The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Moti Yung - One of the best experts on this subject based on the ideXlab platform.
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non Malleability from Malleability simulation sound quasi adaptive nizk proofs and cca2 secure encryption from homomorphic signatures
International Cryptology Conference, 2014Co-Authors: Benoit Libert, Thomas Peters, Marc Joye, Moti YungAbstract:Verifiability is central to building protocols and systems with integrity. Initially, efficient methods employed the Fiat-Shamir heuristics. Since 2008, the Groth-Sahai techniques have been the most efficient in constructing non-interactive witness indistinguishable and zero-knowledge proofs for algebraic relations in the standard model. For the important task of proving membership in linear subspaces, Jutla and Roy (Asiacrypt 2013) gave significantly more efficient proofs in the quasi-adaptive setting (QA-NIZK). For membership of the row space of a t ×n matrix, their QA-NIZK proofs save Ω(t) group elements compared to Groth-Sahai. Here, we give QA-NIZK proofs made of a constant number group elements – regardless of the number of equations or the number of variables – and additionally prove them unbounded simulation-sound. Unlike previous unbounded simulation-sound Groth-Sahai-based proofs, our construction does not involve quadratic pairing product equations and does not rely on a chosen-ciphertext-secure encryption scheme. Instead, we build on structure-preserving signatures with homomorphic properties. We apply our methods to design new and improved CCA2-secure encryption schemes. In particular, we build the first efficient threshold CCA-secure keyed-homomorphic encryption scheme (i.e., where homomorphic operations can only be carried out using a dedicated evaluation key) with publicly verifiable ciphertexts.
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non Malleability from Malleability simulation sound quasi adaptive nizk proofs and cca2 secure encryption from homomorphic signatures
IACR Cryptology ePrint Archive, 2013Co-Authors: Benoit Libert, Thomas Peters, Marc Joye, Moti YungAbstract:Verifiability is central to building protocols and systems with integrity. Initially, efficient methods employed the Fiat-Shamir heuristics. Since 2008, the Groth-Sahai techniques have been the most efficient in constructing non-interactive witness indistinguishable and zero-knowledge proofs for algebraic relations. For the important task of proving membership in linear subspaces, Jutla and Roy (Asiacrypt 2013) gave significantly more efficient proofs in the quasi-adaptive setting (QA-NIZK). For membership of the row space of a t× n matrix, their QA-NIZK proofs save O(2t) group elements compared to GrothSahai. Here, we give QA-NIZK proofs made of a constant number group elements – regardless of the number of equations or the number of variables – and additionally prove them unbounded simulationsound. Unlike previous unbounded simulation-sound Groth-Sahai-based proofs, our construction does not involve quadratic pairing product equations and does not rely on a chosen-ciphertext-secure encryption scheme. Instead, we build on structure-preserving signatures with homomorphic properties. We apply our methods to design new and improved CCA2-secure encryption schemes. In particular, we build the first efficient threshold CCA-secure keyed-homomorphic encryption scheme (i.e., where homomorphic operations can only be carried out using a dedicated evaluation key) with publicly verifiable ciphertexts.
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adaptive concurrent non Malleability with bare public keys
arXiv: Computational Complexity, 2009Co-Authors: Andrew Chichih Yao, Moti Yung, Yunlei ZhaoAbstract:Concurrent non-Malleability (CNM) is central for cryptographic protocols running concurrently in environments such as the Internet. In this work, we formulate CNM in the bare public-key (BPK) model, and show that round-efficient concurrent non-malleable cryptography with full adaptive input selection can be established, in general, with bare public-keys (where, in particular, no trusted assumption is made). Along the way, we clarify the various subtleties of adaptive concurrent non-Malleability in the bare public-key model.
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adaptive concurrent non Malleability with bare public keys
IACR Cryptology ePrint Archive, 2009Co-Authors: Andrew Chichih Yao, Moti Yung, Yunlei ZhaoAbstract:Concurrent non-Malleability (CNM) is central for cryptographic protocols running concurrently in environments such as the Internet. In this work, we formulate CNM in the bare public-key (BPK) model, and show that round-efficient concurrent non-malleable cryptography with full adaptive input selection can be established, in general, with bare public-keys (where, in particular, no trusted assumption is made). Along the way, we clarify the various subtleties of adaptive concurrent nonMalleability in the bare public-key model. The work described in this paper was supported in part by the National Basic Research Program of China Grant (973) 2007CB807900, 2007CB807901, and by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project Number CityU 122105) and CityU Research Grant (9380039). The third author is also supported by NSFC (No. 60703091), the Pu-Jiang and Qi-Ming-Xing Programs of Shanghai and a grant from MSRA. Institute for Theoretical Computer Science (ITCS), Tsinghua University, Beijing, China. andrewcyao@tsinghua.eud.cn Google Inc. and Columbia University, New York, NY, USA. moti@cs.columbia.edu Contact author. Software School, Fudan University, Shanghai 200433, China. ylzhao@fudan.edu.cn Works partially done while visiting Tsinghua university and City University of Hong Kong.
