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Bayesian Networks (BNs) are an increasingly popular modelling technique in cyber security especially due to their capability to overcome data limitations. This is also instantiated by the growth of BN models development in cyber security. However, a comprehensive comparison and analysis of these models is missing. In this paper, we conduct a systematic review of the scientific literature and identify 17 standard BN models in cyber security. We analyse these models based on 9 different criteria and identify important patterns in the use of these models. A key outcome is that standard BNs are noticeably used for problems especially associated with malicious insiders. This study points out the core range of problems that were tackled using standard BN models in cyber security, and illuminates key research gaps.

Summary Background Patients with chronic obstructive pulmonary disease (COPD) have few options for treatment. The efficacy and safety of the phosphodiesterase-4 inhibitor roflumilast have been investigated in studies of patients with moderate-to-severe COPD, but not in those concomitantly treated with longacting inhaled bronchodilators. The effect of roflumilast on lung function in patients with COPD that is moderate to severe who are already being treated with salmeterol or tiotropium was investigated. Methods In two double-blind, multicentre studies done in an outpatient setting, after a 4-week run-in, patients older than 40 years with moderate-to-severe COPD were randomly assigned to oral roflumilast 500 μg or placebo once a day for 24 weeks, in addition to salmeterol (M2-127 study) or tiotropium (M2-128 study). The primary endpoint was change in prebronchodilator forced expiratory volume in 1 s (FEV 1 ). Analysis was by intention to treat. The studies are registered with ClinicalTrials.gov, number NCT00313209 for M2-127, and NCT00424268 for M2-128. Findings In the salmeterol plus roflumilast trial, 466 patients were assigned to and treated with roflumilast and 467 with placebo; in the tiotropium plus roflumilast trial, 371 patients were assigned to and treated with roflumilast and 372 with placebo. Compared with placebo, roflumilast consistently improved mean prebronchodilator FEV 1 by 49 mL (p 1 was noted in both groups. Furthermore, roflumilast had beneficial effects on other lung function measurements and on selected patient-reported outcomes in both groups. Nausea, diarrhoea, weight loss, and, to a lesser extent, headache were more frequent in patients in the roflumilast groups. These adverse events were associated with increased patient withdrawal. Interpretation Roflumilast improves lung function in patients with COPD treated with salmeterol or tiotropium, and could become an important treatment for these patients. Funding Nycomed.

The need to assess security and take protection decisions is at least as old as our civilisation. However, the complexity and development speed of our interconnected technical systems have surpassed our capacity to imagine and evaluate risk scenarios. This holds in particular for risks that are caused by the strategic behaviour of adversaries. Therefore, technology-supported methods are needed to help us identify and manage these risks. In this paper, we describe the attack navigator: a graph-based approach to security risk assessment inspired by navigation systems. Based on maps of a socio-technical system, the attack navigator identifies routes to an attacker goal. Specific attacker properties such as skill or resources can be included through attacker profiles. This enables defenders to explore attack scenarios and the effectiveness of defense alternatives under different threat conditions.

In the last decades we witnessed the creation of a virtual world: cyberspace, which offers plenty of opportunities and challenges. Meanwhile, we are confronted with many conflict situations between different groups of people or countries. In the last years, several events have been described in terms of cyber warfare or the use of cyber weapons, leading to critical international security concerns. At the same time, there is little research on the definitions of what constitutes a cyber weapon and how it can be profiled.The present article gives an answer to the question “How to define cyber weapons?” and proposes a conceptual framework that defines and profiles cyber weapons from a multidisciplinary perspective: cyber and military, considering legal aspects as well. This framework establishes the context of use and the life cycle of cyber weapons, defines them, presents their structure and proposes a way to profile them. The aim of this article is to support decision makers and academia that have to deal with the implications and consequences of cyber weapons. Therefore, to evaluate our framework, we propose a profiling matrix for Stuxnet, Operation Orchard and Black Energy and we conduct an exploratory case study on Stuxnet based on the existing literature and reports. We conclude by presenting our future research.

Report from Dagstuhl seminar 14491. This report documents the program and the outcomes of Dagstuhl Seminar 14491 “Socio-Technical Security Metrics”. In the domain of safety, metrics inform many decisions, from the height of new dikes to the design of nuclear plants. We can state, for example, that the dikes should be high enough to guarantee that a particular area will flood at most once every 1000 years. Even when considering the limitations of such numbers, they are useful in guiding policy. Metrics for the security of information systems have not reached the same maturity level. This is partly due to the nature of security risk, in which an adaptive attacker rather than nature causes the threat events. Moreover, whereas the human factor may complicate safety and security procedures alike, in security this “weakest link” may be actively exploited by an attacker, such as in phishing or social engineering. In order to measure security at the level of socio-technical systems, one therefore needs to compare online hacking against such social manipulations, since the attacker may simply take the easiest path. In this seminar, we searched for suitable metrics that allow us to estimate information security risk in a socio-technical context, as well as the costs and effectiveness of countermeasures. Working groups addressed different topics, including security as a science, testing and evaluation, social dynamics, models and economics. The working groups focused on three main questions: what are we interested in, how to measure it, and what to do with the metrics.

