Darbe nagrinėjami šiuo metu rinkoje naudojami elektroninių atsiskaitymų modeliai ir jų saugumo problemos. Kadangi elektroninių transakcijų metu operuojama svarbiais ir konfidencialiais duomenimis, aukštesnio saugumo lygio užtikrinimo problema visada išlieka itin aktuali. Darbe išnagrinėtos dažniausiai sutinkamos elektroninių atsiskaitymų schemos (tiesioginis atsiskaitymas ir atsiskaitymas per Paypal sistemą), jų saugumo užtikrinimo principai, technikos ir spragos. Atsižvelgiant į dabartinius rinkos poreikius ir informacijos saugumo spragas šiuo metu naudojamuose modeliuose, suprojektuotas aukštesnio saugumo lygio elektroninių atsiskaitymų modelis ir realizuotas šio sprendimo prototipas. Šio prototipo projektas ir realizacija gali būti naudojamos kaip rekomendacijos kūrėjams, tobulinantiems elektroninių atsiskaitymų modelių saugumą. / The work deals with electronic payment models used in the market and their security problems. As electronic transactions operate with important and confidential data, ensuring higher level of security is always an actual issue. The study generally concerns the main electronic payment schemes (direct payment and payment through Paypal), their safety principles, technical decisions and security ensuring gaps. Considering the current market needs and information security gaps in current eCommerce models, a new, ensuring higher level of security in electronic payments, model was designed and a prototype of this decision was implemented. The prototype design and implementation may be used as recommendations for developers, improving electronic payment security models.

"Forschung meets Business" - diese Kombination hat in den vergangenen Jahren immer wieder zu zahlreichen interessanten und fruchtbaren Diskussionen geführt. Mit dem Symposium "Sicherheit in Service-orientierten Architekturen" führt das Hasso-Plattner-Institut diese Tradition fort und lud alle Interessenten zu einem zweitägigen Symposium nach Potsdam ein, um gemeinsam mit Fachvertretern aus der Forschung und Industrie über die aktuellen Entwicklungen im Bereich Sicherheit von SOA zu diskutieren. Die im Rahmen dieses Symposiums vorgestellten Beiträge fokussieren sich auf die Sicherheitsthemen "Sichere Digitale Identitäten und Identitätsmanagement", "Trust Management", "Modell-getriebene SOA-Sicherheit", "Datenschutz und Privatsphäre", "Sichere Enterprise SOA", und "Sichere IT-Infrastrukturen". / 'Research meets Business' is the successful concept of the SOA Security Symposia held at the Hasso-Plattner-Institute that has lead to interesting discussions in the community. The SOA Security Symposium 2010 continued this tradition and invited researchers and representatives from the industry to discuss concepts, issues, and solution in the field of SOA Security. The topics presented in the scope of this symposium focused on the security related topics 'Secure Digital Identities and Identity Management', 'Trust Management', 'Model-driven SOA Security', 'Privacy',' Secure Enterprise SOA', and 'Secure IT-Infrastructures'.

La mutualisation et l'externalisation de données concernent de nombreux domaines y compris celui de la santé. Au-delà de la réduction des coûts de maintenance, l'intérêt est d'améliorer la prise en charge des patients par le déploiement d'outils d'aide au diagnostic fondés sur la réutilisation des données. Dans un tel environnement, la sécurité des données (confidentialité, intégrité et traçabilité) est un enjeu majeur. C'est dans ce contexte que s'inscrivent ces travaux de thèse. Ils concernent en particulier la sécurisation des techniques de recherche d'images par le contenu (CBIR) et de « machine learning » qui sont au c'ur des systèmes d'aide au diagnostic. Ces techniques permettent de trouver des images semblables à une image requête non encore interprétée. L'objectif est de définir des approches capables d'exploiter des données externalisées et sécurisées, et de permettre à un « cloud » de fournir une aide au diagnostic. Plusieurs mécanismes permettent le traitement de données chiffrées, mais la plupart sont dépendants d'interactions entre différentes entités (l'utilisateur, le cloud voire un tiers de confiance) et doivent être combinés judicieusement de manière à ne pas laisser fuir d'information lors d'un traitement.Au cours de ces trois années de thèse, nous nous sommes dans un premier temps intéressés à la sécurisation à l'aide du chiffrement homomorphe, d'un système de CBIR externalisé sous la contrainte d'aucune interaction entre le fournisseur de service et l'utilisateur. Dans un second temps, nous avons développé une approche de « Machine Learning » sécurisée fondée sur le perceptron multicouches, dont la phase d'apprentissage peut être externalisée de manière sûre, l'enjeu étant d'assurer la convergence de cette dernière. L'ensemble des données et des paramètres du modèle sont chiffrés. Du fait que ces systèmes d'aides doivent exploiter des informations issues de plusieurs sources, chacune externalisant ses données chiffrées sous sa propre clef, nous nous sommes intéressés au problème du partage de données chiffrées. Un problème traité par les schémas de « Proxy Re-Encryption » (PRE). Dans ce contexte, nous avons proposé le premier schéma PRE qui permet à la fois le partage et le traitement des données chiffrées. Nous avons également travaillé sur un schéma de tatouage de données chiffrées pour tracer et vérifier l'intégrité des données dans cet environnement partagé. Le message tatoué dans le chiffré est accessible que l'image soit ou non chiffrée et offre plusieurs services de sécurité fondés sur le tatouage. / Cloud computing has emerged as a successful paradigm allowing individuals and companies to store and process large amounts of data without a need to purchase and maintain their own networks and computer systems. In healthcare for example, different initiatives aim at sharing medical images and Personal Health Records (PHR) in between health professionals or hospitals with the help of the cloud. In such an environment, data security (confidentiality, integrity and traceability) is a major issue. In this context that these thesis works, it concerns in particular the securing of Content Based Image Retrieval (CBIR) techniques and machine learning (ML) which are at the heart of diagnostic decision support systems. These techniques make it possible to find similar images to an image not yet interpreted. The goal is to define approaches that can exploit secure externalized data and enable a cloud to provide a diagnostic support. Several mechanisms allow the processing of encrypted data, but most are dependent on interactions between different entities (the user, the cloud or a trusted third party) and must be combined judiciously so as to not leak information. During these three years of thesis, we initially focused on securing an outsourced CBIR system under the constraint of no interaction between the users and the service provider (cloud). In a second step, we have developed a secure machine learning approach based on multilayer perceptron (MLP), whose learning phase can be outsourced in a secure way, the challenge being to ensure the convergence of the MLP. All the data and parameters of the model are encrypted using homomorphic encryption. Because these systems need to use information from multiple sources, each of which outsources its encrypted data under its own key, we are interested in the problem of sharing encrypted data. A problem known by the "Proxy Re-Encryption" (PRE) schemes. In this context, we have proposed the first PRE scheme that allows both the sharing and the processing of encrypted data. We also worked on watermarking scheme over encrypted data in order to trace and verify the integrity of data in this shared environment. The embedded message is accessible whether or not the image is encrypted and provides several services.

