922 resultados para secure protocal
Resumo:
Those living with an acquired brain injury often have issues with fatigue due to factors resulting from the injury. Cognitive impairments such as lack of memory, concentration and planning have a great impact on an individual’s ability to carry out general everyday tasks, which subsequently has the effect of inducing cognitive fatigue. Moreover, there is difficulty in assessing cognitive fatigue, as there are no real biological markers that can be measured. Rather, it is a very subjective effect that can only be diagnosed by the individual. Consequently, the traditional way of assessing cognitive fatigue is to use a self-assessment questionnaire that is able to determine contributing factors. State of the art methods to evaluate cognitive! fa tigue employ cognitive tests in order to analyse performance on predefined tasks. However, one primary issue with such tests is that they are typically carried out in a clinical environment, therefore do not have the ability to be utilized in situ within everyday life. This paper presents a smartphone application for the evaluation of fatigue, which can be used daily to track cognitive performance in order to assess the influence of fatigue.
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Although the impact of multiple adverse events in childhood is well known, it is equally accepted that the variation in individual trajectories and outcomes is significant. Resilience focuses on positive adaption in the face of adversity, offering a counterbalance to deficit-based research and risk averse, procedurally driven practice. Positive relationships and secure attachments are widely considered to be the cornerstone of resilience, yet, within social work practice, there is a tendency to consider attachment only in relation to children and adults. Three biographical narratives are used to explore resilience and attachment through a narrative identity framework, exploring parents' experiences of multiple adversities over their lifespan, their close relationships, and their experiences of child welfare interventions. It argues for the importance of narrative in social work assessment, particularly in relation to families with complex needs, illustrating how this enables a richer, more nuanced understanding of mothers and fathers as individuals in their own right, and provides insight into how alternative narratives might be better supported and developed.
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Homomorphic encryption offers potential for secure cloud computing. However due to the complexity of homomorphic encryption schemes, performance of implemented schemes to date have been unpractical. This work investigates the use of hardware, specifically Field Programmable Gate Array (FPGA) technology, for implementing the building blocks involved in somewhat and fully homomorphic encryption schemes in order to assess the practicality of such schemes. We concentrate on the selection of a suitable multiplication algorithm and hardware architecture for large integer multiplication, one of the main bottlenecks in many homomorphic encryption schemes. We focus on the encryption step of an integer-based fully homomorphic encryption (FHE) scheme. We target the DSP48E1 slices available on Xilinx Virtex 7 FPGAs to ascertain whether the large integer multiplier within the encryption step of a FHE scheme could fit on a single FPGA device. We find that, for toy size parameters for the FHE encryption step, the large integer multiplier fits comfortably within the DSP48E1 slices, greatly improving the practicality of the encryption step compared to a software implementation. As multiplication is an important operation in other FHE schemes, a hardware implementation using this multiplier could also be used to improve performance of these schemes.
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We present two physical layer secure transmission schemes for multi-user multi-relay networks, where the communication from M users to the base station is assisted by direct links and by N decode-and-forward relays. In this network, we consider that a passive eavesdropper exists to overhear the transmitted information, which entails exploiting the advantages of both direct and relay links for physical layer security enhancement. To fulfill this requirement, we investigate two criteria for user and relay selection and examine the achievable secrecy performance. Criterion I performs a joint user and relay selection, while Criterion II performs separate user and relay selections, with a lower implementation complexity. We derive a tight lower bound on the secrecy outage probability for Criterion I and an accurate analytical expression for the secrecy outage probability for Criterion II. We further derive the asymptotic secrecy outage probabilities at high transmit signal-to-noise ratios and high main-to-eavesdropper ratios for both criteria. We demonstrate that the secrecy diversity order is min (MN, M + N) for Criterion I, and N for Criterion II. Finally, we present numerical and simulation results to validate the proposed analysis, and show the occurrence condition of the secrecy outage probability floor
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Organizing and managing channels of distribution is an important marketing task. Due to the emergence of electronic commerce on the Internet, e-channel distribution systems have been adopted by many manufacturers. However, academic and anecdotal evidence both point to the pressures arising from this new e-channel manufacturing environment. Questions marks therefore remain on how the addition of this e-channel affects the traditional marketing strategies of leasing and selling. We set up several two-period dual-channel models in which a manufacturer sells a durable product through both a manufacturer-owned e-channel and an independent reseller (leaser) who adopts selling (leasing) to consumers. Our main results indicate that, direct selling cost aside, product durability plays an important role in shaping the strategies of all members. With either marketing strategy, the additional expansion of an e-channel territory may secure Pareto gains, in which all members benefit.
