Compressed Σ\Sigma-Protocols for Bilinear Group Arithmetic Circuits and Application to Logarithmic Transparent Threshold Signatures

Lai et al. (CCS 2019) have shown how Bulletproof’s arithmetic circuit zero-knowledge protocol (Bootle et al., EUROCRYPT 2016 and Bünz et al., S&P 2018) can be generalized to work for bilinear group arithmetic circuits directly, i.e., without requiring these circuits to be translated into arithmetic circuits. In a nutshell, a bilinear group arithmetic circuit is a standard arithmetic circuit augmented with special gates capturing group exponentiations or pairings. Such circuits are highly relevant, e.g., in the context of zero-knowledge statements over pairing-based languages. As expressing these special gates in terms of a standard arithmetic circuit results in a significant overhead in circuit size, an approach to zero-knowledge via standard arithmetic circuits may incur substantial additional costs. The approach due to Lai et al. shows how to avoid this by integrating additional zero-knowledge techniques into the Bulletproof framework so as to handle the special gates very efficiently. We take a different approach by generalizing Compressed $\Sigma$-Protocol Theory (CRYPTO 2020) from arithmetic circuit relations to bilinear group arithmetic circuit relations. Besides its conceptual simplicity, our approach has the practical advantage of reducing the communication costs of Lai et al.\u27s protocol by roughly a multiplicative factor 3. Finally, we show an application of our results which may be of independent interest. We construct the first k-out-of-n threshold signature scheme (TSS) that allows for transparent setup and that yields threshold signatures of size logarithmic in n. The threshold signature hides the identities of the k signers and the threshold k can be dynamically chosen at aggregation time

Compressed Sigma-Protocols for bilinear circuits and applications to logarithmic-sized transparent Threshold Signature Schemes

Recently, there has been a great development in communication-efficient zero-knowledge (ZK) protocols for arithmetic circuit relations. Since any relation can be translated into an arithmetic circuit relation, these primitives are extremely powerful and widely applied. However, this translation often comes at the cost of losing conceptual simplicity and modularity in cryptographic protocol design.For this reason, Lai et al. (CCS 2019), show how Bulletproof’s communication-efficient circuit zero-knowledge protocol (Bootle et al., EUROCRYPT 2016 and Bünz et al., S&P 2018) can be generalized to work for bilinear group arithmetic circuits directly, without requiring these circuits to be translated into arithmetic circuits. For many natural relations their approach is actually more efficient than the indirect circuit ZK approach. We take a different approach and show that the arithmetic circuit model can be generalized to any circuit model in which (a) all wires take values in (possibly different) Zq-modules and (b) all gates have fan-in2and are either linear or bilinear mappings. We follow a straightforward generalization of Compressed Σ-Protocol Theory (CRYPTO 2020). We compress the communication complexity of a basic Σ-protocol for proving linear statements down to logarithmic. Then, we describe a linearization strategy to handle non-linearities. Besides its conceptual simplicity our approach also has practical advantages; we reduce the constant of the logarithmic component in the communication complexity of the CCS 2019 approach from 16 down to 6 and that of the linear component from 3 down to 1. Moreover, the generalized commitment scheme required for bilinear circuit relations is also advantageous to standard arithmetic circuit ZK protocols, since its application immediately results in a square root reduction of public parameters size. The implications of this improvement can be significant, because many application scenarios result in very large sets of public parameters. As an application of our compressed protocol for proving linear statements we construct the first k-out-of-n threshold signature scheme (TSS) with both transparent setup and threshold signatures of size O(κlog(n)) bits for security parameter κ. Each individual signature is of a so-called BLS type, the threshold signature hides the identities of the k signers and the threshold k can be dynamically chose n at aggregation time. Prior TSSs either result in sub-linear size signatures at the cost of requiring a trusted setup or the cost of the transparent setup amounts to linear (ink) size signatures.</p

