In your Mac, go to Applications -> Utilities -> Disk Utility. Click on the New Image button. Enter the information in the window. In the Volume Size field, you can choose the size of the container that you want to create. There are several preset options, including various CD and DVD sizes. You can pick one from the dropdown list or define your own size with the Custom option. Under the Encryption, select 128-bit AES encryption. There is also an option to choose 256-bit encryption, but that will slow down the whole process. In the Image Format field, select read/write disk image. Here is what you see after configuring: Click Create to generate the disk image. It will prompt you for your password. Enter your password, make sure that it is a strong one. Also, remember to uncheck the box “Remember password in my keychain“, else it will defy the purpose of encrypting your data. Once the disk image is ready, you will be able to find it mounted on your desktop ready to be used. Open up the disk image in your Finder and drag (or copy and paste) your sensitive files into it. When you are done, simply unmount it. Anyone who wants to open the disk image to view the files within will have to enter the password that you have set. That’s it. You have successfully created an encrypted disk image to contain all your confidential files. With this encrypted disk image, you can store it in a corner of your hard disk, bring it around in your flash drive or burn the disk images to your CD/DVD.
