Revealing the unseen: how to expose cloud usage while protecting user privacy

Cloud users have little visibility into the performance characteristics and utilization of the physical machines underpinning the virtualized cloud resources they use. This uncertainty forces users and researchers to reverse engineer the inner workings of cloud systems in order to understand and optimize the conditions their applications operate. At Massachusetts Open Cloud (MOC), as a public cloud operator, we'd like to expose the utilization of our physical infrastructure to stop this wasteful effort. Mindful that such exposure can be used maliciously for gaining insight into other user's workloads, in this position paper we argue for the need for an approach that balances openness of the cloud overall with privacy for each tenant inside of it. We believe that this approach can be instantiated via a novel combination of several security and privacy technologies. We discuss the potential benefits, implications of transparency for cloud systems and users, and technical challenges/possibilities.Accepted manuscrip

Hiding Symbols and Functions: New Metrics and Constructions for Information-Theoretic Security

We present information-theoretic definitions and results for analyzing symmetric-key encryption schemes beyond the perfect secrecy regime, i.e. when perfect secrecy is not attained. We adopt two lines of analysis, one based on lossless source coding, and another akin to rate-distortion theory. We start by presenting a new information-theoretic metric for security, called symbol secrecy, and derive associated fundamental bounds. We then introduce list-source codes (LSCs), which are a general framework for mapping a key length (entropy) to a list size that an eavesdropper has to resolve in order to recover a secret message. We provide explicit constructions of LSCs, and demonstrate that, when the source is uniformly distributed, the highest level of symbol secrecy for a fixed key length can be achieved through a construction based on minimum-distance separable (MDS) codes. Using an analysis related to rate-distortion theory, we then show how symbol secrecy can be used to determine the probability that an eavesdropper correctly reconstructs functions of the original plaintext. We illustrate how these bounds can be applied to characterize security properties of symmetric-key encryption schemes, and, in particular, extend security claims based on symbol secrecy to a functional setting.Comment: Submitted to IEEE Transactions on Information Theor

Bounds on inference

Lower bounds for the average probability of error of estimating a hidden variable X given an observation of a correlated random variable Y, and Fano's inequality in particular, play a central role in information theory. In this paper, we present a lower bound for the average estimation error based on the marginal distribution of X and the principal inertias of the joint distribution matrix of X and Y. Furthermore, we discuss an information measure based on the sum of the largest principal inertias, called k-correlation, which generalizes maximal correlation. We show that k-correlation satisfies the Data Processing Inequality and is convex in the conditional distribution of Y given X. Finally, we investigate how to answer a fundamental question in inference and privacy: given an observation Y, can we estimate a function f(X) of the hidden random variable X with an average error below a certain threshold? We provide a general method for answering this question using an approach based on rate-distortion theory.Comment: Allerton 2013 with extended proof, 10 page

Multicentre narrative research on major depression to integrate the experiences of patients, their caregivers and healthcare providers in Italy

OBJECTIVE: This research aimed to investigate the experience of major depression by integrating the perspectives of patients, caregivers and healthcare providers through narrative-based medicine (NBM) to provide new insights to improve care relationships. DESIGN AND SETTING: The research was conducted in 2019 and involved five Italian psychiatric centres and targeted adult patients, their caregivers and healthcare providers to address data source triangulation. A sociodemographic survey and a narrative plot, based on Natural Semantic Metalanguage were collected. Narratives were analysed through NBM classifications, NVivo software and interpretative coding. PARTICIPANTS: Thirty-six patients with a diagnosis of major depression, 27 caregivers and 33 healthcare providers participated in the research. RESULTS: Among the 96 collected narratives, 'lonely' was the word patients used most frequently, while 'sad' and 'lifeless' were used most respectively by caregivers and healthcare providers. A positive care relationship was crucial for 84% of patients in relation to their care pathway, and nature (36%) and the arts (28%) were the most frequent resources. Caregivers expressed feelings of powerlessness and inadequacy, and 21% of them reported a declining social life while providing care to a loved one with depression. Thirty-one percent of mental health professionals experienced difficulties in their first encounter with patients; however, their emotions progressively moved towards trust and satisfaction. Furthermore, 89% of patients and healthcare providers and 58% of caregivers evaluated writing the narrative to be a positive experience. CONCLUSION: Findings suggested the possible role for language in understanding major depression, thereby improving care relationships between patients and physicians. Care pathways might also be more attentive to caregivers, to reduce their risk of burnout. Finally, narrative medicine could be integrated with the care pathway as an additional space of expression, dialogue, reflection and development of empathy

Arithmetic and Boolean secret sharing MPC on FPGAs in the data center

Multi-Party Computation (MPC) is an important technique used to enable computation over confidential data from several sources. The public cloud provides a unique opportunity to enable MPC in a low latency environment. Field Programmable Gate Array (FPGA) hardware adoption allows for both MPC acceleration and utilization of low latency, high bandwidth communication networks that substantially improve the performance of MPC applications. In this work, we show how designing arithmetic and Boolean Multi-Party Computation gates for FPGAs in a cloud provide improvements to current MPC offerings and ease their use in applications such as machine learning. We focus on the usage of Secret Sharing MPC first designed by Araki et al [1] to design our FPGA MPC while also providing a comparison with those utilizing Garbled Circuits for MPC. We show that Secret Sharing MPC provides a better usage of cloud resources, specifically FPGA acceleration, than Garbled Circuits and is able to use at least a 10 × less computer resources as compared to the original design using CPUs.Accepted manuscrip

