Guest editorial

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Owner-Based Role-Based Access Control OB-RBAC

Administration of an access control model deals with the question of who is authorized to update policies defined on the basis of that model. One of the models whose administration has absorbed relatively large research is the Role-Based Access Control (RBAC) model. All the existing role-based administrative models fall into the category of administrator based decentralized approach. In such an approach, a group of administrators are given firstly, the authority of updating authorizations for operative roles and secondly, the authority of delegating the previous right to other lower-level administrators. However, in organizations with informal and flexible structure, like academic and research-oriented organizations such a sharp distinction between administrative roles and operative roles might not exist. Here, each role may take part in both operative and administrative decisions such that more mission-oriented decisions are made by senior roles and more specialized-level decisions are made by junior roles. In this paper, we study a new class of access control model called Owner-Based Role-Based Access Control (OB-RBAC) which is suitable for such environments. The OB-RBAC model utilizes the advantages of both Discretionary Access Control (DAC)and RBAC. In particular, the OB-RBAC model builds a policy model which not only fulfills the organizational restrictions but enjoys the flexible administration of the DAC model

Managing authorisations

The problem of authorisation, delegation, and authorisation management in distributed systems has been studied at SICS for the last two years. Our main focus has been the development of delegation logic which is based on th eidea of delegation as the explicit yet constrained creation of new privileges

Contractual access control

In this position paper we discuss the issue of enforcing access policies in distributed environments where there is no central system designer/administrator, and consequently no guarantee that policies will be properly implemented by all components of the system. We argue that existing access control models, which are based on the concepts of permission and prohibition, need to be extended with the concept of entitlement. Entitlement to access a resource means not only that the access is permitted but also that the controller of the resource is obliged to grant the access when it is requested. An obligation to grant the access however does not guarantee that it will be granted: agents are capable of violating their obligations. In the proposed approach we discuss a Community Regulation Server that not only reasons about access permissions and obligations, but also updates the normative state of a community according to the contractual performance of its interacting agents

Decentralised privilege management for access control

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Decentraliserad rättighetshantering

With the development of modern computer networks, a new advanced channel for communication emerges. The future Swedish defence will use multiple systems connected with high-speed networks for information sharing. Within this environment, the issue of administration of authorisation is crucial. SaabTech Systems and SICS have in collaboration developed a model and a prototype for decentralised administration of authorisations. The model is based on delegation of authorisations extended with a component to define constraints on delegations. This enables efficient decentralised administration that reflects the management structure of an organization in a natural way, at the same time as it maintains centralised control on the distribution of authorisations. All authorisations must fulfil constraints defined by their sources of authority. The source of authority may, for instance, define in advance how a certain authorisation can be distributed and used, in terms of whom and when it can be delegated. The model supports several schemes for revocation of authorization

Revocation in the privilege calculus

We have previously presented a framework for updating privileges and creating management structures by means of authority certificates. These are used both to create access-level permissions and to delegate authority to other agents. In this paper we extend the framework to support a richer set of revocation schemes. As in the original, we present an associated calculus of privileges, encoded as a logic program, for reasoning about certificates, revocations, and the privileges they create and destroy. The discussion of revocation schemes follows an existing classification in the literature based on three separate dimensions: resilience, propagation, and dominance. The first does not apply to this framework. The second is specified straightforwardly. The third can be encoded but raises a number offurther questions for future investigation