CRiBAC: Community-centric role interaction based access control model

As one of the most efficient solutions to complex and large-scale problems, multi-agent cooperation has been in the limelight for the past few decades. Recently, many research projects have focused on context-aware cooperation to dynamically provide complex services. As cooperation in the multi-agent systems (MASs) becomes more common, guaranteeing the security of such cooperation takes on even greater importance. However, existing security models do not reflect the agents' unique features, including cooperation and context-awareness. In this paper, we propose a Community-based Role interaction-based Access Control model (CRiBAC) to allow secure cooperation in MASs. To do this, we refine and extend our preliminary RiBAC model, which was proposed earlier to support secure interactions among agents, by introducing a new concept of interaction permission, and then extend it to CRiBAC to support community-based cooperation among agents. We analyze potential problems related to interaction permissions and propose two approaches to address them. We also propose an administration model to facilitate administration of CRiBAC policies. Finally, we present the implementation of a prototype system based on a sample scenario to assess the proposed work and show its feasibility. © 2012 Elsevier Ltd. All rights reserved

HUC-HISF: A Hybrid Intelligent Security Framework for Human-centric Ubiquitous Computing

制度:新 ; 報告番号:乙2336号 ; 学位の種類:博士(人間科学) ; 授与年月日:2012/1/18 ; 早大学位記番号:新584

Context-Based Access for Infrequent Requests in Tanzania\u27s Health Care System

Access control is an important aspect of any information system. It is a way of ensuring that users can only access what they are authorised to and no more. This can be achieved by granting users access to resources based on pre-defined organisational and legislative rules. Although access control has been extensively studied, and as a result, a wide range of access control models, mechanisms and systems have been proposed, specific access control requirements for healthcare systems that needs to support the continuity of care in an accountable manner have not been addressed. This results in a gap between what is required by the application domain and what is actually practised, and thus access control solutions implemented for the domain become too restrictive. The continuity of care is defined as the delivery of seamless health care services to patients through integration, coordination and sharing of information between providers. This thesis, therefore, designs a context-based access control model that allows healthcare professionals to bypass access rules in an accountable manner in case of an infrequent access request involving an emergency situation. This research uses the Tanzania\u27s healthcare system as a case study domain

Estabelecimento de redes de comunidades sobreponíveis

Doutoramento em Engenharia InformáticaUma das áreas de investigação em Telecomunicações de interesse crescente prende-se com os futuros sistemas de comunicações móveis de 4a geração e além destes. Nos últimos anos tem sido desenvolvido o conceito de redes comunitárias, no qual os utilizadores se agregam de acordo com interesses comuns. Estes conceitos têm sido explorados de uma forma horizontal em diferentes camadas da comunicação, desde as redes comunitárias de comunicação (Seattle Wireless ou Personal Telco, p.ex.) até às redes de interesses peer-to-peer. No entanto, estas redes são usualmente vistas como redes de overlay, ou simplesmente redes de associação livre. Na prática, a noção de uma rede auto-organizada, completamente orientada ao serviço/comunidade, integralmente suportada em termos de arquitetura, não existe. Assim este trabalho apresenta uma realização original nesta área de criação de redes comunitárias, com uma arquitetura subjacente orientada a serviço, e que suporta integralmente múltiplas redes comunitárias no mesmo dispositivo, com todas as características de segurança, confiança e disponibilização de serviço necessárias neste tipo de cenários (um nó pode pertencer simultaneamente a mais do que uma rede comunitária). Devido à sua importância para os sistemas de redes comunitárias, foi dado particular atenção a aspetos de gestão de recursos e controlo de acessos. Ambos realizados de uma forma descentralizada e considerando mecanismos dotados de grande escalabilidade. Para isso, é apresentada uma linguagem de políticas que suporta a criação de comunidades virtuais. Esta linguagem não é apenas utilizada para o mapeamento da estrutura social dos membros da comunidade, como para, gerir dispositivos, recursos e serviços detidos pelos membros, de uma forma controlada e distribuída.One of the research areas with increasing interest in the field of telecommunications, are the ones related to future telecommunication systems, both 4th generation and beyond. In parallel, during the last years, several concepts have been developed related to clustering of users according to their interested, in the form of community networks. Solutions proposed for these concepts tackle the challenges horizontally, for each layer of the communication stack, ranging from community based communication networks (e.g. Seattle Wireless, or Personal Telco), to interest networks based on peer-to-peer protocols. However, these networks are presented either as free joining, or overlay networks. In practice, the notion of a self-organized, service and community oriented network, with these principles embedded in its design principles, is yet to be developed. This work presents an novel instantiation of a solution in the area of community networks, with a underlying architecture which is fully service oriented, and envisions the support for multiple community networks in the same device. Considerations regarding security, trust and service availability for this type of environments are also taken. Due to the importance of resource management and access control, in the context of community driven communication networks, a special focus was given to the support of scalable and decentralized management and access control methods. For this purpose, it is presented a policy language which supports the creation and management of virtual communities. The language is not only used for mapping the social structure of the community members, but also to, following a distributed approach, manage devices, resources and services owned by each community member

