Re: Securing a TikiWiki site
Tikiwiki has a very flexible viewing/editing permission system. Please see http://twbasics.keycontent.org/tiki-index.php?page=Configuring+Group+Permissions and http://doc.tikiwiki.org/tiki-index.php?page=Permission. You can set permissions on particular categories or on specific pages, galleries, etc. Or you can block access to the site completely and show only a username/password log-in screen, if you like (option is in General Admin, if I recall correctly).
-- Gary