Brief announcement: Malicious security comes for free in consensus with leaders

We consider consensus protocols in the model that is most commonly considered for use in state machine replication, as initiated by Dwork-Lynch-Stockmeyer, then by Castro-Liskov in 1999 with "PBFT."Such protocols guarantee, assuming n players out of which t < n/3 are maliciously corrupted, that the honest players output the same valid value within a finite number of messages, after the (unknown) point in time where both: the network becomes synchronous, and a designated player (the leader) is honest. The state of the art (Hotstuff, PODC'19), achieves linear communication complexity, but at the cost of additional latency, due to one more round-trip with the leader. Furthermore, it relies on constant-size threshold signatures schemes (TSS), for which all prior-known constructions require a costly interactive (or trusted) setup. We remove all of these limitations. The communication bottleneck of PBFT lies in the subprotocol, denoted as "view change,"in which the leader forwards 2t+1 signed messages to each player. Then, each player checks that these 2t+1 messages satisfy some predicate, which we denote "non-supermajority''. We replace this with a responsive subprotocol, with linear communication complexity, that enables players to check this predicate. Its construction is elementary, since it requires only black box use of any TSS. In the full version of our paper \citemalicious2 we achieve three things. Firstly, we further optimize this subprotocol from succinct arguments of many signed messages, which we instantiate from Attema-Cramer-Rambaud \cite[2021-3-9 version]ACR20. As an introduction to these methods, we discuss here the simplest case, which is the construction in \citeACR20 of the first logarithmic-sized TSS with transparent setup. Second, we also address another complexity challenge pointed in Hotstuff, namely, that protocols with fast termination in favorable runs, have so far quadratic complexity, due to an even more complex view change. Third, we enable halting in finite time with (amortized) linear complexity, which was an unsolved question so far when external validity is required

vanA in Enterococcus faecium, Enterococcus faecalis, and Enterococcus casseliflavus detected in French cattle.

The goal of this study was to assess the presence of enterococci species presenting van-mediated glycopeptide resistance in French cattle. Fecal samples were collected from healthy and sick animals, and enterococci were screened for vancomycin resistance. Vancomycin resistance was principally encountered in Enterococcus gallinarum and Enterococcus casseliflavus strains. However, glycopeptide resistance was detected in three different species of enterococci (E. faecalis, E. faecium, and E. casseliflavus). Molecular characterization of the genetic support proved that they all presented the prototypic VanA element. Interestingly, the E. casseliflavus strain displayed a remarkable VanB phenotype/vanA-vanC genotype. Transferability, associated resistances, and factors of vanA cotransfer were sought. This study proved that acquired vanA genes can still be detected in food-producing animals more than a decade after the avoparcin ban. Indeed, calves, which are recurrently exposed to antibiotics in France, may allow the re-emergence of glycopeptide resistance through coselection factors, and this might potentially be concerning for human health

Ligament Healing After Anterior Cruciate Ligament Rupture: An Important New Patient Pathway?

Recent studies have shown satisfactory functional results after spontaneous healing of a ruptured anterior cruciate ligament (ACL). However, current literature on this topic may exclude important parting selection, outcome measures, and long-term results. Rehabilitation protocols applied in those studies, as well as objective assessments appear far from the usual gold standard after ACL reconstruction. Ideally, outcomes measures should be based on the same testing procedures that are recommended to clear an athlete to return to sport following ACL reconstruction. There is still a lot to understand in how an injured ACL may heal, and therefore ACL injury management should be individualized to each patient and carefully discussed

Trends of Exposure to Acrylamide as Measured by Urinary Biomarkers Levels within the HBM4EU Biomonitoring Aligned Studies (2000–2021)

