Protect a folder with special password

Hi all,

I'm a starter with svn and just use it installed on sourceforge for my
project. We have three admins working on it and still there is a folder
where I want to backup stuff in, that is not supposed to be read by
everybody. Is there a quick command that allows me to add password to a
folder so that nobody can co oder ci anything?

Thanks in advance for your help!

-- 
Cheers,
Rainer