A SEMANTIC BASED POLICY MANAGEMENT FRAMEWORK FOR CLOUD COMPUTING ENVIRONMENTS

Cloud computing paradigm has gained tremendous momentum and generated intensive interest. Although security issues are delaying its fast adoption, cloud computing is an unstoppable force and we need to provide security mechanisms to ensure its secure adoption. In this dissertation, we mainly focus on issues related to policy management and access control in the cloud. Currently, users have to use diverse access control mechanisms to protect their data when stored on the cloud service providers (CSPs). Access control policies may be specified in different policy languages and heterogeneity of access policies pose significant problems.An ideal policy management system should be able to work with all data regardless of where they are stored. Semantic Web technologies when used for policy management, can help address the crucial issues of interoperability of heterogeneous CSPs. In this dissertation, we propose a semantic based policy management framework for cloud computing environments which consists of two main components, namely policy management and specification component and policy evolution component. In the policy management and specification component, we first introduce policy management as a service (PMaaS), a cloud based policy management framework that give cloud users a unified control point for specifying authorization policies, regardless of where the data is stored. Then, we present semantic based policy management framework which enables users to specify access control policies using semantic web technologies and helps address heterogeneity issues of cloud computing environments. We also model temporal constraints and restrictions in GTRBAC using OWL and show how ontologies can be used to specify temporal constraints. We present a proof of concept implementation of the proposed framework and provide some performance evaluation. In the policy evolution component, we propose to use role mining techniques to deal with policy evolution issues and present StateMiner, a heuristic algorithm to find an RBAC state as close as possible to both the deployed RBAC state and the optimal state. We also implement the proposed algorithm and perform some experiments to demonstrate its effectiveness

Application of Risk Metrics for Role Mining

Incorporating risk consideration in access control systems has recently become a popular research topic. Related to this is risk awareness which is needed to enable access control in an agile and dynamic way. While risk awareness is probably known for an established access control system, being aware of risk even before the access control system is defined can mean identification of users and permissions that are most likely to lead to dangerous or error-prone situations from an administration point of view. Having this information available during the role engineering phase allows data analysts and role engineers to highlight potentially risky users and permissions likely to be misused. While there has been much recent work on role mining, there has been little consideration of risk during the process. In this thesis, we propose to add risk awareness to role mining. We aggregate the various possible risk factors and categorize them into four general types, which we refer to as risk metrics, in the context of role mining. Next, we propose a framework that incorporates some specific examples of each of these risk metrics before and after role mining. We have implemented a proof-of-concept prototype, a Risk Awareness system for Role Mining (aRARM) based on this framework and applied it to two case studies: a small organizational project and a university database setting. The aRARM prototype is automatically able to detect different types of risk factors when we add different types of noise to this data. The results from the two case studies draw some correlation between the behavior of the different risk factors due to different types and amounts of noise. We also discuss the effect of the different types and amounts of noise on the different role mining algorithms implemented for this study. While the detection rating value for calculating the risk priority number has previously been calculated after role mining, we attempt to find an initial estimate of the detection rating before role mining

A Novel Access Control Model Based on the Structure of Applications

Nowadays, access control has an important role in the management of access to resources in the networks and applications. The establishment of access control in applications is important particularly. Traditional methods of access control, manage the users’ access only at data-centric level. In this paper a new model is presented in which the access control in applications is performed not only at data-centric level but also at component and plug-in levels. By applying the proposed model, the execution of plug-ins or components will be authorized only in the case of enrollment process and in the necessary authorities. In addition, users can access to plug-ins and components only in the case of gaining the necessary authorities. By using the proposed model, the access control can be applied based on both operational needs and applications capabilities accurately

An Access Control Model for NoSQL Databases

Current development platforms are web scale, unlike recent platforms which were just network scale. There has been a rapid evolution in computing paradigm that has created the need for data storage as agile and scalable as the applications they support. Relational databases with their joins and locks influence performance in web scale systems negatively. Thus, various types of non-relational databases have emerged in recent years, commonly referred to as NoSQL databases. To fulfill the gaps created by their relational counter-part, they trade consistency and security for performance and scalability. With NoSQL databases being adopted by an increasing number of organizations, the provision of security for them has become a growing concern. This research presents a context based abstract model by extending traditional role based access control for access control in NoSQL databases. The said model evaluates and executes security policies which contain versatile access conditions against the dynamic nature of data. The goal is to devise a mechanism for a forward looking, assertive yet flexible security feature to regulate access to data in the database system that is devoid of rigid structures and consistency, namely a document based database such as MongoDB

