"Using an encrypted or hashed IP would mean that sysops would be unable to
identify proxy servers or dynamic IP pools. This information is vital when
tracking vandalism or blocking users." -
http://bugzilla.wikipedia.org/show_bug.cgi?id=556
The IP should be visible to sysops but not to users and the general web
audience. You need to implement a "Show IP" sysop-only special page with a
form where a sysop can paste the encoded text and get the IP corresponding to
it.
--
NSK
Admin of
http://portal.wikinerds.org
Project Manager of
http://www.nerdypc.org
Project Manager of
http://www.adapedia.org