Abstract:
Nowadays, there is growing need to share information from various database
systems inside an organization or across an organization. A federated database system
was proposed to support this need. The database system was composed of two levels, a
local level and a federation level. The database system at the federation level
integrates and shares information from various database systems at the local level.
Currently, federated database systems still have some difficulties and problems in
managing heterogeneous access control policies from different local database systems.
This thesis studied and designed an access control model, which supports such
heterogeneity management for federated database systems.
The thesis proposes federated role-based access control models (FRBAC) by
extending the existing capabilities of traditional role-based access control models
(RBAC). It argues that RBAC is more efficient and flexible for managing
heterogeneity and changes in access control polices in a federated database system
than other traditional access control models like MAC and DAC. In our models, the
access controls are separated into a local access control level and a federated access
control level. In the local access control level, it was composed of a local access
control policy and a public access control policy. The public access control policy was
proposed to support autonomy for a local administrator in defining the policy to
control access from the federation. For access control at the federation level, it had the
federated access control policy. This access control policy integrates and interoperates
public access control policies from various local database systems.
Furthermore, using the FRBAC methodology to build the access control
policy, check the authorization, and control the changes among access control policies
is proposed. Moreover, FRBAC reference models with formal definitions and
functions are provided. For proof of the concept’s effectiveness, a case study in
applying FRBAC models to a federated healthcare system is demonstrated.