Guenter Schaefer, Professor, Technische Universität Ilmenau, Germany. After obtaining his Ph.D. degree (1998) he worked at Ecole Nationale Supérieure des Télécommunications, Paris, France (1999 - 2000). Between 2000 and 2005, he was researcher at Technische Universitaet Berlin, Germany where he was leading the network security laboratory. Since 2005 he is at his current post leading the Telematics/Computer Networks research group. His research interests lie in the areas of network security, networking protocols, mobile communications, and innovative communication services/architectures, and he regularly gives courses on network security, networking subjects and basics of computer science. Michael Rossberg, PostDoc Researcher, Technische Universität Ilmenau, Germany. In 2011 he obtained his Ph.D. in computer science with a thesis on peer-to-peer-based auto-configuration of large scale IPsec VPNs. His research interests lie in network security and performance evaluation/optimization. In 2010, Michael Rossberg and Guenter Schaefer were jointly awarded with the third prize of the German IT Security Award for their work on automatic configuration of large scale VPNs. Translated by Herbert Eppel at HE Translations, Leicester, UK (https://HETranslations.uk) DISCLAIMER: By including the link to this site, this does not mean the site is endorsed by Wiley