47 research outputs found
TOWARD LOWER COMMUNICATION IN GARBLED CIRCUIT EVALUATION
Secure Multi-party Computation (SMC) is a classical problem in theoretical security. In a SMC problem, two or more parties must compute correctly a function f on their respective inputs x and y, while preserving the privacy of their inputs and additional security properties.
One of the approaches proposed for addressing the SMC problem relies on the design of Garbled Circuit (GC). In Garbled Circuits (GCs), the function to be computed is represented as a Boolean circuit composed of binary gates. The input and output wire of each gate is masked such that the party evaluating the Garbled Boolean Circuits (GBC) cannot gain any information about the inputs or the intermediate results that appear during the function evaluation. The complexity of today's most efficient GC protocol depends linearly on the size of the Boolean circuit representation of the evaluated function. The total cost and run-time interaction between parties increase linearly with the number of gates and can be huge for complex GBCs. Actually, interest has grown in the efficiency of this technique and in its applications to computation outsourcing in untrusted environments.
A recent work shows that XOR gates in a Boolean circuit have no cost for the secure computation protocol. Therefore, circuits with a reduced number of non-XOR gates are more convenient and one of the possible ways to reduce the complexity of the computation is to reduce the number of non-XOR gates in the Boolean circuit.
Recalling that, the main aim of this work is to reduce the number of non-XOR gates, which directly results in a reduced number of interactions between the parties and transfer complexity at runtime, we present different approaches for reducing the communication cost of Secure Multi-party Computation (SMC) and improving the overall computation time and efficiency of the execution of SMC
Effect of hydro-alcoholic Portulaca-Oleracea extract on oxidative damage induced by bacterial Lipopolysaccharide (LPS) in liver of rat
زمینه و هدف: استرس اکسیداتیو یک نقش کلیدی در بروز بسیاری از بیماریها دارد. خرفه حاوی انواع اسیدهای چرب غیر اشباع و ترکیباتی مانند : آلفا-توکوفرول، اسید‌آسکوربیک و گلوتاتیون می‌باشد. که اثرات آنتی اکسیدانی دارند، بنابراین شاید بتواند نقشی موثر جهت پیشگیری و درمان بیماری‌های مرتبط با استرس‌اکسیداتیو داشته باشد. جهت بررسی این امر، استرس اکسیداتیو در یک مدل حیوانی از طریق تزریق لیپو ساکارید باکتریایی (LPS) القا گردید. در مرحله بعدی اثر عصاره هیدروالکلی خرفه بر بهبود آسیب اکسیداتیو القا شده توسط LPS در کبد موشهای صحرایی مورد بررسی قرار گرفت. روش‌ بررسی: موشهای صحرایی نر نژاد ویستار در 4 گروه قرار گرفتند. عصاره خرفه (400 mg/kg) طی یک دوره 14 روزه از طریق تزریق دهانی (گاواژ) به حیوانات داده شد. LPS (1000 µg/kg) ، به صورت داخل صفاقی تزریق گردید. میزان فعالیت آنزیمهای آنتی اکسیدان از طریق اندازه گیری کاتالاز(CAT) ، سوپراکسیددسموتاز(SOD) و گلوتاتیون ردوکتاز (GR) در بافت کبد گروههای مختلف صورت گرفت. میزان پروکسیداسیون لیپیدی نیز به عنوان مارکری برای تعیین آسیب اکسیداتیو اندازه گیری شد. همچنین مطالعات بافت شناسی نیز صورت گرفت. یافته ‌ها: LPS موجب تحریک و افزایش فعالیت آنزیم SOD، CAT و کاهش فعالیت GR نسبت به گروه کنترل شد. همچنین LPS موجب افزایش مالون دی آلدئید(MDA) کبد شد. از طرفی در گروه پیشگیری عصاره خرفه به صورت معناداری فعالیت آنزیم های SOD، CAT و GRرا نسبت به گروه LPS افزایش داد و باعث کاهش معنادار MAD نسبت به گروه دریافت کننده LPS گردید. بحث و نتیجه گیری : به نظر می رسد خرفه به علت دارا بودن میزان بالایی از ترکیبات انتی اکسیدانی می‌تواند به عنوان یک محصول طبیعی، برای پیشگیری از آسیب و بیماری های ناشی از استرس اکسیداتیو استفاده شود
Analysis of Energy-Efficient Buildings through Simulation and Formal Methods
In the last few years, the increasing interest in energy saving has led to invest resources in many research fields, in order to develop new tech-nologies to reduce energy consumption. One such field is energy man-agement systems for buildings. The interactions between the system con-trolling the building and its environment are complicated by the fact that they involve important timing properties, which can be expressed through a variety of formalisms. This paper introduces a formal model, expressed in a temporal logic language, through which designers can evaluate the temporal behavior of buildings\u2019 energy management systems. To this end, the formal model is analyzed through simulation, that is, through the generation of traces satisfying the temporal logic model
Toward Design of Garbled Circuits Using Quantum Gates
