name: Carlos Serr�o email: url: privateEmail: tag: updated: The author is a professor at ISCTE, a Portuguese public University specilized in Management and Computer Science, teaching subjects like IT Management and E-Commerce. The author is also IT Research and Development Consultant at ADETTI, a portuguese R&D institution, where he is specialized in information security, colaborating in several European Community IT projects: OKAPI, OCTALIS and OCCAM.