Yongjun Zhang - One of the best experts on this subject based on the ideXlab platform.
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Rapid Stress Relaxation and Moderate Temperature of Malleability Enabled by the Synergy of Disulfide Metathesis and Carboxylate Transesterification in Epoxy Vitrimers
ACS Macro Letters, 2019Co-Authors: Mao Chen, Yeping Wu, Xiuli Zhao, Lin Zhou, Yongjun ZhangAbstract:Vitrimers make up a class of polymeric materials combining the advantages of thermosets and thermoplastics, because they can be reprocessed while being at the same time permanently cross-linked. However, a long heating duration or an elevated temperature is necessary for most vitrimers to relax the stress from deformation and exhibit Malleability. Herein, a disulfide-containing carboxylic acid is applied as a curing agent to synthesize epoxy vitrimers with simultaneous disulfide metathesis and carboxylate transesterification. The insoluble networks exhibit rapid stress relaxation and have relaxation times ranging from 1.5 s (200 °C) to 5500 s (60 °C), while the temperature of Malleability is as low as 65 °C. Moreover, this vitrimer can be efficiently reprocessed at 100 °C in 1 h with full recovery of mechanical strength for at least four cycles. Additionally, such a material is simply synthesized from commercially available chemicals and may have potential applications in the electronics industry where a ...
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Rapid Stress Relaxation and Moderate Temperature of Malleability Enabled by the Synergy of Disulfide Metathesis and Carboxylate Transesterification in Epoxy Vitrimers
2019Co-Authors: Mao Chen, Lin Zhou, Xiuli Zhao, Yongjun ZhangAbstract:Vitrimers make up a class of polymeric materials combining the advantages of thermosets and thermoplastics, because they can be reprocessed while being at the same time permanently cross-linked. However, a long heating duration or an elevated temperature is necessary for most vitrimers to relax the stress from deformation and exhibit Malleability. Herein, a disulfide-containing carboxylic acid is applied as a curing agent to synthesize epoxy vitrimers with simultaneous disulfide metathesis and carboxylate transesterification. The insoluble networks exhibit rapid stress relaxation and have relaxation times ranging from 1.5 s (200 °C) to 5500 s (60 °C), while the temperature of Malleability is as low as 65 °C. Moreover, this vitrimer can be efficiently reprocessed at 100 °C in 1 h with full recovery of mechanical strength for at least four cycles. Additionally, such a material is simply synthesized from commercially available chemicals and may have potential applications in the electronics industry where a high temperature is not allowed
łukasz Mazurek - One of the best experts on this subject based on the ideXlab platform.
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on the Malleability of bitcoin transactions
Financial Cryptography, 2015Co-Authors: Marcin Andrychowicz, Stefan Dziembowski, Daniel Malinowski, łukasz MazurekAbstract:We study the problem of Malleability of Bitcoin transactions. Our first two contributions can be summarized as follows: (i) we perform practical experiments on Bitcoin that show that it is very easy to maul Bitcoin transactions with high probability, and (ii) we analyze the behavior of the popular Bitcoin wallets in the situation when their transactions are mauled; we conclude that most of them are to some extend not able to handle this situation correctly.
Yunlei Zhao - One of the best experts on this subject based on the ideXlab platform.
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adaptive concurrent non Malleability with bare public keys
arXiv: Computational Complexity, 2009Co-Authors: Andrew Chichih Yao, Moti Yung, Yunlei ZhaoAbstract:Concurrent non-Malleability (CNM) is central for cryptographic protocols running concurrently in environments such as the Internet. In this work, we formulate CNM in the bare public-key (BPK) model, and show that round-efficient concurrent non-malleable cryptography with full adaptive input selection can be established, in general, with bare public-keys (where, in particular, no trusted assumption is made). Along the way, we clarify the various subtleties of adaptive concurrent non-Malleability in the bare public-key model.
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adaptive concurrent non Malleability with bare public keys
IACR Cryptology ePrint Archive, 2009Co-Authors: Andrew Chichih Yao, Moti Yung, Yunlei ZhaoAbstract:Concurrent non-Malleability (CNM) is central for cryptographic protocols running concurrently in environments such as the Internet. In this work, we formulate CNM in the bare public-key (BPK) model, and show that round-efficient concurrent non-malleable cryptography with full adaptive input selection can be established, in general, with bare public-keys (where, in particular, no trusted assumption is made). Along the way, we clarify the various subtleties of adaptive concurrent nonMalleability in the bare public-key model. The work described in this paper was supported in part by the National Basic Research Program of China Grant (973) 2007CB807900, 2007CB807901, and by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project Number CityU 122105) and CityU Research Grant (9380039). The third author is also supported by NSFC (No. 60703091), the Pu-Jiang and Qi-Ming-Xing Programs of Shanghai and a grant from MSRA. Institute for Theoretical Computer Science (ITCS), Tsinghua University, Beijing, China. andrewcyao@tsinghua.eud.cn Google Inc. and Columbia University, New York, NY, USA. moti@cs.columbia.edu Contact author. Software School, Fudan University, Shanghai 200433, China. ylzhao@fudan.edu.cn Works partially done while visiting Tsinghua university and City University of Hong Kong.