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The notion of educating the public through generic healthy eating messages has pervaded dietary health promotion efforts over the years and continues to do so through various media, despite little evidence for any enduring impact upon eating behaviour. There is growing evidence, however, that tailored interventions such as those that could be delivered online can be effective in bringing about healthy dietary behaviour change. The present paper brings together evidence from qualitative and quantitative studies that have considered the public perspective of genomics, nutrigenomics and personalised nutrition, including those conducted as part of the EU-funded Food4Me project. Such studies have consistently indicated that although the public hold positive views about nutrigenomics and personalised nutrition, they have reservations about the service providers' ability to ensure the secure handling of health data. Technological innovation has driven the concept of personalised nutrition forward and now a further technological leap is required to ensure the privacy of online service delivery systems and to protect data gathered in the process of designing personalised nutrition therapies.
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With the rapid development of internet-of-things (IoT), face scrambling has been proposed for privacy protection during IoT-targeted image/video distribution. Consequently in these IoT applications, biometric verification needs to be carried out in the scrambled domain, presenting significant challenges in face recognition. Since face models become chaotic signals after scrambling/encryption, a typical solution is to utilize traditional data-driven face recognition algorithms. While chaotic pattern recognition is still a challenging task, in this paper we propose a new ensemble approach – Many-Kernel Random Discriminant Analysis (MK-RDA) to discover discriminative patterns from chaotic signals. We also incorporate a salience-aware strategy into the proposed ensemble method to handle chaotic facial patterns in the scrambled domain, where random selections of features are made on semantic components via salience modelling. In our experiments, the proposed MK-RDA was tested rigorously on three human face datasets: the ORL face dataset, the PIE face dataset and the PUBFIG wild face dataset. The experimental results successfully demonstrate that the proposed scheme can effectively handle chaotic signals and significantly improve the recognition accuracy, making our method a promising candidate for secure biometric verification in emerging IoT applications.
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Rapid and affordable tumor molecular profiling has led to an explosion of clinical and genomic data poised to enhance the diagnosis, prognostication and treatment of cancer. A critical point has now been reached at which the analysis and storage of annotated clinical and genomic information in unconnected silos will stall the advancement of precision cancer care. Information systems must be harmonized to overcome the multiple technical and logistical barriers to data sharing. Against this backdrop, the Global Alliance for Genomic Health (GA4GH) was established in 2013 to create a common framework that enables responsible, voluntary and secure sharing of clinical and genomic data. This Perspective from the GA4GH Clinical Working Group Cancer Task Team highlights the data-aggregation challenges faced by the field, suggests potential collaborative solutions and describes how GA4GH can catalyze a harmonized data-sharing culture.
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Cryptographic algorithms have been designed to be computationally secure, however it has been shown that when they are implemented in hardware, that these devices leak side channel information that can be used to mount an attack that recovers the secret encryption key. In this paper an overlapping window power spectral density (PSD) side channel attack, targeting an FPGA device running the Advanced Encryption Standard is proposed. This improves upon previous research into PSD attacks by reducing the amount of pre-processing (effort) required. It is shown that the proposed overlapping window method requires less processing effort than that of using a sliding window approach, whilst overcoming the issues of sampling boundaries. The method is shown to be effective for both aligned and misaligned data sets and is therefore recommended as an improved approach in comparison with existing time domain based correlation attacks.
