http://hoohoo.ncsa.uiuc.edu/docs/PEMPGP.html
http://www-ns.rutgers.edu/www-security/reference.html
http://www.eit.com/creations/s-http
http://ciac.llnl.gov/ciac/ToolsUnixNetSec.html
NCSA: Using PEM/PGP
Rutgers' Security Page
Secure HTTP
Security Tools