This article belongs to the Special Issue Analysis of Human Biomonitoring Data and Risk Assessment of Human Exposure to Environmental Chemicals: What Do We Learn for Prevention?Acrylamide, a substance potentially carcinogenic in humans, represents a very prevalent contaminant in food and is also contained in tobacco smoke. Occupational exposure to higher concentrations of acrylamide was shown to induce neurotoxicity in humans. To minimize related risks for public health, it is vital to obtain data on the actual level of exposure in differently affected segments of the population. To achieve this aim, acrylamide has been added to the list of substances of concern to be investigated in the HBM4EU project, a European initiative to obtain biomonitoring data for a number of pollutants highly relevant for public health. This report summarizes the results obtained for acrylamide, with a focus on time-trends and recent exposure levels, obtained by HBM4EU as well as by associated studies in a total of seven European countries. Mean biomarker levels were compared by sampling year and time-trends were analyzed using linear regression models and an adequate statistical test. An increasing trend of acrylamide biomarker concentrations was found in children for the years 2014–2017, while in adults an overall increase in exposure was found to be not significant for the time period of observation (2000–2021). For smokers, represented by two studies and sampling for, over a total three years, no clear tendency was observed. In conclusion, samples from European countries indicate that average acrylamide exposure still exceeds suggested benchmark levels and may be of specific concern in children. More research is required to confirm trends of declining values observed in most recent years.This work received external funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 733032 and received co-funding from the author’s organizations. The Norwegian Institute of Public Health (NIPH) contributed to the funding of the Norwegian Environmental Biobank (NEB). The laboratory measurements were partly funded by the Research Council of Norway through research projects (275903 and 268465).info:eu-repo/semantics/publishedVersio

Time Trends of Acrylamide Exposure in Europe: Combined Analysis of Published Reports and Current HBM4EU Studies

This article belongs to the Special Issue Analysis of Human Biomonitoring Data and Risk Assessment of Human Exposure to Environmental Chemicals: What Do We Learn for Prevention?More than 20 years ago, acrylamide was added to the list of potential carcinogens found in many common dietary products and tobacco smoke. Consequently, human biomonitoring studies investigating exposure to acrylamide in the form of adducts in blood and metabolites in urine have been performed to obtain data on the actual burden in different populations of the world and in Europe. Recognizing the related health risk, the European Commission responded with measures to curb the acrylamide content in food products. In 2017, a trans-European human biomonitoring project (HBM4EU) was started with the aim to investigate exposure to several chemicals, including acrylamide. Here we set out to provide a combined analysis of previous and current European acrylamide biomonitoring study results by harmonizing and integrating different data sources, including HBM4EU aligned studies, with the aim to resolve overall and current time trends of acrylamide exposure in Europe. Data from 10 European countries were included in the analysis, comprising more than 5500 individual samples (3214 children and teenagers, 2293 adults). We utilized linear models as well as a non-linear fit and breakpoint analysis to investigate trends in temporal acrylamide exposure as well as descriptive statistics and statistical tests to validate findings. Our results indicate an overall increase in acrylamide exposure between the years 2001 and 2017. Studies with samples collected after 2018 focusing on adults do not indicate increasing exposure but show declining values. Regional differences appear to affect absolute values, but not the overall time-trend of exposure. As benchmark levels for acrylamide content in food have been adopted in Europe in 2018, our results may imply the effects of these measures, but only indicated for adults, as corresponding data are still missing for children.This work has received external funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 733032 and received co-funding from the author’s organizations. The Norwegian Institute of Public Health (NIPH) has contributed to the funding of the Norwegian Environmental Biobank (NEB). The laboratory measurements have partly been funded by the Research Council of Norway through research projects (275903 and 268465).info:eu-repo/semantics/publishedVersio

Executive Summary of the Second International Guidelines for the Diagnosis and Management of Pediatric Acute Respiratory Distress Syndrome (PALICC-2)