Steps towards adaptive situation and context-aware access: a contribution to the extension of access control mechanisms within pervasive information systems

L'évolution des systèmes pervasives a ouvert de nouveaux horizons aux systèmes d'information classiques qui ont intégré des nouvelles technologies et des services qui assurent la transparence d'accès aux resources d'information à n'importe quand, n'importe où et n'importe comment. En même temps, cette évolution a relevé des nouveaux défis à la sécurité de données et à la modélisation du contrôle d'accès. Afin de confronter ces challenges, differents travaux de recherche se sont dirigés vers l'extension des modèles de contrôles d'accès (en particulier le modèle RBAC) afin de prendre en compte la sensibilité au contexte dans le processus de prise de décision. Mais la liaison d'une décision d'accès aux contraintes contextuelles dynamiques d'un utilisateur mobile va non seulement ajouter plus de complexité au processus de prise de décision mais pourra aussi augmenter les possibilités de refus d'accès. Sachant que l'accessibilité est un élément clé dans les systèmes pervasifs et prenant en compte l'importance d'assurer l'accéssibilité en situations du temps réel, nombreux travaux de recherche ont proposé d'appliquer des mécanismes flexibles de contrôle d'accès avec des solutions parfois extrêmes qui depassent les frontières de sécurité telle que l'option de "Bris-de-Glace". Dans cette thèse, nous introduisons une solution modérée qui se positionne entre la rigidité des modèles de contrôle d'accès et la flexibilité qui expose des risques appliquées pendant des situations du temps réel. Notre contribution comprend deux volets : au niveau de conception, nous proposons PS-RBAC - un modèle RBAC sensible au contexte et à la situation. Le modèle réalise des attributions des permissions adaptatives et de solution de rechange à base de prise de décision basée sur la similarité face à une situation importanteÀ la phase d'exécution, nous introduisons PSQRS - un système de réécriture des requêtes sensible au contexte et à la situation et qui confronte les refus d'accès en reformulant la requête XACML de l'utilisateur et en lui proposant une liste des resources alternatives similaires qu'il peut accéder. L'objectif est de fournir un niveau de sécurité adaptative qui répond aux besoins de l'utilisateur tout en prenant en compte son rôle, ses contraintes contextuelles (localisation, réseau, dispositif, etc.) et sa situation. Notre proposition a été validé dans trois domaines d'application qui sont riches des contextes pervasifs et des scénarii du temps réel: (i) les Équipes Mobiles Gériatriques, (ii) les systèmes avioniques et (iii) les systèmes de vidéo surveillance.The evolution of pervasive computing has opened new horizons to classical information systems by integrating new technologies and services that enable seamless access to information sources at anytime, anyhow and anywhere. Meanwhile this evolution has opened new threats to information security and new challenges to access control modeling. In order to meet these challenges, many research works went towards extending traditional access control models (especially the RBAC model) in order to add context awareness within the decision-making process. Meanwhile, tying access decisions to the dynamic contextual constraints of mobile users would not only add more complexity to decision-making but could also increase the possibilities of access denial. Knowing that accessibility is a key feature for pervasive systems and taking into account the importance of providing access within real-time situations, many research works have proposed applying flexible access control mechanisms with sometimes extreme solutions that depass security boundaries such as the Break-Glass option. In this thesis, we introduce a moderate solution that stands between the rigidity of access control models and the riskful flexibility applied during real-time situations. Our contribution is twofold: on the design phase, we propose PS-RBAC - a Pervasive Situation-aware RBAC model that realizes adaptive permission assignments and alternative-based decision-making based on similarity when facing an important situation. On the implementation phase, we introduce PSQRS - a Pervasive Situation-aware Query Rewriting System architecture that confronts access denials by reformulating the user's XACML access request and proposing to him a list of alternative similar solutions that he can access. The objective is to provide a level of adaptive security that would meet the user needs while taking into consideration his role, contextual constraints (location, network, device, etc.) and his situation. Our proposal has been validated in three application domains that are rich in pervasive contexts and real-time scenarios: (i) Mobile Geriatric Teams, (ii) Avionic Systems and (iii) Video Surveillance Systems