Examining urban and rural differences in how distance to care influences the initiation and completion of treatment among insured cervical cancer patients

Background: Although rural cancer patients encounter substantial barriers to care, they more often report receiving timely care than urban patients. We examined whether geographic distance, a contributor to urban-rural health disparities, differentially influences treatment initiation and completion among insured urban and rural cervical cancer patients. Methods: We identified women diagnosed with cervical cancer from 2004 to 2013 from a statewide cancer registry linked to multipayer, insurance claims. Primary outcomes were initiation of guideline-concordant care within 6 weeks of diagnosis and, among stage IB2-IVA cancer patients, completion of concurrent chemoradiotherapy (CCRT) in 56 days. We estimated risk ratios using modified Poisson regressions, stratified by urban/rural status, to examine the association between distance and treatment timing (initiation or completion). Results: Among 999 stage IA-IVA patients, 48% initiated guideline-concordant care within 6 weeks of diagnosis, and 37% of 492 stage IB2-IVA cancer patients completed CCRT in 56 days. In urban areas, stage IA-IVA patients who lived 15 miles from the nearest treatment facility were less likely to initiate timely treatment compared with those <5 miles [risk ratio (RR): 0.72; 95% confidence intervals (CI), 0.54-0.95]. Among IB2-IVA stage cancer patients, rural women residing 15 miles from the nearest radiation facility were more likely to complete CCRT in 56 days (RR: 2.49; 95% CI, 1.12-5.51). Conclusions: Geographic distance differentially influences the initiation and completion of treatment among urban and rural cervical cancer patients. Impact: Distance was an access barrier for insured cervical cancer patients in urban areas whereas rural patients may require more intensive outreach, support, and resources, even among those living closer to treatment

Evaluating the urban-rural paradox: The complicated relationship between distance and the receipt of guideline-concordant care among cervical cancer patients

Objective: Urban-rural health disparities are often attributed to the longer distances rural patients travel to receive care. However, a recent study suggests that distance to care may affect urban and rural cancer patients differentially. We examined whether this urban-rural paradox exists among patients with cervical cancer. Methods: We identified individuals diagnosed with cervical cancer from 2004 to 2013 using a statewide cancer registry linked to multi-payer, insurance claims. Our primary outcome was receipt of guideline-concordant care: surgery for stages IA1–IB1; external beam radiation therapy (EBRT), concomitant chemotherapy, and brachytherapy for stages IB2–IVA. We estimated risk ratios (RR) using modified Poisson regressions, stratified by urban/rural location, to examine the association between distance to nearest facility and receipt of treatment. Results: 62% of 999 cervical cancer patients received guideline-concordant care. The association between distance and receipt of care differed by type of treatment. In urban areas, cancer patients who lived ≥15 miles from the nearest surgical facility were less likely to receive primary surgical management compared to those <5 miles from the nearest surgical facility (RR: 0.77, 95% CI: 0.60–0.98). In rural areas, patients living ≥15 miles from the nearest brachytherapy facility were more likely to receive treatment compared to those <5 miles from the nearest brachytherapy facility (RR: 1.71, 95% CI: 1.14–2.58). Distance was not associated with the receipt of chemotherapy or EBRT. Conclusions: Among cervical cancer patients, there is evidence supporting the urban-rural paradox, i.e., geographic distance to cancer care facilities is not consistently associated with treatment receipt in expected or consistent ways. Healthcare systems must consider the diverse and differential barriers encountered by urban and rural residents to improve access to high quality cancer care

Effectiveness and cost effectiveness of pharmacist input at the ward level: a systematic review and meta-analysis

Background Pharmacists play important role in ensuring timely care delivery at the ward level. The optimal level of pharmacist input, however, is not clearly defined. Objective To systematically review the evidence that assessed the outcomes of ward pharmacist input for people admitted with acute or emergent illness. Methods The protocol and search strategies were developed with input from clinicians. Medline, EMBASE, Centre for Reviews and Dissemination, The Cochrane Library, NHS Economic Evaluations, Health Technology Assessment and Health Economic Evaluations databases were searched. Inclusion criteria specified the population as adults and young people (age >16 years) who are admitted to hospital with suspected or confirmed acute or emergent illness. Only randomised controlled trials (RCTs) published in English were eligible for inclusion in the effectiveness review. Economic studies were limited to full economic evaluations and comparative cost analysis. Included studies were quality-assessed. Data were extracted, summarised. and meta-analysed, where appropriate. Results Eighteen RCTs and 7 economic studies were included. The RCTs were from USA (n=3), Sweden (n=2), Belgium (n=2), China (n=2), Australia (n=2), Denmark (n=2), Northern Ireland, Norway, Canada, UK and Netherlands. The economic studies were from UK (n=2), Sweden (n=2), Belgium and Netherlands. The results showed that regular pharmacist input was most cost effective. It reduced length-of-stay (mean= -1.74 days [95% CI: -2.76, -0.72], and increased patient and/or carer satisfaction (Relative Risk (RR) =1.49 [1.09, 2.03] at discharge). At £20,000 per quality-adjusted life-year (QALY)-gained cost-effectiveness threshold, it was either cost-saving or cost-effective (Incremental Cost Effectiveness Ratio (ICER) =£632/ QALY-gained). No evidence was found for 7-day pharmacist presence. Conclusions Pharmacist inclusion in the ward multidisciplinary team improves patient safety and satisfaction and is cost-effective when regularly provided throughout the ward stay. Research is needed to determine whether the provision of 7-day service is cost-effective.Peer reviewe