Abstract\u2014Two-party Secure Multi-party Computation (SMC) is a classical problem in theoretical security. The Garbled Circuit (GC) approach has been proposed as a method for solving SMC using Boolean circuits. Actually, interest has grown in the efficiency of this technique and in its applications to computation outsourcing in untrusted environments. A recent work shows that EXOR gates in a Boolean circuit have no cost for the secure computation protocol. Therefore, circuits with a reduced number of non-EXOR gates are more convenient. In this work, we discuss Garbled Circuit construction for two-party secure function evaluation using quantum gates (QG). We observe that, in some cases, the quantumGCinvolves a lower number of non-EXOR gates than the corresponding classical GC implementations, resulting in a reduced cost in terms of Oblivious Transfer (OT) communication at run time
Comparison of the Perspectives of Managers, Employees and Clients Regarding the Individual Barriers of Family Planning Counseling in Healthcare Centers of Isfahan in 2012
Background: Family planning is a lifestyle that is selected voluntarily and is based on the knowledge, attitude and responsible decision making by couples in order to promote the health and welfare of the family and the advancement of the society. In this regard, family planning counseling plays an important role in making informed decisions if used properly and in a responsible way. Detection of individual barriers in family planning counseling based on the viewpoints of managers, employees and clients who are key participants in the healthcare service provision is a major step towards appropriate planning to modify or eliminate such barriers. Objectives: The present study was conducted with the goal of comparing managers', employees' and clients' viewpoints about individual barriers in family planning counseling in health care centers in Isfahan in 2012. Patients and Methods: This was a cross-sectional one-step three-group comparative descriptive study conducted on 295 subjects including 59 managers, 110 employees and 126 clients in medical health care centers in Isfahan in 2012. The managers and employees were selected by census sampling, and the clients were recruited through convenient random sampling. The data collection tool was a researcher-designed questionnaire, which was designed in two sections of fertility and personal characteristics, and viewpoint measurement. Descriptive and inferential statistical tests were used to analyze the data. Results: The obtained results showed significant differences between mean scores of viewpoints in three groups of managers, employees and clients concerning individual barriers in family planning counseling. In addition, most of the managers, employees and clients reported individual barriers as an intermediate level barrier in the process of family planning counseling. Conclusions: Results indicate that subjects in three studied groups hold different views regarding the individual barriers in family planning counseling. This difference in the perspectives may be a factor that affects the quality of the provided services. Therefore, it is necessary for the healthcare providers to consider the main concerns of their clients regarding family planning
Glucuronidase Expression in Transgenic Tobacco Roots with a Parasponia Promoter on Infection with Meloidogyne javanica
The expression of a g-us reporter gene linked to a Parasponia andersonii hemoglobin promoter has been studied in transgenic tobacco plants after infection by Meloidogyne javanica. Transgenic roots were harvested at different times after nematode inoculation, and stained histochemically for expression of the gus gene. During the early stages of infection (0-2 weeks) there was little expression in giant cells, in contrast to other cells of the root. In later stages of infection (3-6 weeks) there was strong gus expression in giant cells, with virtually no expression in other cells of the root. The Parasponia hemoglobin promoter therefore appears to direct down-regulation of linked genes on induction of giant cells, but up-regulation in mature giant cells. This reflects different metabolic activities in the giant cells depending on their stage of development. The Parasponia hemoglobin promoter may respond to oxygen tension in giant cells. This suggests that oxygen tension may be limited in the metabolically active giant cells that are associated with egg-laying females
Exploiting Quantum Gates in Secure Computation
