Tine Verhanneman

Uniform application-level access control enforcement of organizationwide policies

Fine-grained and expressive access control policies on application resources need to be enforced in application-level code. Uniformly enforcing a single policy (referred to as the organizationwide policy) in diverse applications is challenging with current technologies. This is due to a poor delimitation of the responsibilities of application deployer and security officer, which hampers a centralized management of a policy and therefore compromises the uniformity of its enforcement. To address this problem, the concept of an access interface is introduced as a contract between an organization-wide authorization engine and the various applications that need its services. The access interface provides support for the central management of the policy by the security officer. By means of a view connector, the application deployer ensures that each application complies with this contract, so that the policy can be enforced

Requirements traceability to support evolution of access control

One of the hurdles in the enforcement of access control remains the translation of the organizations high level policy, that drives the access control decisions, down to technology specific deployment descriptors, configuration files and code. This huge gap between the high level policy and the access logic has as a consequence that it is hard to trace implementation fragments to the actual requirement they contribute to, and to support evolution. The notion of an access interface is introduced as a contract between the authorization engine and the various applications using its services. A so-called view connector makes sure that the application behaves consistently with this contract. The implementation is based on aspect orientation, rendering the whole design more robust in the light of unanticipated changes.

Adaptable Access Control Policies for Medical Information Systems

IT enforced access control policies in medical information systems have to be fine-grained and dynamic. We justify this observation on the basis of legislation and on the basis of the evolution within the healthcare domain. Consequently, a reconfigurable or at least adaptable implementation of access control facilities has become extremely important. For this purpose, current technology provides insufficient support. We highlight a basic solution to address shortcomings by using interception techniques. In addition, we identify further research that is required to address the challenges of dynamic and fine-grained access control in the long run.

A Modular Access Control Service for Supporting Application-Specific Policies

Aspect-oriented software development techniques can help modularize the enforcement of application-specific access control policies. Middleware platforms must cater to a variety of applications. The access control services integrated in these platforms support only access control policies with limited expressiveness and typically enforce only an invocation access policy. Enforcing such a policy only takes into account information in the method invocation and fails to include application state or context in the access decision process

Implementing a modular access control service to support application-specific policies in CaesarJ

Ideally, the enforcement of application-specific policies in an access control service should be untangled from the application logic. The access control services that are provided in state-of-the-art application servers typically fail to support such a separation. Aspect-Oriented Software Development techniques can be used to alleviate such shortcomings. This paper describes the design and implementation of a modular access control service that improves the separation between application logic and access control. The prototype has been implemented in CaesarJ.