Sean Lewis has over six years of computer security experience, focusing mainly on UNIX systems - hardening, penetration testing and kernel-level lockdown of servers in various roles. Sean has designed systems for various large organizations that assume critical network roles and must be among the top host-based secured machines on the network. Using open source technology, these systems are not only some of the most secure machines you can find, they are also some of the least expensive. Sean is a Checkpoint Certified Security Administrator, and has in-depth knowledge of firewall installation and maintenence as well as penetration testing and evasion tactics with popular firewall products in use in Corporate America. Sean has also designed networks of varying scales, including a high-speed, high-availibility B2B e-business trading infrastructure that attracts millions of hits per month. Sean also has experience with Windows NT and 2000 security as well as a large deal of work with networking devices such as switches and routers. He also has published several documents regarding Windows NT and IIS security, including 'quick checklists' for post-installs and ongoing maintenence currently in use by several large organizations.