Secure Multi-party Computation (SMC) has been introduced to allow the computation of generic functions between two parties that want to keep secret the input they use, and share only the computed result. One of the approach proposed to solve the SMC problem relies on the design of Garbled Circuits (GC), that are Boolean circuits that can be evaluated collaboratively achieving the SMC goal. Recently, there is a growing interest on the efficiency of this technique and on its potential applications to computation outsourcing in untrusted environments. One of the possible ways to reduce the complexity of the computation is to lower the number of non-EXOR gates in the Boolean circuit, since those gates have no cost for the execution of the secure computation protocol. In this work, we discuss the possibility to construct Garbled Circuit using quantum gates (QG), observing that, in some cases, the quantum GC requires a lower number of non-EXOR gates with respect to the corresponding classical GC implementations, thus improving the overall efficiency of the execution of the SMC protocol
The role of feedback in clinical education: Principles, strategies, and models
Introduction: Feedback is an inseparable and integral part of learning. It promotes students' learning towards achieving goals. In the training of health professions, little feedback or a paucity of feedback can be observed. Giving correct feedback is another important matter that must be taken into account. Therefore, the aim of this study was to present the principles of feedback, its effective characteristics, the strategies, and models of feedback. Methods: In order to identify the relevant articles, online databases as Elsevier, Google Scholar, SID, and Magiran were searched using keywords such as feedback, clinical evaluation, clinical education, and feedback models were used. About Persian articles, the year of 1385, and Latin articles the year of 2000 have been considered as a base year. Totally, 49 articles were met the review potentiality. 34 articles were identified as relevant ones and included in the study as well as 15 papers were excluded due to being irrelevant. Results: Feedback must be considered as one of the most important tenets of clinical education like an agent for reflection and improvement. Feedback will be considered effective when it is intended as a certain period in education and its principles and characteristics will be considered and presented with appropriate strategies and models. If feedback is provided in an appropriate manner and with suitable information, the performance of the learner can be improved. Conclusion: Constructive and meaningful feedback is an essential part of teaching and learning for students to get instrumental information. Thus, teachers and clinical instructors must receive adequate training on feedback. Familiarity with models and strategies of feedback can pave the way towards providing effective and constructive feedback
An OBDD-Based Technique for the Efficient Synthesis of Garbled Circuits
Secure Multi-party Computation (SMC) protocols are exploited to perform collaborative computation of a function between two or more parties while keeping the privacy of the private inputs and sharing the computed result only. The Garbled Circuit (GC) protocol, proposed by Yao, is one of the possible approaches to solve the SMC problem, based on the evaluation of the Boolean Circuit representing the given function.
Recently, the question to improve efficiency in secure multi-party computation has gained much interest. One of the proposed techniques to increase the efficiency of the GC protocol is based on the reduction of the number of non-XOR gates in the Boolean circuit, since the evaluation of XOR gates have no cost for the execution of the whole protocol.
The aim of this work is to define a post-processing procedure that, given an optimized GC, decreases the number of non-XOR gates by transforming some parts of the circuit. The strategy is based on the fact that some gates behave as XORs apart from one output and then, if that input never occurs, those gates can be replaced by a XOR without changing the output of the overall network. The technique we propose is based on the analysis of the GC by using Ordered Binary Decision Diagrams (OBDD) representation. We present the application of our technique to some standard circuits to show the effectiveness of our proposal
A multiple valued logic approach for the synthesis of garbled circuits
Secure Multi-party Computation (SMC) protocols enable two or more parties to compute collaboratively generic functions while keeping secret their inputs, sharing only the final result. To achieve this goal, a technique relying on the design of Garbled Circuits (GC) has been firstly proposed by Yao. Garbled circuits are Boolean circuits that can be evaluated using a distributed protocol for computing the result for each gate, till computing the output values. To improve the efficiency of this technique and exploit SMC protocols in practical applications, such as computation outsourcing in untrusted environments, a number of optimizations have been introduced. In this paper we analyze the deployment of Multiple Valued Logic techniques for the design of GC, discussing their impact on the overall computation and communication costs