About permissions of files.....

I will change owner and permission(700) of some directories and files on my SuSE Linux 9.0. Owner of these directories will be root. Can anyone reach these directories and files if s/he does not know the root password. I wonder that : if someone updates(not new installation),the OS, can s/he change root password? I think SuSE Update asks the user root password, but i am not sure about update via CD. I dont know any secure way to hide my special files except this way. If anyone has better idea tell me the most secure way.. Thanks. -------------------------------------------------------------------- mail2web - Check your email from the web at http://mail2web.com/ .