Lock Folders and Application, How?

Well, you can create a password protected Image using Disk Utility. That is the way that I keep my documents from prying eyes.

1. Open Disk Utility

2. Click on "New Image"

3. Set your folder size that you need, name it, ect. Make sure to set the encryption to either 128-bit AES or 256-bit AES to password protect it.

4. Create your image, it will prompt you to put in the password while it is creating it.

5. After it is done creating the image, highlight your new image and hit Command + I. A new window will open, notice the image in the top left hand corner of the new window, drag a folder icon onto that image to change the image to that of a folder. This will fool people into believe that it is a folder.

6. You are now done

 

There's no real easy way to do this exactly the way that you're thinking of doing it.

Easiest way to hide your porn^H^H^H^H private files is to just put them in an encrypted container, ie DMG/ZIP/RAR.

Or you could start changing user and group permissions.

Really depends on what exactly you want to do.