När barn börjar i förskolan kan det innebära en stor omställning där barnen får möjligheter till att skapa nya relationer. Relationerna som utvecklas i förskolan kommer att ligga till grund för barns välbefinnande. Syftet med studien är att undersöka och bidra med kunskaper om hur pedagoger arbetar för att stödja trygga relationer/anknytning till barn i åldern 1–3 år, samt hur pedagoger svarar på barns behov av trygghet i utforskandet under leksituationer. Två kvalitativa metoder tillämpades; strukturerade icke-deltagande observationer, samt semistrukturerade intervjuer. Anknytningsteorin tillämpades genom en tematisk analysmetod. Resultatet i studien visade att pedagogernas strategier var grundläggande för hur trygga relationer ska utvecklas till barnen. Pedagogerna tillämpade och berättade att den viktigaste strategin var lyhördhet, närvaro och anpassningsbarhet för att möta barnens kontaktsökande. Vår slutsats är att pedagogernas relationsarbete visade sig ha betydelse för barns välmående och för barns lek. Förskollärarna synliggör anknytningens olika aspekter som beskrivs vara grundläggande i hur barns relationer utvecklas, alla barns relationer ser olika ut och utvecklas på olika sätt. Vidare tar även förskollärarna upp hur viktigt det är att relationsskapandet ska ske på barns villkor för att en trygg relation ska vara möjlig. / When children start preschool, it involves a big adjustment where the children get opportunities to create new relationships. The relationships that develop in preschool will form the basis of the child's development and their well-being. The purpose of the study is to examine and contribute knowledge about how preschool teachers work to promote safe relationships with children in the age of 1–3 years old, as well as how preschool teachers respond to children's needs for security in the exploration during free play. Two qualitative methods were applied: structured non-participatory observations, as well as semi-structured interviews. The attachment theory was applied through a thematic analysis method. The results of the present study showed that the preschool teachers strategies were fundamental of how secure relationships should develop to the children. The preschool teachers applied and said that the most important strategy was sensitivity, presence, and adaptable preschool teachers to meet the children's contact-seeking. Our conclusion is that the preschool teachers relationship work proved to be important for children's well-being and for children's play. The preschool teachers describe the various aspects of attachment that are fundamental in how children's relationships develop. All children's relationships look different and develop in different ways. The preschool teachers want to highlight that the relationship must take place on the child's terms in order so a secure relationship can be possible.

This study investigates the possible use of GNSS synchronized PTP grandmasters as a general method for synchronizing IP audio equipment. Two relatively low cost GNSS synchronized PTP grandmaster clocks were built and tested in various real world scenarios. Low latency audio streams were sent over internet between GNSS synchronized audio devices via the protocol SRT, Secure Reliable Transport, and the result was compared to using the commercially available service Jamkazam. It was found that the solution with distributed GNSS synchronized IP audio devices worked well over both LAN and WAN, but the specific SRT solution tested was not suited for really low latency usage like NMP, Networked Music Performance. Further studies are needed to find alternate SRT solutions or other protocols for use when very low latency performance is needed. It was also found that the lowest latency possible was not the most desirable latency when used for monitoring mixes in an NMP context. A latency of 15-20 ms was generally the most preferred, indicating monitor mixes for IEM, In Ear Monitoring, might benefit from introducing delays in the signal chain. More studies are needed to investigate this further.

