change permissions for files and directories under home directory

Question

I share a linux server with several persons. Is it better to change the permissions of files and directories under my home? I wonder others or group users will have access to or even modify my files.

Except ~/public_html, is it all right to change the permissions of all the other files and directories including hidden ones to be unreadable, unwritable and unexecutable for other and group users?

I find some directory under my home has permission like this "drwsrws---". I saw somewhere online that "s" is set-UID or set-groupID flag. But What does "s" mean actually for the group users? Is it safe to drop it?

Thanks and regards!

Answer 1

Yes, you should change files/folders that you don't want read by others like this:

chmod go-rwx SECRET_FILE_OR_FOLDER

(this makes it unable to be read, written or by anyone else.)

You should also make sure you have the right modes on your home directory, eg,

chmod go-w ~