Heterogeneous deniable authenticated encryption for location-based services.

The location-based services can provide users with the requested location information. But users also need to disclose their current location to the location-based service provider. Therefore, how to protect user's location privacy is a major concern. In this paper, we propose a heterogeneous deniable authenticated encryption scheme called HDAE for location-based services. The proposed scheme permits a sender in a public key infrastructure environment to transmit a message to a receiver in an identity-based environment. Our design utilizes a hybrid encryption method combing the tag-key encapsulation mechanism (tag-KEM) and the data encapsulation mechanism (DEM), which is well adopted for location-based services applications. We give how to design an HDAE scheme utilizing a heterogeneous deniable authenticated tag-KEM (HDATK) and a DEM. We also construct an HDATK scheme and provide security proof in the random oracle model. Comprehensive analysis shows that our scheme is efficient and secure. In addition, we give an application of the HDAE to a location-based services system.

Risk Factors for In-Hospital Mortality in Heart Failure Patients: Does Rurality, Payer or Admission Source Matter?

PURPOSE: Considering the high prevalence of heart failure and the economic burden of the disease, factors that influence in-hospital mortality are of importance in improving outcomes of care for this patient population. The purpose of this study was to examine the determinants of in-hospital mortality for adult heart failure patients. METHODS: The study design is a retrospective observational study design using the 2010 Nebraska Hospital Discharge data set including 4,319 hospitalizations for 3,521 heart failure patients admitted to 79 hospitals in Nebraska. Hierarchical logistic regression models including patient- and hospital-specific random intercepts were analyzed. Covariates included in the analysis were patient age in years, gender, comorbidity status, length of stay, primary payer, type and source of admission, transfers, and rurality of county of residence. RESULTS: Overall, 3.5% of heart failure patients died during their hospital stay. In logistic regression analysis that adjusted for age, sex, and comorbidities, the odds of dying in hospital for heart failure patients increased with age (OR = 1.03, 95% CI: 1.01-1.04), co-morbidity (OR = 1.15; 95% CI: 1.05-1.25) and length of stay (OR = 1.03, 95% CI: 1.01-1.05). The patient's gender, payer source, rurality of county of residence, source, and type of admission were not risk factors for in-hospital death. CONCLUSION: Increasing age, comorbidity and length of stay were risk factors for in-hospital death for heart failure. An understanding of the risk factors for in-hospital death is critical to improving outcomes of care for heart failure patients.