ENCRYPT YOUR DATA
Encrypt important data for better security
IT WILL TAKE
YOU WILL LEARN Different ways of encrypting things in Big Sur
YOU’LL NEED macOS 11, external drive optional
Encryption is a great way to keep your personal data and files secure: it means that the only person who can access your data is you. In this tutorial, we’ll discover how to encrypt your Mac’s startup disk, external drives and Time Machine backups. We’ll also discover how to create disk images that you can share securely.
As far as your Mac is concerned a disk image is like any other disk, but as it’s a virtual drive you can have more than one on a single storage device. Disk images are ideal for emailing, for making available as downloads, or for uploading to shared cloud storage, but do make sure you don’t send the password with the image or you’ll defeat the whole purpose of encrypting your data.
Four options
There are four key options here. A read/write disk image, aka a .dmg; a sparse image; a sparse bundle; and a CD/DVD master. With .dmgs you need to specify the file size, which is useful if you know you’re dealing with a file size limit for uploads or email. Sparse images are more flexible; they can grow if more space is needed by the files they contain.
The difference is that a sparse image is one file and a sparse bundle is made of multiple files, so if you’re backing up and only a few things have changed, then a backup system such as Time Machine only needs to backup the changed bits of the bundle, not the whole thing.