604 research outputs found

    Assessing and countering reaction attacks against post-quantum public-key cryptosystems based on QC-LDPC codes

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    Code-based public-key cryptosystems based on QC-LDPC and QC-MDPC codes are promising post-quantum candidates to replace quantum vulnerable classical alternatives. However, a new type of attacks based on Bob's reactions have recently been introduced and appear to significantly reduce the length of the life of any keypair used in these systems. In this paper we estimate the complexity of all known reaction attacks against QC-LDPC and QC-MDPC code-based variants of the McEliece cryptosystem. We also show how the structure of the secret key and, in particular, the secret code rate affect the complexity of these attacks. It follows from our results that QC-LDPC code-based systems can indeed withstand reaction attacks, on condition that some specific decoding algorithms are used and the secret code has a sufficiently high rate.Comment: 21 pages, 2 figures, to be presented at CANS 201

    Analysis of reaction and timing attacks against cryptosystems based on sparse parity-check codes

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    In this paper we study reaction and timing attacks against cryptosystems based on sparse parity-check codes, which encompass low-density parity-check (LDPC) codes and moderate-density parity-check (MDPC) codes. We show that the feasibility of these attacks is not strictly associated to the quasi-cyclic (QC) structure of the code but is related to the intrinsically probabilistic decoding of any sparse parity-check code. So, these attacks not only work against QC codes, but can be generalized to broader classes of codes. We provide a novel algorithm that, in the case of a QC code, allows recovering a larger amount of information than that retrievable through existing attacks and we use this algorithm to characterize new side-channel information leakages. We devise a theoretical model for the decoder that describes and justifies our results. Numerical simulations are provided that confirm the effectiveness of our approach

    From Construction Workers to Architects: Developing Scientific Research Capacity in Low-Income Countries

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    Solving global health challenges in a sustainable manner depends on explicitly addressing scientific capacity-building needs, as well as establishing long-term, meaningful partnerships with colleagues in the developing world

    A Phase II study of pulse dose imatinib mesylate and weekly paclitaxel in patients aged 70 and over with advanced non-small cell lung cancer

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    Background: In non-small cell lung cancer (NSCLC), interstitial hypertension is a barrier to chemotherapy delivery, and is mediated by platelet derived growth factor receptor (PDGFR). Antagonizing PDGFR with imatinib may improve intra-tumoral delivery of paclitaxel, increasing response rate (RR).Methods: This single-stage, open-label phase II study evaluated pulse dose imatinib and weekly paclitaxel in elderly patients with advanced NSCLC. Eligible patients were aged ≥ 70 with untreated, stage IIIB-IV NSCLC and ECOG performance status 0-2. Primary endpoint was RR. Secondary endpoints included median progression free and overall survival (PFS, OS) and correlatives of PDGFR pathway activation. Baseline Charlson Comorbidity Index (CCI) and Vulnerable Elder Survey-13 (VES-13) were correlated with outcomes.Results: Thirty-four patients with median age 75 enrolled. Eleven of 29 (38%) were frail by VES-13 score. Overall RR was 11/34 (32%; 95% CI 17%-51%), meeting the primary endpoint. Median PFS and OS were 3.6 and 7.3 months, respectively. High tumoral PDGF-B expression predicted inferior PFS. Frail patients by VES-13 had significantly worse median PFS (3.2 vs. 4.5 months; p=0.02) and OS (4.8 vs. 12 months; p=0.02) than non-frail.Conclusions: The combination of imatinib and paclitaxel had encouraging activity as measured by the primary endpoint of RR. However, PFS and OS were typical for elderly patients treated with single agent chemotherapy and the regimen is not recommended for further study. Adjunct imatinib did not overcome the established association of tumoral PDGF-B expression with inferior PFS. VES-13 was a powerful predictor of poor survival outcomes. Frailty should be further studied as a predictor of non-benefit from chemotherapy.Trial Registration: ClinicalTrials.gov NCT01011075. © 2012 Bauman et al.; licensee BioMed Central Ltd

    A teleofunctional account of evolutionary mismatch.

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    This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s10539-016-9527-1When the environment in which an organism lives deviates in some essential way from that to which it is adapted, this is described as "evolutionary mismatch," or "evolutionary novelty." The notion of mismatch plays an important role, explicitly or implicitly, in evolution-informed cognitive psychology, clinical psychology, and medicine. The evolutionary novelty of our contemporary environment is thought to have significant implications for our health and well-being. However, scientists have generally been working without a clear definition of mismatch. This paper defines mismatch as deviations in the environment that render biological traits unable, or impaired in their ability, to produce their selected effects (i.e., to perform their proper functions in Neander's sense). The machinery developed by Millikan in connection with her account of proper function, and with her related teleosemantic account of representation, is used to identify four major types, and several subtypes, of evolutionary mismatch. While the taxonomy offered here does not in itself resolve any scientific debates, the hope is that it can be used to better formulate empirical hypotheses concerning the effects of mismatch. To illustrate, it is used to show that the controversial hypothesis that general intelligence evolved as an adaptation to handle evolutionary novelty can, contra some critics, be formulated in a conceptually coherent way

    Impact of mental health problems on case fatality in male cancer patients

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    Background: Although mortality rates are elevated in psychiatric patients relative to their healthy counterparts, little is known about the impact of mental health on survival in people with cancer. / Methods and results: Among 16 498 Swedish men with cancer, survival was worse in those with a history of psychiatric hospital admissions: multiply-adjusted hazard ratio (95% confidence interval) comparing cancer mortality in men with and without psychiatric admissions: 1.59 (1.39, 1.83). / Conclusion: Survival in cancer patients is worse among those with a history of psychiatric disease. The mechanisms underlying this association should be further explored

    Arthritis of the base of the thumb

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    The purpose of this article is to outline the pathophysiology and epidemiology of arthritis of the base of the thumb. The usual presentation and diagnosis will be discussed along with the current conservative treatment options. Surgical treatment options are determined by the stage of the arthritis as well as the demands of the patient. The current standard surgical treatment options will be reviewed along with their results in the literature

    Surgical stabilization for symptomatic carpometacarpal hypermobility; a randomized comparison of a dorsal and a volar technique and a cohort of the volar technique

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    BACKGROUND: Hypermobility of the first carpometacarpal joint is mostly surgically treated with a volar approached stabilization by Eaton, but recent studies indicate the importance of the dorsoradial and intermetacarpal ligaments (DRL and IML) for carpometacarpal joint stability. The aim of this study was to compare a dorsal and volar technique for primary carpometacarpal hypermobility regarding pain and functional outcome. METHODS: Patients with non-degenerative, painful carpometacarpal hypermobility were included and were randomly assigned to either the volar technique using the FCR, or a dorsal technique using the ECRL. After premature termination of the trial, we followed all patients treated with the volar approach. Pain, strength, and ADL function using DASH and Michigan Hand Questionnaires (MHQ) were measured at baseline and 3 and 12 months after surgery. RESULTS: After including 16 patients, the randomized trial comparing the volar and dorsal technique was terminated because of significant increased pain in the dorsal group. Although none of the other outcome measures were significant in the underpowered comparison, in line with the pain scores, all variables showed a trend towards a worse outcome in the dorsal group. Between 2009 and 2012, 57 thumbs were surgically stabilized. We found significant better pain and MHQ scores, and after 1 year improved grip and key pinch strength. Patients returned to work within 8 (±7) weeks, of which 85 % in their original job. CONCLUSIONS: Surgical stabilization of the thumb is an effective method for patients suffering from hypermobility regarding pain, daily function, and strength. We recommend a volar approach. Level of Evidence: Level I, therapeutic stud
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