  In the field of access control, delegation is an important aspect that is
considered as a part of the administration mechanism. Thus, a complete access
control must provide a flexible administration model to manage delegation.
Unfortunately, to our best knowledge, there is no complete model for describing
all delegation requirements for role-based access control. Therefore, proposed
models are often extended to consider new delegation characteristics, which is
a complex task to manage and necessitate the redefinition of these models. In
this paper we describe a new delegation approach for extended role-based access
control models. We show that our approach is flexible and is sufficient to
manage all delegation requirements.