Elizabeth T Kneeland - One of the best experts on this subject based on the ideXlab platform.
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emotion Malleability beliefs and coping with the college transition
Emotion, 2020Co-Authors: Elizabeth T Kneeland, John F DovidioAbstract:First-year students navigating the transition to undergraduate life experience an increase in psychopathology, yet some students thrive while others struggle. The current study examined whether first-year students' beliefs about emotion's Malleability predicted emotion regulation and mental health during this critical period. First-year college students completed a battery of self-report questionnaires at the beginning and end of the fall semester. Students who held more malleable views of emotion at the semester's onset reported more of a decrease in depression, more of an increase in the use of cognitive reappraisal, and decreased reliance on rumination as emotion regulation strategies during the fall semester. As hypothesized, emotion regulation played a significant role linking emotion Malleability beliefs to depression. Students' beliefs that emotions were more malleable at the beginning of the semester predicted less depression at the end of the semester through greater use of cognitive reappraisal and less use of rumination. These results suggest that emotion Malleability beliefs are systematically related to emotion regulation and mental health adjustment during this stressful transition and could be targets for intervention. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
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Emotion Malleability Beliefs Influence the Spontaneous Regulation of Social Anxiety
Cognitive Therapy and Research, 2016Co-Authors: Elizabeth T Kneeland, John F Dovidio, Susan Nolen-hoeksema, June GruberAbstract:The current study examined how manipulating individuals’ beliefs about emotion’s Malleability influences the choices they make in how they spontaneously regulate their anxiety during a stressful social situation. Participants were randomly assigned to receive either an experimental manipulation that emotions are malleable or that emotions are fixed then completed an impromptu, brief speech task designed to elicit anxiety. We predicted that participants in the malleable emotion condition, compared to those in the fixed condition, would engage in more cognitive reappraisal to change the unfolding of an emotion earlier in the emotion generative process; we predicted that participants in the fixed emotion condition would engage in more expressive suppression, a late stage regulation strategy. Consistent with these predictions, participants in the malleable condition reported spontaneously engaging in more cognitive reappraisal during the stressful speech task, although this greater use of reappraisal was not significantly associated with a decrease in negative affect. These results suggest that beliefs about emotion Malleability can systematically influence subsequent emotion regulatory behavior.
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beliefs about emotion s Malleability influence state emotion regulation
Motivation and Emotion, 2016Co-Authors: Elizabeth T Kneeland, John F Dovidio, Susan Nolenhoeksema, June GruberAbstract:The current study examined how manipulating information about whether emotions are fixed or malleable influences the extent to which individuals engage in different emotion regulation strategies. We hypothesized that fixed, compared to malleable, emotion beliefs would produce less effort invested in emotion regulation. Participants were randomly assigned to experimental conditions emphasizing that emotions are malleable or fixed, and then completed an autobiographical negative emotion induction. Participants reported seven different emotion regulation strategies they used during the recall task. Participants in the fixed emotion condition, compared to those in the malleable emotion condition, reported engaging significantly less in self-blame and perspective-taking. They engaged somewhat, but not significantly, less in all of the other strategies, except acceptance. These results suggest that emotion Malleability beliefs can be experimentally manipulated and systematically influence subsequent emotion regulatory behavior. Implications for affective science and mental health are discussed.
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emotion Malleability beliefs emotion regulation and psychopathology integrating affective and clinical science
Clinical Psychology Review, 2016Co-Authors: Elizabeth T Kneeland, John F Dovidio, Jutta Joormann, Margaret S ClarkAbstract:Beliefs that individuals hold about whether emotions are malleable or fixed, also referred to as emotion Malleability beliefs, may play a crucial role in individuals' emotional experiences and their engagement in changing their emotions. The current review integrates affective science and clinical science perspectives to provide a comprehensive review of how emotion Malleability beliefs relate to emotionality, emotion regulation, and specific clinical disorders and treatment. Specifically, we discuss how holding more malleable views of emotion could be associated with more active emotion regulation efforts, greater motivation to engage in active regulatory efforts, more effort expended regulating emotions, and lower levels of pathological distress. In addition, we explain how extending emotion Malleability beliefs into the clinical domain can complement and extend current conceptualizations of major depressive disorder, social anxiety disorder, and generalized anxiety disorder. This may prove important given the increasingly central role emotion dysregulation has been given in conceptualization and intervention for these psychiatric conditions. Additionally, discussion focuses on how emotion beliefs could be more explicitly addressed in existing cognitive therapies. Promising future directions for research are identified throughout the review.