This thesis is about assessments of young people in secure accommodations. Institutional assessments relate to the paradox in child welfare of combining control and care. The procedure raises questions about their implications for young people, their caseworkers and evolving care trajectories. Although institutional assessments of young people have a historical heritage, research about their implications is lacking. The aim of the thesis is to explore young people’s and their caseworkers’ experiences of assessments in secure accommodations and their implications for young people’s care trajectories. Methods used are primarily repeated interviews with 16 young people during a period of two years and one interview with their caseworkers. Surveys about 85 youths, participatory observations and written assessments are also included. This thesis takes an interactionist approach and the material has been analysed with the main concept of care trajectory along with the concepts of self-presentation, total institution, institutional identity and texts as coordinators. The results are presented in four papers. The concluding analysis shows that assessments in secure accommodations can be divided into three elements: the practice, the text and the placement. These three elements have different implications for the young people and the caseworkers. For the young people the practice and the placement converge into an assessment universe that, with the text, intensifies their shaping of self-identity. The young people’s experiences are characterised by lack of control over their self-presentations, the present and the future. For the caseworkers, the practice has implications for their understanding of the young people’s individual troubles, the text for negotiating with other actors and the placement in their efforts to achieve change in the young people’s troublesome situations. The assessments’ implications for stability and foreseeability in the young people’s further care trajectories are limited. Moreover, the procedure of assessing young people in itself contains instability through involving several professionals in different parts of the assessment and decision-making process. Despite lack of stability, the thesis reveals that some young people experience the assessment as a place for self-development and where the course of the care trajectory changes to the better.

Secure multi-party computation (secure MPC) has been established as the de facto paradigm for protecting privacy in distributed computation. One of the earliest secure MPC primitives is the Shamir's secret sharing (SSS) scheme. SSS has many advantages over other popular secure MPC primitives like garbled circuits (GC) -- it provides information-theoretic security guarantee, requires no complex long-integer operations, and often leads to more efficient protocols. Nonetheless, SSS receives less attention in the signal processing community because SSS requires a larger number of honest participants, making it prone to collusion attacks. In this dissertation, I propose an agent-based computing framework using SSS to protect privacy in distributed signal processing. There are three main contributions to this dissertation. First, the proposed computing framework is shown to be significantly more efficient than GC. Second, a novel game-theoretical framework is proposed to analyze different types of collusion attacks. Third, using the proposed game-theoretical framework, specific mechanism designs are developed to deter collusion attacks in a fully distributed manner. Specifically, for a collusion attack with known detectors, I analyze it as games between secret owners and show that the attack can be effectively deterred by an explicit retaliation mechanism. For a general attack without detectors, I expand the scope of the game to include the computing agents and provide deterrence through deceptive collusion requests. The correctness and privacy of the protocols are proved under a covert adversarial model. Our experimental results demonstrate the efficiency of SSS-based protocols and the validity of our mechanism design.

This thesis is about assessments of young people in secure accommodations. Institutional assessments relate to the paradox in child welfare of combining control and care. The procedure raises questions about their implications for young people, their caseworkers and evolving care trajectories. Although institutional assessments of young people have a historical heritage, research about their implications is lacking. The aim of the thesis is to explore young people’s and their caseworkers’ experiences of assessments in secure accommodations and their implications for young people’s care trajectories. Methods used are primarily repeated interviews with 16 young people during a period of two years and one interview with their caseworkers. Surveys about 85 youths, participatory observations and written assessments are also included. This thesis takes an interactionist approach and the material has been analysed with the main concept of care trajectory along with the concepts of self-presentation, total institution, institutional identity and texts as coordinators. The results are presented in four papers. The concluding analysis shows that assessments in secure accommodations can be divided into three elements: the practice, the text and the placement. These three elements have different implications for the young people and the caseworkers. For the young people the practice and the placement converge into an assessment universe that, with the text, intensifies their shaping of self-identity. The young people’s experiences are characterised by lack of control over their self-presentations, the present and the future. For the caseworkers, the practice has implications for their understanding of the young people’s individual troubles, the text for negotiating with other actors and the placement in their efforts to achieve change in the young people’s troublesome situations. The assessments’ implications for stability and foreseeability in the young people’s further care trajectories are limited. Moreover, the procedure of assessing young people in itself contains instability through involving several professionals in different parts of the assessment and decision-making process. Despite lack of stability, the thesis reveals that some young people experience the assessment as a place for self-development and where the course of the care trajectory changes to the better.

No description available.

This paper describes four tools for verification security protocols Athena, Casper, Isabelle and Murphi. Each tool is briefly characterized and implementation of protocol Needham Schroeder. One part of this paper is comparing of selected tools. The second part of this paper describes in detail a tool Athena and mentions examples of verified protocols. By each protocol is stated a specifications of communication, a detected attack and results of own verification. At the end compares this paper verification results with already publicated attacks.