We know that several chemicals can be combined to form explosives. Therefore, we do not want these to end up in airplanes together. Similarly, in the architecture of complex systems, it is often possible to combine the results of several system services to acquire illegitimate benefits or disrupt operation. For example, in what is called simboxing, telephone services are purchased from different providers, and a composite service is set up which redirects incoming calls to the service purchased from the target provider, bypassing interconnection fees. Due to their complex nature, such attacks are extremely hard to predict and prevent. This paper provides a first systematic description and classification of the phenomenon of system abuse by service composition, as well as an analysis to identify the most common types of attacks in the design phase. We employ attack trees to express ways to achieve the goal of obtaining a service at a cost lower than the regular amount charged. We use the purchase of railway tickets as a running example, where the atomic services are the rights to travel between two directly adjacent stations. These can potentially be composed in various ways to travel cheaper, for example where there are stations A, B, and C on a railway line, and a single ticket from B to A via C is cheaper than a return ticket from B to C. Our method provides the foundations for systematically discovering such issues.

International audience; BACKGROUND: Treatment of pulmonary embolism with low-molecular-weight heparin and vitamin K antagonists, such as warfarin, is not ideal. We aimed to assess non-inferiority of idrabiotaparinux, a reversible longlasting indirect inhibitor of activated factor X, to warfarin in patients with acute symptomatic pulmonary embolism. METHODS: In our randomised, double-blind, double-dummy, non-inferiority trial, we enrolled adults with objectively documented acute symptomatic pulmonary embolism attending 291 centres in 37 countries. We excluded patients who were pregnant, had active bleeding, kidney failure, or malignant hypertension, or were at high risk of death, bleeding, or adverse reactions to study drugs. We randomly allocated patients to receive 5-10 days' enoxaparin 1*0 mg/kg twice daily followed by subcutaneous idrabiotaparinux (starting dose 3*0 mg) or adjusted-dose warfarin (target international normalised ratio 2*0-3*0); regimens lasted 3 months or 6 months dependent on clinical presentation. Block randomisation was done with a central interactive computerised system, stratified by study centre and intended treatment duration. The primary efficacy outcome was recurrent venous thromboembolism at 99 days after randomisation. We estimated the odds ratio and 95% CI with a Mantel-Haenzsel χ(2) analysis (non-inferiority margin 2*0) in the intention-to-treat population. The main safety outcome was clinically relevant bleeding (major or non-major) in all patients at day 99. This study is registered with ClinicalTrials.gov, number NCT00345618. FINDINGS: Between Aug 1, 2006, and Jan 31, 2010, we enrolled 3202 patients aged 18-96 years. 34 (2%) of 1599 patients randomly allocated to receive enoxaparin-idrabiotaparinux and 43 (3%) of 1603 patients randomly allocated to receive enoxaparin-warfarin had recurrent venous thromboembolism (odds ratio 0*79, 95% CI 0*50-1*25; p(non-inferiority)=0*0001). 72 (5%) of 1599 patients in the enoxaparin-idrabiotaparinux group and 106 (7%) of 1603 patients in the enoxaparin-warfarin group had clinically relevant bleeding (0*67, 0*49-0*91; p(superiority)=0*0098). We noted similar differences in outcomes in those patients treated to 6 months. INTERPRETATION: Idrabiotaparinux could provide an attractive alternative to warfarin for the long-term treatment of pulmonary embolism, and seems to be associated with reduced bleeding. FUNDING: Sanofi-Aventis (Paris, France).

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Nieuwe technieken maken het opslaan en verwerken van informatie eenvoudiger. Sterker nog: ze maken de weg vrij om gegevens vast te leggen voordat duidelijk is welk inzicht we eigenlijk nastreven. Toezicht wint zo terrein ten opzichte van de kennisverwerving. Voorbeelden van toenemend toezicht zijn elektronische dossiers over burgers, informatievergaring door de politie en in private initiatieven zoals Google Earth. Deze systemen maken het mogelijk om op grote schaal verbanden te ontdekken en afwijkingen op te sporen, zonder dat er duidelijke kennisvragen aan vooraf gaan. De relatie tussen inzicht en toezicht is bepalend voor hoe we met de verzamelde kennis omgaan. Ligt de nadruk daarbij op inzicht, overzicht, toezicht, of nog iets anders?

