive guide to the links between community resilience and health or family planning
Multiplying by Division: Mapping the Collection at University of North Texas Libraries
The University of North Texas (UNT) Libraries has developed a unique collection assessment tool, the Collection Map, to provide support for a new accessâbased collection development philosophy. UNT Librarians realized the limitations of traditional assessment methods to gauge the impact of emerging acquisitions models such as demandâdriven acquisitions (DDA) and large interdisciplinary eâbook collections. What was needed was a flexible, nimble assessment system to track access, holdings, and interlibrary loan (ILL) activity for each academic discipline. The Collection Map is a database that links items, and their associated data, to any one of several dozen overlapping subcollections via Library of Congress call numbers (LCCNs). The Collection Mapâs unique manyâtoâmany relationship of subcollections to items and data enables librarians to demonstrate support for subject areas and to make more informed collecting decisions. This article describes the components and creation of the Collection Map, including manipulation of existing systems to extract data
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