Context-Aware and Adaptive Usage Control Model

Information protection is a key issue for the acceptance and adoption of pervasive computing systems where various portable devices such as smart phones, Personal Digital Assistants (PDAs) and laptop computers are being used to share information and to access digital resources via wireless connection to the Internet. Because these are resources constrained devices and highly mobile, changes in the environmental context or device context can affect the security of the system a great deal. A proper security mechanism must be put in place which is able to cope with changing environmental and system context. Usage CONtrol (UCON) model is the latest major enhancement of the traditional access control models which enables mutability of subject and object attributes, and continuity of control on usage of resources. In UCON, access permission decision is based on three factors: authorisations, obligations and conditions. While authorisations and obligations are requirements that must be fulfilled by the subject and the object, conditions are subject and object independent requirements that must be satisfied by the environment. As a consequence, access permission may be revoked (and the access stopped) as a result of changes in the environment regardless of whether the authorisations and obligations requirements are met. This constitutes a major shortcoming of the UCON model in pervasive computing systems which constantly strive to adapt to environmental changes so as to minimise disruptions to the user. We propose a Context-Aware and Adaptive Usage Control (CA-UCON) model which extends the traditional UCON model to enable adaptation to environmental changes in the aim of preserving continuity of access. Indeed, when the authorisation and obligations requirements are fulfilled by the subject and object, and the conditions requirements fail due to changes in the environmental or the system context, our proposed model CA-UCON triggers specific actions in order to adapt to the new situation, so as to ensure continuity of usage. We then propose an architecture of CA-UCON model, presenting its various components. In this model, we integrated the adaptation decision with usage decision architecture, the comprehensive definition of each components and reveals the functions performed by each components in the architecture are presented. We also propose a novel computational model of our CA-UCON architecture. This model is formally specified as a finite state machine. It demonstrates how the access request of the subject is handled in CA-UCON model, including detail with regards to revoking of access and actions undertaken due to context changes. The extension of the original UCON architecture can be understood from this model. The formal specification of the CA-UCON is presented utilising the Calculus of Context-aware Ambients (CCA). This mathematical notation is considered suitable for modelling mobile and context-aware systems and has been preferred over alternatives for the following reasons: (i) Mobility and Context awareness are primitive constructs in CCA; (ii) A system's properties can be formally analysed; (iii) Most importantly, CCA specifications are executable allowing early validation of system properties and accelerated development of prototypes. For evaluation of CA-UCON model, a real-world case study of a ubiquitous learning (u-learning) system is selected. We propose a CA-UCON model for the u-learning system. This model is then formalised in CCA and the resultant specification is executed and analysed using an execution environment of CCA. Finally, we investigate the enforcement approaches for CA-UCON model. We present the CA-UCON reference monitor architecture with its components. We then proceed to demonstrate three types of enforcement architectures of the CA-UCON model: centralised architecture, distributed architecture and hybrid architecture. These are discussed in detail, including the analysis of their merits and drawbacks

Smart object-oriented access control: Distributed access control for the Internet of Things

