Search

Showing total 2 results
Start Over Search Limiters Full Text Search Limiters Peer Reviewed Topic calibration
2 results

1. Calibration Done Right: Noiseless Flush+Flush Attacks

Author

Clementine Maurice, Guillaume Didier, Délégation générale de l'armement (DGA), Ministère de la Défense, Département d'informatique de l'École normale supérieure (DI-ENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS), Embedded Security and Cryptography / Sécurité cryptographie embarquée (EMSEC), SYSTÈMES LARGE ÉCHELLE (IRISA-D1), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Bretagne Sud (UBS)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National de Recherche en Informatique et en Automatique (Inria)-École normale supérieure - Rennes (ENS Rennes)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-CentraleSupélec-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Bretagne Sud (UBS)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Self-adaptation for distributed services and large software systems (SPIRALS), Inria Lille - Nord Europe, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189 (CRIStAL), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), This work has been partly funded by the French Direction G´en´erale de l’Armement, and by the ANR-19-CE39-0007 MIAOUS. Some experiments presented in this paper were carried out using the Grid’5000 testbed, supported by a scientific interest group hosted by Inria and including CNRS, RENATER and several Universities as well as other organizations (see https://www.grid5000.fr)., Grid'5000, ANR-19-CE39-0007,MIAOUS,Attaques sur la micro-architecture des systèmes ubiquitaires(2019), Département d'informatique - ENS Paris (DI-ENS), École normale supérieure - Paris (ENS-PSL), Security & PrIvaCY (SPICY), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Université de Lille-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
0303 health sciences, Interconnection, Leak, Hardware_MEMORYSTRUCTURES, Computer science, business.industry, Word error rate, 020207 software engineering, 02 engineering and technology, ComputerSystemsOrganization_PROCESSORARCHITECTURES, [INFO.INFO-CR]Computer Science [cs]/Cryptography and Security [cs.CR], 03 medical and health sciences, 0202 electrical engineering, electronic engineering, information engineering, Calibration, Central processing unit, Cache, Line (text file), business, Computer hardware, 030304 developmental biology
Abstract

International audience; Caches leak information through timing measurements and side-channel attacks. Several attack primitives exist with different requirements and trade-offs. Flush+Flush is a stealthy and fast one that uses the timing of the clflush instruction depending on whether a line is cached. We show that the CPU interconnect plays a bigger role than previously thought in these timings and in Flush+Flush error rate. In this paper, we show that a naive implementation that does not account for the topology of the interconnect yields very high error rates, especially on modern CPUs as the number of cores increases. We therefore reverse-engineer this topology and revisit the calibration phase of Flush+ Flush for different attacker models to determine the correct threshold for clflush hits and misses. We show that our method yields closeto-noiseless side-channel attacks by attacking the AES T-tables implementation of OpenSSL, and by building a covert channel. We obtain a maximal capacity of 5.8 Mbit/s with our method, compared to 1.9 Mbit/s with a naive Flush+Flush implementation on an Intel Core i9-9900 CPU.

Published
2021

2. Use of Two-Part Regression Calibration Model to Correct for Measurement Error in Episodically Consumed Foods in a Single-Replicate Study Design: EPIC Case Study

