Dynamic User Role Assignment in Remote Access Control

The Role-Based Access Control (RBAC) model has been widely applied to a single domain in which users are known to the administrative unit of that domain, beforehand. However, the application of the conventional RBAC model for remote access control scenarios is not straightforward. In such scenarios, the access requestor is outside of the provider domain and thus, the user population is heterogeneous and dynamic. Here, the main challenge is to automatically assign users to appropriate roles of the provider domain. Trust management has been proposed as a supporting technique to solve the problem of remote access control. The key idea is to establish a mutual trust between the requestor and provider based on credentials they exchange. However, a credential doesn't convey any information about the behavior of its holder during the time it is being used. Furthermore, in terms of privileges granted to the requestor, existing trust management systems are either too restrictive or not restrictive enough. In this paper, we propose a new dynamic user-role assignment approach for remote access control, where a stranger requests for access from a provider domain. Our approach has two advantages compared to the existing dynamic user-role assignment techniques. Firstly, it addresses the principle of least privilege without degrading the efficiency of the access control system. Secondly, it takes into account both credentials and the past behavior of the requestor in such a way that he cannot compensate for the lack of necessary credentials by having a good past behavior.