Technology pole of Greater Florianópolis Competitive companies are one of the bases of a nation’s economic development. Among the proven success strategies in this field are Scientific and Technology Parks, whose mission is to promote intelligence that expands corporate competitiveness. In this context, Florianópolis stands out in Brazil for its development based on the promotion of innovation....

Many initiatives exist that integrate e-health systems on a large scale. One of the main technical challenges is access control, although several frameworks and solutions, like XACML, are becoming standard practice. Data is no longer shared within one affinity domain but becomes ubiquitous, which results in a loss of control. As patients will be less willing to participate without additional co...

Today, when organizations perform access control over their resources they are not only interested in the user’s identity, but in other data such as user’s attributes or contextual information. These requirements can be found, for example, in a network access control scenario where end users pay for a specific access level and depending on it, they can get different network quality of service. ...

MD. Surgeon in the Head and Neck Group, Instituto Alfa de Gastroenterologia (IAG), Hospital das Clínicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil. PhD. Surgeon in the Head and Neck Group, Instituto Alfa de Gastroenterologia (IAG), Hospital das Clínicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil. MD. Resident in He...

In this paper we describe our approach to a policy management system and a policy enforcement point which is integrated into the Globus Toolkit middleware. Our system enables the specification and modification of resource policies by administrative parties through a graphical user interface and the secure association with and transport of these policies to the policy decision components.

In order to collaborate large numbers of heterogeneous distributed devices over multiple domains within a modern large-scale device collaboration system, a fine-grained, flexible and secure approach is required for device authentication and authorization. This paper proposed a Multiple-Policy supported Attribute-Based Access Control model and its architecture to address these demands. With eXte...

Many languages and algebras have been proposed in recent years for the specification of authorization policies. For some proposals, such as XACML, the main motivation is to address real-world requirements, typically by providing a complex policy language with somewhat informal evaluation methods; others try to provide a greater degree of formality – particularly with respect to policy evaluatio...

We explore the implications of supporting bags (i.e. multisets) in a data model and associated query language, and present some formal results concerned with the algebraic properties of bags. We extend previous work to provide a formal basis for query optimization and for defining the appropriate semantics for bag operations in data models supporting ba.gs.

In collaborative environments where resources must be shared across multiple sites, the access control policies of the participants must be combined in order to define a coherent policy. The relevant challenge in composing access policies is to deal with inconsistencies or modality conflicts. This difficulty exacerbates when the policies to compose are specified independently by different entit...