We introduce Delegation Logic (DL), a logic-based knowledge representation (i.e., language) that deals with authorization in large-scale, open, distributed systems. Of central importance in any system for deciding whether requests should be authorized in such a system are delegation of authority, negation of authority, and con icts between authorities. DL's approach to these issues and to the i...

We experimentally investigate delegation and communication as two alternative means of coordinations among individuals with misaligned interests. We implement in the laboratory two delegation-communication games in which a principal chooses whether to delegate her decision-making authority to an informed agent or to make the decision herself after a cheap-talk communication with the agent. In t...

Access control is a fundamental and essential mechanism to maintain security in ubiquitous computing (UbiComp). Flexibility is an important property for general access control system, which can be achieved by access or authority delegation. Existing delegation mechanisms are "subject-centered", thus in order to make sure that the unavailability of some users does not prevent the syste...

e-Government organisations are facilitated and conducted using workflow management systems. Role-based access control (RBAC) is recognised as an efficient access control model for large organisations. The application of RBAC in workflow systems cannot, however, grant permissions to users dynamically while business processes are being executed. We currently observe a move away from predefined st...

Three perspectives on delegation in the European Union are presented in this article. The transactioncosts perspective focuses on information asymmetries between policy makers and implementers. According to the commitment perspective, policy makers delegate authority as a solution to commitment problems. The consensus-building perspective views the decision to delegate as a trade-off between de...

This paper describes the concept of a delegation issuing service (DIS), which is a service that issues X.509 attribute certificates on behalf of an attribute authority (typically a manager). The paper defines the X.509 certificate extensions that are being proposed for the 2005 edition of X.509 in order to implement the DIS concept, as well as the additional steps that a relying party will need...

This comparative case study assesses the effects of an empowered staff management model on staff perceptions of the delegation of authority, opportunities to participate in decision making, supervisory relations, supervisory relations, prison management, job satisfaction and burnout. Indices of staff work environment were created by factor analysis of responses of 149 staff to organizational cl...

In this paper we describe how we have added support for dynamic delegation of authority that is enacted via the issuing of credentials from one user to another, to the XACML model for authorisation decision making. Initially we present the problems and requirements that such a model demands, considering that multiple domains will typically be involved. We then describe our architected solution ...