Christos Triantaphyllidis worked from 2001 to 2004 at the Computer Center of the Department of Physics at the University of Thessaloniki. Since 2004 he works at the Grid Operations Center at the Aristotle University of Thessaloniki as a subcontractor in research projects, such as EGEE, SEE-GRID, EUChinaGrid and HellasGrid. His main focus is in the area of security with particular emphasis on security policies and the management of the national Certification Authority (HellasGrid CA). He has extensive experience on the administration of distributed computing systems, emphasizing on the design and implementation of tools for large scale deployment and administration. Since 2006 he has been representing the HellasGrid CA at the European body EUGridPMA.