Resumo:
This paper presents a new encryption scheme implemented at the physical layer of wireless networks employing orthogonal frequency-division multiplexing (OFDM). The new scheme obfuscates the subcarriers by randomly reserving several subcarriers for dummy data and resequences the training symbol by a new secure sequence. Subcarrier obfuscation renders the OFDM transmission more secure and random, while training symbol resequencing protects the entire physical layer packet, but does not affect the normal functions of synchronization and channel estimation of legitimate users while preventing eavesdroppers from performing these functions. The security analysis shows the system is robust to various attacks by analyzing the search space using an exhaustive key search. Our scheme is shown to have a better performance in terms of search space, key rate and complexity in comparison with other OFDM physical layer encryption schemes. The scheme offers options for users to customize the security level and key rate according to the hardware resource. Its low complexity nature also makes the scheme suitable for resource limited devices. Details of practical design considerations are highlighted by applying the approach to an IEEE 802.11 OFDM system case study.
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Pine wilt disease (PWD) is perhaps the most serious threat to pine forests worldwide. Since it´s discovery in the early XXth century by Japanese forest researchers, and the relationship with its causative agent, the pinewood nematode (PWN) Bursaphelenchus xylophilus, in the 1970s, PWD has wreaked havoc wherever it appears. Firstly in the Far East (Japan, China and Korea) and now, more recently in 1999, in the EU (Portugal). The forest sector in Portugal plays a major role in the Portuguese economy with a 12% contribution to the industrial gross domestic product, 3.2% of the gross domestic product, 10% of foreign trade and 5% of national employment. Maritime pine (Pinus pinaster) is one of the most important pine productions, and industrial activity, such as the production of wood and resin, as well as coastal protection associated with sand dunes. Also, stone pine (Pinus pinea) plays an important role in the economy with a share derived from the exports of high-quality pineon seed. Thus, the tremendous economical and ecological impact of the introduction of a pest and pathogen such as the PWN, although as far as is known, the only species susceptible to the nematode is maritime pine. Immediately following detection, the research team involved (Univ. Évora, INIAP) informed the national plant quarantine and forest authorities, which relayed the information to Brussels and the appropriate EU authorities. A task force (GANP), followed by a national program (PROLUNP) was established. Since then, national surveys have been taking place, involving MADRP (Ministry of Agriculture), the University of Évora and several private corporations (e.g. UNAC). Forest growers in the area are particularly interested and involved since the area owned by the growers organizations totals 700 000 ha, largely affected by PWD. Detection of the disease has led to serious consequences and restrictions regarding exploration and commercialization of wood. A precautionary phytosanitary strip, 3 km-wide, has been recently (2007) established surrounding the affected area. The Portuguese government, through its national program PROLUNP, has been deeply involved since 1999, and in conjunction with the EU (Permanent Phytosanitary Committee, and FVO) and committed to controlling this nematode and the potential spread to the rest of the country and to the rest of the EU. The global impact of the presence of Bursaphelenchus xylophilus or the threat of its introduction and the resulting pine wilt disease in forested areas in different parts of the world is of increasing concern economically. The concern is exacerbated by the prevailing debate on climate change and the putative impact this could have on the vulnerability of the world’s pine forests to this disease. The scientific and regulatory approach taken in different jurisdictions to the threat of pine wilt disease varies from country to country depending on the perceived vulnerability of their pine forests to the disease and/or to the economic cost due to lost trade in wood products. Much of the research surrounding pine wilt disease has been located in the northern hemisphere, especially in southern Europe and in the warmer, coastal, Asian countries. However, there is an increased focus on this problem also in those countries in the southern hemisphere where plantations of susceptible pine have been established over the years. The forestry sector in Australia and New Zealand are on “high alert” for this disease and are practicing strict quarantine procedures at all ports of entry for wood products. As well, there is heightened awareness, as there is worldwide, for the need to monitor wood packaging