Home Network Permissions

Hello,

I've both been searching around for ages, and trying to work it out myself, but no luck.

I am currently tying to set up folder synchronizing over the home network between my laptop and my desktop, and I've got this to work very well. My problem arose when I realized (obviously) that to synchronize folders over a network they must be shared. Both computers are currently running WindowsXP.

This is where my question comes. Is there anyway to restrict permissions of the folders that I'm sharing? Either restricting the access of a shared folder by password, limiting access of the folder to one computer, or even making it so that only one computer has access to another computer (some sort of IP file sharing?)

Any help very much appreciated.

Thanks