R. Shirey. <a href="http://www.ietf.org/rfc/rfc4949.txt"><cite>Internet Security Glossary, Version 2.</cite></a>. IETF RFC 4949. August 2007. URL: <a href="http://www.faqs.org/rfcs/rfc4949.html">http://www.faqs.org/rfcs/rfc4949.html</a>