429 research outputs found

    A multivariate noise-free HE proposal

    Get PDF
    Recently, new ideas to build homomorphic noise-free encryption schemes have been proposed. The starting point of these schemes deals with private-key encryption schemes whose secret key is a rational function. By construction, these schemes are not homomorphic. To get homomorphic properties, nonlinear homomorphic operators are derived from the secret key. In this paper, we adopt the same approach to build a HE. We obtain a multivariate encryption scheme in the sense that the knowledge of the CPA attacker can be turned into an over-defined system of nonlinear equations. The factoring assumption is introduced in order to make a large class of attacks based on Groebner basis irrelevant. While we did not propose a formal security proof relying on a classical cryptographic assumption, we hopefully provide convincing evidence for security

    Designing homomorphic encryptions with rational functions

    Get PDF
    New ideas to build homomorphic encryption schemes based on rational functions have been recently proposed. The starting point is a private-key encryption scheme whose secret key is a rational function ϕ/ϕ2˘7\phi/\phi\u27. By construction, such a scheme is not homomorphic. To get homomorphic properties, nonlinear homomorphic operators are derived from the secret key. In this paper, we adopt the same approach to build HE. We obtain a multivariate encryption scheme in the sense that the knowledge of the CPA attacker can be turned into an over-defined system of nonlinear equations (contrarily to LWE-based encryptions). The factoring assumption is introduced in order to make a large class of algebraic attacks (based on Groebner bases) irrelevant. We extensively analyze the security of our scheme against algebraic attacks. In particular, we exhibit the fundamental role played by symmetry in these attacks. We also formally show that some of these attacks are exponential-time. While we did not propose a formal security proof relying on a classical cryptographic assumption, we hopefully provide convincing evidence for security

    State Mandated Prenatal Human Immunodeficiency Virus Screening at a Large Community Hospital

    Get PDF
    Purpose: To describe the initial experience of state mandated prenatal HIV screening at a large community hospital.Methods: HIV screening was provided to all pregnant women as of October 1, 1999. All HIV-positive women identified received aggressive antiretroviral therapy to reduce the likelihood for vertical transmission. Neonates were screened for HIV at zero, six, and 12 months of age.Results: Seven pregnant women (0.3%) and two additional family members tested positive for HIV. All seven infants born to the identified HIV-positive women have tested negative for infection. We estimated that six of nine cases of HIV infection identified would have been missed under a policy of voluntary HIV screening.Conclusions: Universal screening for HIV in pregnancy is achievable and desirable and provides the best opportunity to minimize the number of new neonatal HIV infections

    Advanced power sources for space missions

    Get PDF
    Approaches to satisfying the power requirements of space-based Strategic Defense Initiative (SDI) missions are studied. The power requirements for non-SDI military space missions and for civil space missions of the National Aeronautics and Space Administration (NASA) are also considered. The more demanding SDI power requirements appear to encompass many, if not all, of the power requirements for those missions. Study results indicate that practical fulfillment of SDI requirements will necessitate substantial advances in the state of the art of power technology. SDI goals include the capability to operate space-based beam weapons, sometimes referred to as directed-energy weapons. Such weapons pose unprecedented power requirements, both during preparation for battle and during battle conditions. The power regimes for these two sets of applications are referred to as alert mode and burst mode, respectively. Alert-mode power requirements are presently stated to range from about 100 kW to a few megawatts for cumulative durations of about a year or more. Burst-mode power requirements are roughly estimated to range from tens to hundreds of megawatts for durations of a few hundred to a few thousand seconds. There are two likely energy sources, chemical and nuclear, for powering SDI directed-energy weapons during the alert and burst modes. The choice between chemical and nuclear space power systems depends in large part on the total duration during which power must be provided. Complete study findings, conclusions, and eight recommendations are reported

    Lindsay Anderson and the Legacy of Free Cinema

    Get PDF
    Accepting that Free Cinema’s legacy has been found on British cinema and television screens in the work of directors other than Lindsay Anderson, this article investigates whether Anderson’s own films and television programmes made after the mid-1970s (including not only those that were released but others that were not completed) reveal a continuing commitment to what he liked to call the Free Cinema ‘tradition’ of film-making. In so doing it draws critical attention to Anderson’s lesser known later works such as The Old Crowd, Is That All There Is?, In Celebration, The Whales of August and Glory! Glory! as well as to unmade projects such as The Grand Babylon Hotel, Dress Gray, Vile Bodies, Empire and If (2). . .

