Restrain acces to folders and files

I'm using an aspire one with linpus. I wanna know how i can restrain the access to some folders. Make sure you have to type a password or something.

Thank you very much

 

Two options immediately come to mind:
a. Make certain the One requires people to login. Unfortunately Acers updates tend to destroy that setting.
b. Install an encryption program (e.g. truecrypt) and put all the files you do not wish to be public in the encrypted container.

I myself went with option b.

 

One option is to create a new user, and give only that user access to those files (chmod og-rwx <file>), (chown <otheruser> <file>).

Problem is, after this you can still access the files with sudo, which in AA1 doesn't ask for a password. So you need to make it ask for a password. I'm not completely sure how to do it, so I've started another therad discussing it: "Making sudo ask for a password?"

After this, you can only access the files 1) with sudo, using the "user" password. 2) by switching to the other user (su <otheruser>), and then accessing the files.