OBJECTIVES: We sought to update our 2015 work in the Second Pediatric Acute Lung Injury Consensus Conference (PALICC-2) guidelines for the diagnosis and management of pediatric acute respiratory distress syndrome (PARDS), considering new evidence and topic areas that were not previously addressed. DESIGN: International consensus conference series involving 52 multidisciplinary international content experts in PARDS and four methodology experts from 15 countries, using consensus conference methodology, and implementation science. SETTING: Not applicable. PATIENTS: Patients with or at risk for PARDS. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Eleven subgroups conducted systematic or scoping reviews addressing 11 topic areas: 1) definition, incidence, and epidemiology; 2) pathobiology, severity, and risk stratification; 3) ventilatory support; 4) pulmonary-specific ancillary treatment; 5) nonpulmonary treatment; 6) monitoring; 7) noninvasive respiratory support; 8) extracorporeal support; 9) morbidity and long-term outcomes; 10) clinical informatics and data science; and 11) resource-limited settings. The search included MEDLINE, EMBASE, and CINAHL Complete (EBSCOhost) and was updated in March 2022. Grading of Recommendations, Assessment, Development, and Evaluation methodology was used to summarize evidence and develop the recommendations, which were discussed and voted on by all PALICC-2 experts. There were 146 recommendations and statements, including: 34 recommendations for clinical practice; 112 consensus-based statements with 18 on PARDS definition, 55 on good practice, seven on policy, and 32 on research. All recommendations and statements had agreement greater than 80%. CONCLUSIONS: PALICC-2 recommendations and consensus-based statements should facilitate the implementation and adherence to the best clinical practice in patients with PARDS. These results will also inform the development of future programs of research that are crucially needed to provide stronger evidence to guide the pediatric critical care teams managing these patients.</p

EU-wide exposure data of 11 chemical substance groups from the HBM4EU Aligned Studies (2014–2021)

Funding Information: The authors would like to thank everybody who contributed to the HBM4EU Aligned Studies: the participating children, teenagers, adults and their families, the fieldworkers that collected the samples and database managers that made the information available to HBM4EU, the HBM4EU project partners, especially those from WP7 for developing all materials supporting the fieldwork, WP9 for organizing the QA/QC scheme under HBM4EU and all laboratories who performed the analytical measurements. We would like to acknowledge Sun Kyoung Jung from the National Institute of Environmental Research of South-Korea for providing the KoNEHS Cycle III results (crt adjusted). HBM4EU is co-financed under Horizon 2020 (grant agreement No 733032). The authors thank all principal investigators of the contributing studies for their participation and contribution to the HBM4EU Aligned Studies and the national program owners for their financial support. Further details on funding for all the participating studies can be found in the Supplemental Material, Table S12.As one of the core elements of the European Human Biomonitoring Initiative (HBM4EU) a human biomonitoring (HBM) survey was conducted in 23 countries to generate EU-wide comparable HBM data. This survey has built on existing HBM capacity in Europe by aligning national or regional HBM studies, referred to as the HBM4EU Aligned Studies. The HBM4EU Aligned Studies included a total of 10,795 participants of three age groups: (i) 3,576 children aged 6–12 years, (ii) 3,117 teenagers aged 12–18 years and (iii) 4,102 young adults aged 20–39 years. The participants were recruited between 2014 and 2021 in 11–12 countries per age group, geographically distributed across Europe. Depending on the age group, internal exposure to phthalates and the substitute DINCH, halogenated and organophosphorus flame retardants, per- and polyfluoroalkyl substances (PFASs), cadmium, bisphenols, polycyclic aromatic hydrocarbons (PAHs), arsenic species, acrylamide, mycotoxins (deoxynivalenol (total DON)), benzophenones and selected pesticides was assessed by measuring substance specific biomarkers subjected to stringent quality control programs for chemical analysis. For substance groups analyzed in different age groups higher average exposure levels were observed in the youngest age group, i.e., phthalates/DINCH in children versus teenagers, acrylamide and pesticides in children versus adults, benzophenones in teenagers versus adults. Many biomarkers in teenagers and adults varied significantly according to educational attainment, with higher exposure levels of bisphenols, phthalates, benzophenones, PAHs and acrylamide in participants (from households) with lower educational attainment, while teenagers from households with higher educational attainment have higher exposure levels for PFASs and arsenic. In children, a social gradient was only observed for the non-specific pyrethroid metabolite 3-PBA and di-isodecyl phthalate (DiDP), with higher levels in children from households with higher educational attainment. Geographical variations were seen for all exposure biomarkers. For 15 biomarkers, the available health-based HBM guidance values were exceeded with highest exceedance rates for toxicologically relevant arsenic in teenagers (40%), 3-PBA in children (36%), and between 11 and 14% for total DON, Σ (PFOA + PFNA + PFHxS + PFOS), bisphenol S and cadmium. The infrastructure and harmonized approach succeeded in obtaining comparable European wide internal exposure data for a prioritized set of 11 chemical groups. These data serve as a reference for comparison at the global level, provide a baseline to compare the efficacy of the European Commission's chemical strategy for sustainability and will give leverage to national policy makers for the implementation of targeted measures.publishersversionpublishe

