Managing UCONabc policies in modern distributed computing systems is a challenge for traditional approaches. The provisioning model has trouble to keep track and to synchronize large numbers of distributed policies, outsourcing model may suffer from network overhead and single point of failure. This paper describes an approach to manage distributed UCONabc policies, derived from the combination of authorization assertions and policy templates. It combines the benefits of provisioning and outsourcing, eliminating their respective drawbacks. Prototyping details and performance evaluation are shown, messages are 42.7% smaller than provisioning and response times are faster than outsourcing.

The business-driven access control used in cloud computing is not well suited for tracking fine-grained user service consumption. UCONABCapplies continuous authorization reevaluation, which requires usage accounting that enables fine-grained access control for cloud computing. However, it was not designed to work in distributed and dynamic authorization environments like those present in cloud computing. During a continuous (periodical) reevaluation, an authorization exception condition, disparity among usage accounting and authorization attributes may occur. This proposal aims to provide resilience to the UCONABCcontinuous authorization reevaluation, by dealing with individual exception conditions while maintaining a suitable access control in the cloud environment. The experiments made with a proof-of-concept prototype show a set of measurements for an application scenario (e-commerce) and allows for the identification of exception conditions in the authorization reevaluation.

The dynamic environment of business coalition (BC) requires a flexible access control approach to deal with user management and policy writing. However, the traditional approach applied to BC assigns to access control a burden, mainly to the service provider, thus requiring ad hoc schemes to mitigate the lack of controls developed to BC needs. We present a brokered access control architecture, based on UCONABC, to obtain an integrated usage control management for BC. The broker intermediates contract establishment between service provider and consumer, and derives from it the policies to regulate the usage at service-level. The consumer defines user-level policies to control the usage of the contracted services. We developed a Web services based prototype to evaluate the feasibility of our proposal. The proposed architecture enables distribution of duties and integration of usage control management in a loosely coupled fashion, providing the flexibility desired in BC environments.

The decentralization of corporate policy administration aiming to maintain the unified management of user permissions is a hard task. The heterogeneity and complexity of corporate environments burdens the security administrator with writing equally complex policies. This paper proposes an architecture based on Web Services, policy provisioning, and authorization certificates, to build up a loosely coupled unified administrative control for corporate environments. A certificate-based permission management scheme is used to derive new policies in the local domains of each branch. These new policies will update the corporate repository which, in turn, will configure the corresponding policies in the local domains of each branch. The Web Services technology provides the underlying protocols for the development of a prototype which shows the feasibility of our proposal.