Encryption is good for protecting sensitive data you don’t want anyone else to see. If some bad guy nabs your laptop while you’re out at a coffee shop or bar, you can rest assured knowing that the data is encrypted. The process of encrypting files is easy, and I’ll to show you step-by-step how to do it.
First, open up Disk Utility. Use spotlight search (upper right-hand corner or spacebar+command) to find it.
Once you’re there, go to File>New Image>Image From Folder.
Okay, now we are really having fun. But don’t get too crazy just yet, as we are just getting started on this magical encryption journey.
This part is pretty straightforward. Disk Utility will prompt you to pick a folder. Select the folder you want to encrypt, name it whatever you want, and choose 256 AES encryption. Disk Utility will prompt you for a password. This is important. If you forget the password, you probably won’t be able to recover your files—so don’t forget it. Here’s the best guide for creating passwords that are easy to remember, but also stand up to “brute force” attacks, meaning someone using software to rapidly guess millions of passwords on your precious encrypted files.
When you click on that encrypted file, which will now be saved as a .dmg, it will prompt you for the same password you just entered. (Hopefully you haven’t already forgotten it.)
Enter the password, and you’re in. That’s it. You’re done. All of your precious data is now protected by encryption.
source: gizmodo.com by William Turton