Ensuring that data and devices are secure is of critical importance to information technology. While access control has held a key role in traditional computer security, its role in the evolving Internet of Things is less clear. In particular, the access control literature has suggested that new challenges, such as multi-user controls, fine-grained controls, and dynamic controls, prompt a foundational re-thinking of access control. We analyse these challenges, finding instead that the main foundational challenge posed by the Internet of Things involves decentralization: accurately describing access control in Internet of Things environments (e.g., the Smart Home) requires a new model of multiple, independent access control systems. To address this challenge, we propose a meta-model (i.e., a model of models): Smart Object-Oriented Access Control (SOOAC). This model is an extension of the XACML framework, built from principles relating to modularity adapted from object-oriented programming and design. SOOAC draws attention to a new class of problem involving the resolution of policy conflicts that emerge from the interaction of smart devices in the home. Contrary to traditional (local) policy conflicts, these global policy conflicts emerge when contradictory policies exist across multiple access control systems. We give a running example of a global policy conflict involving transitive access. To automatically avoid global policy conflicts before they arise, we extend SOOAC with a recursive algorithm through which devices communicate access requests before allowing or denying access themselves. This algorithm ensures that both individual devices and the collective smart home are secure. We implement SOOAC within a prototype smart home and assess its validity in terms of effectiveness and efficiency. Our analysis shows that SOOAC is successful at avoiding policy conflicts before they emerge, in real time. Finally, we explore improvements that can be made to SOOAC and suggest directions for future work

User-controlled Identity Management Systems using mobile devices

Thousands of websites providing an array of diversified online services have been the crucial factor for popularising the Internet around the world during last 15 years. The current model of accessing the majority of those services requires users to register with a Service Provider - an administrative body that offers and provides online services. The registration procedure involves users providing a number of pieces of data about themselves which are then stored at the provider. This data provides a digital image of the user and is commonly known as the Identity of the user in that provider. To access different online services, users register at different providers and ultimately end up with a number of scattered identities which become increasingly difficult to manage. It is one of the major problems of the current setting of online services. What is even worse is that users have less control over the data stored in these providers and have no knowledge how their data is treated by providers. The concept of Identity Management has been introduced to help users facilitate the management of their identities in a user-friendly, secure and privacy-friendly way and thus, to tackle the stated problems. There exists a number of Identity Management models and systems, unfortunately, none of them has played a pivotal role in tackling the problems effectively and comprehensively. Simultaneously, we have experienced another trend expanding at a remarkable rate: the consumption and the usage of smart mobile devices. These mobile devices are not only growing in numbers but also in capability and capacity in terms of processing power and memory. Most are equipped with powerful hardware and highly-dynamic mobile operating systems offering touch-sensitive intuitive user-interfaces. In many ways, these mobile devices have become an integrated part of our day-to-day life and accompany us everywhere we go. The capability, portability and ubiquitous presence of such mobile devices lead to the core objective of this research: the investigation of how such mobile devices can be used to overcome the limitations of the current Identity Management Systems as well as to provide innovative online services. In short, this research investigates the need for a novel Identity Management System and the role the current generation of smart mobile devices can play in realising such a system. In this research it has been found that there exist different inconsistent notions of many central topics in Identity Management which are mostly defined in textual forms. To tackle this problem, a comprehensive mathematical model of Identity and Identity Management has been developed. The model has been used to analyse several phenomenons of Identity Management and to characterise different Identity Management models. Next, three popular Identity Management Systems have been compared using a taxonomy of requirements to identify the strength and weakness of each system. One of the major findings is that how different privacy requirements are satisfied in these systems is not standardised and depends on a specific implementation. Many systems even do not satisfy many of those requirements which can drastically affect the privacy of a user. To tackle the identified problems, the concept of a novel Identity Management System, called User-controlled Identity Management System, has been proposed. This system offers better privacy and allows users to exert more control over their data from a central location using a novel type of provider, called Portable Personal Identity Provider, hosted inside a smart mobile device of the user. It has been analysed how the proposed system can tackle the stated problems effectively and how it opens up new doors of opportunities for online services. In addition, it has been investigated how contextual information such as a location can be utilised to provide online services using the proposed provider. One problem in the existing Identity Management Systems is that providers cannot provide any contextual information such as the location of a user. Hosting a provider in a mobile device allows it to access different sensors of the device, retrieve contextual information from them and then to provide such information. A framework has been proposed to harness this capability in order to offer innovative services. Another major issue of the current Identity Management Systems is the lack of an effective mechanism to combine attributes from multiple providers. To overcome this problem, an architecture has been proposed and it has been discussed how this architecture can be utilised to offer innovative services. Furthermore, it has been analysed how the privacy of a user can be improved using the proposed provider while accessing such services. Realising these proposals require that several technical barriers are overcome. For each proposal, these barriers have been identified and addressed appropriately along with the respective proof of concept prototype implementation. These prototypes have been utilised to illustrate the applicability of the proposals using different use-cases. Furthermore, different functional, security and privacy requirements suitable for each proposal have been formulated and it has been analysed how the design choices and implementations have satisfied these requirements. Also, no discussion in Identity Management can be complete without analysing the underlying trust assumptions. Therefore, different trust issues have been explored in greater details throughout the thesis

