Enterprise Mac Security: Mac OS X Snow Leopard

1.15. Using Encrypted Disk Images

Encrypted disk images offer you a place to keep files in an encrypted form. Let's say for speed or compatibility reasons you don't want to keep your entire home folder encrypted as you would by using FileVault, but you do want to keep certain folders encrypted. You can employ the use of encrypted disk images, which are much like ZIP files that compress a bunch of files into one file. Anyone attempting to access the data within them will need a password to do so.

To create an encrypted disk image, open Disk Utility and click New Image in the toolbar. The resulting screen (see Figure 1-21) will have a wide variety of options. The Volume Size and Encryption settings are the most important to consider when creating ...