materials for all imported goods. In carrying out the necessary monitoring and assessment of products for B. xylophilus and its vectors substantial costs are incurred especially when decisions have to be made rapidly and regardless of whether the outcome is positive or negative. Australia’s response recently to the appearance of some dying pines in a plantation illustrated the high sensitivity of some countries to this disease. Some $200,000 was spent on the assessment in order to save a potential loss of millions of dollars to the disease. This rapid, co-ordinated response to the report was for naught, because once identified it was found not to be B. xylophilus. This illustrates the particular importance of taking the responsibility at all levels of management to secure the site and the need of a rapid, reliable diagnostic method for small nematode samples for use in the field. Australia is particularly concerned about the vulnerability of its 1million hectares of planted forests, 80% of which are Pinus species, to attack from incursions of one or more species of the insect vector. Monochamus alternatus incursions in wood pallets have been reported from Brisbane, Queensland. The climate of this part of Australia is such that the Pinus plantations are particularly vulnerable to the potential outcome of such incursions, and the state of Queensland is developing a risk management strategy and a proactive breeding programme in response to this putative threat. New Zealand has 1.6 million hectares of planted forests and 89% of the commercial forest is Pinus radiata. Although the climate where these forests are located tends to be somewhat cooler than that in Australia the potential for establishment and development of the disease in that country is believed to be high. The passage alone of 200,000 m³/year of wood packaging through New Zealand ports is itself sufficient to require response. The potential incursion of insect vectors of pinewood nematode through the port system is regarded as high and is monitored carefully. The enormous expansion of global trade and the continued use of unprocessed/inadequately-processed wood for packaging purposes is a challenge for all trading nations as such wood packaging material often harbours disease or pest species. The extent of this problem is readily illustrated by the expanding economies and exports of countries in south-east Asia. China. Japan and Korea have significant areas of forestland infested with B. xylophilus. These countries too are among the largest exporting countries of manufactured goods. Despite the attempts of authorities to ensure that only properly treated wood is used in the crating and packaging of goods B. xylophilus and/or its insect vector infested materials is being recorded at ports worldwide. This reminds us, therefore, of the ease with which this nematode pest can gain access to forest lands in new geographic locations through inappropriate use, treatment or monitoring of wood products. It especially highlights the necessity to find an alternative to using low-grade lumber for packaging purposes. Lest we should believe that all wood products are always carriers of B. xylophilus and its vectors, it should be remembered that international trade of all kinds has occurred for thousands of years and that lumber-born pests and diseases do not have worldwide distribution. Other physico-biological factors have a significant role in the occurrence, establishment and sustainability of a disease. The question is often raised as to why the whole of southern Europe doesn’t already have B. xylophilus and pine wilt disease. European countries have traded with countries that are infested with B. xylophilus for hundreds of years. Turkey is an example of a country that appears to be highly vulnerable to pine wilt disease due to its extensive forests in the warm, southern region where the vector, Monochamus galloprovincialis, occurs. However, there is no record of the presence of B. xylophilus occurring there despite the importation of substantial quantities of wood from several countries In many respects, Portugal illustrates both the challenge and the dilemma. In recent times B. xylophilus was discovered there in the warm coastal region. The research, administrative and quarantine authorities responded rapidly and B. xylophilus appears to have been confined to the region in which it was found. The rapid response would seem to have “saved the day” for Portugal. Nevertheless, it raises again the long-standing questions, how long had B. xylophilus been in Portugal before it was found? If Lisbon was the port of entry, which seems very likely, why had B. xylophilus not entered Lisbon many years earlier and established populations and the pine wilt disease? Will the infestation in Portugal be sustainable and will it spread or will it die out within a few years? We still do not have sufficient understanding of the biology of this pest to know the answers to these questions.