Role recommender-RBAC: Optimizing user-role assignments in RBAC

In a rapidly changing IT environment, access to the resources involved in various projects might change randomly based on the role-based access control (RBAC) system. Hence, the security administrator needs to dynamically maintain the role assignments to users for optimizing user-role assignments. The manual updation of user-role assignments is prone to error and increases administrative workload. Therefore, a role recommendation model is introduced for the RBAC system to optimize user-role assignments based on user behaviour patterns. It is shown that the model automatically revokes and refurbishes the user-role assignments by observing user access behaviour. This model is used in the cloud for providing Role-Assignment-as-a-Service to optimize the cost of built-in roles. Several experiments are conducted to verify the proposed model using the Amazon access sample dataset. The experimental results show that the efficiency of the proposed model is 50% higher than the state-of-the-art

Identity Management and Authorization Infrastructure in Secure Mobile Access to Electronic Health Records

We live in an age of the mobile paradigm of anytime/anywhere access, as the mobile device is the most ubiquitous device that people now hold. Due to their portability, availability, easy of use, communication, access and sharing of information within various domains and areas of our daily lives, the acceptance and adoption of these devices is still growing. However, due to their potential and raising numbers, mobile devices are a growing target for attackers and, like other technologies, mobile applications are still vulnerable. Health information systems are composed with tools and software to collect, manage, analyze and process medical information (such as electronic health records and personal health records). Therefore, such systems can empower the performance and maintenance of health services, promoting availability, readability, accessibility and data sharing of vital information about a patients overall medical history, between geographic fragmented health services. Quick access to information presents a great importance in the health sector, as it accelerates work processes, resulting in better time utilization. Additionally, it may increase the quality of care. However health information systems store and manage highly sensitive data, which raises serious concerns regarding patients privacy and safety, and may explain the still increasing number of malicious incidents reports within the health domain. Data related to health information systems are highly sensitive and subject to severe legal and regulatory restrictions, that aim to protect the individual rights and privacy of patients. Along side with these legislations, security requirements must be analyzed and measures implemented. Within the necessary security requirements to access health data, secure authentication, identity management and access control are essential to provide adequate means to protect data from unauthorized accesses. However, besides the use of simple authentication models, traditional access control models are commonly based on predefined access policies and roles, and are inflexible. This results in uniform access control decisions through people, different type of devices, environments and situational conditions, and across enterprises, location and time. Although already existent models allow to ensure the needs of the health care systems, they still lack components for dynamicity and privacy protection, which leads to not have desire levels of security and to the patient not to have a full and easy control of his privacy. Within this master thesis, after a deep research and review of the stat of art, was published a novel dynamic access control model, Socio-Technical Risk-Adaptable Access Control modEl (SoTRAACE), which can model the inherent differences and security requirements that are present in this thesis. To do this, SoTRAACE aggregates attributes from various domains to help performing a risk assessment at the moment of the request. The assessment of the risk factors identified in this work is based in a Delphi Study. A set of security experts from various domains were selected, to classify the impact in the risk assessment of each attribute that SoTRAACE aggregates. SoTRAACE was integrated in an architecture with requirements well-founded, and based in the best recommendations and standards (OWASP, NIST 800-53, NIST 800-57), as well based in deep review of the state-of-art. The architecture is further targeted with the essential security analysis and the threat model. As proof of concept, the proposed access control model was implemented within the user-centric architecture, with two mobile prototypes for several types of accesses by patients and healthcare professionals, as well the web servers that handles the access requests, authentication and identity management. The proof of concept shows that the model works as expected, with transparency, assuring privacy and data control to the user without impact for user experience and interaction. It is clear that the model can be extended to other industry domains, and new levels of risks or attributes can be added because it is modular. The architecture also works as expected, assuring secure authentication with multifactor, and secure data share/access based in SoTRAACE decisions. The communication channel that SoTRAACE uses was also protected with a digital certificate. At last, the architecture was tested within different Android versions, tested with static and dynamic analysis and with tests with security tools. Future work includes the integration of health data standards and evaluating the proposed system by collecting users’ opinion after releasing the system to real world.Hoje em dia vivemos em um paradigma móvel de acesso em qualquer lugar/hora, sendo que os dispositivos móveis são a tecnologia mais presente no dia a dia da sociedade. Devido à sua portabilidade, disponibilidade, fácil manuseamento, poder de comunicação, acesso e partilha de informação referentes a várias áreas e domínios das nossas vidas, a aceitação e integração destes dispositivos é cada vez maior. No entanto, devido ao seu potencial e aumento do número de utilizadores, os