Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with the Invariant Sections being the chapters Chapter 13 ("Contributions") and the Colophon ("About this document"), with Front-Cover Texts being the text "The Open-source PKI Book, A guide to PKIs and Open-source Implementations" and with Back-Cover Texts being the text "The author's studies are funded by State's Scholarship Foundation (SSF) of Greece". A copy of the license is included in Appendix E entitled "GNU Free Documentation License".