Author

Agogo, George O, der Voet, Hilko van, Veer, Pieter Van't, Ferrari, Pietro, Leenders, Max, Muller, David C, Sánchez-Cantalejo, Emilio, Bamia, Christina, Braaten, Tonje, Knüppel, Sven, Johansson, Ingegerd, van Eeuwijk, Fred A, Boshuizen, Hendriek, LS IRAS EEPI GRA (Gezh.risico-analyse), IRAS RATIA-SIB, Risk Assessment of Toxic and Immunomodulatory Agents, [Agogo,GO, Boshuizen,H] National Institute for Public Health and the Environment, Bilthoven, The Netherlands. [Agogo,GO, Voet,HV, Eeuwijk,FAV, Boshuizen,H] Biometris, Wageningen University and Research Center, Wageningen, The Netherlands.[Veer,PV, Boshuizen,H] Department of Human Nutrition, Wageningen University and Research Center, Wageningen, The Netherlands. [Ferrari,P] Nutritional Epidemiology Group, International Agency for Research on Cancer, Lyon, France. [Leenders,M] Department of Gastroenterology and Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands. [Muller,DC] Genetic Epidemiology Group, International Agency for Research on Cancer, Lyon, France. [Sánchez-Cantalejo,E] Andalusian School of Public Health, Granada, Spain. CIBER de Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain. [Bamia,C] WHO Collaborating Center for Food and Nutrition Policies, Department of Hygiene, Epidemiology and Medical Statistics, University of Athens Medical School, Athens, Greece. [Braaten,T] Department of Community Medicine, University of Tromsø, Tromsø, Norway. [Knüppel,S] Department of Epidemiology, German Institute of Human Nutrition Potsdam-Rehbrücke, Potsdam, Germany. [Johansson,I] Department of Odontology, Umea University, Umea, Sweden., However, the publication cost will be covered by Wageningen University and Research Centre, Biometris, P.O. Box 100, 6700 AC WAGENINGEN should the paper be accepted for a publication., LS IRAS EEPI GRA (Gezh.risico-analyse), IRAS RATIA-SIB, and Risk Assessment of Toxic and Immunomodulatory Agents

Subjects
Male, Parametric Analysis, Medicin och hälsovetenskap, Nutrition and Disease, Calibration (statistics), Test Statistics, lcsh:Medicine, markers, Overfitting, Statistical Inference, outcomes, Medical and Health Sciences, Wiskundige en Statistische Methoden - Biometris, Mathematical and Statistical Techniques, Neoplasms, Surveys and Questionnaires, Voeding en Ziekte, Statistics, Medicine, Prospective Studies, lcsh:Science, Multidisciplinary, Maximum Likelihood Estimation, Regression analysis, Estudios Prospectivos, Replicate, Diseases::Neoplasms [Medical Subject Headings], Middle Aged, PE&RC, Neoplasias, Diet Records, Europe, Survival Rate, Biometris, nutrition, Physical Sciences, Calibration, instruments, Regression Analysis, Dieta, Female, dietary self-report, Statistics (Mathematics), Bayesian Statistics, Research Article, Adult, Heteroscedasticity, Analytical, Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Epidemiologic Methods::Epidemiologic Study Characteristics as Topic::Epidemiologic Studies::Cohort Studies::Longitudinal Studies::Prospective Studies [Medical Subject Headings], General Science & Technology, Logit, Phenomena and Processes::Physiological Phenomena::Nutritional Physiological Phenomena::Diet [Medical Subject Headings], Research and Analysis Methods, Analytical, Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Epidemiologic Methods::Data Collection::Nutrition Assessment [Medical Subject Headings], Analytical, Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Epidemiologic Methods::Epidemiologic Study Characteristics as Topic::Epidemiologic Studies::Cohort Studies::Longitudinal Studies [Medical Subject Headings], Covariate, MD Multidisciplinary, Humans, cancer, Statistical Methods, Statistical Hypothesis Testing, Mathematical and Statistical Methods - Biometris, Aged, VLAG, disease, Observational error, Models, Statistical, business.industry, lcsh:R, Evaluación Nutricional, Feeding Behavior, Estudios Longitudinales, Estudios Epidemiológicos, Survival Analysis, Nutrition Assessment, lcsh:Q, Food Habits, business, Mathematics, Analytical, Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Epidemiologic Methods::Epidemiologic Study Characteristics as Topic::Epidemiologic Studies [Medical Subject Headings], Generalized Linear Model
Abstract

Journal Article; In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted two-part regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM) and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC) study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model. Yes

Published
2014