Traceable Policy-Based Signatures with Delegation

In PKC 2014, a policy-based signature (PBS) scheme was proposed by Bellare and Fuchsbauer in which a signer can only sign messages conforming to some policy specified by an issuing authority. PBS construction supports the delegation of signing policy keys with possible restrictions to the original policy. Although the PBS scheme is meant to restrict the signing privileges of the scheme’s users, singers could easily share their signing keys with others without being held accountable since PBS does not have a tracing capability, and a signing policy key defines a policy that should be satisfied by the message only. In this work, we build on PBS and propose a traceable policy-based signature scheme (TPBS) where we employ a rerandomizable signature scheme, a digital signature scheme, and a zero-knowledge proof system as its building blocks. TPBS introduces the notion of anonymized identity keys that are used with the policy keys for signing. Thus it achieves traceability without compromising the delegatability feature of the PBS scheme. Additionally, TPBS ensures non-frameability under the assumption of a corrupted tracing authority. We define and formally prove the security notions of the generic TPBS scheme. Finally, we propose an instantiation of TPBS utilizing the Pointcheval Sanders rerandomizable signature scheme, Abe et al.’s structure-preserving signature scheme, and Groth-Sahai NIZK system, and analyze its efficiency

Unlinkable Policy-based Sanitizable Signatures

In CT-RSA 2020, P3S was proposed as the first policy-based sanitizable signature scheme which allows the signer to designate future message sanitizers by defining an access policy relative to their attributes rather than their keys. However, since P3S utilizes a policy-based chameleon hash (PCH), it does not achieve unlinkability which is a required notion in privacy-preserving applications. Moreover, P3S requires running a procedure to share the secret trapdoor information for PCH with each new sanitizer before sanitizing a new message. We further observe that in order to maintain the transparency in P3S’s multiple-sanitizers setting, the signature size should grow linearly with the number of sanitizers. In this work, we propose an unlinkable policy-based sanitizable signature scheme (UP3S) where we employ a rerandomizable digital signature scheme and a traceable attribute-based signature scheme as its building blocks. Compared to P3S, UP3S achieves unlinkability, does not require new secrets to be shared with future sanitizers prior to sanitizing each message, and has a fixed signature size for a given sanitization policy. We define and formally prove the security notions of the generic scheme, propose an instantiation of UP3S utilizing the Pointcheval-Sanders rerandomizable signature scheme and DTABS traceable attribute-based signature scheme, and analyze its efficiency. Finally, we compare UP3S with P3S in terms of the features of the procedures, scalability, and security models

Socio-Cultural Gender Norms and Economic Barriers in The Context of Rural High School Girls’ Dropout in Bangladesh: A Qualitative Study

While attending high schools, in Bangladesh, rural school girls face the pressure of socio-cultural gender norms and the barriers of economic deprivation. This paper aims to analyze the multifaceted connection between gender norms and economic deprivation of families in rural Bangladesh; and how the dynamics of the connection affect high school girls’ opportunities of further education. The paper identifies the major factors that lead girls to drop out of school. In-depth qualitative interview sessions were conducted with 5 rural high school dropout girls. The analysis incorporates both thematic and narrative analyses. The study finds that gender norms, socioeconomic realities, deprivation and poverty work as barriers; and affect girl’s future education by restricting girl’s opportunities and social mobility with the support of discriminatory gender norms and practices. Parents compromise on girls’ education by giving gender norms a priority. Instead of encouraging girls’ future education parents tend to ensure their daughter’s future in an early marriage. Among the financially challenged families, girls’ domestic duties are prioritized over their aspiration of getting education. Most parents are concerned about the sexual security/chastity of their girls, which also force girls to drop out of high schools. Few parents/guardians who encourage and support girls’ education usually take the initiative to bring changes by resisting social norms that obstruct and limit girls’ opportunities. The paper concludes that in the context of persistent socio-cultural gender norms, resistance against regressive gender ideologies and social norms are needed to bring positive changes in gender socialization

Gender disparity in minimum dietary diversity failure among currently breastfed children aged 6–23 months in Bangladesh: evidence from Bangladesh Multiple Indicator Cluster Survey, 2019

Research on children's dietary diversity plays a crucial role in designing effective health interventions. Thus, this study aimed to identify the factors contributing to minimum dietary diversity failure (MDDF) among male and female children aged 6–23 months in Bangladesh. The data for this study was obtained from the Bangladesh Multiple Indicator Cluster Survey, 2019, which included children currently breastfed within a specific age range. Multivariable binary logistic regression was employed to assess the strength and significance of the association. The findings revealed that approximately 59⋅4 % of children in Bangladesh experienced MDDF, with 57⋅8 % of male children and 61 % of female children affected. Proportion test uncovered a significant gender disparity (χ2=6⋅58, P-value = 0⋅01) among children aged 6–23 months. However, the multivariable binary logistic regression analysis revealed that both male and female children shared common risk factors for MDDF, which included child age, maternal educational status, wealth status, number of antenatal care visits, and division. In our study, we observed varied spatial patterns in minimal dietary diversity. Sherpur, Netrokona, Sunamganj, and Sylhet districts showed the highest failure rates. Notably, all are flood-affected areas, impacting food availability and diversity. For targeted regional development programmes, district mapping results may offer valuable insights to policymakers, especially in areas with a high prevalence of dietary diversity failure. By understanding these risk factors, policymakers and stakeholders can implement targeted strategies to improve dietary diversity among children, promoting better health and well-being for the young population in Bangladesh

Socio-Cultural Gender Norms and Economic Barriers in the Context of Rural High School Girls' Dropout in Bangladesh: A Qualitative Study