Contains fulltext : 75763.pdf (author's version ) (Open Access) Foundations of Security Analysis and Design V

In this paper, we investigate ethical issues involved in the development and implementation of Internet voting technology. From a phenomenological perspective, we describe how voting via the Internet mediates the relation between people and democracy. In this relation, trust plays a major role. The dynamics of trust in the relation between people and their world forms the basis for our analysis of the ethical issues involved. First, we consider established principles of voting, confirming the identity of our democracy, which function as expectations in current experiments with online voting in the Netherlands. We investigate whether and how Internet voting can meet these expectations and thereby earn trust, based on the experiments in the Netherlands. We identify major challenges, and provide a basis for ethical and political discussion on these issues, especially the changed relation between public and private. If we decide that we want to vote via the Internet, more practical matters come into play in the implementation of the technology. The choices involved here are discussed in relation to the mediating role of concrete voting technologies in the relation between citizen and state.

Contains fulltext : 32048_voloma.pdf (Publisher’s version ) (Open Access) Contains fulltext : 72122.pdf (Publisher’s version ) (Open Access) Radboud Universiteit Nijmegen, 21 januari 2008 Promotor : Jacobs, B.P.F. Co-promotores : Poll, E., Becker, M. 226 p.

A qualitative case study of the e-voting discourses in the UK and the Netherlands was performed based on the theory of strategic niche management. In both countries, eight e-voting experts were interviewed on their expectations, risk estimations, cooperation and learning experiences. The results show that differences in these variables can partly explain the variations in the embedding of e-voting in the two countries, from a qualitative point of view.

In this paper, we analyse the concept of vote buying based on examples that try to stretch the meaning of the concept. Which ex- amples can still be called vote buying, and which cannot? We propose several dimensions that are relevant to qualifying an action as vote buy- ing or not. As a means of protection against vote buying and coercion, the concept of receipt-freeness has been proposed. We argue that, in or- der to protect against a larger set of vote buying activities, the concept of receipt-freeness should be interpreted probabilistically. We propose a general definition of probabilistic receipt-freeness by adapting existing definitions of probabilistic anonymity to voting.

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Formal methods have provided us with tools to check both anonymity of protocols and - more specifically - receipt-freeness of voting protocols. One of the frameworks used for proving anonymity is epistemic logic. However, to the best of our knowledge, epistemic logic has never been used to prove receipt-freeness of voting protocols. Still, the concept of indistinguishability used in formalizing anonymity seems to apply to receipt-freeness as well: a vote for one party should be indistinguishable from a vote for another party, even if the voter supplies additional in- formation outside the scope of the protocol. In this paper, we formalize this aspect of anonymity relations, in order to provide an alternative formalization of receipt-freeness in voting protocols, based on epistemic logic.

Social aspects of security of information systems are often discussed in terms of “actual security��? and “perceived security��?. This may lead to the hypothesis that e-voting is controversial because in paper voting, actual and perceived security coincide, whereas they do not in electronic systems. In this paper, we argue that the distinction between actual and perceived security is problematic from a philosophical perspective, and we develop an alternative approach, based on the notion of trust. We investigate the different meanings of this notion in computer science, and link these to the philosophical work of Luhmann, who distinguishes between familiarity, confidence and trust. This analysis yields several useful distinctions for discussing trust relations with respect to information technology. We apply our framework to electronic voting, and propose some hypotheses that can possibly explain the smooth introduction of electronic voting machines in the Netherlands in the early nineties.

Contains fulltext : 35875.pdf (Publisher’s version ) (Closed access) Congres CEPE 2005, 17 juli 2005

In this paper, we discuss one particular feature of Internet voting, verifiability, against the background of scientific literature and experiments in the Netherlands. In order to conceptually clarify what verifiability is about, we distinguish classical verifiability from constructive veriability in both individual and universal verification. In classical individual verifiability, a proof that a vote has been counted can be given without revealing the vote. In constructive individual verifiability, a proof is only accepted if the witness (i.e. the vote) can be reconstructed. Analogous concepts are de- fined for universal veriability of the tally. The RIES system used in the Netherlands establishes constructive individual verifiability and constructive universal verifiability, whereas many advanced cryptographic systems described in the scientific literature establish classical individual verifiability and classical universal verifiability. If systems with a particular kind of verifiability continue to be used successfully in practice, this may influence the way in which people are involved in elections, and their image of democracy. Thus, the choice for a particular kind of verifiability in an experiment may have political consequences. We recommend making a well-informed democratic choice for the way in which both individual and universal verifiability should be realised in Internet voting, in order to avoid these unconscious political side-effects of the technology used. The safest choice in this respect, which maintains most properties of current elections, is classical individual verifiability combined with constructive universal verifiability. We would like to encourage discussion about the feasibility of this direction in scientific research.