A randomized open-label trial on the use of budesonide/formoterol (Symbicort®) as an alternative reliever medication for mild to moderate asthmatic attacks

BACKGROUND Conventionally, a nebulized short-acting β-2 agonist like salbutamol is often used as the reliever in acute exacerbations of asthma. However, recent worldwide respiratory outbreaks discourage routine use of nebulization. Previous studies have shown that combined budesonide/formoterol (Symbicort®, AstraZeneca) is effective as both a maintenance and reliever anti-asthmatic medication. METHODS We performed a randomized, open-label study from March until August 2011 to compare the bronchodilatory effects of Symbicort® vs. nebulized salbutamol in acute exacerbation of mild to moderate asthmatic attack in an emergency department. Initial objective parameters measured include the oxygen saturation, peak expiratory flow rate (PEFR) and respiratory rate. During clinical reassessment, subjective parameters [i.e., Visual Analog Scale (VAS) and 5-point Likert scale of breathlessness] and the second reading of the objective parameters were measured. For the 5-point Likert scale, the patients were asked to describe their symptom relief as 1, much worse; 2, a little worse; 3, no change; 4, a little better; 5, much better. RESULTS Out of the total of 32 patients enrolled, 17 patients (53%) were randomized to receive nebulized salbutamol and 15 (47%) to receive Symbicort®. For both treatment arms, by using paired t- and Wilcoxon signed rank tests, it was shown that there were statistically significant improvements in oxygen saturation, PEFR and respiratory rate within the individual treatment groups (pre- vs. post-treatment). Comparing the effects of Symbicort® vs. nebulized salbutamol, the average improvement of oxygen saturation was 1% in both treatment arms (p = 0.464), PEFR 78.67 l/min vs. 89.41 l/min, respectively (p = 0.507), and respiratory rate 2/min vs. 2/min (p = 0.890). For subjective evaluation, all patients reported improvement in the VAS (average 2.45 cm vs. 2.20 cm), respectively (p = 0.765). All patients in both treatment arms reported either "a little better" or "much better" on the 5-point Likert scale, with none reporting "no change" or getting worse. CONCLUSION This study suggests that there is no statistical difference between using Symbicort® vs. nebulized salbutamol as the reliever for the first 15 min post-intervention

Factors associated with nosocomial SARS-CoV transmission among healthcare workers in Hanoi, Vietnam, 2003

BACKGROUND: In March of 2003, an outbreak of Severe Acute Respiratory Syndrome (SARS) occurred in Northern Vietnam. This outbreak began when a traveler arriving from Hong Kong sought medical care at a small hospital (Hospital A) in Hanoi, initiating a serious and substantial transmission event within the hospital, and subsequent limited spread within the community. METHODS: We surveyed Hospital A personnel for exposure to the index patient and for symptoms of disease during the outbreak. Additionally, serum specimens were collected and assayed for antibody to SARS-associated coronavirus (SARS-CoV) antibody and job-specific attack rates were calculated. A nested case-control analysis was performed to assess risk factors for acquiring SARS-CoV infection. RESULTS: One hundred and fifty-three of 193 (79.3%) clinical and non-clinical staff consented to participate. Excluding job categories with <3 workers, the highest SARS attack rates occurred among nurses who worked in the outpatient and inpatient general wards (57.1, 47.4%, respectively). Nurses assigned to the operating room/intensive care unit, experienced the lowest attack rates (7.1%) among all clinical staff. Serologic evidence of SARS-CoV infection was detected in 4 individuals, including 2 non-clinical workers, who had not previously been identified as SARS cases; none reported having had fever or cough. Entering the index patient's room and having seen (viewed) the patient were the behaviors associated with highest risk for infection by univariate analysis (odds ratios 20.0, 14.0; 95% confidence intervals 4.1–97.1, 3.6–55.3, respectively). CONCLUSION: This study highlights job categories and activities associated with increased risk for SARS-CoV infection and demonstrates that a broad diversity of hospital workers may be vulnerable during an outbreak. These findings may help guide recommendations for the protection of vulnerable occupational groups and may have implications for other respiratory infections such as influenza