Harmonized human biomonitoring in European children, teenagers and adults: EU-wide exposure data of 11 chemical substance groups from the HBM4EU Aligned Studies (2014–2021)

HBM4EU is co-financed under Horizon 2020 (grant agreement No 733032).As one of the core elements of the European Human Biomonitoring Initiative (HBM4EU) a human biomonitoring (HBM) survey was conducted in 23 countries to generate EU-wide comparable HBM data. This survey has built on existing HBM capacity in Europe by aligning national or regional HBM studies, referred to as the HBM4EU Aligned Studies. The HBM4EU Aligned Studies included a total of 10,795 participants from three age groups: (i) 3,576 children aged 6-12 years, (ii) 3,117 teenagers aged 12-18 years, and (iii) 4,102 young adults aged 20-39 years. The participants were recruited between 2014 and 2021 in 11-12 countries per age group, geographically distributed across Europe. Depending on the age group, internal exposure to phthalates and the substitute DINCH, halogenated and organophosphorus flame retardants, per- and polyfluoroalkyl substances (PFASs), cadmium, bisphenols, polycyclic aromatic hydrocarbons (PAHs), arsenic species, acrylamide, mycotoxins (deoxynivalenol (total DON)), benzophenones and selected pesticides was assessed by measuring substance specific biomarkers subjected to stringent quality control programs for chemical analysis. For substance groups analyzed in different age groups higher average exposure levels were observed in the youngest age group, i.e., phthalates/DINCH in children versus teenagers, acrylamide and pesticides in children versus adults, and benzophenones in teenagers versus adults. Many biomarkers in teenagers and adults varied significantly according to educational attainment, with higher exposure levels of bisphenols, phthalates, benzophenones, PAHs, and acrylamide in participants (from households) with lower educational attainment, while teenagers from households with higher educational attainment have higher exposure levels for PFASs and arsenic. In children, a social gradient was only observed for the non-specific pyrethroid metabolite 3-PBA and di-isodecyl phthalate (DiDP), with higher levels in children from households with higher educational attainment. Geographical variations were seen for all exposure biomarkers. For 15 biomarkers, the available health-based HBM guidance values were exceeded with the highest exceedance rates for toxicologically relevant arsenic in teenagers (40%), 3-PBA in children (36%), and between 11 and 14% for total DON, Σ (PFOA + PFNA + PFHxS + PFOS), bisphenol S and cadmium. The infrastructure and harmonized approach succeeded in obtaining comparable European-wide internal exposure data for a prioritized set of 11 chemical groups. These data serve as a reference for comparison at the global level, provide a baseline to compare the efficacy of the European Commission's chemical strategy for sustainability, and will give leverage to national policymakers for the implementation of targeted measures.info:eu-repo/semantics/publishedVersio