    @inproceedings {JavierLopez2004a,
	title = {On a Taxonomy of Systems for Authentication and/or Authorization Services},
	booktitle = {TERENA Networking Conference},
	year = {2004},
	month = {June},
	address = {Rhodes, Greece},
	abstract = {<p>In this work we elaborate on a taxonomy of systems that provide either joint solutions for both authentication and authorization problems, or solutions for only one of the problems. Basically, we do not focus our work on theoretical systems that have been proposed only in the literature. On the other hand, we focus on: (i) systems that are already developed; (ii) systems that are under development or deployment; and (iii) systems that are still in the initial stages of design but are supported by international working groups or bodies. More precisely, we elaborate on a taxonomy of systems that are (or will be soon) available to final users.</p>},
	author = {Javier Lopez and Jose A. Montenegro and Rolf Oppliger and Guenther Pernul}
}