dispositivos móveis são cada vez mais alvos de ataques, e tal como outras tecnologias, aplicações móveis continuam a ser vulneráveis. Sistemas de informação de saúde são compostos por ferramentas e softwares que permitem recolher, administrar, analisar e processar informação médica (tais como documentos de saúde eletrónicos). Portanto, tais sistemas podem potencializar a performance e a manutenção dos serviços de saúde, promovendo assim a disponibilidade, acessibilidade e a partilha de dados vitais referentes ao registro médico geral dos pacientes, entre serviços e instituições que estão geograficamente fragmentadas. O rápido acesso a informações médicas apresenta uma grande importância para o setor da saúde, dado que acelera os processos de trabalho, resultando assim numa melhor eficiência na utilização do tempo e recursos. Consequentemente haverá uma melhor qualidade de tratamento. Porém os sistemas de informação de saúde armazenam e manuseiam dados bastantes sensíveis, o que levanta sérias preocupações referentes à privacidade e segurança do paciente. Assim se explica o aumento de incidentes maliciosos dentro do domínio da saúde. Os dados de saúde são altamente sensíveis e são sujeitos a severas leis e restrições regulamentares, que pretendem assegurar a proteção dos direitos e privacidade dos pacientes, salvaguardando os seus dados de saúde. Juntamente com estas legislações, requerimentos de segurança devem ser analisados e medidas implementadas. Dentro dos requerimentos necessários para aceder aos dados de saúde, uma autenticação segura, gestão de identidade e controlos de acesso são essenciais para fornecer meios adequados para a proteção de dados contra acessos não autorizados. No entanto, além do uso de modelos simples de autenticação, os modelos tradicionais de controlo de acesso são normalmente baseados em políticas de acesso e cargos pré-definidos, e são inflexíveis. Isto resulta em decisões de controlo de acesso uniformes para diferentes pessoas, tipos de dispositivo, ambientes e condições situacionais, empresas, localizações e diferentes alturas no tempo. Apesar dos modelos existentes permitirem assegurar algumas necessidades dos sistemas de saúde, ainda há escassez de componentes para accesso dinâmico e proteção de privacidade , o que resultam em níveis de segurança não satisfatórios e em o paciente não ter controlo directo e total sobre a sua privacidade e documentos de saúde. Dentro desta tese de mestrado, depois da investigação e revisão intensiva do estado da arte, foi publicado um modelo inovador de controlo de acesso, chamado SoTRAACE, que molda as diferenças de acesso inerentes e requerimentos de segurança presentes nesta tese. Para isto, o SoTRAACE agrega atributos de vários ambientes e domínios que ajudam a executar uma avaliação de riscos, no momento em que os dados são requisitados. A avaliação dos fatores de risco identificados neste trabalho são baseados num estudo de Delphi. Um conjunto de peritos de segurança de vários domínios industriais foram selecionados, para classificar o impacto de cada atributo que o SoTRAACE agrega. O SoTRAACE foi integrado numa arquitectura para acesso a dados médicos, com requerimentos bem fundados, baseados nas melhores normas e recomendações (OWASP, NIST 800-53, NIST 800-57), e em revisões intensivas do estado da arte. Esta arquitectura é posteriormente alvo de uma análise de segurança e modelos de ataque. Como prova deste conceito, o modelo de controlo de acesso proposto é implementado juntamente com uma arquitetura focada no utilizador, com dois protótipos para aplicações móveis, que providênciam vários tipos de acesso de pacientes e profissionais de saúde. A arquitetura é constituída também por servidores web que tratam da gestão de dados, controlo de acesso e autenticação e gestão de identidade. O resultado final mostra que o modelo funciona como esperado, com transparência, assegurando a privacidade e o controlo de dados para o utilizador, sem ter impacto na sua interação e experiência. Consequentemente este modelo pode-se extender para outros setores industriais, e novos níveis de risco ou atributos podem ser adicionados a este mesmo, por ser modular. A arquitetura também funciona como esperado, assegurando uma autenticação segura com multi-fator, acesso e partilha de dados segura baseado em decisões do SoTRAACE. O canal de comunicação que o SoTRAACE usa foi também protegido com um certificado digital. A arquitectura foi testada em diferentes versões de Android, e foi alvo de análise estática, dinâmica e testes com ferramentas de segurança. Para trabalho futuro está planeado a integração de normas de dados de saúde e a avaliação do sistema proposto, através da recolha de opiniões de utilizadores no mundo real

BYOD NETWORK: Enhancing Security through Trust–Aided Access Control Mechanisms

The growth of mobile devices both in variety and in computational abilities have given birth to a concept in the corporate world known as Bring Your Own Device (BYOD). Under this concept, Employees are allowed to bring personally owned mobile devices for official work. Though relatively new, it has gained up to 53% patronage among organisations, and it is expected to hit 88% in the near future. Its popularity is driven by significant advantages ranging from reduced cost, employee satisfaction to improved productivity. However, the concept also introduces new security challenges; for instance, the organisation looses the ownership of devices used for official work, to the employees. Implying that the employees own and manage the devices they use to work, including seeing to the security needs of such devices. With this development, protecting the corporate network becomes pertinent and even more challenging with an audacious need for outwittingconventional access control mechanisms, giving the highly dynamic nature of mobile devices. Considering the fact that BYOD is also a type of pervasive/dynamic environment, this work studies similar dynamic environments, relating to how their security challenges are addressed, and from such bases a Trust-Aided Dynamic Access Control Approach is proposed for enhancing the security of BYOD devices. Through computational analysis, this scheme has been seen to be security-compliant and could significantly improving the overall security of BYOD networks