I'm not sure how much info you need, hope this is enough

You don't actually send the file to your friend - they'll have to download the file from you. But yes, you can share a file with only one person using DC. The transfer is only as secure as any other time that you use the Gnutella network.

If you're sharing a sensitive file, you'll need to be careful that it's not inadvertently shared with others - add the file for sharing just before you begin the Direct Connect. And stop sharing it as soon as your friend's downloaded the file.

You can either add the file to your shared folder (tools > options > sharing will show you the location) or if it's a folder, add that folder for sharing (tools > options > sharing > use the Add button). Apply to save a change.

If you want to make sure that the only person who can download the file is your friend - start LW & reduce your upload slots to 1 just before you begin (tools > options > uploads > slots), so that your friend takes your only upload slot. That way, other people won't be able to download from you until you have free upload slots.

Check out the links below for some more info

Direct connect IP address.

How to use Bitzi Web Lookup .. & How to use Magnet Links & Direct Connect/Browse/Chat