Mr. Housley is the Founder of Vigil Security, LLC, and he is coauthor of “Planning for PKI” and “Implementing Email and Security Tokens” published by John Wiley & Sons. He has over 25 years of communications and computer security experience. For four years, he served as the Security Area Director for the Internet Engineering Task Force (IETF), and he is presently serving as Chair of the IETF. His expertise is in security protocols, system engineering, system security architectures, and product definition. He is the author of the Cryptographic Message Syntax (CMS), the security foundation for S/MIME. He is one of the authors of the Internet X.509 Certificate Profile (RFC 5280), commonly called PKIX Part 1. He is one of the authors of the SDNS Message Security Protocol (MSP), the security cornerstone of the U.S. Defense Message System (DMS). He contributed to IEEE 802.11 Wireless LAN security standards, particularly IEEE 802.11i.