Redmine

Hi all.
First of all, congratulations for the excelent software.
I'm using the wiki to create technical and comercial content.
Technical-> Dashboard with ip's, ssh accounts, database users and passwords, for production and development environments.
Comercial-> New releases, marketing, institucional informations, etc...

I don't want block a wiki page for all users, technic and customers can't see it. I want block some tech pages from customer view and vice-versa. I don't want my customer seeing technical information as ssh accounts/passwords.
Is there a way to do it?
Thanks in advance and sorry for bad english.