A Risk And Trust Security Framework For The Pervasive Mobile Environment

A pervasive mobile computing environment is typically composed of multiple fixed and mobile entities that interact autonomously with each other with very little central control. Many of these interactions may occur between entities that have not interacted with each other previously. Conventional security models are inadequate for regulating access to data and services, especially when the identities of a dynamic and growing community of entities are not known in advance. In order to cope with this drawback, entities may rely on context data to make security and trust decisions. However, risk is introduced in this process due to the variability and uncertainty of context information. Moreover, by the time the decisions are made, the context data may have already changed and, in which case, the security decisions could become invalid.With this in mind, our goal is to develop mechanisms or models, to aid trust decision-making by an entity or agent (the truster), when the consequences of its decisions depend on context information from other agents (the trustees). To achieve this, in this dissertation, we have developed ContextTrust a framework to not only compute the risk associated with a context variable, but also to derive a trust measure for context data producing agents. To compute the context data risk, ContextTrust uses Monte Carlo based method to model the behavior of a context variable. Moreover, ContextTrust makes use of time series classifiers and other simple statistical measures to derive an entity trust value.We conducted empirical analyses to evaluate the performance of ContextTrust using two real life data sets. The evaluation results show that ContextTrust can be effective in helping entities render security decisions

Proceedings of the 2nd International Workshop on Security in Mobile Multiagent Systems

This report contains the Proceedings of the Second Workshop on Security on Security of Mobile Multiagent Systems (SEMAS2002). The Workshop was held in Montreal, Canada as a satellite event to the 5th International Conference on Autonomous Agents in 2001. The far reaching influence of the Internet has resulted in an increased interest in agent technologies, which are poised to play a key role in the implementation of successful Internet and WWW-based applications in the future. While there is still considerable hype concerning agent technologies, there is also an increasing awareness of the problems involved. In particular, that these applications will not be successful unless security issues can be adequately handled. Although there is a large body of work on cryptographic techniques that provide basic building-blocks to solve specific security problems, relatively little work has been done in investigating security in the multiagent system context. Related problems are secure communication between agents, implementation of trust models/authentication procedures or even reflections of agents on security mechanisms. The introduction of mobile software agents significantly increases the risks involved in Internet and WWW-based applications. For example, if we allow agents to enter our hosts or private networks, we must offer the agents a platform so that they can execute correctly but at the same time ensure that they will not have deleterious effects on our hosts or any other agents / processes in our network. If we send out mobile agents, we should also be able to provide guarantees about specific aspects of their behaviour, i.e., we are not only interested in whether the agents carry out-out their intended task correctly. They must defend themselves against attacks initiated by other agents, and survive in potentially malicious environments. Agent technologies can also be used to support network security. For example in the context of intrusion detection, intelligent guardian agents may be used to analyse the behaviour of agents on a firewall or intelligent monitoring agents can be used to analyse the behaviour of agents migrating through a network. Part of the inspiration for such multi-agent systems comes from primitive animal behaviour, such as that of guardian ants protecting their hill or from biological immune systems