Resumo:
A temática da violência (e do bullying) nas escolas em Portugal tem vindo, nos anos mais recentes, a assumir uma crescente visibilidade fruto de variados fatores, entre os quais podemos destacar o aparente aumento no número de incidentes reportados envolvendo alunos, professores e pessoal não docente ou, ainda, como resultado da maior atenção dispensada ao(s) fenómeno(s) pela comunicação social. Na relação que se estabelece entre alunos, o bullying (e ultimamente o cyberbullying) tem igualmente ocupado um maior espaço de discussão no contexto português pela elevada complexidade que o carateriza e pelas diversas consequências negativas e irreversíveis que acarreta para vítimas, agressores, famílias e escolas. Para que sejam encontradas estratégias e soluções eficazes na abordagem ao(s) fenómeno(s), torna-se necessário aprofundar – e partilhar – o(s) conhecimento(s) em torno dos fatores e das dinâmicas que caraterizam o fenómeno e que contribuem para a sua (re)ocorrência. Procurámos, portanto, refletir sobre o papel que a escola, enquanto organização com uma missão muito própria ‒ e todos os demais elementos que a integram (diretores, docentes, assistentes operacionais, alunos e respetivas famílias) ‒ devem efetivamente desempenhar no sentido de serem promovidas e implementadas políticas e medidas que possam acautelar e solucionar quaisquer manifestações de violência, com especial incidência nos episódios de bullying. Sobressai, em primeira instância, a necessidade de sensibilizar e de mobilizar toda a comunidade escolar, prestando especial atenção ao papel vital que cada sujeito desempenha. Destaque-se, por outro lado, a aposta que deve ser feita na vertente da (in)formação de professores, não docentes, alunos e pais com o claro propósito de serem criados climas de escola positivos e seguros. Dividimos o trabalho empírico da nossa investigação em dois momentos. Do estudo comparativo (resultante da recolha de informação baseada na pesquisa e análise documental) que levámos a cabo na primeira parte a um conjunto de doze programas de prevenção e de intervenção de bullying implementados (e igualmente avaliados) em países anglo-saxónicos, procurámos identificar os seus componentes fundamentais (princípios teóricos subjacentes às intervenções, objetivos pretendidos, destinatários, níveis/fases de ação, componentes/estratégias de atuação e materiais de apoio disponibilizados). Pudemos verificar que essas iniciativas assentaram numa perspetiva sistémica da problemática do bullying que sublinha a necessidade de mudanças persistentes e contibuadas ao nível da sensibilização, da consciencialização e de transformações nas atitudes da população escolar no seu todo. Este exercício possibilitou, por outro lado, a identificação e a assimiliação de algumas das boas práticas experimentadas com esses programas. Na segunda parte, desenvolvemos um projeto-piloto numa escola Secundária com o 3.º Ciclo do Ensino Básico ao longo do ano letivo de 2010/2011 (envolvendo diretamente na iniciativa duas turmas ‒ uma do 7.º e outra do 10.º ano ‒ e os respetivos professores), sendo de destacar que a temática se tornou mais familiar para a maior parte dos participantes (por via da mobilização, da sensibilização e da formação desses atores). Na sequência da aplicação de dois questionários a 190 alunos no âmbito do projeto-piloto, foi ainda possível apurar que as percentagens de vitimação de bullying presencial moderado se situam abaixo dos 10%, sendo que para as ofensas sofridas de modo mais intenso esses níveis não ultrapassam os 5% para qualquer uma das formas de agressão apresentadas. Os dados indicaram igualmente as ofensas diretas verbais e indiretas como sendo as mais frequentes entre os inquiridos, surgindo em terceiro lugar as de pendor direto físico. Os índices de vitimação apresentam valores superiores junto dos alunos mais novos, independentemente do seu género. Perto de 45% dos sujeitos objeto de agressão admitiu não ter reportado o sucedido a uma terceira pessoa. Cerca de 27% dos jovens confessou assumir uma atitude passiva ou de indiferença perante uma agressão testemunhada. Foi, por outro lado, possível constatar que um conjunto significativo de jovens admitiu conhecer um colega da escola que tenha sido já gozado ou ameaçado no ciberespaço.
Resumo:
As tecnologias de informação e comunicação na área da saúde não são só um instrumento para a boa gestão de informação, mas antes um fator estratégico para uma prestação de cuidados mais eficiente e segura. As tecnologias de informação são um pilar para que os sistemas de saúde evoluam em direção a um modelo centrado no cidadão, no qual um conjunto abrangente de informação do doente deve estar automaticamente disponível para as equipas que lhe prestam cuidados, independentemente de onde foi gerada (local geográfico ou sistema). Este tipo de utilização segura e agregada da informação clínica é posta em causa pela fragmentação generalizada das implementações de sistemas de informação em saúde. Várias aproximações têm sido propostas para colmatar as limitações decorrentes das chamadas “ilhas de informação” na saúde, desde a centralização total (um sistema único), à utilização de redes descentralizadas de troca de mensagens clínicas. Neste trabalho, propomos a utilização de uma camada de unificação baseada em serviços, através da federação de fontes de informação heterogéneas. Este agregador de informação clínica fornece a base necessária para desenvolver aplicações com uma lógica regional, que demostrámos com a implementação de um sistema de registo de saúde eletrónico virtual. Ao contrário dos métodos baseados em mensagens clínicas ponto-a-ponto, populares na integração de sistemas em saúde, desenvolvemos um middleware segundo os padrões de arquitetura J2EE, no qual a informação federada é expressa como um modelo de objetos, acessível através de interfaces de programação. A arquitetura proposta foi instanciada na Rede Telemática de Saúde, uma plataforma instalada na região de Aveiro que liga oito instituições parceiras (dois hospitais e seis centros de saúde), cobrindo ~350.000 cidadãos, utilizada por ~350 profissionais registados e que permite acesso a mais de 19.000.000 de episódios. Para além da plataforma colaborativa regional para a saúde (RTSys), introduzimos uma segunda linha de investigação, procurando fazer a ponte entre as redes para a prestação de cuidados e as redes para a computação científica. Neste segundo cenário, propomos a utilização dos modelos de computação Grid para viabilizar a utilização e integração massiva de informação biomédica. A arquitetura proposta (não implementada) permite o acesso a infraestruturas de e-Ciência existentes para criar repositórios de informação clínica para aplicações em saúde.
