macOS does not provide a simple Finder command that adds a password directly to an ordinary folder. A built-in way to protect a group of files is to place them in an encrypted disk image created with Disk Utility. The disk image requires its password when it is opened.
Create an encrypted disk image from a folder
- Open Disk Utility.
- Choose File > New Image > Image from Folder.
- Select the folder you want to protect and click Open.
- Choose where to save the disk image.
- Open the Encryption menu and select an encryption option.
- Create and verify a strong password.
- Choose an appropriate image format and save the image.
Test it before removing the original folder
Open the new disk image and confirm that the expected files are present and accessible with the password. Only after you have verified the protected copy and have an appropriate backup should you consider deleting an unencrypted original.
Do not forget the password
Apple warns that if you forget the password for an encrypted disk image, you will not be able to open the image and view its files. Avoid storing the password in an obvious location next to the protected image.
Protecting the whole Mac
If your real goal is to protect all data on the Mac when someone does not know your login credentials, use FileVault rather than creating separate disk images for every folder. Disk images are better suited to a specific collection of files that needs its own encryption boundary.
Matt Jacobs has been working as an IT consultant for small businesses since receiving his Master’s degree in 2003. While he still does some consulting work, his primary focus now is on creating technology support content for SupportYourTech.com.
His work can be found on many websites and focuses on topics such as Microsoft Office, Apple devices, Android devices, Photoshop, and more.