While attending high schools, in Bangladesh, rural school girls face the pressure of socio-cultural gender norms and the barriers of economic deprivation. This paper aims to analyze the multifaceted connection between gender norms and economic deprivation of families in rural Bangladesh; and how the dynamics of the connection affect high school girls' opportunities of further education. The paper identifies the major factors that lead girls to drop out of school. In-depth qualitative interview sessions were conducted with 5 rural high school dropout girls. The analysis incorporates both thematic and narrative analyses. The study finds that gender norms, socioeconomic realities, deprivation and poverty work as barriers; and affect girl's future education by restricting girl's opportunities and social mobility with the support of discriminatory gender norms and practices. Parents compromise on girls' education by giving gender norms a priority. Instead of encouraging girls' future education parents tend to ensure their daughter's future in an early marriage. Among the financially challenged families, girls' domestic duties are prioritized over their aspiration of getting education. Most parents are concerned about the sexual security/chastity of their girls, which also force girls to drop out of high schools. Few parents/guardians who encourage and support girls' education usually take the initiative to bring changes by resisting social norms that obstruct and limit girls' opportunities. The paper concludes that in the context of persistent socio-cultural gender norms, resistance against regressive gender ideologies and social norms are needed to bring positive changes in gender socialization

Double burden of malnutrition among women of reproductive age in Bangladesh: A comparative study of classical and Bayesian logistic regression approach

Abstract Although the prevalence of undernutrition among women of reproductive age has declined in Bangladesh, the increase in the prevalence of overnutrition remains a major challenge. To achieve Sustainable Development Goal 2.2, it is important to identify the drivers of the double burden of malnutrition on women in Bangladesh. The Bangladesh Demographic and Health Survey, 2017–2018 was used to model the relationship between the double burden of malnutrition among women and the risk factors using a logistic regression model under the classical and Bayesian frameworks and performed the comparison between the regression models based on the narrowest confidence interval. Regarding the Bayesian application, the Metropolis‐Hastings algorithm with two types of prior information (historical and noninformative prior) was used to simulate parameter estimates from the posterior distributions. The Boruta algorithm was used to determine the significant predictors. Almost half of reproductive aged women experienced a form of malnutrition (12% were underweight, 26.1% were overweight, and 6.8% were obese). In terms of the narrowest interval estimate, it was found that Bayesian logistic regression with informative priors performs better than the noninformative priors and the classical logistic regression model. Women who were older, highly educated, from rich families, unemployed, and from urban residences were more likely to experience the double burden of malnutrition. This study recommended using the historical prior as the informative prior rather than the flat/noninformative prior to estimating the parameter uncertainty if historical data are available. The double burden of malnutrition among women is a major public health challenge in Bangladesh. This study was to determine the impact of effective risk factors on the double burden of malnutrition among women by applying the Bayesian framework. Using both informative and noninformative priors, “historical prior” was proposed as informative prior information. The main strength is that the proposed prior (historical prior) provided improved estimation as compared to the flat prior distribution

Determining the risk factors of under-five morbidity in Bangladesh: a Bayesian logistic regression approach

Abstract Purpose Child morbidity prevents Bangladesh from reaching the target for the Sustainable Development Goals (target 3.2) despite the country’s success in reducing child mortality rates. As a result, it's crucial to consider a child's health-related issues. Therefore, this study aims to explore the prevalence and factors associated with under-five child morbidity in Bangladesh. Methods The Bangladesh Demographic and Health Survey, 2017–2018, a secondary cross-sectional survey data, was used in this study, which collected information using a two-stage systematic sampling design. After association test, Bayesian estimation of binary logistic regression model was used to identify the significant risk factors of morbidity among under-five children, and a trace plot was used to try to figure out the convergence of simulation. Results According to the prevalence analysis of this study, it can be noted that more than one-thirds of under-five children in Bangladesh suffered from at least one of the child health-related problems, and of these, the highest prevalence of child morbidity was found in the Barisal division of Bangladesh (~ 42%). According to the Bayesian logistic regression results, higher child age and maternal education are associated with a potential decrease in the risk of child morbidity in Bangladesh. Again, male children had a 7% higher risk of morbidity than female children. Another finding was that underweight children suffered 31% more fever/diarrhea/ acute respiratory infection (ARI) related problems than others. Conclusions According to this study’s findings, child morbidity is still a significant issue in Bangladesh. Therefore, progress on risk factors, such as maternal education, child nutrition, etc., should be the focus of policymakers' intervention

Snow Avalanche Hazard Mapping Using a GIS-Based AHP Approach: A Case of Glaciers in Northern Pakistan from 2012 to 2022

Snow avalanches are a type of serious natural disaster that commonly occur in snow-covered mountains with steep terrain characteristics. Susceptibility analysis of avalanches is a pressing issue today and helps decision makers to implement appropriate avalanche risk reduction strategies. Avalanche susceptibility maps provide a preliminary method for evaluating places that are likely to be vulnerable to avalanches to stop or reduce the risks of such disasters. The current study aims to identify areas that are vulnerable to avalanches (ranging from extremely high and low danger) by considering geo-morphological and geological variables and employing an Analytical Hierarchy Approach (AHP) in the GIS platform to identify potential snow avalanche zones in the Karakoram region in Northern Pakistan. The Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) was used to extract the elevation, slope, aspect, terrain roughness, and curvature of the study area. This study includes the risk identification variable of land cover (LC), which was obtained from the Landsat 8 Operational Land Imager (OLI) satellite. The obtained result showed that the approach established in this study provided a quick and reliable tool to map avalanches in the study area, and it might also work with other glacier sites in other parts of the world for snow avalanche susceptibility and risk assessments