Resumo:
The promise of a truly mobile experience is to have the freedom to roam around anywhere and not be bound to a single location. However, the energy required to keep mobile devices connected to the network over extended periods of time quickly dissipates. In fact, energy is a critical resource in the design of wireless networks since wireless devices are usually powered by batteries. Furthermore, multi-standard mobile devices are allowing users to enjoy higher data rates with ubiquitous connectivity. However, the bene ts gained from multiple interfaces come at a cost in terms of energy consumption having profound e ect on the mobile battery lifetime and standby time. This concern is rea rmed by the fact that battery lifetime is one of the top reasons why consumers are deterred from using advanced multimedia services on their mobile on a frequent basis. In order to secure market penetration for next generation services energy e ciency needs to be placed at the forefront of system design. However, despite recent e orts, energy compliant features in legacy technologies are still in its infancy, and new disruptive architectures coupled with interdisciplinary design approaches are required in order to not only promote the energy gain within a single protocol layer, but to enhance the energy gain from a holistic perspective. A promising approach is cooperative smart systems, that in addition to exploiting context information, are entities that are able to form a coalition and cooperate in order to achieve a common goal. Migrating from this baseline, this thesis investigates how these technology paradigm can be applied towards reducing the energy consumption in mobile networks. In addition, we introduce an additional energy saving dimension by adopting an interlayer design so that protocol layers are designed to work in synergy with the host system, rather than independently, for harnessing energy. In this work, we exploit context information, cooperation and inter-layer design for developing new energy e cient and technology agnostic building blocks for mobile networks. These technology enablers include energy e cient node discovery and short-range cooperation for energy saving in mobile handsets, complemented by energy-aware smart scheduling for promoting energy saving on the network side. Analytical and simulations results were obtained, and veri ed in the lab on a real hardware testbed. Results have shown that up to 50% energy saving could be obtained.
Resumo:
Building secure systems is difficult for many reasons. This paper deals with two of the main challenges: (i) the lack of security expertise in development teams, and (ii) the inadequacy of existing methodologies to support developers who are not security experts. The security standard ISO 14508 (Common Criteria) together with secure design techniques such as UMLsec can provide the security expertise, knowledge, and guidelines that are needed. However, security expertise and guidelines are not stated explicitly in the Common Criteria. They are rather phrased in security domain terminology and difficult to understand for developers. This means that some general security and secure design expertise are required to fully take advantage of the Common Criteria and UMLsec. In addition, there is the problem of tracing security requirements and objectives into solution design,which is needed for proof of requirements fulfilment. This paper describes a security requirements engineering methodology called SecReq. SecReq combines three techniques: the Common Criteria, the heuristic requirements editorHeRA, andUMLsec. SecReqmakes systematic use of the security engineering knowledge contained in the Common Criteria and UMLsec, as well as security-related heuristics in the HeRA tool. The integrated SecReq method supports early detection of security-related issues (HeRA), their systematic refinement guided by the Common Criteria, and the ability to trace security requirements into UML design models. A feedback loop helps reusing experiencewithin SecReq and turns the approach into an iterative process for the secure system life-cycle, also in the presence of system evolution.