    A VRU-simulator for the evaluation of pedestrian- and cyclist-vehicle interaction – Design criteria and implementation

    Get PDF
    The closer investigation of road user interaction and individual behavior aspects of vulnerable road users requires human-in-the-loop simulator studies in order to achieve systematic results without bringing the test subjects in real danger. So far, there are only a limited number of pedestrian or bicycle simulators, so the main challenge is to define appropriate criteria for respective simulator environments and to build them accordingly. This paper explains an approach for this design process and describes the resulting simulators, recently brought into operation. First study results already give a hint about their effectiveness

    Explaining variation in cancer survival between 11 jurisdictions in the International Cancer Benchmarking Partnership: a primary care vignette survey

    Get PDF
    OBJECTIVES: The International Cancer Benchmarking Partnership (ICBP) is a collaboration between 6 countries and 12 jurisdictions with similar primary care-led health services. This study investigates primary care physician (PCP) behaviour and systems that may contribute to the timeliness of investigating for cancer and subsequently, international survival differences. DESIGN: A validated survey administered to PCPs via the internet set out in two parts: direct questions on primary care structure and practice relating to cancer diagnosis, and clinical vignettes, assessing management of scenarios relating to the diagnosis of lung, colorectal or ovarian cancer. PARTICIPANTS: 2795 PCPs in 11 jurisdictions: New South Wales and Victoria (Australia), British Columbia, Manitoba, Ontario (Canada), England, Northern Ireland, Wales (UK), Denmark, Norway and Sweden. PRIMARY AND SECONDARY OUTCOME MEASURES: Analysis compared the cumulative proportion of PCPs in each jurisdiction opting to investigate or refer at each phase for each vignette with 1-year survival, and conditional 5-year survival rates for the relevant cancer and jurisdiction. Logistic regression was used to explore whether PCP characteristics or system differences in each jurisdiction affected the readiness to investigate. RESULTS: 4 of 5 vignettes showed a statistically significant correlation (p<0.05 or better) between readiness to investigate or refer to secondary care at the first phase of each vignette and cancer survival rates for that jurisdiction. No consistent associations were found between readiness to investigate and selected PCP demographics, practice or health system variables. CONCLUSIONS: We demonstrate a correlation between the readiness of PCPs to investigate symptoms indicative of cancer and cancer survival rates, one of the first possible explanations for the variation in cancer survival between ICBP countries. No specific health system features consistently explained these findings. Some jurisdictions may consider lowering thresholds for PCPs to investigate for cancer—either directly, or by specialist referral, to improve outcomes

    Adapting an evidence-supported optimization program for mental health and sport performance in collegiate athletes to fit youth from ethnic/racial minority and low-income neighborhoods: A National Institutes of Health stage model feasibility study

    Get PDF
    The current study addresses the need to empirically develop effective mental health interventions for youth from ethnic/racial minority and low-income neighborhoods. Using Stage Model evaluation methods supported by the National Institutes of Health in the US to address underutilization of mental healthcare among racial/ethnic minority youth, this feasibility study demonstrates empirical adaptation of an innovative sport-specific psychological intervention for use in youth from ethnic/racial minority and low-income neighborhoods. An international group of professionals familiar with sport performance and mental health intervention serving the target population experientially examined the adapted intervention protocols in workshops and provided feedback. Survey results indicated the professionals found the intervention components were easy to administer and likely to be safe, enjoyable, engaging and efficacious for youth mental health and sport performance. The protocols were revised based on feedback from these professionals and the intervention was examined in a case trial involving an Asian American youth who evidenced Social Anxiety Disorder. Case study results indicated the intervention could be implemented with integrity, and severity of psychiatric symptoms and factors interfering with sport performance decreased after intervention implementation. The participant’s relationships with family, coaches and teammates were also improved
    • …
    corecore